Progress Test 4 Flashcards
(21 cards)
What is Boyles Law? And what is it’s formula?
At a constant temperature the volume of gas is inversely proportional to it’s pressure. Decrease of the volume of gas will increase the pressure.
(PV=K1)
What is Charles law and the formula?
The volume of gas at a constant pressure is directly proportional to it’s absolute temperature. An increase of temperature will increase the volume of gas at a constant pressure.
(V=K2T)
If Density decreases when pressure decreases, but density increases when temperature decrease, both due to an increase of altitude what has more effect on the density?
The decrease of pressure creating a decrease of density has more of an effect.
What two things is air density related to?
Temperature and pressure.
What is denser, cold air or warm air?
Cold air.
True or False? Less dense air gives better aircraft performance.
False, denser air leads to better aircraft performance. The thicker air provides more oxygen per until volume.
What does altimeter measure?
The altimeter measures pressure not the height, when flying at an equal pressure setting to the one outside the altitude will be correct.
When flying from a Low Pressure to a High Pressure will the altimeter over-read or under-read?
Under-read if not corrected for.
The country is divided into ASR’s (altimeter Setting Regions), Describe what these provide?
They each provide a Regional Pressure Setting (RPS), this is the lowest forecasted pressure setting for the next two hours and is updated hourly.
What is an ‘Altitude’ as a reported level on
altimeter setting?
Where the altimeter sub-scale is set to the QNH which is the height above mean sea level.
What is ‘Height’ as a reported level on altimeter setting?
Where the sub-scale is set to the QFE which is the height above ground of the aerodrome.
What is ‘Flight Level’ as a reported level on the altimeter setting?
Where the altimeter sub-scale is set to the standard pressure setting (1013.2), a specific level must be flown depending on wether the aircraft is flying VFR or IFR.
What is QNE?
QNE is the height of an aerodrome threshold, the altimeter sub-scale is set to 1013.2. Used for airport as high altitudes where QFE will not be possible.
What is a Transition Altitude?
The point that an aircraft must change from the QNH to the SPS to fly at flight levels. This is normally 3,000ft in the UK open FIR but can go up to 6,000ft around London and Manchester TMA’s.
What is a Transition Level?
The point that an aircraft must change from the SPS to QNH. This will be notified to the pilot by ATC. This is the first available flight level 1000ft above the transition altitude.
What are Isotherms?
Points of equal temperature.
As warm air is less dense than cold air, what ‘column’ of air is higher warm or cold?
Warm air.
What is an ISA lapse rate?
The average ISA increase in either temperature, density or pressure.
What is temperature inversion?
Where the temperature increases as altitude increases.
What are the three causes of temperature inversion?
Subsidence, Frontal Inversion and Radiation Inversion.
What is subsidence as a causes of temperature inversion?
An air mass that is descending is a Subsidence so this associates more with High Pressure systems (anti-cyclones). The descending warming air acts as a lift on the atmosphere at low level, trapping pollutants beneath.
