WorksheetsMod 3
Total questions: 141
Worksheet time: 2hrs 21mins
Name
Class
Date
1.
HELICOPTER
a)
uilt a two-engine coaxial helicopter that lifted a pilot untethered.
b)
built a tethered observation helicopter that achieved an altitude of 50 m with payload.
c)
uses rotating wings to provide lift, propulsion, and control.
d)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
2.
ROTOR BLADES
a)
rotate about the vertical axis, describing a disk in a horizontal or nearly horizontal plane.
b)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
c)
uses autorotation as the normal working state of the rotor.
d)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
3.
vertical; horizontal
a)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
b)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed (hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske engine).
c)
Rotor blades rotate about the _______ axis, describing a disk in a _______ or nearly _______ plane.
d)
Has three or more blades attached to the hub without hinges and the hub is attached to the rotor shaft by a universal joint arrangement.
4.
zero
a)
Gyroplane No. 1 had four rotors with four biplane blades each (rotors 8 m in diameter, gross weight 580 kg, 45 hp Antoinette engine). It made a tethered flight with a passenger at an altitude of about 1 meter for about 1 minute.
b)
Efficient vertical flight means a __________.
c)
In _______, Cierva founded the Cierva Autogiro Company in England, which was his base thereafter. In the next decade about 500 of his autogiros were produced, many by licensees of the Cierva Company
d)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
5.
Translational Velocity
a)
received the first american certificate of airworthiness for helicopters.
b)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
c)
uses two contra-rotating rotors of equal size and loading, so that the torques of the rotors are equal and opposing.
d)
Rate of change of linear position.
6.
low power loading
a)
demonstrated a spring-powered model to the Russian academy of sciences.
b)
Efficient vertical flight means a __________.
c)
built a small steam-driven model; he also invented the word "helicopter".
d)
constructed a 10-kg steam-powered model.
7.
Power Loading (lbs/hp)
a)
ratio of rotor power required to rotor thrust.
b)
built helicopters with a side-byside configuration, in 1938
c)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
d)
developed a series of single rotor helicopters under the direction of Yuriev. The TsAGI I-EA (1931) had a four-bladed main rotor (rotor 11 m in diameter, gross weight 1100 kg, 120 hp engine) with cyclic and collective control, and two small contrarotating antitorque rotors.
8.
Power Required
a)
installed power and fuel consumption of the aircraft are proportional to the _________.
b)
consists of two or more identical, equally spaced blades attached to a central hub.
c)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
d)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
9.
low power loading
a)
generally considered the first practical, truly operational
b)
For a rotary wing, low disk loading is the key to a ______.
c)
The fact that the rotor is a __________ increases the first cost and maintenance cost.
d)
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
10.
disk loading
a)
built the VS- 300, a helicopter with a single three-bladed main rotor and a small antitorque tail rotor (rotor 9 min diameter, gross weight S20 kg, 100 hp Franklin engine). Lateral and longitudinal control was by main rotor cyclic, and directional control was by means of the tail rotor. The tail rotor was driven by a shaft from the main rotor. The pilot's controls were like the present standard (cyclic stick, pedals, and a collective stick with a twist grip throttle). Considerable experimentation was required to develop a configuration with suitable control characteristics. The first configuration had three auxiliary rotors (one vertical and two horizontal) on the tail for control and stability.
b)
High disk loading is appropriate for rotors operating at _________ and at a _______ equal to only a fraction of the gross weight.
c)
In 1942, the___________, a derivative of the VS-300, was constructed (three-bladed rotor 11.6 meters in diameter, gross weight 1100 kg, 185 hp Warner engine). This helicopter model went into production and several hundred were built during World War II.
d)
ratio of rotor thrust to rotor disk area
11.
Conservation of Momentum
a)
uses small auxiliary rotor to provide the torque balance (and yaw control).
b)
experimented with several types of helicopters, eventually settling on the single main rotor and tail rotor configuration. He developed the control rotor, a gyro stabilizer bar with aerodynamic surfaces that the pilot controlled to adjust the rotor orientation. He built the Model 360 helicopter in 1947 (two-bladed rotor 10.7 m in diameter, gross weight 950 kg, 178 hp Franklin engine).
c)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
d)
requires that the rotor lift be obtained by accelerating air downward.
12.
Induced Power Loss
a)
constitutes the absolute minimum of power required for equilibrium flight.
b)
In 1954, ____ also developed the first twin-engine turbine powered helicopter, an HTK-1 synchropter with two Boeing engines (total 350 shp) replacing a single 240 hp piston engine of the same weight in the same position.
c)
constructed a 10-kg steam-powered model.
d)
Helicopters uses the lowest _______ of all VTOL aircraft designs and has the most efficientvertical flight capability.
13.
Induced Power Loading
a)
built a 3.5kg flying steam-driven model.
b)
The use of _______ at the blade root allows free motion of the blade normal to and in the plane of the disk.
c)
He introduced the flapping hinge for the helicopter rotor.
d)
proportional to the square root of the rotor disk loading.
14.
disk loading decreases
a)
efficiency of the rotor thrust generation increases as the ________.
b)
fore and aft placement of the main rotors on the fuselage usually with overlap of the rotor disks and with the rear rotor raised vertically above the front rotor.
c)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
d)
requires that the rotor lift be obtained by accelerating air downward.
15.
Induced Power
a)
High aspect ratio blades are required for __________.
b)
inversely proportional to the rotor radius
c)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
d)
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
16.
100 to 500 pascals (2 to 10 psf)
a)
The problem during the 19th century was the lack of ________.
b)
Disk loading characteristic of helicopters is in the range of _______.
c)
constructed a 10-kg steam-powered model.
d)
uilt a two-engine coaxial helicopter that lifted a pilot untethered.
17.
high axial velocity; thrust
a)
High disk loading is appropriate for rotors operating at _________ and at a _______ equal to only a fraction of the gross weight.
b)
efficiency of the rotor thrust generation increases as the ________.
c)
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
d)
Large diameter rotor is required for _______.
18.
disk loading
a)
ratio of rotor power required to rotor thrust.
b)
He recognized that the problem was a lack of an adequate (meaning light) engine. He concluded that no helicopter would be able to fly until engines were available with a weight-to-power ratio below 1 to 2 kg/hp.
c)
Helicopters uses the lowest _______ of all VTOL aircraft designs and has the most efficientvertical flight capability.
d)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
19.
large diamter, low disk loading
a)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
b)
In 1924, the _________ with flapping rotor blades was built (four bladed rotor 11 m in diameter, 100 hp Le Rhone rotary engine). An Avro 504K aircraft fuselage and ailerons on outrigger spars were used.
c)
constructed models powered by elastic elements and made sketches of helicopters.
d)
permits each blade to rise and fall as it turns
20.
Rotor
a)
Gyroplane No. 1 had four rotors with four biplane blades each (rotors 8 m in diameter, gross weight 580 kg, 45 hp Antoinette engine). It made a tethered flight with a passenger at an altitude of about 1 meter for about 1 minute.
b)
For low speeds. the propulsive force is obtained from the ______, by tilting the thrust vector forward.
c)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
d)
constructed a helicopter with two three-bladed rotors mounted on trusses in a side-by-side configuration (rotors 7 meters in diameter, gross weight 950 kg, 160 hp Bramo engine). The rotor had an articulated hub and tapered blades. Directional and longitudinal control were by cyclic, roll control by differential collective. Vertical and horizontal tail surfaces were used for stability and trim in forward flight, and the rotor shafts were inclined inward for stability. This helicopter set records for speed (122.5 kph), altitude (2440 m), and endurance (1 hr 21 min). It was a well-developed machine with good control, performance, and reliability.
21.
position, attitude, and velocity.
a)
High aspect ratio blades are required for __________.
b)
constructed a machine that made the first flight with a pilot. lt had two contrarotating rotors in tandem configuration with two fabric-covered blades each (rotors 6 m in diameter, gross weight 260 kg, 24 hp Antoinette engine connected to the rotors by belts). Control was by vanes in the rotor slipstream and was not very effective. This helicopter achieved an altitude of about 0.3 m for about 20 sec; it had problems with mechanical design and with lack of stability.
c)
The rotor controls _______, _______, and ________.
d)
requires that the rotor lift be obtained by accelerating air downward.
22.
high power requirement
a)
engine).
b)
developed the PV-3, a tandem rotor helicopter.
c)
built a helicopter with four six-bladed rotors at the ends of intersecting beams (gross weight 1600 kg, 180 hp engine at the center). It had good control, utilizing differential collective of the four rotors, and made many flights with passengers up to an altitude of 4 to 6 meters. (Collective pitch is a change made in the mean blade pitch angle to control the rotor thrust magnitude.) This was the first rotorcraft ordered by the U.S. Army, but after the expenditure of $200,000 the project was finally abandoned as being too complex mechanically.
d)
the price of a vertical flight includes _____.
23.
large transmission
a)
developed a helicopter with a single main rotor and a vertical tail rotor for torque balance (two-bladed main rotor 15 m in diameter, gross weight 1300 kg, 200 hp rotary engine). A separate engine was used for the tail rotor (80 hp Thulin rotary engine mounted directly to the tail rotor). The main rotor blades were free to flap but were connected by cables to form a teetering rotor. Control was by cyclic pitch of the main rotor, produced using a swashplate. Flights were made, but never at more than 1 meter altitude. There were difficulties with directional control because of the separate engines for the main rotor and tail rotor, and the project was abandoned after a bad crash.
b)
ratio of rotor thrust to rotor disk area
c)
A ________________ is required to deliver power to the rotor at low speed and high torque.
d)
involves climb and descent with the rotor horizontal, and hence with purely axial flow through the rotor disk.
24.
mechanically complex system
a)
enables the pitch angle of the blades to change.
b)
The fact that the rotor is a __________ increases the first cost and maintenance cost.
c)
constructed the first helicopter with turbine power, installing a single turboshaft engine (175 shp Boeing engine) in its K- 225 helicopter.
d)
Since that time the turboshaft engine has become the standard powerplant for all but the smallest helicopters. The invention of the helicopter may be considered complete by the early _______.
25.
rotor is a source of vibration
a)
In 1924, the _________ with flapping rotor blades was built (four bladed rotor 11 m in diameter, 100 hp Le Rhone rotary engine). An Avro 504K aircraft fuselage and ailerons on outrigger spars were used.
b)
The ___________, hence increased maintenance costs, passenger discomfort, and pilot fatigue.
c)
A ________________ is required to deliver power to the rotor at low speed and high torque.
d)
HTK-1 Synchropter
26.
high alternating loads
a)
There are __________ on the rotor, reducing the structural component life and increasing the maintenance cost.
b)
The ___________, hence increased maintenance costs, passenger discomfort, and pilot fatigue.
c)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed (hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske engine).
d)
was a stick with a propeller on top, which was spun by hand and released.
27.
Conventional Helicopter Rotor
a)
consists of two or more identical, equally spaced blades attached to a central hub.
b)
A ________________ is required to deliver power to the rotor at low speed and high torque.
c)
For a rotary wing, low disk loading is the key to a ______.
d)
proportional to the square root of the rotor disk loading.
28.
shaft torque
a)
developed the servo-tab control method of rotor pitch control, in which the rotor blade is twisted rather than rotated about a pitch bearing at the root. Kaman also developed a helicopter of the synchropter configuration.
b)
The design task focuses on the configuration of the ________.
c)
The blades of a conventional rotor are maintained in uniform rotational motion, usually by a ___________ from the engine.
d)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
29.
efficient vertical flight
a)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed (hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske engine).
b)
Large diameter rotor is required for _______.
c)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
d)
uilt a two-engine coaxial helicopter that lifted a pilot untethered.
30.
good aerodynamic efficiency
a)
The vertically mounted drag hinge allows the ________.
b)
High aspect ratio blades are required for __________.
c)
In 1946, the __________ (rotor 10.7 meters in diameter, gross weight 950 kg, 178 hp Franklin engine received the first American certificate of airworthiness for helicopters.
d)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
31.
Centrifugal Stiffening
a)
The vertically mounted drag hinge allows the ________.
b)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
c)
helicopter
d)
predominantly about the blade root.
32.
rotor hub
a)
First twin-engine turbine powered helicopter.
b)
The design task focuses on the configuration of the ________.
c)
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
d)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
33.
hinge
a)
-light and reliable engine
b)
The fact that the rotor is a __________ increases the first cost and maintenance cost.
c)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
d)
The use of _______ at the blade root allows free motion of the blade normal to and in the plane of the disk.
34.
zero; low
a)
Because the bending moment is _______ at the blade hinge, it must be ___ throughout the root area, and no hub moment is transmitted through the blade root to the helicopter.
b)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
c)
consists of two or more identical, equally spaced blades attached to a central hub.
d)
The vertically mounted drag hinge allows the ________.
35.
lag motion (lead-lag)
a)
b)
constitutes the absolute minimum of power required for equilibrium flight.
c)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
d)
-develop means of controlling the helicopter, including balancing the rotor torque
36.
Flapping Hinge
a)
uses autorotation as the normal working state of the rotor.
b)
permits each blade to rise and fall as it turns
c)
The problem during the 19th century was the lack of ________.
d)
built a 3.5kg flying steam-driven model.
37.
lead-lag motion
a)
For low speeds. the propulsive force is obtained from the ______, by tilting the thrust vector forward.
b)
The vertically mounted drag hinge allows the ________.
c)
built a 3.5kg flying steam-driven model.
d)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
38.
Pitch Motion
a)
built a 3.5kg flying steam-driven model.
b)
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
c)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
d)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
39.
Feathering Motion
a)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
b)
built a helicopter with coaxial twobladed rotors (rotors 16.5 m in diameter, gross weight of 2000 kg, 450 hp engine). The rotors had an articulated hub (flap and lag hinges); control was by cyclic for pitch and roll, and differential torque for directional control. The aircraft had satisfactory control characteristics and held records for speed (44.7 kph), altitude (158 m), duration (1 hr 2 min), and closed-circuit distance (44 km).
c)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
d)
The fact that the rotor is a __________ increases the first cost and maintenance cost.
40.
Articulated Rotor
a)
Two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a seesaw arrangement.
b)
The blades are attached to the hub with flap and lag hinges.
c)
constitutes the absolute minimum of power required for equilibrium flight.
d)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
41.
Teetering Rotor
a)
built a tethered observation helicopter that achieved an altitude of 50 m with payload.
b)
Two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a seesaw arrangement.
c)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
d)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
42.
a)
b)
constructed the first helicopter with turbine power, installing a single turboshaft engine (175 shp Boeing engine) in its K- 225 helicopter.
c)
power-off descent of the helicopter
d)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
43.
The rotor has no lag hinges.
a)
was a stick with a propeller on top, which was spun by hand and released.
b)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
c)
The rotor has no lag hinges.
d)
uses rotating wings to provide lift, propulsion, and control.
44.
Gimballed Rotor
a)
built a small steam-driven model; he also invented the word "helicopter".
b)
example of single main rotor and tail rotor configuration
c)
Has three or more blades attached to the hub without hinges and the hub is attached to the rotor shaft by a universal joint arrangement.
d)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
45.
seesaw
a)
developed helicopters with the coaxial configuration, including the Ka-15 helicopter (three-bladed rotors 10 m in diameter, gross weight 1370 kg, 225 hp engine).
b)
c)
helicopter
d)
Teetering rotor consists of two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a teetering or_________ arrangement.
46.
universal joint
a)
developed the PV-3, a tandem rotor helicopter.
b)
the first practical use of the direct-lift rotary wing.
c)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
d)
Gimballed Rotor has three or more blades attached to the hub without hinges and the hub is attached to the rotor shaft by a gimbal or ________ arrangement.
47.
Teetering Hinge
a)
proportional to the square root of the rotor disk loading.
b)
example of a tandem rotor helicopter configuration
c)
ratio of rotor thrust to rotor disk area
d)
allows the main rotor hub to tilt.
48.
Feathering Hinge
a)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
b)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
c)
constitutes the absolute minimum of power required for equilibrium flight.
d)
enables the pitch angle of the blades to change.
49.
Hingeless Rotor
a)
developed the servo-tab control method of rotor pitch control, in which the rotor blade is twisted rather than rotated about a pitch bearing at the root. Kaman also developed a helicopter of the synchropter configuration.
b)
High aspect ratio blades are required for __________.
c)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
d)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
50.
Rigid Rotor
a)
example of single main rotor and tail rotor configuration
b)
Hingeless rotor is also called ______.
c)
constructed a machine that made the first flight with a pilot. lt had two contrarotating rotors in tandem configuration with two fabric-covered blades each (rotors 6 m in diameter, gross weight 260 kg, 24 hp Antoinette engine connected to the rotors by belts). Control was by vanes in the rotor slipstream and was not very effective. This helicopter achieved an altitude of about 0.3 m for about 20 sec; it had problems with mechanical design and with lack of stability.
d)
Rate of change of linear position.
51.
single main rotor and tail rotor configuration
a)
A ________________ is required to deliver power to the rotor at low speed and high torque.
b)
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
c)
For a rotary wing, low disk loading is the key to a ______.
d)
uses small auxiliary rotor to provide the torque balance (and yaw control).
52.
twin main rotor configuration
a)
consists of two or more identical, equally spaced blades attached to a central hub.
b)
uses rotating wings to provide lift, propulsion, and control.
c)
uses two contra-rotating rotors of equal size and loading, so that the torques of the rotors are equal and opposing.
d)
Because the bending moment is _______ at the blade hinge, it must be ___ throughout the root area, and no hub moment is transmitted through the blade root to the helicopter.
53.
tandem helicopter configuration
a)
built a machine with four two-bladed rotors (two 7.6 meters in diameter and two 6.4 meters in diameter) to provide lift, five horizontal propellers for attitude control, two propellers for propulsion, and one propeller in front for yaw control all powered by a single 120 hp Le Rhone engine. It set the first helicopter distance record, 360 meters.
b)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed (hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske engine).
c)
fore and aft placement of the main rotors on the fuselage usually with overlap of the rotor disks and with the rear rotor raised vertically above the front rotor.
d)
For a rotary wing, low disk loading is the key to a ______.
54.
AgustaWestland AW109
a)
A ________________ is required to deliver power to the rotor at low speed and high torque.
b)
fore and aft placement of the main rotors on the fuselage usually with overlap of the rotor disks and with the rear rotor raised vertically above the front rotor.
c)
example of single main rotor and tail rotor configuration
d)
developed the PV-3, a tandem rotor helicopter.
55.
CH-46 Sea Knight
a)
efficiency of the rotor thrust generation increases as the ________.
b)
example of a tandem rotor helicopter configuration
c)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
d)
received the first american certificate of airworthiness for helicopters.
56.
General Vertical Flight
a)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
b)
requires that the rotor lift be obtained by accelerating air downward.
c)
Two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a seesaw arrangement.
d)
involves climb and descent with the rotor horizontal, and hence with purely axial flow through the rotor disk.
57.
Autorotation
a)
In 1924, the _________ with flapping rotor blades was built (four bladed rotor 11 m in diameter, 100 hp Le Rhone rotary engine). An Avro 504K aircraft fuselage and ailerons on outrigger spars were used.
b)
built a small steam-driven model; he also invented the word "helicopter".
c)
built a 3.5kg flying steam-driven model.
d)
power-off descent of the helicopter
58.
Autogiro or autogyro
a)
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
b)
uses autorotation as the normal working state of the rotor.
c)
In 1932, Cierva added ________ to replace the airplane control surfaces, which were not very effective at low speeds. He used direct tilt of the rotor hub for longitudinal and lateral control.
d)
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
59.
Three major problems that had to be overcome to achieve a successful vehicle:
a)
developed helicopters with the coaxial configuration, including the Ka-15 helicopter (three-bladed rotors 10 m in diameter, gross weight 1370 kg, 225 hp engine).
b)
uses rotating wings to provide lift, propulsion, and control.
c)
Find:
d)
generally considered the first practical, truly operational
60.
-light and reliable engine
a)
First twin-engine turbine powered helicopter.
b)
-light and reliable engine
c)
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
d)
built a helicopter with a rotor turned by propellers on the blades, to eliminate the torque problem; the machine was mechanically too complex. Cyclic control was obtained by warping the blades with aerodynamic control tabs.
61.
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
a)
example of single main rotor and tail rotor configuration
b)
He introduced the flapping hinge for the helicopter rotor.
c)
developed the PV-3, a tandem rotor helicopter.
d)
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
62.
-develop means of controlling the helicopter, including balancing the rotor torque
a)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
b)
The fact that the rotor is a __________ increases the first cost and maintenance cost.
c)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
d)
-develop means of controlling the helicopter, including balancing the rotor torque
63.
Chinese flying top (400 BC)
a)
built helicopters with a side-byside configuration, in 1938
b)
was a stick with a propeller on top, which was spun by hand and released.
c)
rotate about the vertical axis, describing a disk in a horizontal or nearly horizontal plane.
d)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
64.
Leonardo da Vinci (late 15th Century)
a)
K-225 Helicopter
b)
ratio of rotor power required to rotor thrust.
c)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
d)
requires that the rotor lift be obtained by accelerating air downward.
65.
Mikhail V. Lomonosov (Russia, 1754)
a)
demonstrated a spring-powered model to the Russian academy of sciences.
b)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
c)
built a helicopter using two rotors positioned on the tips of a biplane wing in a side-by-side configuration. They used rigid wooden propellers for the rotors and obtained control by tilting the entire rotor.
d)
Gimballed Rotor has three or more blades attached to the hub without hinges and the hub is attached to the rotor shaft by a gimbal or ________ arrangement.
66.
Launoy and Bienvenu (France, 1784)
a)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
b)
constructed a helicopter with two coaxial rotors of four biplane blades each (180 hp; a 1920 craft of similar design that used rotors 6.4 min diameter and a 45 hp Hispano engine had inadequate lift). For control, he warped the biplane blades to change their pitch angle. Pescara was the first to demonstrate effective cyclic for control of the main rotors. (Cyclic pitch is a sinusoidal, once-per-revolution change made in the blade pitch to tilt the rotor disk.) Pescara's helicopter set a distance record (736 meters) but had stability problems.
c)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
d)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
67.
Sir George Cayley (England, 1790's)
a)
constructed models powered by elastic elements and made sketches of helicopters.
b)
built a helicopter with coaxial twobladed rotors (rotors 16.5 m in diameter, gross weight of 2000 kg, 450 hp engine). The rotors had an articulated hub (flap and lag hinges); control was by cyclic for pitch and roll, and differential torque for directional control. The aircraft had satisfactory control characteristics and held records for speed (44.7 kph), altitude (158 m), duration (1 hr 2 min), and closed-circuit distance (44 km).
c)
In 1942, the___________, a derivative of the VS-300, was constructed (three-bladed rotor 11.6 meters in diameter, gross weight 1100 kg, 185 hp Warner engine). This helicopter model went into production and several hundred were built during World War II.
d)
68.
cheap, reliable, light engine.
a)
requires that the rotor lift be obtained by accelerating air downward.
b)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
c)
The problem during the 19th century was the lack of ________.
d)
develop and coined the word autogiro
69.
W.H Phillips (England, 1842)
a)
constructed a 10-kg steam-powered model.
b)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
c)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
d)
For a rotary wing, low disk loading is the key to a ______.
70.
Viscomte Gustave de Ponton d'Amecourt (France, 1863)
a)
uilt a two-engine coaxial helicopter that lifted a pilot untethered.
b)
built a small steam-driven model; he also invented the word "helicopter".
c)
engine).
d)
helicopter
71.
Alphonse Penaud (France, 1870's)
a)
High disk loading is appropriate for rotors operating at _________ and at a _______ equal to only a fraction of the gross weight.
b)
experimented with models. XD
c)
proportional to the square root of the rotor disk loading.
d)
helicopter
72.
Enrico Forlanini (Italy, 1878)
a)
The problem during the 19th century was the lack of ________.
b)
built a 3.5kg flying steam-driven model.
c)
In 1932, Cierva added ________ to replace the airplane control surfaces, which were not very effective at low speeds. He used direct tilt of the rotor hub for longitudinal and lateral control.
d)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
73.
Thomas Edison (United States, 1880's)
a)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
b)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
c)
He recognized that the problem was a lack of an adequate (meaning light) engine. He concluded that no helicopter would be able to fly until engines were available with a weight-to-power ratio below 1 to 2 kg/hp.
d)
In 1946, the __________ (rotor 10.7 meters in diameter, gross weight 950 kg, 178 hp Franklin engine received the first American certificate of airworthiness for helicopters.
74.
Renard (France, 1904)
a)
received the first american certificate of airworthiness for helicopters.
b)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
c)
The rotor controls _______, _______, and ________.
d)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
75.
Breguet-Richet (France, 1907)
a)
uses small auxiliary rotor to provide the torque balance (and yaw control).
b)
There are __________ on the rotor, reducing the structural component life and increasing the maintenance cost.
c)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
d)
Gyroplane No. 1 had four rotors with four biplane blades each (rotors 8 m in diameter, gross weight 580 kg, 45 hp Antoinette engine). It made a tethered flight with a passenger at an altitude of about 1 meter for about 1 minute.
76.
Paul Cornu (France 1907)
a)
Find:
b)
constructed a machine that made the first flight with a pilot. lt had two contrarotating rotors in tandem configuration with two fabric-covered blades each (rotors 6 m in diameter, gross weight 260 kg, 24 hp Antoinette engine connected to the rotors by belts). Control was by vanes in the rotor slipstream and was not very effective. This helicopter achieved an altitude of about 0.3 m for about 20 sec; it had problems with mechanical design and with lack of stability.
c)
uses two contra-rotating rotors of equal size and loading, so that the torques of the rotors are equal and opposing.
d)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
77.
Emile and Henry Berliner (United States, 1909)
a)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske
b)
developed the servo-tab control method of rotor pitch control, in which the rotor blade is twisted rather than rotated about a pitch bearing at the root. Kaman also developed a helicopter of the synchropter configuration.
c)
uilt a two-engine coaxial helicopter that lifted a pilot untethered.
d)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
78.
Igor Sikorsky (Russia, 1910)
a)
A ________________ is required to deliver power to the rotor at low speed and high torque.
b)
built a helicopter with two coaxial three-bladed rotors (rotors 5.8 m in diameter, 25 hp Anzani engine) that could lift 180 kg but not its own weight plus the pilot.
c)
Efficient vertical flight means a __________.
d)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
79.
Boris N. Yuriev (Russia, 1912)
a)
built a machine with a two-bladed main rotor and a small antitorque tail rotor (main rotor 8 m in diameter, gross weight 200 kg, 25 hp Anzani engine). This helicopter made no successful flight, but Yuriev went on to supervise helicopter development in the Soviet Union.
b)
The use of _______ at the blade root allows free motion of the blade normal to and in the plane of the disk.
c)
In 1932, Cierva added ________ to replace the airplane control surfaces, which were not very effective at low speeds. He used direct tilt of the rotor hub for longitudinal and lateral control.
d)
was a stick with a propeller on top, which was spun by hand and released.
80.
Petroczy and von Karman (Austria, 1916)
a)
He recognized that the problem was a lack of an adequate (meaning light) engine. He concluded that no helicopter would be able to fly until engines were available with a weight-to-power ratio below 1 to 2 kg/hp.
b)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
c)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
d)
built a tethered observation helicopter that achieved an altitude of 50 m with payload.
81.
George de Bothezat (United States, 1922)
a)
built a helicopter with four six-bladed rotors at the ends of intersecting beams (gross weight 1600 kg, 180 hp engine at the center). It had good control, utilizing differential collective of the four rotors, and made many flights with passengers up to an altitude of 4 to 6 meters. (Collective pitch is a change made in the mean blade pitch angle to control the rotor thrust magnitude.) This was the first rotorcraft ordered by the U.S. Army, but after the expenditure of $200,000 the project was finally abandoned as being too complex mechanically.
b)
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
c)
Hingeless rotor is also called ______.
d)
The blades of a conventional rotor are maintained in uniform rotational motion, usually by a ___________ from the engine.
82.
Etienne Oemichen (France, 1924)
a)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
b)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
c)
built a helicopter with four six-bladed rotors at the ends of intersecting beams (gross weight 1600 kg, 180 hp engine at the center). It had good control, utilizing differential collective of the four rotors, and made many flights with passengers up to an altitude of 4 to 6 meters. (Collective pitch is a change made in the mean blade pitch angle to control the rotor thrust magnitude.) This was the first rotorcraft ordered by the U.S. Army, but after the expenditure of $200,000 the project was finally abandoned as being too complex mechanically.
d)
built a machine with four two-bladed rotors (two 7.6 meters in diameter and two 6.4 meters in diameter) to provide lift, five horizontal propellers for attitude control, two propellers for propulsion, and one propeller in front for yaw control all powered by a single 120 hp Le Rhone engine. It set the first helicopter distance record, 360 meters.
83.
Marquis Raul Pateras Pescara (Spain, 1924)
a)
built the VS- 300, a helicopter with a single three-bladed main rotor and a small antitorque tail rotor (rotor 9 min diameter, gross weight S20 kg, 100 hp Franklin engine). Lateral and longitudinal control was by main rotor cyclic, and directional control was by means of the tail rotor. The tail rotor was driven by a shaft from the main rotor. The pilot's controls were like the present standard (cyclic stick, pedals, and a collective stick with a twist grip throttle). Considerable experimentation was required to develop a configuration with suitable control characteristics. The first configuration had three auxiliary rotors (one vertical and two horizontal) on the tail for control and stability.
b)
For low speeds. the propulsive force is obtained from the ______, by tilting the thrust vector forward.
c)
constructed a helicopter with two coaxial rotors of four biplane blades each (180 hp; a 1920 craft of similar design that used rotors 6.4 min diameter and a 45 hp Hispano engine had inadequate lift). For control, he warped the biplane blades to change their pitch angle. Pescara was the first to demonstrate effective cyclic for control of the main rotors. (Cyclic pitch is a sinusoidal, once-per-revolution change made in the blade pitch to tilt the rotor disk.) Pescara's helicopter set a distance record (736 meters) but had stability problems.
d)
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
84.
Emile and Henry Berliner (United States, 1920-1925)
a)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
b)
built a helicopter using two rotors positioned on the tips of a biplane wing in a side-by-side configuration. They used rigid wooden propellers for the rotors and obtained control by tilting the entire rotor.
c)
The blades of a conventional rotor are maintained in uniform rotational motion, usually by a ___________ from the engine.
d)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske
85.
Louis Brennan (England, 1920's)
a)
built a helicopter with a rotor turned by propellers on the blades, to eliminate the torque problem; the machine was mechanically too complex. Cyclic control was obtained by warping the blades with aerodynamic control tabs.
b)
c)
Hingeless rotor is also called ______.
d)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
86.
A.G. von Baumhauer (Holland, 1924-1929)
a)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
b)
developed a helicopter with a single main rotor and a vertical tail rotor for torque balance (two-bladed main rotor 15 m in diameter, gross weight 1300 kg, 200 hp rotary engine). A separate engine was used for the tail rotor (80 hp Thulin rotary engine mounted directly to the tail rotor). The main rotor blades were free to flap but were connected by cables to form a teetering rotor. Control was by cyclic pitch of the main rotor, produced using a swashplate. Flights were made, but never at more than 1 meter altitude. There were difficulties with directional control because of the separate engines for the main rotor and tail rotor, and the project was abandoned after a bad crash.
c)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
d)
First helicopter with turbine engine.
87.
Corradino d'Ascanio (Italy, 1930)
a)
constructed a helicopter with two coaxial rotors (rotors 13 meters in diameter 95 hp engine). The two-bladed rotors had flap hinges and free-feathering hinges. Control by servo tabs on the blade was used to obtain cyclic and collective pitch changes. For several years this machine held records for altitude (18 m), endurance (8 min 45 sec), and distance (1078 m). The stability and control characteristics were marginal.
b)
For a rotary wing, low disk loading is the key to a ______.
c)
constructed a 10-kg steam-powered model.
d)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
88.
M.B. Blecker (United States, 1930)
a)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
b)
First to demonstrate effective cyclic for control of the main rotors.
c)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
d)
predominantly about the blade root.
89.
Central Aero-Hydrodynamic Institute of the Soviet Union
a)
developed a series of single rotor helicopters under the direction of Yuriev. The TsAGI I-EA (1931) had a four-bladed main rotor (rotor 11 m in diameter, gross weight 1100 kg, 120 hp engine) with cyclic and collective control, and two small contrarotating antitorque rotors.
b)
Rate of change of linear position.
c)
Large diameter rotor is required for _______.
d)
constructed a helicopter with two coaxial rotors of four biplane blades each (180 hp; a 1920 craft of similar design that used rotors 6.4 min diameter and a 45 hp Hispano engine had inadequate lift). For control, he warped the biplane blades to change their pitch angle. Pescara was the first to demonstrate effective cyclic for control of the main rotors. (Cyclic pitch is a sinusoidal, once-per-revolution change made in the blade pitch to tilt the rotor disk.) Pescara's helicopter set a distance record (736 meters) but had stability problems.
90.
autogiro
a)
the first practical use of the direct-lift rotary wing.
b)
constructed models powered by elastic elements and made sketches of helicopters.
c)
K-225 Helicopter
d)
-develop means of controlling the helicopter, including balancing the rotor torque
91.
Juan de la Cierva (Spanish, 1920's-1930's)
a)
develop and coined the word autogiro
b)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
c)
In 1942, the___________, a derivative of the VS-300, was constructed (three-bladed rotor 11.6 meters in diameter, gross weight 1100 kg, 185 hp Warner engine). This helicopter model went into production and several hundred were built during World War II.
d)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
92.
C-3 autogiro
a)
helicopter
b)
In 1922, Cierva built the ___________with a five-bladed rigid rotor and "a tendency to fall over sideways."
c)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
d)
Rotor blades rotate about the _______ axis, describing a disk in a _______ or nearly _______ plane.
93.
C-4 autogiro
a)
developed a hingeless rotor autogiro that also used cyclic control of the rotors.
b)
uses small auxiliary rotor to provide the torque balance (and yaw control).
c)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
d)
In 1954, ____ also developed the first twin-engine turbine powered helicopter, an HTK-1 synchropter with two Boeing engines (total 350 shp) replacing a single 240 hp piston engine of the same weight in the same position.
94.
C-6 autogiro
a)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
b)
uses autorotation as the normal working state of the rotor.
c)
In 1924, the _________ with flapping rotor blades was built (four bladed rotor 11 m in diameter, 100 hp Le Rhone rotary engine). An Avro 504K aircraft fuselage and ailerons on outrigger spars were used.
d)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
95.
C-6
a)
built a machine with a two-bladed main rotor and a small antitorque tail rotor (main rotor 8 m in diameter, gross weight 200 kg, 25 hp Anzani engine). This helicopter made no successful flight, but Yuriev went on to supervise helicopter development in the Soviet Union.
b)
A helicopter with its rotary wings can generate aerodynamic forces even when the velocity of the vehicle itself is _______.
c)
The _______ is generally regarded as Cierva 's first successful autogiro (1926).
d)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
96.
1925
a)
In _______, Cierva founded the Cierva Autogiro Company in England, which was his base thereafter. In the next decade about 500 of his autogiros were produced, many by licensees of the Cierva Company
b)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
c)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
d)
the first practical use of the direct-lift rotary wing.
97.
rotor control
a)
In 1932, Cierva added ________ to replace the airplane control surfaces, which were not very effective at low speeds. He used direct tilt of the rotor hub for longitudinal and lateral control.
b)
predominantly about the blade root.
c)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
d)
The design task focuses on the configuration of the ________.
98.
Raoul Hafner (England, 1935)
a)
demonstrated a spring-powered model to the Russian academy of sciences.
b)
-develop means of controlling the helicopter, including balancing the rotor torque
c)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
d)
involves climb and descent with the rotor horizontal, and hence with purely axial flow through the rotor disk.
99.
E. Burke Wilford (United States; 1930's)
a)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
b)
The vertically mounted drag hinge allows the ________.
c)
fore and aft placement of the main rotors on the fuselage usually with overlap of the rotor disks and with the rear rotor raised vertically above the front rotor.
d)
developed a hingeless rotor autogiro that also used cyclic control of the rotors.
100.
Louis Breguet (France, 1946)
a)
built the G-11 E, a helicopter with two coaxial contrarotating rotors (three-bladed rotor 8.5 m in diameter, gross weight 1300 kg, 240 hp Potex engine). The rotors had fully articulated hubs with flap and lag dampers
b)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
c)
Two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a seesaw arrangement.
d)
requires that the rotor lift be obtained by accelerating air downward.
101.
Stanley Hiller (United States, 1946-1948)
a)
The blades are attached to the hub with flap and lag hinges.
b)
experimented with several types of helicopters, eventually settling on the single main rotor and tail rotor configuration. He developed the control rotor, a gyro stabilizer bar with aerodynamic surfaces that the pilot controlled to adjust the rotor orientation. He built the Model 360 helicopter in 1947 (two-bladed rotor 10.7 m in diameter, gross weight 950 kg, 178 hp Franklin engine).
c)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
d)
High aspect ratio blades are required for __________.
102.
Charles Kaman (Kaman Aircraft in the United States, 1946-1948)
a)
requires that the rotor lift be obtained by accelerating air downward.
b)
Gimballed Rotor has three or more blades attached to the hub without hinges and the hub is attached to the rotor shaft by a gimbal or ________ arrangement.
c)
predominantly about the blade root.
d)
developed the servo-tab control method of rotor pitch control, in which the rotor blade is twisted rather than rotated about a pitch bearing at the root. Kaman also developed a helicopter of the synchropter configuration.
103.
Mikhail Mil' (USSR, 1949)
a)
proportional to the square root of the rotor disk loading.
b)
engine).
c)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
d)
allows control of the AOA of the blade, and hence control of the aerodynamic forces on the rotor.
104.
Nikolai I Kamov (USSR, 1952)
a)
The rotor has no lag hinges.
b)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
c)
developed helicopters with the coaxial configuration, including the Ka-15 helicopter (three-bladed rotors 10 m in diameter, gross weight 1370 kg, 225 hp engine).
d)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
105.
Alexander Yakolev (USSR, 1952)
a)
constructed a machine that made the first flight with a pilot. lt had two contrarotating rotors in tandem configuration with two fabric-covered blades each (rotors 6 m in diameter, gross weight 260 kg, 24 hp Antoinette engine connected to the rotors by belts). Control was by vanes in the rotor slipstream and was not very effective. This helicopter achieved an altitude of about 0.3 m for about 20 sec; it had problems with mechanical design and with lack of stability.
b)
The ___________, hence increased maintenance costs, passenger discomfort, and pilot fatigue.
c)
Rate of change of linear position.
d)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
106.
Kaman Aircraft Company (United States, 1951)
a)
In 1923, the _________ was built and achieved successful flight. It had a four-bladed rotor with flap hinges on the blades (rotor 9.8 min diameter, 110 hp Le Rhone engine). Control was by conventional airplane aerodynamic surfaces.
b)
constructed the first helicopter with turbine power, installing a single turboshaft engine (175 shp Boeing engine) in its K- 225 helicopter.
c)
rotate about the vertical axis, describing a disk in a horizontal or nearly horizontal plane.
d)
constructed a 10-kg steam-powered model.
107.
Kaman
a)
In 1954, ____ also developed the first twin-engine turbine powered helicopter, an HTK-1 synchropter with two Boeing engines (total 350 shp) replacing a single 240 hp piston engine of the same weight in the same position.
b)
Rotor blades rotate about the _______ axis, describing a disk in a _______ or nearly _______ plane.
c)
constructed the first helicopter with turbine power, installing a single turboshaft engine (175 shp Boeing engine) in its K- 225 helicopter.
d)
constructed models powered by elastic elements and made sketches of helicopters.
108.
1950's
a)
ratio of rotor thrust to rotor disk area
b)
engine).
c)
The vertically mounted drag hinge allows the ________.
d)
Since that time the turboshaft engine has become the standard powerplant for all but the smallest helicopters. The invention of the helicopter may be considered complete by the early _______.
109.
Louis Breguet and Rene Dorand (France, 1935)
a)
built a helicopter with coaxial twobladed rotors (rotors 16.5 m in diameter, gross weight of 2000 kg, 450 hp engine). The rotors had an articulated hub (flap and lag hinges); control was by cyclic for pitch and roll, and differential torque for directional control. The aircraft had satisfactory control characteristics and held records for speed (44.7 kph), altitude (158 m), duration (1 hr 2 min), and closed-circuit distance (44 km).
b)
First to demonstrate effective cyclic for control of the main rotors.
c)
enables the pitch angle of the blades to change.
d)
The rotor has no lag hinges.
110.
E.H. Henrich Focke (Germany, 1936)
a)
b)
constructed a helicopter with two three-bladed rotors mounted on trusses in a side-by-side configuration (rotors 7 meters in diameter, gross weight 950 kg, 160 hp Bramo engine). The rotor had an articulated hub and tapered blades. Directional and longitudinal control were by cyclic, roll control by differential collective. Vertical and horizontal tail surfaces were used for stability and trim in forward flight, and the rotor shafts were inclined inward for stability. This helicopter set records for speed (122.5 kph), altitude (2440 m), and endurance (1 hr 21 min). It was a well-developed machine with good control, performance, and reliability.
c)
demonstrated a spring-powered model to the Russian academy of sciences.
d)
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
111.
Anton Flettner (Germany, 1938-1940)
a)
Hingeless rotor is also called ______.
b)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske
c)
HTK-1 Synchropter
d)
constructed a machine that made the first flight with a pilot. lt had two contrarotating rotors in tandem configuration with two fabric-covered blades each (rotors 6 m in diameter, gross weight 260 kg, 24 hp Antoinette engine connected to the rotors by belts). Control was by vanes in the rotor slipstream and was not very effective. This helicopter achieved an altitude of about 0.3 m for about 20 sec; it had problems with mechanical design and with lack of stability.
112.
engine).
a)
constructed a helicopter with two three-bladed rotors mounted on trusses in a side-by-side configuration (rotors 7 meters in diameter, gross weight 950 kg, 160 hp Bramo engine). The rotor had an articulated hub and tapered blades. Directional and longitudinal control were by cyclic, roll control by differential collective. Vertical and horizontal tail surfaces were used for stability and trim in forward flight, and the rotor shafts were inclined inward for stability. This helicopter set records for speed (122.5 kph), altitude (2440 m), and endurance (1 hr 21 min). It was a well-developed machine with good control, performance, and reliability.
b)
First to demonstrate effective cyclic for control of the main rotors.
c)
Blade pitch change that is usually accomplished by movement about a hinge or bearing.
d)
engine).
113.
C.G. Pullin (Britain, 1938)
a)
built a tethered observation helicopter that achieved an altitude of 50 m with payload.
b)
example of single main rotor and tail rotor configuration
c)
predominantly about the blade root.
d)
built helicopters with a side-byside configuration, in 1938
114.
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
a)
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
b)
worked on sketches of a machine for vertical flight utilizing a screw-type propeller.
c)
built a small steam-driven model; he also invented the word "helicopter".
d)
developed a series of helicopters of the single main rotor and tail rotor configuration, including in 1949 the Mi-1 (three-bladed 14 m diameter, gross weight 2250 kg, 570 hp engine).
115.
Ivan P. Bratukhin (TsAGI in the USSR, 1939-1940)
a)
demonstrated a spring-powered model to the Russian academy of sciences.
b)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
c)
The design task focuses on the configuration of the ________.
d)
For a rotary wing, low disk loading is the key to a ______.
116.
Focke-Achgelis Fa-223
a)
Efficient vertical flight means a __________.
b)
There was considerable effort in rotary wing development in Germany during World War II, including the ______ in 1941. This helicopter, which had two three-bladed rotors in the side-by-side configuration (rotors 12 m in diameter, gross
c)
consists of two or more identical, equally spaced blades attached to a central hub.
d)
built the G-11 E, a helicopter with two coaxial contrarotating rotors (three-bladed rotor 8.5 m in diameter, gross weight 1300 kg, 240 hp Potex engine). The rotors had fully articulated hubs with flap and lag dampers
117.
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
a)
constructed a helicopter with two coaxial rotors (rotors 13 meters in diameter 95 hp engine). The two-bladed rotors had flap hinges and free-feathering hinges. Control by servo tabs on the blade was used to obtain cyclic and collective pitch changes. For several years this machine held records for altitude (18 m), endurance (8 min 45 sec), and distance (1078 m). The stability and control characteristics were marginal.
b)
A ________________ is required to deliver power to the rotor at low speed and high torque.
c)
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
d)
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
118.
Igor Sikorsky (1941)
a)
built the VS- 300, a helicopter with a single three-bladed main rotor and a small antitorque tail rotor (rotor 9 min diameter, gross weight S20 kg, 100 hp Franklin engine). Lateral and longitudinal control was by main rotor cyclic, and directional control was by means of the tail rotor. The tail rotor was driven by a shaft from the main rotor. The pilot's controls were like the present standard (cyclic stick, pedals, and a collective stick with a twist grip throttle). Considerable experimentation was required to develop a configuration with suitable control characteristics. The first configuration had three auxiliary rotors (one vertical and two horizontal) on the tail for control and stability.
b)
the first practical use of the direct-lift rotary wing.
c)
The blades of a conventional rotor are maintained in uniform rotational motion, usually by a ___________ from the engine.
d)
He recognized that the problem was a lack of an adequate (meaning light) engine. He concluded that no helicopter would be able to fly until engines were available with a weight-to-power ratio below 1 to 2 kg/hp.
119.
E.H. Henrich Focke (Germany, 1936)
a)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
b)
developed the servo-tab control method of rotor pitch control, in which the rotor blade is twisted rather than rotated about a pitch bearing at the root. Kaman also developed a helicopter of the synchropter configuration.
c)
HTK-1 Synchropter
d)
constructed a helicopter with two three-bladed rotors mounted on trusses in a side-by-side configuration (rotors 7 meters in diameter, gross weight 950 kg, 160 hp Bramo engine). The rotor had an articulated hub and tapered blades. Directional and longitudinal control were by cyclic, roll control by differential collective. Vertical and horizontal tail surfaces were used for stability and trim in forward flight, and the rotor shafts were inclined inward for stability. This helicopter set records for speed (122.5 kph), altitude (2440 m), and endurance (1 hr 21 min). It was a well-developed machine with good control, performance, and reliability.
120.
Anton Flettner (Germany, 1938-1940)
a)
He recognized that the problem was a lack of an adequate (meaning light) engine. He concluded that no helicopter would be able to fly until engines were available with a weight-to-power ratio below 1 to 2 kg/hp.
b)
developed a synchropter design, with two rotors in a side-by-side configuration but highly intermeshed (hub separation 0.6 m). The FL-282 had two-bladed articulated rotors (rotors 12 m in diameter, gross weight 1000 kg, 14:0 hp SiemensHalske engine).
c)
built a helicopter with two coaxial three-bladed rotors (rotors 5.8 m in diameter, 25 hp Anzani engine) that could lift 180 kg but not its own weight plus the pilot.
d)
In 1922, Cierva built the ___________with a five-bladed rigid rotor and "a tendency to fall over sideways."
121.
C.G. Pullin (Britain, 1938)
a)
Teetering rotor consists of two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a teetering or_________ arrangement.
b)
built helicopters with a side-byside configuration, in 1938
c)
ratio of rotor power required to rotor thrust.
d)
inversely proportional to the rotor radius
122.
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
a)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
b)
Rate of change of linear position.
c)
the W-S (two-bladed rotors 4.6 m in diameter, gross weight 380 kg, SO hp Weir engine), and in 1939 the W-6 (three-bladed rotors 7.6 m in diameter, gross weight 1070 kg, 20S hp de Havilland engine) for G. & J. Weir Ltd.
d)
The ___________, hence increased maintenance costs, passenger discomfort, and pilot fatigue.
123.
Ivan P. Bratukhin (TsAGI in the USSR, 1939-1940)
a)
The rotor controls _______, _______, and ________.
b)
constructed the Omega I helicopter with two three-bladed rotors in a sideby- side configuration (rotors 7 meters in diameter, gross weight 2300 kg, two 350 hp engines).
c)
built a helicopter using two rotors positioned on the tips of a biplane wing in a side-by-side configuration. They used rigid wooden propellers for the rotors and obtained control by tilting the entire rotor.
d)
constructed models powered by elastic elements and made sketches of helicopters.
124.
Louis Breguet (France, 1946)
a)
developed an autogiro incorporating cyclic pitch control by means of a "spider" control mechanism to replace the direct tilt of the rotor hub.
b)
built a helicopter with two side-by-side rotors, using a two-cylinder engine; he introduced the flapping hinge for the helicopter rotor.
c)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
d)
built the G-11 E, a helicopter with two coaxial contrarotating rotors (three-bladed rotor 8.5 m in diameter, gross weight 1300 kg, 240 hp Potex engine). The rotors had fully articulated hubs with flap and lag dampers
125.
R-4 (VS-316)
a)
In 1942, the___________, a derivative of the VS-300, was constructed (three-bladed rotor 11.6 meters in diameter, gross weight 1100 kg, 185 hp Warner engine). This helicopter model went into production and several hundred were built during World War II.
b)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
c)
engine).
d)
was a stick with a propeller on top, which was spun by hand and released.
126.
Sikorsky's aircraft (VS-300, VS-316?)
a)
For low speeds. the propulsive force is obtained from the ______, by tilting the thrust vector forward.
b)
Hingeless rotor is also called ______.
c)
First to demonstrate effective cyclic for control of the main rotors.
d)
generally considered the first practical, truly operational
127.
helicopter
a)
The blades are attached to the hub without flap or lag hinges although often with a feathering bearing or hinge.
b)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
c)
The use of _______ at the blade root allows free motion of the blade normal to and in the plane of the disk.
d)
helicopter
128.
Lawrence Bell (Bell Helicopter Company in the United States, 1943)
a)
Find:
b)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
c)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
d)
experimented with models. XD
129.
Bell Model 47
a)
built the VS- 300, a helicopter with a single three-bladed main rotor and a small antitorque tail rotor (rotor 9 min diameter, gross weight S20 kg, 100 hp Franklin engine). Lateral and longitudinal control was by main rotor cyclic, and directional control was by means of the tail rotor. The tail rotor was driven by a shaft from the main rotor. The pilot's controls were like the present standard (cyclic stick, pedals, and a collective stick with a twist grip throttle). Considerable experimentation was required to develop a configuration with suitable control characteristics. The first configuration had three auxiliary rotors (one vertical and two horizontal) on the tail for control and stability.
b)
weight 4300 kg, 1000 hp Bramo engine), had an absolute ceiling of S000 m, a range of 300 km, a cruise speed of 120 kph with six passengers, and a useful load of 900 kg.
c)
In 1946, the __________ (rotor 10.7 meters in diameter, gross weight 950 kg, 178 hp Franklin engine received the first American certificate of airworthiness for helicopters.
d)
For a rotary wing, low disk loading is the key to a ______.
130.
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
a)
First twin-engine turbine powered helicopter.
b)
Helicopters may be defined as an aircraft utilizing ________, ________ rotary wings to provide lift for flight.
c)
Frank N. Piasecki (Piasecki Helicopter Corporation in the United States,
d)
fore and aft placement of the main rotors on the fuselage usually with overlap of the rotor disks and with the rear rotor raised vertically above the front rotor.
131.
1945)
a)
built a helicopter with four wing-like blades. Power was delivered to a propeller on each blade from an engine in the fuselage. Control was by aerodynamic surfaces on the blades and by a tail on the aircraft.
b)
developed the PV-3, a tandem rotor helicopter (three-bladed rotors 12.5 meters in diameter, gross weight 3100 kg, 600 hp Pratt and Whitney engine).
c)
Efficient vertical flight means a __________.
d)
built a helicopter with four six-bladed rotors at the ends of intersecting beams (gross weight 1600 kg, 180 hp engine at the center). It had good control, utilizing differential collective of the four rotors, and made many flights with passengers up to an altitude of 4 to 6 meters. (Collective pitch is a change made in the mean blade pitch angle to control the rotor thrust magnitude.) This was the first rotorcraft ordered by the U.S. Army, but after the expenditure of $200,000 the project was finally abandoned as being too complex mechanically.
132.
K-225 Helicopter
a)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
b)
Because the bending moment is _______ at the blade hinge, it must be ___ throughout the root area, and no hub moment is transmitted through the blade root to the helicopter.
c)
K-225 Helicopter
d)
the price of a vertical flight includes _____.
133.
a)
built a machine with a two-bladed main rotor and a small antitorque tail rotor (main rotor 8 m in diameter, gross weight 200 kg, 25 hp Anzani engine). This helicopter made no successful flight, but Yuriev went on to supervise helicopter development in the Soviet Union.
b)
demonstrated a spring-loaded model to the French Academy of Sciences. It had two contrarotating rotors of four blades each (constructed of feathers), powered by a flexed bow.
c)
d)
uses two contra-rotating rotors of equal size and loading, so that the torques of the rotors are equal and opposing.
134.
From Kaman Aircraft Company
a)
experimented with models. XD
b)
First helicopter with turbine engine.
c)
built a helicopter with a two-bladed teetering main rotor and a tail rotor, using the gyro stabilizer bar developed by Arthur Young in the United States during the 1930's.
d)
ratio of rotor power required to rotor thrust.
135.
HTK-1 Synchropter
a)
Two blades forming a continuous structure are attached to the rotor shaft with a single flap hinge in a seesaw arrangement.
b)
received the first american certificate of airworthiness for helicopters.
c)
rotate about the vertical axis, describing a disk in a horizontal or nearly horizontal plane.
d)
HTK-1 Synchropter
136.
a)
uses rotating wings to provide lift, propulsion, and control.
b)
c)
The ___________, hence increased maintenance costs, passenger discomfort, and pilot fatigue.
d)
built helicopters with a side-byside configuration, in 1938
137.
From Kaman Aircraft Company
a)
First twin-engine turbine powered helicopter.
b)
Motion about the vertical hinge produces deflection of the blade in the plane of the disk.
c)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
d)
involves climb and descent with the rotor horizontal, and hence with purely axial flow through the rotor disk.
138.
Bell Model 47
a)
-light and strong structure for the rotor, hub, and blades while maintaining good aerodynamic efficiency
b)
received the first american certificate of airworthiness for helicopters.
c)
involves climb and descent with the rotor horizontal, and hence with purely axial flow through the rotor disk.
d)
predominantly about the blade root.
139.
Frank N. Piasecki
a)
High disk loading is appropriate for rotors operating at _________ and at a _______ equal to only a fraction of the gross weight.
b)
built a helicopter with coaxial twobladed rotors (rotors 16.5 m in diameter, gross weight of 2000 kg, 450 hp engine). The rotors had an articulated hub (flap and lag hinges); control was by cyclic for pitch and roll, and differential torque for directional control. The aircraft had satisfactory control characteristics and held records for speed (44.7 kph), altitude (158 m), duration (1 hr 2 min), and closed-circuit distance (44 km).
c)
uses autorotation as the normal working state of the rotor.
d)
developed the PV-3, a tandem rotor helicopter.
140.
Renard (France, 1904)
a)
power-off descent of the helicopter
b)
Disk loading characteristic of helicopters is in the range of _______.
c)
built a helicopter with four six-bladed rotors at the ends of intersecting beams (gross weight 1600 kg, 180 hp engine at the center). It had good control, utilizing differential collective of the four rotors, and made many flights with passengers up to an altitude of 4 to 6 meters. (Collective pitch is a change made in the mean blade pitch angle to control the rotor thrust magnitude.) This was the first rotorcraft ordered by the U.S. Army, but after the expenditure of $200,000 the project was finally abandoned as being too complex mechanically.
d)
He introduced the flapping hinge for the helicopter rotor.
141.
Marquis Raul Pateras Pescara
a)
In 1942, the___________, a derivative of the VS-300, was constructed (three-bladed rotor 11.6 meters in diameter, gross weight 1100 kg, 185 hp Warner engine). This helicopter model went into production and several hundred were built during World War II.
b)
First to demonstrate effective cyclic for control of the main rotors.
c)
developed the Yak-24, a helicopter with two fourbladed rotors in tandem configuration. A number of dynamic problems were encountered in the development of this helicopter, but it eventually (1955) went into production.
d)
developed the PV-3, a tandem rotor helicopter (three-bladed rotors 12.5 meters in diameter, gross weight 3100 kg, 600 hp Pratt and Whitney engine).
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