06 Machmeter Flashcards
1
Q
What is the basic operation of a Machmeter:
- What feeds it
- Components
A
- Fed by both Static Pressure and Pitot Pressure
- Static pressure is fed into the case
- Pitot pressure is fed directly into a pressure capsule
- Air speed capsule: Pressure capsule, fed by Pitot pressure, located at the rear of the Machmeter
- Altitude capsule: Aneroid, located at the top of the Machmeter
- The combination of the expansion and contraction of both capsules converts to the Mach Number reading
2
Q
What is the equation of the Mach Number?
A
Mach Number = TAS / LSS
3
Q
What Errors are associated with the Mach Meter?
A
- Instrument
- Manoeuvring
- Position
- Note: Barometric and temperature errors have already been corrected by the instrument
4
Q
What is the equation for the Local Speed of Sound (LSS)?
A
LSS = 38.95 x Sqrt (Temp in K)
5
Q
What acronym can be used to work out the blockages in the feed tubes for a Mach Meter?
A
PUD SOD
Or POC SUC
6
Q
What happens to the following with an increase of temperature in the horizontal plane?
- TAS
- LSS
- Mach number
- CAS
A
- TAS increases
- LSS increases
- Mach number remains constant
- CAS remains constant
7
Q
What errors are does a combined ASI and Mach Meter suffer from?
A
- Instrument
- Manoeuvre
- Position
- Compressibility
- Density
