ATPL Instruments and Navigation Aids
2024/2025 Exam Questions Marking
Scheme New Update | A+ Rated
What is the Mach number formula? - 🧠ANSWER ✔✔Mach numer =
TAS/LSS
How do you calculate the LSS? - 🧠ANSWER ✔✔38.94 x square root of
temperature in degrees kelvin
What is 0degrees Celsius in Kelvin? - 🧠ANSWER ✔✔273 degrees kelvin
Is the speed of sound faster at higher altitudes or lower - 🧠ANSWER
✔✔Lower
Is the speed of sound faster at higher temperatures or lower? - 🧠ANSWER
✔✔Higher
If altitude is increased at constant TAS does Mach number do? -
🧠ANSWER ✔✔Increase
What is VMO? - 🧠ANSWER ✔✔Maximum operating IAS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
,What is MMO? - 🧠ANSWER ✔✔The maximum operating speed in Mach.
What errors does the Mach meter suffer from? - 🧠ANSWER ✔✔Instrument,
pressure, blockages
If the pitot tube becomes blocked during a climb the Mach meter will... -
🧠ANSWER ✔✔Overead
If the static port becomes blocked during a climb the Mach meter will... -
🧠ANSWER ✔✔Under read
What is the temperature deviation from ISA if an aircraft is at FL340 and
has a TAS of 498kts and a Mach number 0.815? - 🧠ANSWER ✔✔+25.56•c
What is Mach number if TAS is 498kts and LSS is 595 knots? - 🧠ANSWER
✔✔0.837
What is the altitude if a TAS of 395 corresponds to Mach 0.67? -
🧠ANSWER ✔✔FL297
What is the altitude if a TAS of 460knots = 0.73 Mach? - 🧠ANSWER
✔✔13,200ft
What inputs does the ADC get? - 🧠ANSWER ✔✔Pitot, static, total
temperature and angle of attack
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
, What outputs does an ADC provide? - 🧠ANSWER ✔✔Altitude, V/S, IAS,
Mach Number, VMO and MMO, AOA, TAT, SAT
What is TAT? - 🧠ANSWER ✔✔SAT + the maximum Ram rise
What is SAT? - 🧠ANSWER ✔✔TAT corrected for maximum possible Ram
rise
What is the formula for calculating Sat? - 🧠ANSWER ✔✔Ts= Tm / (1+(0.2
x k x m^2))
If TAT indicates -26• and aircraft is at mach 0.8 what is the static outside air
temp? - 🧠ANSWER ✔✔-54.02
If an aircraft is travelling at 0.77 and indicating -24• on the TAT the TAS will
be? - 🧠ANSWER ✔✔447.35
What are the 2 types of flight directors? - 🧠ANSWER ✔✔Split cue and
intergrated cue
What is PLI? - 🧠ANSWER ✔✔Pitch limit indicators (when stick shaker will
engage)
How much margin do pilots get a stall warning - 🧠ANSWER ✔✔5% above
stall
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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PRIVACY STATEMENT. ALL RIGHTS RESERVED
2024/2025 Exam Questions Marking
Scheme New Update | A+ Rated
What is the Mach number formula? - 🧠ANSWER ✔✔Mach numer =
TAS/LSS
How do you calculate the LSS? - 🧠ANSWER ✔✔38.94 x square root of
temperature in degrees kelvin
What is 0degrees Celsius in Kelvin? - 🧠ANSWER ✔✔273 degrees kelvin
Is the speed of sound faster at higher altitudes or lower - 🧠ANSWER
✔✔Lower
Is the speed of sound faster at higher temperatures or lower? - 🧠ANSWER
✔✔Higher
If altitude is increased at constant TAS does Mach number do? -
🧠ANSWER ✔✔Increase
What is VMO? - 🧠ANSWER ✔✔Maximum operating IAS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
1
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,What is MMO? - 🧠ANSWER ✔✔The maximum operating speed in Mach.
What errors does the Mach meter suffer from? - 🧠ANSWER ✔✔Instrument,
pressure, blockages
If the pitot tube becomes blocked during a climb the Mach meter will... -
🧠ANSWER ✔✔Overead
If the static port becomes blocked during a climb the Mach meter will... -
🧠ANSWER ✔✔Under read
What is the temperature deviation from ISA if an aircraft is at FL340 and
has a TAS of 498kts and a Mach number 0.815? - 🧠ANSWER ✔✔+25.56•c
What is Mach number if TAS is 498kts and LSS is 595 knots? - 🧠ANSWER
✔✔0.837
What is the altitude if a TAS of 395 corresponds to Mach 0.67? -
🧠ANSWER ✔✔FL297
What is the altitude if a TAS of 460knots = 0.73 Mach? - 🧠ANSWER
✔✔13,200ft
What inputs does the ADC get? - 🧠ANSWER ✔✔Pitot, static, total
temperature and angle of attack
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
2
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, What outputs does an ADC provide? - 🧠ANSWER ✔✔Altitude, V/S, IAS,
Mach Number, VMO and MMO, AOA, TAT, SAT
What is TAT? - 🧠ANSWER ✔✔SAT + the maximum Ram rise
What is SAT? - 🧠ANSWER ✔✔TAT corrected for maximum possible Ram
rise
What is the formula for calculating Sat? - 🧠ANSWER ✔✔Ts= Tm / (1+(0.2
x k x m^2))
If TAT indicates -26• and aircraft is at mach 0.8 what is the static outside air
temp? - 🧠ANSWER ✔✔-54.02
If an aircraft is travelling at 0.77 and indicating -24• on the TAT the TAS will
be? - 🧠ANSWER ✔✔447.35
What are the 2 types of flight directors? - 🧠ANSWER ✔✔Split cue and
intergrated cue
What is PLI? - 🧠ANSWER ✔✔Pitch limit indicators (when stick shaker will
engage)
How much margin do pilots get a stall warning - 🧠ANSWER ✔✔5% above
stall
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
3
PRIVACY STATEMENT. ALL RIGHTS RESERVED
