Flight Planning Flashcards
Ram Air Temperature (RAT) is defined as ?
defined as the sum of the OAT (ambient Outside Air Temperature),
plus some of the ram temperature rise.
Whats a Temperature probe sensor recovery factor ?
Represents the amount of ram temperature rise indicated by the probe.
OAT temp = -50c sensory recovery factor of 0.8, Ram temp rise at a given Mach number is 30°C calculate RAT ?
OAT of -50°C + 0.8 (80%) of 30°C (24°C) = -26°C RAT
Total Air Temperature (TAT) ?
is the sum of the OAT (which is known sometimes as the True Outside Air
Temperature [TOT]) and the full theoretical ram temperature rise due to compressibility effects.
Calculate TAT if OAT is -50c and ram temp rise is 30c ?
OAT of -50°C + the full 30°C temperature rise = -20°C TAT
Standard temperature at FL110 (11000 ft) is ?
15°C at MSL - [11 x1.98°C] = -6.78°C)
the pressure rise also
causes the airspeed indicator (ASI) to ?
Over read at high speeds
EAS is simply ?
IAS corrected for compressibility error
In the B727 the corrections for instrument and position error are
less than 1 kt so for practical purposes,
in this aircraft IAS = ?
CAS
find EAS for an aircraft flying at 300 KCAS at FL300 ?
Enter the F factor table at 300 kt and FL300 and obtain the F Factor of 0.95.
Step 2
Multiply the IAS by the F factor to obtain EAS: 300 x .95 = 285 EAS.
For practical purposes, the Indicated Mach Number is the ?
True Mach Number TMN
The Formula used to compute the speed of sound in knots is ?
Mach 1.0 (in kt) = Square root of OAT in degrees K x 39 -1
To then compute the TAS for any Mach Number other than 1?
TAS = Square root of OAT in degrees K x 39 x M -1 (where M = Mach Number)
To convert the Celsius temperature to Kelvin, simply add ?
simply add 273 to the Celsius
temperature.
find the speed of sound at MSL in ISA: (15°C) ?
M1.0 = (15C + 273 K) = V288 K x 39 -1 = 661 kt
example, find the speed of sound at MSL in ISA: (15°C)
M1.0 = (15C + 273 K) = V288 K x 39 -1 = 661 kt
Similarly, Mach 0.80M at the same temperature = ?
V288 K x 39 x .8 -1 = 528 kt
Find the speed of sound at the tropopause in ISA: (-56°C) ?
M1.0 = (-56C + 273 K) = V217 K x 39 -1 = 574 kt
Find the speed of sound at the tropopause in ISA: (-56°C)
M1.0 = (-56C + 273 K) = V217 K x 39 -1
= 574 kt
Similarly, 0.80M at the same temperature = ?
V217 K x 39 x .8 -1 = 459 kt
find the TAS at 0.80M at FL310 at a temperature of ISA+10 ?
The OAT must be computed by applying the ISA variation to the ISA OAT at FL310 from page
3-106 of the B727 POH.
ISA OAT at FL310 is -46°C.
ISA+10 therefore will be a temperature of -36°C. convert the OAT to Kelvin. In this example -36°C = 237K (-36°C + 273) M0.8 = V237 K x 39 x .8 -1 = 479 kt
find the Mach Number at a TAS of 455 kt with an OAT of -50°C ?
Calculate the TAS for 1.00M at -50°C ({V223K [-50 + 273]} x 39 -1 = 581 kt).
2
Divide the TAS given of 455 by the TAS of 1.00M of 581 (455/581 = 0.783 M).
find the OAT at a TAS of 420 kt and a Mach Number of 0.70M ?
Calculate the TAS of 1.00M for 420 kt at 0.70M (420+1/0.7 = 600 kt). The 1kt accounts for the
overread error of the formula.
Divide the TAS of 600 kt by 39, then square the answer and subtract 273k to find the OAT
of -36°C (420+1/0.7 = [600 kt/39) squared - 273 = -35°C)
For example, refer to the B727 POH page 2-8. A B727 has a BRW of 72000 kg and a climb is to be made to
FL350. From the table it can be seen that with a BRW of 72000 kg the climb to FL350 will take 22 minutes
and cover 136 nm in nil wind (ANM) while consuming 2750 kg of fuel at a published TAS of 418 kt. The forecast wind 2/3 of the way up results in a headwind component for the climb of -30 kt.
Follow these steps to determine how many miles will be covered over the ground (GNM) ?
Divide the 136 ANM by the time interval (ETI) of 22 minutes and multiply by 60 to find climb
TAS. 136/22 x 60 = 371 kt (this is far less than the published figure which should be ignored)
Step 2
Add the wind component to the TAS to find the climb groundspeed. 371 + -30 = 341 GS
Step 3
Multiply the Groundspeed by the ETI and divide by 60 to find the GNM.
341 x 22/60 = 125 GNM
we need to look at how to choose a particular cruise level for a flight. The
B727 is designed to cruise at FL’s in the mid to low ?
300s i.e FL300-FL350
Will weather, winds or trip length effect what cruising level you pick in the exam ?
No
How does thrust limits effect cruising levels ?
This refers to the ability of an aircraft to reach a particular level for a given gross weight and speed. It is based on the available engine thrust, from the forecast ISA deviation
at the proposed level. For exam purposes the forecast level from the RSWT nearest to the proposed level is used to determine the ISA deviation.
What is optimal flight level ?
This refers to the Flight Level, which will be the most economical level in terms of fuel efficiency for a particular gross weight and speed. This will not necessarily be the maximum level, which the aircraft can reach. Page 2-14 also lists optimum levels.
How does buffet limits effect flight level ?
This refers to the maximum level achievable aerodynamically, considering stall margins
and high-speed Mach buffet at various weights and turbulence intensity. These margins are graphically presented on pages 2-11, 2-12 and 2-13.
To ensure that the aircraft does not exceed its buffet
boundaries, draw ?
draw a line across the graph at the Flight Level under consideration and ensure that the SZW will
reach or exceed that FL. If it does, the gap between the
high and low speed sides is the available speed range.
For example, with a top of climb weight of 82000 kg (82t) what is the maximum FL achievable for an
Easterly flight at 0.82M with temperatures of ISA+10 at top of climb with moderate turbulence forecast?
Note the possible IFR hemispherical levels for the flight (East or West) and note your Mach
Number schedule and the temperature deviation from ISA at the various levels from the RSWT.
In this example, the flight is to the EAST so the possible options are FL290, FL330 or FL370
(FL410 is very unlikely in this aircraft).
Choose an IFR level and check that your Start Zone Weight or Top of Climb weight does not
exceed the maximum permitted thrust limited weight for the ISA deviation at top of climb and speed
it can be seen that at FL290 our SZW of 82t is
less than the new maximum weight of 83.2t at ISA+10 so this level is the highest FL available.
The final step is to ensure that at our chosen FL we are within the aerodynamic envelope of the
buffet boundaries.
The optimum FL is not necessarily the same as the maximum FL why ?
On a hot day an aircraft may not be
capable of achieving the optimum FL, while on a cold day the maximum FL may be well above the
optimum. This is because the maximum (thrust limited) FL depends on temperature, weight and speed,
however the optimum FL depends only on weight and speed. Optimum weights for each FL are shown on
page 2-14.
What is the EMZW ?
Since the weight of an aircraft is not constant, but reduces as fuel burns during a flight, the choice of
optimum level is not made on the basis of the Brakes Release Weight (BRW) or Landing Weight (LW), but
rather at the average weight for the flight (half way along) which we call the Mid-Zone Weight (MZW).
Usually the MZW is not known before a flight plan and so the MZW must be estimated. In this case it is
known as the Estimated Mid-Zone Weight (EMZW).
The optimum level for a flight at a particular Mach Number is ?
the level, which provides the
closest match between the optimum weight and the EMZW (refer to the ATPL(A) Examination
Information Booklet page 29 para 2.3).
EMZW = ?
EMZW = BRW- [(distance x 10 kg/nm)/2 + 1600 kg].
Why do we need to add an extra 1600 kg of fuel to the first half of the flight to calculate a more accurate EMZW ?
A typical climb consumes around 3100 kg and covers around 150 nm. 10kg/nm over 150 nm is
1500 kg. This is 1600 kg less than the total climb fuel of about 3100 kg.
In high-speed and high altitude flight, the air temperature around the leading edge of airframe surfaces over or around 250 kts ?
O may rise by up to 30°C or more above OAT due to compression
O may rise by up to 10°C or more above OAT due to decompression
O may rise by up to 15°C or more above OAT due to compression
O may rise by up to 20°C or more above OAT due to decompression
O may rise by up to 30°C or more above OAT due to compression
350 CAS at 20,000 ft PA. equals what EAS (CAS)?
338 TAS
340 TAS
343 TAS
347 TAS
340 TAS refer to table (F correction Factors for TAS ) page 1-6 in the 727 Handbook
In the absence of an accurate forecast or METAR, how would you determine the pressure height of the aerodrome?
None of these
Set altimeter to density height
Set altimeter to ELEV
Set altimeter to 1013.2 hPa
Set altimeter to 1013.2 hPa
If the OAT is-40°C and the temperature probe has a recover factor of 0.8, with a RAM rise of 30°C; what RAT will the probe read?
-10°C RAT
-30°C RAT
-28°C RAT
-20°C RAT
-16°C RAT
OAT of -40°C + (0.8 x 30°C) = -40°C + 24°C = -16°C RAT
At CAS 160KT and P.A. 35,000 what is the Mach Number?
0.49
The Mach Number is ?
a speed in knots converted to a percentage of the speed of sound at ISA
a speed ratio of how fast the aircraft is going compared to the speed of sound but has no relevance to the current ambient
conditions
a direct speed number relative to the speed of sound and does not change with the current ambient conditions
a speed ratio of how fast the aircraft is going compared to the speed of sound in the current ambient conditions
a speed ratio of how fast the aircraft is going compared to the speed of sound in the current ambient conditions
Given Mach 0.82 FL310, ACTUAL TAT = -14, ISA TAT = -16: Find the ISA variation and OAT ?
ISA Difference +2 and OAT 44°C
ISA Difference +4 and OAT -42°C
ISA Difference +5 and OAT -41°C
ISA Difference +6 and OAT -38°C
Given ACTUAL TAT = -14 and ISA TAT = -16: ISA Difference is + 2
ISA OAT from page 3 - 106 = -46
OAT = ISA OAT + ISA Difference = -46 + 2 = -44°C
Correct Answer: ISA Difference +2 and OAT -44°C
Question 10 of 20
What is the standard temp at A090?
Type your answer correct to 2 decimal places with no symbols or spaces. e.g. for 11.2°C, just type: 11.20
Standard temperature at A090 (9000 ft): 15°C at MSL - (9x 1.98°C) = 15 - 17.82° = -2.82°C
Correct Answer: -2.82
I think it’s important you can calculate these, but they are listed on page 3 - 106 of the B727 handbook in the “O” column.
In high speed flight (above 250 kts) ?
the pressure fall results in an under-read error in AS from the total pressure fall
the pressure rise results in an under-read error in AS from the total pressure fall
the pressure fall results in an over-read error in IAS from the total pressure rise
the pressure rise results in an over-read error in AS from the total pressure rise
the pressure rise results in an over-read error in AS from the total pressure rise
In regards to the difference between TAS and CAS which is truest?
CAS and TAS are closest at lower altitudes
CAS equals TAS
CAS and TAS have a constant difference irrespective of altitude
CAS and TAS are closest at higher altitudes
CAS and TAS are closest at lower altitudes
Refer to table (F Correction Factors For TAS) page 1 - 6 in the B727 handbook.
You can see at any given CAS the correction factor decreases with altitude.
At 200KT CAS, at 10,000 feet; TAS equals CAS
Yet at 200 KT at 40,000 feet; TAS equals 0.96 x CAS
CAS
Using your maps only. Calculate the direct distance Darwin NT (YPDN) to Cairns QLD (YBCS)?
875 NM
906 NM
990 NM
830 NM
906 NM
What is the standard temp at FL450?
Standard temperature at FL450 (45,000 ft): 15°C at MSL - (45 x 1.98°C) = 15 - 89.1° = -74.10°C
However above 36,090 AMSL feet (the Tropopause), the temperature remains at -56°C up to 66,000 AMSL
I think it’s important you can calculate these, but they are listed on page 3 - 106 of the B727 handbook in the “O” column.
So in a current 2019 version jet airliner you will never have OAT below -56°C.
Correct Answer: -56.00 (we did accept 56.00 as well, but CASA won’t)
At CAS 280KT and P.A. 35,000 what is the Mach Number?
Please type your answer to two decimal places with no symbols or spaces. e.g. for Mach Number 0.755 just type 0.76
0.82
the cockpit TAT indicates -12°C at FL330 at 0.82M; The OAT is ?
From page 3 - 106 of the B727 handbook
FL330 at Mach 0.82 should have an ISA TAT of -20
Bu -12°C is + 8°C warmer than the ISA TAT of -20°C
The OAT from column “O” on page 3-106 -5 -50°C
+ 8°C warmer than ISA OAT of -50°C = -42°C
Correct Answer : -42
Mach meter uses_________to determine the Mach Number ?
the current aircraft TAS and OAT
the current aircraft CAS and Density Height
the current aircraft TAS and Flight Level
the current aircraft CAS and Flight Level / Pressure Altitude
the current aircraft CAS and Flight Level / Pressure Altitude
Pilots need to be cautious of aircraft Mach numbers ?
particularly at high altitude where high TAS result in low Mach numbers
particularly at low altitude where high TAS result in high Mach numbers
Particularly at high altitude where high TAS result in high Mach numbers
particularly at low altitude where high TAS result in low Mach numbers
Particularly at high altitude where high TAS result in high Mach numbers
Flying too close to Mach 1.0 can be extremely dangerous without the correct design features to reduce buffeting and improve control-
ability.
Using your maps only. Calculate the direct distance Melbourne VIC (YMML) to RAF Curtin WA (YCIN)?
1648 NM
1520 NM
1725 NM
1864 NM
1648 NM
What wind is to be used to determine accurate climb figures in your CASA ATPL exams?
Use the met data, wind and temperature deviation, closest to 2/3rds of the height of the initial cruise level
Use the met data, wind and temperature deviation, closest to one half of the height of the initial cruise level
Interpolate the met data, wind and temperature deviation, closest to 1/4 and 2/4 and 3/4 of the height of the initial cruise level
Interpolate the met data, wind and temperature deviation, closest to 1/3 and 2/3 of the height of the initial cruise level
Use the met data, wind and temperature deviation, closest to 2/3rds of the height of the initial cruise level
Climb. Candidates should use the met data, wind and temperature
deviation, closest to 2/3rds of the height of the initial cruise level; also refer to
the Handbook, page 2-2, paragraph 9 et seq. For a climb from one level to
another, e.g. FL220 to FL310, then the winds and temperatures should be
used from the height 2/3rds between the two levels. In his case FL.280.
In a constant Mach cruise ?
engine RPM will need to be reduced during cruise
engine RPM will constantly change during cruise
engine RPM will need to be increased during cruise
engine RPM will need to remain constant during cruise
engine RPM will need to be reduced during cruise
As fuel is burned off, less lift is required, so the AofA reduces. This increases cruise speed and requires a reduction in RPM to keep a
constant Mach cruise.
What is TAS at M0.78 at 32,000 feet in knots?
© 455 kts
© 464 kts
© 471 kts
© 450 kts
32,000 feet OAT = 15 -32 x 1.98 = 15 - 63 = -48°C
TAS = VOAT in degrees Kelvin x (39 x Mach Number) -1
M 1.0 =V (-48°C + 273 ) x (39 x 0.78) - 1= V225 x (39 x 0.78) -1 = 455 kts
If only considering fuel economy, the most efficient cruise method is ?
LRC
cruise climb
step climb cruise
constant mach cruise
cruise climb
The cruise climb maintains the most efficient engine RPM and the most efficient AofA. To do this the aircraft climbs slowly during the
cruise. In reality though this method is rarely used due to conflicting traffic and the clearances that would be required for constant level
changes. A step climb is usually used as a more practical alternative.
How many ground nautical miles (GNM) will it take to climb in the B727 to FL330 at BRW of 68,000 kg with a headwind of 40 knots at ISA
+10?
Use Table 2.3 page 2-9
Look up table 21 minutes and convert to hours 21/60 = 0.35 hours
Multiply time by wind speed per hour = 0.35 x -40 kt wind = -14 nm
Look up table 131 nm and add -14 nm = 131 + -14 = 117 GNM
Correct Answer: 117.00
What is TAS at M0.8 at 25,000 feet in knots?
0 472 kts
O 480 kts
O 468 kts
0 464 kts
25,000 feet OAT = 15 - 25 x 1.98 = 15 - 49.5 = -34.5 = -35°C
TAS = VOAT in degrees Kelvin x (39 x Mach Number) -1
M 1.0 =V (-35°C + 273 ) x (39 x 0.8) - 1= V238 x (39 x 0.8) -1 = 480 kt
How many ground nautical miles (GNM) will it take to climb in the B727 to FL310 at BRW of 76,000 kg with a headwind of 20 knots at ISA
+10?
Use Table 2.3 page 2-9
Look up table 23 minutes and convert to hours 23/60 = 0.383333333 hours
Multiply time by wind speed per hour = 0.38333333 x-20 kt wind = -7.666666666 nm
Look up table 146 nm and add -7.666666 nm = 146+ -7.6666666 = 138.33 GNM
Correct Answer: 138.33
Given: CAS 280 kts, Pres Alt 38,000 ft, Ind. Air Temp -10°C; Find True Air Temperature ?
Use your CR computer.
-46°C
-40°C
-42°C
-52°C
-38°C
-46°C
For climb calculation winds from RSWT will most commonly be used from ?
O FL240
© FL340
O FL180
O FL300
FL240
Winds for climb are to be used at 2/3rds of the climb height. The most common cruise levels will be above FL300
FL180 + 2/3 = 27000 feet = FL270
FL240 + 2/3 = 36000 feet = FL360
Halfway between these two is FL210 which has no RSWT
21000 + 2/3 = 31500 feet
On the balance of probability at ISA or close to ISA the aircraft will be climbing above 31,500 feet. Therefore FL240 is the most common
cruise level.
You will not be required to calculate this. We have included calculations to reduce arguments about this answer, since most textbooks
are wrong and say FL235, which does not have weather forecasts.
According to your textbooks and the calculations, the old RSWT charts were prepared for flight levels FL185, FL235, FL300, FL340, FL385,
FL445, which correspond with pressures of ?
600 hPa, 500 hPa, 400 hPa, 300 hPa, 200 hPa, 100 hPa
350 hPa, 300 hPa, 250 hPa, 200 hPa, 150 hPa, 100 hPa
450 hPa, 400 hPa, 350 hPa, 250 hPa, 200 hPa, 150 hPa
500 hPa, 400 hPa, 300 hPa, 250 hPa, 200 hPa, 150 hPa
500 hPa, 400 hPa, 300 hPa, 250 hPa, 200 hPa, 150 hPa