Altimetry Flashcards
What is height?
The vertical distance between the aircraft and a given surface
What is altitude?
The vertical distance between an aircraft and the MSL
What is elevation?
Vertical distance between a point on the earths surface and MSL
What is indicated altitude?
The reading on the altimeter when it is set to local pressure at MSL
What is true altitude?
The actual vertical distance above MSL
What is the pressure altitude?
The height of the aircraft above the standard pressure datum 1013.25hPa
How are flight levels determined?
By magnetic track
What flight levels do VFR aircraft fly at?
Track of 0 degrees to 179 degrees, odd number + 500 e.g FL55
Track of 180 degrees to 359 degrees, even number + 500 e.g FL65
What flight levels do IFR aircraft use?
Track of 0 degrees to 179 degrees, odd number e.g FL50
Track of 180 degrees to 359 degrees, even number e.g FL60
What is the transition altitude?
The level at which you begin to use standard pressure setting on departure
What is the transition level?
The level at which you begin to use QNH on approach
What is the gap between the transition altitude and transition level called?
The transition layer
What happens to indicated altitude when you change from a higher QNH to SPS?
Indicated altitude decreases
What happens to indicated altitude when you change from a lower QNH to SPS?
Indicated altitude increases
What happens to the true altitude if the pressure is sloped upwards as you travel?
It increases
What happens to the true altitude if the pressure is sloped downwards as you travel?
It decreases (from high to low look out below)
When would you use area QNH?
When flying cross-country
When would you use aerodrome QNH?
When arriving or departing an aerodrome
What happens to your true altitude when you fly from cold to warm on a constant pressure setting?
It increases
What happens to your true altitude when you fly from warm to cold on a constant pressure setting?
It decreases
What is the equation for temperature error correction (TEC)
TEC = height/1000 x 4 x ISA deviation
How do we apply TEC when the ISA deviation is warmer?
Add the TEC to the indicated to get the true
Subtract the TEC from the true to get the indicated
How do we apply TEC when the ISA deviation is colder?
Subtract the TEC from the indicated to get the true
Add the TEC to the true to get the indicated
