Mnemonics and Main Memory Items | Instruments Flashcards
The mnemonic to remember blockages effects while climbing and descending for the ASI?
CPO = Climbing - Pitot(blocked) - Over-read
CSU = Climbing - Static(blocked) - Under-read
DPU - Descending - Pitot(blocked) - under-read
DSO - Descending - Static - Over-read
What does the blue line on a multi-engined ASI represent?
Vyse, the best rate of climb with one engine inoperative
How to remember AH pitch and roll limitations:
East/west the earth rolls = roll limited
North/south is like pitch axis = Pitch limited
AH:
Pendulous Acceleration will show -
Pendulous Deceleration will show -
Erection Error during acceleration will show -
Erection error during deceleration will show -
How to remember:
Pendulous Acceleration will show - False right bank
Pendulous Deceleration will show - false left bank
Erection Error during acceleration will show - false pitch up
Erection error during deceleration will show - false pitch down
Acceleration normally an aircraft will pitch up, and pitch down during deceleration. Acceleration is right.
AH turning errors:
Turning through 90°:
Turning through 180°:
Turning through 270°:
Turning through 360°:
One way to remember -
Turning through 90°: Under reads bank angle; Pitch error – indicating a climb
Turning through 180°: Bank angle correct; Pitch error – indicating a climb (maximum pitch up error)
Turning through 270°: Over reads bank angle; Pitch error – indicating a climb
Turning through 360°: Bank angle correct; Pitch correct
90 is lower than 270, thus 270 show excess bank and 90 under bank.
Formula for turn radius:
m/s^2 / 10 x tan bank angle.
m/s = 0.5 x knots.
Diameter = radius x 2
Circumference = diameter x 3.14
Air-driven AH gyro: kept in the vertical by
Electrical AH gyro: kept in the vertical
pendulous vanes/air jets
two mercury switches sending signals to torque motors
Formula for apparent drift:
15 x sine of the latitude
NH: Drift is to the
SH: Drift is to the =
right = clockwise (-)
left anti-clockwise (+)
For the DI or DG to measure change of heading during a banked turn, the gyro must be maintained in
The aircraft’s vertical and not the true vertical
Remembering gyro magnetic compass process:
FEAT
Flux - Error detector - Amplifier - Torque motor
Remembering gyro magnetic compass process:
FEAT
Flux - Error detector - Amplifier - Torque motor
Relevant to altimeter:
Using static alternate inside cabin will indicate -
Climb. Cabin pressure in an unpressurized aircraft is lower
The altimeter indicates true altitude:
A
in standard atmosphere only
Mach number =
Thus TAS(relevant to MN) =
LSS is directly proportional to -
using this knowledge, if OAT increases when at a constant TAS:
Or just use to CX2!
TAS/LSS
MN x LSS
Temperature.
Mach number decreases
LSS reduce with -
Temperature
Full Scale Deflection:
- Full scale deflection in RNAV ENR Mode =
- Full scale deflection in RNAV APP Mode =
- Full scale deflection for a VOR =
- Full scale deflection for a LLZ =
- Full scale deflection for a G/S =
Full Scale Deflection:
- Full scale deflection in RNAV ENR Mode = 5 NM
- Full scale deflection in RNAV APP Mode = 1.25 NM
- Full scale deflection for a VOR = 10°
- Full scale deflection for a LLZ = 2.5°
- Full scale deflection for a G/S = 0.7°
2-dot EFIS display:
- one dot in RNAV ENR = 2.5 NM (some questions only have 2NM as an option, but if 2.5NM is available, select 2.5NM)
- one dot in RNAV APP = 0.625 NM
- one dot in VOR = 5°
- one dot in ILS = 1.25° (LLZ)
5-dot EFIS display:
- one dot is 1 NM in RNAV ENR (full scale = 5 dots = 5 NM)
- one dot is 0.25 NM in RNAV APP (full scale = 5 dots = 1.25NM)
- one dot is 2° in VOR
- one dot is 0.5° in ILS (LLZ)
A leak in the pitot total pressure line of a non-pressurized aircraft to an airspeed indicator would cause it to:
under-read.
The mnemonic CPO CUS DPU DPO only applies to blocked line(static or dynamic)
When an alternate static source is fed from within the cabin, it results in the static pressure sensed being:
lower than ambient due to aerodynamic suction
When the alternate static source pressure is used, vented in the cabin(lower pressure), the following instrument indications are observed:
- The altimeter indicates -
- The ASI indicates an airspeed -
- The VSI shows a momentary -
- The altimeter indicates a slightly higher altitude than actual
- The ASI indicates an airspeed greater than the actual airspeed
- The VSI shows a momentary climb and then stabilizes if the altitude is held constant
Mnemonic to remeber IAS, CAS, EAS and TAS relationship -
ICET PCD.
IAS + Position/instrument error = CAS
CAS + Compressibility error = EAS
EAS + density error = TAS
In a standard atmosphere and at the sea level, the equivalent airspeed (EAS) is(relevant to TAS):
equal to the TAS
During a descent at a constant calibrated airspeed (CAS) below the tropopause in ISA conditions, what happens to the TAS, MN, LSS and EAS respectively:
During a descent at a constant Mach number below the tropopause in ISA conditions, what happens to IAS and TAS respectively:
TAS decrease, MN decrease and speed of sound increase and EAS increase
TAS increase and IAS increase
The indicated Mach number is independent of:
temperature
Relevant to mach number:
TAS =
MN x LSS
Mach number is independent of -
LSS is directly proportional to -
temperature
Temperature
Considering an airspeed indicator, a second striped needle, if installed, indicates:
The velocity maximum operating (VMO) is a speed expressed in:
VMO
CAS or EAS
At a given altitude, the hysteresis error of an altimeter varies substantially with the:
time passed at this altitude
A compass made for the NH, the CG will be located -
On the southern side of the needle. For SH the opposite applies
The direct reading magnetic compass is made aperiodic (dead beat) by:
keeping the magnetic assembly mass close to the compass point and by using damping wires
Magnetic compass turning error mnemonic:
North -
South -
UNOS for north
ONUS for South.
UNOS is north because the first letter is “up”, NH is up from SH
At the magnetic equator, when accelerating after take off on heading West, a direct reading pivot suspended compass:
indicates the correct heading
