Chapter 4 - Altimeter-Setting Procedures Flashcards
Altimeter-Setting Procedures
What is the name of the knob which allows a pilot to select the local pressure setting on their altimeter?
The subscale-setting knob
What is QNH? How else may it be referenced?
The mean sea level pressure, causing an altimeter to indicate altitude
As altitude
Why is it extremely important to be able to accurately refer to correct QNH?
QNH varies from time to time and from place to place
The ground and obstacles are usually shown on maps as heights AMSL
What is QFE? How else may it be referenced?
The pressure level at the aerodrome elevation
Height
What is the most common altimeter setting for circuit/aerodrome work?
QFE
What is the name for the altimeter sub scale being set to 1013.2 hectopascals?
Pressure Altitude (PA)
How is pressure altitude easily discerned from altitude?
It is called Flight Level
How many regional pressure settings are there in the UK? How else is this known?
20
Regional QNH
Define ‘transition altitude’
The altitude below which the vertical position of the aircraft is controlled by reference to altitude
In what conditions is standard pressure (1013) used by aircraft?
For all aircraft in controlled airspace and all aircraft in uncontrolled airspace above 3,000 feet
What is ‘transition level’?
The lowest flight level available for cruising above the transition altitude
What is the area between the transition altitude and the transition level?
The transition layer
How should altitudes be written in a flight plan?
As altitudes for that part of the flight below the transition altitude and flight levels for that part which is above the transition level
What are the three main considerations for choosing an appropriate cruising level in flight?
- Terrain clearance
- ATS requirements
- Compliance with the semicircular rule
What can happen en-route if regional pressure decreases but the pressure setting is not updated? What else can affect altitude in this way and why?
The aircraft can lose height/altitude
Temperature. Colder temperatures are found in denser air. The altimeter will read higher than it is and consequently the aircraft will need to descend to maintain the same apparent altitude
What must always be considered when selecting a flight level for cruise?
The regional pressure setting below this and the resulting separation from traffic at the transition altitude
What should a pilot do (with regard to altitude) when flying beneath a CTR or a TMA below the transition altitude? Why?
Use the QNH for an aerodrome within the area
This will prevent inadvertent penetration of the controlled airspace
What will a pilot usually be given when penetrating a MATZ?
QFE
What is a ‘clutch QFE’?
The lowest QFE available when there is more than one aerodrome in a combined MATZ
In level flight above 3,000 feet amsl, pilots flying IFR must 1013 set, and conform to…
The semicircular rule when selecting cruising levels
VFR flights above the transition altitude may use…for navigation, however when choosing to use the…, they must use…on the sub scale
QNH
Semi-circular rule
1013
What is the simple rule for calculating cruising levels for your flight?
IFR= 1,000s
VFR= 500s
Left (West) is even levels
Right (East) is odd levels
On radar approach, which altimeter setting is used by ATC?
QNH
On missed approach, which setting should be used (unless otherwise instructed)?
QNH
