FLIGHT INSTRUMENTS Flashcards
- A 2 axis gyro, measuring vertical changes will have:
b two degrees of freedom, vertical axis
- The properties of a gyro are:
- mass
- rigidity
- inertia
- precession
- rotational speed
b. 2 & 4
- An aircraft fitted with a DRMC upon landing in a northerly direction will indicate:
a no change
- Which of the following will effect a direct reading compass?
- ferrous metals
- non-ferrous metals
- electrical equipment
1 & 3
- A vibrator may be fitted to an altimeter to overcome:
a friction
- An aircraft is flying at constant indicated altitude, over a warm airmass. The altimeter reading will be:
c less than the real altitude
- The machmeter consists of:
b an airspeed indicator with an altimeter capsule
- CAS is IAS corrected for:
a position and instrument error
- A DGI has;
c two degrees of freedom & a horizontal spin axis
- An aircraft is flying at an indicated altitude of 16,000ft. The outside air temperature is –300 C What is the true altitude of the aircraft?
b 15,200 ft
- The main cause of error in a DRMC is:
b turning
- QNH is:
c the equivalent sea level pressure at the airfield
- What is the Schuler period?
b 84 minutes
- The vertical reference of a data generation unit is:
d vertical axis with 2 degree of freedom
- The torque motor of a gyro stabilised magnetic compass:
a precesses the directional gyro
- A factor giving an error on a direct indicating compass would be:
c acceleration on east/west headings
- A rate integrating gyro is used in:
- inertial attitude unit
- autopilot system
- stabiliser servo mechanism system
- inertial navigation unit
- rate of turn indicator
a 1& 4
18. The errors of a DGI are: earth rate transport wander banking when pitched up annual movement of poles mechanical problems
c 1, 2, 3, & 5
- An Air Data Computer (ADC) obtains altitude from:
b. barometric data from static source
- If the needle and the ball of a Turn & Slip indicator both show right, what does it indicate:
b. turn to right & too much bank
- What formula gives the total temperature (TT) from the static temperature (TS):
b TT = TS (1 + 0.2 KrM2)
- The Inertial Strapdown Unit of an IRS is programmed with co-ordinates during alignment in order to:
a establish the trihedron with reference to the earth
- When descending through an isothermal layer at constant CAS, what does the TAS do?
decrease
- What is VMO calculated from:
EAS
- Descending from FL390 at maximum groundspeed, what will the pilot be limited by:
b. MMO initially then VMO at a specified altitude
- At constant weight, regardless of altitude, an aircraft always lifts off at a constant:
d CAS
- VFE is the maximum speed that:
a. the flaps can be operated
- The white arc on the ASI indicates:
c. VS0 at the lower end and VFE at the upper end
- An ASI circuit consists of pressure sensors. The Pitot Probe measures:
d total pressure
- Mach number is defined as the ratio of:
b TAS to LSS
- If a pitot source is blocked in an ASI, and the drain hole is blocked, but the static source is open, what will happen?
d ASI behaves like an altimeter
- In a turn at constant angle of bank … the rate of turn is:
c. independent of weight and inversely proportional a to TAS
- The Turn Indicator is a useful gyroscopic instrument. When used in association with an attitude indicator will show:
angular velocity about the yaw axis
direction of turn
angular velocity about true vertical axis
speed of turn
angular velocity about the yaw axis
direction of turn
If an aircraft, fitted with a DRMC, takes off on a westerly heading, in the northern hemisphere, the DRMC will indicate:
a a turn to the north
When turning through 900 at constant attitude and bank, a classic Artificial Horizon indicates:
c nose up and bank angle too low
The factors which will affect a Turn Indicator are:
- angle of bank
- aircraft speed
- aircraft weight
b. 1 & 2
To obtain heading information from a Gyro Stabilised platform, the gyros should have:
a 1 degree of freedom and a horizontal axis
What are the inputs to the ADC?
- OAT
- dynamic pressure
- TAT
- static pressure
- electric power
- pitot pressure
- AOA
d. 3, 4, 5, 6, & 7
- The properties of a Turn Indicator are:
One degree of freedom
two degrees of freedom
two springs connected to the aircraft frame spin axis in the longitudinal plane
spin axis parallel to the yaw axis
spin axis horizontal
1, &6
- A gravity erector system corrects errors on a:
b. artificial horizon
- In a Gyro magnetic Compass the flux gate transmits information to the:
c error detector
- VNO is the max. speed which:
b should only be exceeded in still air and with caution.
- If while level at FL 270, at a constant CAS, temperature falls, what happens to the Mach No.?
c remains constant.
- If the static vent becomes blocked on an unpressurised a/c, what could you do?
b break the VSI glass.
- What does the “barbers pole” on an ASI indicate?
a VMO & altitude.
- On board a/c, true altitude shown from:
b pressure altitude.
- On a turn and slip indicator, needle to the left and ball to the right indicates:
c turn to the left, not enough bank.
- What is density altitude:
a altitude in the standard atmosphere at which the prevailing density is equal to the density in the standard atmosphere
- A radio altimeter is:
d a/c based and measures true height.
- An a/c is travelling at 120 kts, what angle of bank would be required for a rate 1(one) turn:
c. 18°
- An a/c is travelling at 100 kts forward speed on a 30 glideslope. What is its rate of descent?
a 500 ft/min.
- If the pitot tube is leaking (and the pitot drain is blocked) in a non-pressurised a/c, the ASI will:
a under-read.
- An RMI rose is mechanically stuck on 090 degrees. The ADF pointer indicates 225 degrees. What is the relative bearing to the beacon?
b 135 degrees.
- Using a classic Artificial Horizon, the a/c performs a right turn through 270 degrees at a constant angle of bank and rate of turn. The indication is:
a Nose up, too much bank.
- In a DGI what error is caused by the gyro movement relative to the earth?
b. Transport Wander
- In a right turn while taxiing, the correct indications are:
d Needle right, ball left.
- An aircraft is taking of on a runway heading 045°, in still air, with a compass having 0° deviation. The runway is on an agonic line. What are the northerly turning errors (northern hemisphere)?
a. compass moves to less than 045°
- True heading can be converted into magnetic heading using a compass and:
a A map with isogonal lines.
- At sea level ISA, TAS:
a Equals CAS
What will the altimeter read if the layers beneath the aircraft are all colder than standard?
b read higher then the real altitude
The flux valve in a RIMC
a is supplied with AC current (usually 487.5 Hz).
The indications of a machmeter are independent of:
a Temperature (OAT)
An artificial horizon has:
d 2 degree of freedom and a vertical axis.
The rigidity of a gyro is improved by:
a Increasing RPM and concentrating the mass on the periphery of the rotor.
What is the speed of sound at sea level ISA
b 661kts.
What is the speed of sound at 25,000 ft and -28 degrees C.
d 610kts.
What is the speed of sound at 30,000 ft and -40 degrees C.
b 595kts.
- If a constant CAS is maintained in a climb, what happens to the mach number
increases
- A compass swing is used to:
align compass north with magnetic north.
- The TAT probe measures TAT by:
d TAT = SAT + heating due to compressibility.
- If a pitot tube and drains are blocked at altitude by icing, during a descent the ASI will:
b under read.
- An IRS is aligned when turned on so as to:
a calculate the computed trihedron.
- The advantages of an ADC over a traditional pitot - static system (list):
- Position and compressibility correction.
- reduced lag
- ability to supply many instruments
- ability to act as an altimeter following failure.
a. 1, 2 & 3
- The frequency band used for a Radio Altimeter is:
a. SHF
- What is the purpose of the latitude nut in a DGI?
c. to correct for earth rate
- Total Air Temp is always _ _ _ _ _ _ than Static Air Temp and the difference varies with _ _ _ _ .
c warmer, CAS.
- In a slightly banked turn, the turn needle will indicate:
c angular velocity about the vertical axis.
- The Primary Flying Display (PFD) displays information dedicated to:
b. flight path
- What are the inputs to the FMS?
- Radio Aids
- Engine Parameters
- Air Data
- Route Data
- Terminal Data
- Operating Data
c. All of the above
- What are the upper and lower limits of the yellow arc on an ASI?
c. lower limit VNO and upper limit VNE
- What does the blue line on an ASI of a twin propeller engined aircraft indicate?
a. VYSE
- The gravity erecting device on a vertical gyro is used on which instrument:
c. artificial horizon
- In a VSI lag error is improved by:
c. use of an accelerometer system
- An aircraft fitted with a DRMC is landing in a southerly direction, in the Southern Hemisphere. What indications will be seen on the DRMC?
no apparent turn
- What is the maximum drift of a gyro, due to earth rate:
15° per hour
- An aircraft is flying a true track of 3600 from 50 south to 50 north. What is the change in apparent wander rate:
c. - 50 per hour
- When turning through 1800 at constant attitude and bank, a classic Artificial Horizon indicates:
a nose up and correct angle of bank
- What is the Schuler period?
d. 84 minutes
- Mach number is defined as:
c. The ratio of dynamic pressure to static pressure
- You are flying at a constant FL 290 and constant mach number. The total temperature increases by 50. The CAS will:
a. remain approximately constant
- An aircraft turns from south-west to south-east when situated at 450N, what heading should you roll out on if using a DRMC?
115°
- What is SAT?
ambient temperature measured in °C
- If an aircraft climbs, at constant mach No, in ISA conditions what happens to the TAS and the CAS?
d. TAS decreases and CAS decreases
- Where is the earth rate wander, and the transport wander of a gyro equal to zero?
b. Equator
- What happens when the static pressure supply, to an altimeter, becomes blocked during a descent?
d. indicates altitude at which blockage occurred
- What happens when the static vent supplying an ASI is blocked, and the ram air inlet remains clear?
ASI acts opposite to an altimeter
- In a left turn while taxiing, the correct indications are:
Needle left, ball right.
- VLO is defined as:
the maximum speed at which the landing gear may be retracted or extended
- VNE is defined as:
the speed which must never be exceeded
- In a left turn, the ball of the turn co-ordinator is out to the right, what corrective action is required?
c. more left bank
- In a gyro magnetic compass, where does the torque motor get its information from?
d. amplifier
If an aircraft is descending at constant mach number, and the total air temperature remains constant, what happens to the CAS?
increases
What are the advantages of a laser gyro compared to a conventional gyro?
a. has a longer cycle life
A machmeter measures the ratio of:
b. (pitot pressure minus static pressure) to static pressure
Which instrument has a 2° rotation in the horizontal axis?
a. artificial horizon
The maximum drift error sensed by an uncompensated DGI will be:
a. 15° per hour
The green arc on the ASI is used to identify which speed range:
c. VS1 to VNO
Pressure altitude may be defined as:
b. pressure measured in the standard atmosphere
- What is the effect on an altimeter reading if variations in static pressure occur near to the pressure source?
a change in the position error
- What is the value of the angle of magnetic dip at the South Pole?
90°
standby artificial horizon must have the following properties:
- a remote gyro
- its own power supply
- only to be used in emergency
- its own gyro
- one for each certified pilot
d. 2& 4
- During a descent at constant CAS and total temperature, the mach no:
decreases
- The single most significant item which makes a servo altimeter more accurate is:
a. electromagnetic pick-off
- Which of the following gyro instruments has one degree of freedom?
b. turn indicator
If a large aircraft is slide slipped to starboard, and the port static vent is blocked, what will the altimeter read?
a. under read
Mach number is determined from: (PT = total pressure, PS = static pressure)
d. (PT - PS) / PS
The right static vent is blocked, when the aircraft yaws to the right. Does the altimeter:
b. under read
If the radio altimeter fails:
a. height information disappears
During a descent at a constant mach number, there is an increase of total temperature by 50. What effect does this have on CAS?
c. increases by 10 kts
VNO is defined as:
a. maximum structural cruising speed
If the left static vent is blocked, and the right static vent is clear. What will the altimeter read if the aircraft maintains constant level?
c. if side slipping to the left, altimeter will over read.
- An aircraft is flying at constant indicated altitude, over a cold airmass. The altimeter reading will be:
a. greater than the real altitude
- The machmeter compares: (PT = total pressure, PS = static pressure)
c. (PT - PS) to PS
- From where does the air data computer (ADC) obtain aircraft altitude?
c. absolute barometric sensor on aircraft fuselage
- An aircraft is accelerating to take-off on a runway with a QDM of 045°. Which way does the DRMC move, if the aircraft is in the Northern Hemisphere?
a. less than 45°
- When turning right onto north, through 900, what heading on your DIC should you roll out on, if the aircraft is in the Northern Hemisphere?
c. 340°
- What does a radio altimeter, for an aircraft in the landing configuration, measure:
a. height of aircraft wheels above the ground
- Why is a servo altimeter better than a sensitive altimeter?
a. it has a pick-off coil
- In an altimeter what is fed to: the capsule (i) and to the case (ii)?
a. (i) vacuum (ii) static input
- What principle does the radio altimeter work on?
frequency modulation and carrier wave
- What is indicated on the ASI when the static vent blocks during a descent?
over reads
- A rate integrating gyro is used in:
c. inertial navigation system
- What are the components of a Ring Laser Gyro?
c. 2 beams of laser light
- Where on the earth’s surface is the earth rate drift of a DGI equal to 15.04° per hour?
d. 90°
- If you maintain the same CAS and Altitude (FL270), and the temperature increases, what happens to the Mach No?
c. remains the same
- If CAS is kept constant, what happens to the Mach No?
a. as the altitude increases the mach No will increase
- The pendulous type correction detector fitted to the DGI provides:
a. torque on the sensitive axis
- An aircraft is fitted with two altimeters. One is corrected for position error, the other is not corrected for position error:
d. at high speed the non-compensated altimeter will show a higher altitude
- Density altitude is defined as:
c. the altitude corresponding to the standard atmosphere compensated for ambient
density
- The pitot tube of an ASI gives a direct reading of:
c. total pressure
- When descending from FL230 to FL50 at maximum speed, the limitations which apply are:
c. MMO then VMO
- The pressure measured at the forward face of the Pitot probe is:
c. total pressure
- What has inputs from the flux valve:
a. error detector
- Machmeter readings are subject to which of the following errors:
d. position/pressure error
- Sound propagates at a speed which depends only on:
b. temperature
- What aircraft system uses a frequency of 4,400 MHz?
b. radio altimeter
- A low altitude Radio Altimeter, used in precision approaches, has the following characteristics:
- 1540MHz to 1660 MHz range
- pulse transmissions
- frequency modulation
- height range between 0 and 5,000ft
- an accuracy of +/- 2ft between 0 and 500ft
b. 3 and 4
- A modern low altitude Radio Altimeter uses the principle of:
b. Frequency modulated waves, where the difference between the transmitted wave and the received wave is measured.
- The frequencies used in a low altitude Radio Altimeter are:
c. 4200 MHz to 4400 MHz
- The difference between Magnetic North and True North can be derived by:
d. map with isogonal lines
- A direction gyro gets its directional information from:
direct reading magnetic compass
- What is the principle of operation of a VSI:
differential pressure across a capsule
- In a Remote Indicating Compass, what component feeds the Amplifier?
d. error detector
- An aircraft turns right, through 900, onto North, at 48N, using a direct indicating compass. The aircraft is turning at rate 2. What heading should the aircraft roll out on?
c. 330°
- What is the normal operating range of a low altitude Radio Altimeter?
0 to 2,500ft
- What is a radio altimeter used for?
to determine aircraft height above ground level
- Why must Latitude and Longitude be inserted into an IRS?
a. to determine the aircraft position relative to the earth
- An aircraft is flying a true track of 3600 from 50 south to 50 north. What is the average apparent wander rate:
a. 0° per hour
- You commence a rate 2 turn from south-east to south-west, in the Northern Hemisphere. On what heading do you stop the turn?
b. 255°
A directional gyro is valid only for a short period of time. The causes of this inaccuracy are:
- earth rotation
- longitudinal accelerations
- a/c motion over the earth
- mechanical defects
- gyro mass
1, 3& 4
VMO / MMO alarm system, on an airline aircraft, is fitted with an aneroid capsule which is:
subjected to static pressure and an anemometer subjected to dynamic pressure
- An aircraft, in the southern hemisphere, is decelerating to land on a westerly heading. The direct reading magnetic compass will indicate:
an apparent turn to north
- What is the input to a VSI?
static pressure
- The component(s) used to align an inertial strap-down unit in the horizontal plane is/are:
a. Accelerometers and gyroscopes
- A ring laser gyro consists of:
c. A laser split into two beams
- The Directional Gyro Indicator (DGI) can:
d. have 2° of freedom
- The Pitot tube comprises a mast to position it below the skin of the aircraft for:
a. avoid disturbance from aerodynamic flow about the aircraft
- Using a classic Artificial Horizon, the a/c performs a right turn through 360 degrees at a constant angle of bank and rate of turn. The indication is:
d. Bank and pitch correct.
