Navigation Factors Flashcards
Altimeter settings
QNH is given as ____
It indicates height from what datum
- ALTITUDE
- AMSL
Altimeter settings
QFE is given as ____
It indicates height from what datum
- HEIGHT
- Above Aerodrome reference point
Altimeter settings
SPS is given as ____
It indicates height from what datum
SPS = Standard Pressure Setting
- FLIGHT LEVEL
- 1013 hPa
What is set on the subscale of a kollsman window when given an ALTITUDE
QNH
What is set on the subscale of a kollsman window when given a HEIGHT
QFE
What is set on the subscale of a kollsman window when given a FLIGHT LEVEL
STANDARD PRESSURE SETTING
(SPS)
1013 hPa
The UK FIR Transition Altitude is typically what
3000 ft
The Transition Altitudes sits ABOVE or BELOW the Transition Level
BELOW
The Transition Level sits ABOVE or BELOW the Transition Altitude
ABOVE
What is the layer called that sits between the Transition Altitude and Transition Level
TRANSITION LAYER
The Transition Level is referenced to what pressure setting in the kollsman window
1013 hPa
The Transition Altitude is referenced to what pressure setting in the kollsman window
QNH
When flying from a LOW pressure to a HIGH pressure, what will the altimeter do;
OVER READ or UNDER READ
UNDER READ
You are higher than you think you are
When flying from HIGH pressure to a LOW pressure, what will the altimeter do;
OVER READ or UNDER READ
OVER READ
You are lower than you think you are
What does the following abbreviation mean
ASR
ALTIMETER SETTING REGION
What does the following abbreviation mean
RPS
REGIONAL PRESSURE SETTING
An RPS pressure setting is given to a pilot is the ____ forecast setting for the next ____ hour(s), updated ever ____ hour(s)
- LOWEST
- 2 hours
- 1 hour
What conditions is an altimeter calibrated to
ISA CONDITIONS;
Temp: 15℃ @ Sea Level
Lapse rate: 2℃ per 1000 ft
Density: 1.225 kg/m^3
Deviation from ISA results in altimeter error
For the same pressure setting, a column of warm air is TALLER or SHORTER than a column of cold air
TALLER
Warm air is less dense so pressure levels are more widely spaced
When flying from COLD air to WARM air for a given pressure setting, what will the altimeter do
OVER READ or UNDER READ
UNDER READ
Higher than you think you are
When flying from WARM air to COLD air for a given pressure setting, what will the altimeter doe
OVER READ or UNDER READ
OVER READ
Lower than you think you are
What is the definition of a pressure altitude
Altitude an aircraft would fly at if the atmospheric pressure were the same as ISA (1013 hPa)
In other words, if you were flying at 3000 ft on QNH of 1026, if we set the kollsman window to 1013 hPa our altimeter would actually read 2610 ft
1026 - 1013 = 13
13 * 30 = 390ft difference
WIND OF PRESSURE, WIND OFF ALTITUDE
3000 - 390 = 2610 ft
An ASI is susceptible to ____ errors, which are caused by a difference in temperature to ISA for the given ____ altitude
- DENSITY
- PRESSURE
Find the TAS for a flight occurring at altitude 3000ft on QNH 1026 hPa. Outside Air Temperature (OAT) is 0℃. CAS is 92 kts
Use a wizz wheel
TAS 94 kts
- Calculate pressure altitude first. REMEMBER pressure altitude is if we had 1013 hPa set in the kollsman window. Currently we have 1026
1026 - 1013 = 13. 13 x 30 = 390. 3000ft - 390ft = 2610ft - On the flight computer in the pressure altitude and air temperature window, set the pressure altitude to 2610ft to 0℃
- On the inner scale, find CAS 92kts
- Read the TAS on the outer scale. TRUE AIRSPEED = 94 kts
Airspeed compressibility needs to be considered for aircraft faster than ____ kts
300 kts
On aviation charts, grid lines reference TRUE or MAGNETIC north
TRUE NORTH
Every aviation chart must show ____ variation for what ____ that it covers
- Magnetic
- Area it covers
Items such as headsets, mobile phones, iPads can influence the ____ by as much as up to ____%
- Compass heading
- 30%
The name given to the point where the aircraft compass is calibrated as best as possible and remaining minor errors placarded.
COMPASS SWING
The compass errors after being calibrated are placarded on the what
COMPASS DEVIATION CARD
The earths magnetic field is 3-D, made up of 3 components. These components are;
- Total magnetic field (T)
- Horizontal (H)
- Vertical (Z)
Compass dip is more significant at HIGHER or LOWER altitudes
HIGHER
Closer to the magnetic poles
When setting the DI against a compass heading, what must the pilot do with the aircraft (3 states aircraft must have)
- Constant heading
- Constant speed
- wings level
What does the following abbreviation mean
UNOS
Undershoot North
Overshoot South
In the northern hemisphere, referencing UNOS, when turning onto a northernly heading, what should a pilot do
Roll out BEFORE compass indicates North
In NH, because of compass dip, the compass will turn slower than you, so you roll out before the compass reads north as it will eventually catch up
In the northern hemisphere, referencing UNOS, when turning onto a southernly heading, what should a pilot do
Roll out AFTER the compass indicates South
In NH, because of compass dip, the compass will turn faster than you, so you roll out before the compass reads north as it will eventually catch up
What is the rule of thumb to calculate how many degrees to undershoot or overshoot by in a turn
1/2 the latitude + 15॰
If at a latitude of 52॰
52 / 2 = 26
26 + 15 = 41॰
What does the following abbreviation mean
ANDS
Accelerate North
Decelerate South
On an easterly heading
If the aircraft accelerates, the compass ring will swing TOWARDS or AWAY from us, and will indicate a turn ____
- Towards
- North
On an easterly heading
If the aircraft decelerates, the compass ring will swing TOWARDS or AWAY from us, and will indicate a turn ____
- Away
- South
What is a way to remember TVMDC
True
Virgins
Make
Dull
Companions
What do each of the following stand for;
T
V
M
D
C
True Virgins Make Dull Companions
True Heading
Variation
Magnetic Heading
Deviation
Compass Heading
Where can a pilot find sunrise and sunset times
Aeronautical Information Publication
(AIP)
What is the ANO definition of night time
half an hour after sunset
half an hour before sunrise
What is the ICAO definition of night time
Hours between end of evening civil twilight and beginning of morning civil twilight.
Civil twilight ends in the evening when center of the suns disc is 6॰ below the horizon
Civil twilight begins in the morning when the center of the suns disc is 6॰ below the horizon
20nm from your destination, cruising at 5000ft at 77kts ground speed, you wish to be at 2000ft 5nm before the destination. What should your RoD be?
256ft/min
- Calculate height to lose. 5000ft - 2000ft = 3000ft
- Calculate distance to lose the height. 20nm - 5nm = 15nm available
- REMEMBER: 1 knot = 1nm/ph. So if we travel 77kts, 77/60 = 1.28nm per minute
- 15 nm to travel so 15 / 1.28nm/pm = 11.7 min
- 3000 ft to lose over 11.7m sp 3000 / 11.7 = 256ft/pm
A wind velocity is made up of which 2 components
- Headwind
- Crosswind
Using the clock code method, roughly what is the cross wind component;
Runway 06. Wind 040॰ 22kts
Roughly 7.3kts
- Subtract wind direction from runway direction 60 - 40 = 20
- Every 5॰ is 5 minutes on the clock face so 20 minutes.
- 3 x 20 minutes = 60 minutes on the clock face, so 20 is 1/3rd of 60
- Therefore, we need 1/3rd of the wind
- 22 / 3 = 7.33kts
When worked out on a wizz wheel, the cross wind component is 8 kts, very close!
Using a flight computer CRP-1, work out the cross with component;
Runway 32. Wind 290 22kts
10 kts
- Set wind direction on the ture heading on the wizz wheel
- Set the speed dot to o and mark a dot 22 kts down
- Turn the wizz wheel to the runway heading of 320॰
- Note the dot has moved to the right. Read off the cross wind component = 10 kts, headwind component is 20kts
Use the clock down method to get roughly the same figure. 320 - 290 = 30
30 mins is half of 60 mins, so 22 /2 = 11kts. Very close!
What is the specific gravity of AVGAS
0.72
What is the weight of 120 litres of AVGAS (SG 0.72) in KG and also Lbs
- 86.4 kg
- 190 lbs
120 L x 0.72 sg = 84.6 kg
84.6kg x 2.2 = 190 lbs
Calculate your true altitude given that:
Indicated altitude: 6,200 ft
QNH: 1030 hPa
Calibrated outside air temperature: 10℃
Assume 1hPa = 30ft
Use Wizz Wheel
6340 ft
- Determine the pressure altitude. We know 6200ft for 1030hPa. 1030hPa - 1013hPa = 17hPa
- 17hPa x 30ft = 510ft
- 6200ft - 510ft = 5690ft
- On CRP-1 computer, set 5690ft against the OAT of +10℃
- Looking on the inner scal, where the 60 minute red triangle equals 6000ft, align the red indicator line to 6200ft (original IA)
- On the outscale, note this is equal to 6340ft
When flying VFR under SERA rules (no UK CAA exemption) on an altimeter setting of 1013 hPa above a Transition Altitude of 3,000 ft, Magnetic Heading 274॰, which is compensating for 5॰ drift to the left, what recommended FL should be flown if Class A airspace above starts at FL60?
FL45
Things to remember first;
1. Transition altitude is 3000ft. Transition layer is 1000ft, so first available FL doesnt start until 4000ft minimum.
2. We are flying VRF. For VRF flights using the ICAO semi-circle rule, you flight and ODD or EVEN tracks PLUS 500ft.
Workings Out:
1. Determine semi circule ODD or EVEN from track. Track is 274॰ less 5॰ drift to the left, track is 269॰
2. As per the VFR semi circle, this is an EVEN track (i.e. between 180॰ and 359॰)
3. Transition Level MUST start at 4000ft since transition altitude is 3000ft.
4. 4000ft is an EVEN track, so we can use 4000ft PLUS 500ft for VFR = FL45
CAS is IAS corrected for what 2 factors
- Position Error
- Instrument Error
