IFR Navaids - Pressure Instruments

Landing at an airport you have correctly set QNH 1023 hPa as the reference pressure on your altimeter. The altimeter indicates 1200 ft after landing. Suppose that you then change the pressure reference to standard setting (1013 hPa).

What will your altimeter indicate (use 1 hPa = 30 ft)?

• 0 ft

• 900 ft

• 1200 ft

• 1500 ft

Which of the following statements regarding the density of the air is correct?

• Density increases when the temperature rises and the air pressure falls.

• Density decreases when the temperature falls and the air pressure is constant.

• Density decreases when the temperature is constant and the air pressure increases.

• Density decreases when the temperature is constant and the air pressure falls.

What is the effect on true altitude if an aircraft is flown from warm air to cold air with the same QNH value?

• True altitude is higher.

• True altitude is the same because QNH is the same.

• True altitude is lower.

• True altitude is the same because the altimeter is corrected for temperature error by the bimetallic strip.

Equivalent air speed is found by allowing for compressibility error. The correction value is...

• Always added to the CAS.

• Increased when density is low and airspeed is low.

• Nil at sea level since the ASI is calibrated to sea level conditions.

An aerodrome elevation is 500ft. When QNE is set on the altimeter of an aircraft sitting on an aerodrome, the instrument reads 650ft. What are the approximate values of:

1) 1 QNH

2) 2 QFE (30ft = 1 hPa)

• 1008 1035

• 1018 991

• 1008 991

• 1018 1035

An aircraft is cruising between A and B, maintaining an IAS of 200 knots and an indicated altitude of 8000’. The QNH over A and B remains constant but the temperature gets colder towards B. What is the effect on the aircrafts: 1. TAS & 2. True altitude

• more same

• less less

• same more

• less more

• more less

Which of the following pressure values set on the altimeter will give approximate pressure altitude:

• QNH

• QFE

• QFF

• QNE

If the static line blocks completely in the pitot static system during a climb, what is the effect on the pressure instruments?

• ASI will over read, VSI will read zero, the altimeter will read constant value.

• ASI will over read, VSI shows a reduced ROC , the altimeter will read a constant value.

• ASI will under read, VSI will show a ROD, the altimeter will show a reducing height.

• ASI will under read VSI will read zero, the altimeter will read constant value.

At an aerodrome 300 ft AMSL, the aerodrome pressure is 1010 hPa. The altimeter will read correctly when the subscale is set to... (30ft = 1 hPa)

• 1020.0

• 1013.2

• 1010.0

• 1000.0

Which of the following definitions best describes QNH?

• The pressure prevailing at an airfield, the setting of which on the altimeter sub-scale will cause the altimeter to read zero on landing and take-off.

• The pressure prevailing at an airfield, the setting of which on the altimeter sub-scale will cause the altimeter to read airfield elevation on landing and take-off.

• Setting the standard mean sea level pressure of 1013.25 hPa to make the altimeter read the airfield elevation (pressure altitude).

• Setting the pressure scale to make the altimeter read airfield height above sea level on landing and take-off.