Question 56-1 : If the outside temperature at 35 000 feet is 40°c the local speed of sound is ? [ Procedure VFR ]
595 kt
Admin .lss varies with the square root of absolute temperature .formula lss = 39 x square root of oat+273 .lss = 39 x square root of 233.lss = 595 kt
Question 56-2 : The error in altimeter readings caused by the variation of the static pressure near the source is known as ?
Position error
Variation of the static pressure near the source is known as position error .barometric error is caused by setting the wrong number in the altimeter window .instrument error is caused by the imperfections of manufacture .hysteresis errors are caused by the irregular elasticity of the capsule
Question 56-3 : If the static source of an altimeter becomes blocked during a descent the instrument will ?
Continue to display the reading at which the blockage occurred
Question 56-4 : If the static source to an altimeter becomes blocked during a climb the instrument will ?
Continue to indicate the reading at which the blockage occurred
Question 56-5 : If the static source to an airspeed indicator asi becomes blocked during a descent the instrument will ?
Over read
. 959.the asi is a sensitive differential pressure gauge which measures and promptly indicates the difference between pitot total pressure and static pressure total pressure static pressure = dynamic pressure .these two pressures are equal when the aircraft is parked on the ground in calm air .when the aircraft moves through the air the pressure on the pitot line becomes greater than the pressure in the static lines this difference in pressure is registered by the airspeed pointer on the face of the instrument .thus while descending the total pressure increases* and the static pressure from the static source does not your airspeed indicator will over read .*while descending density increases so total pressure increases
Question 56-6 : A leak in the pitot total pressure line of a non pressurized aircraft to an airspeed indicator would cause it to ?
Under read
.airspeed indicator asi .the asi is a sensitive differential pressure gauge which measures and promptly indicates the difference between pitot impact/dynamic pressure and static pressure these two pressures are equal when the aircraft is parked on the ground in calm air when the aircraft moves through the air the pressure on the pitot line becomes greater than the pressure in the static lines this difference in pressure is registered by the airspeed pointer on the face of the instrument which is calibrated in miles per hour knots nautical miles per hour or both . 980 ..airspeed indication on the airspeed indicator is .total pressure static pressure = dynamic pressure .therefore with a leak in the pitot total pressure line it is similar to a reduction of speed a reduction of the relative flow entering in the pitot tube the airspeed indicator will under read
Question 56-7 : Machmeter readings are subject to ?
Position pressure error
Admin .machmeter errors .mach number is proportional to the ratio of pitot pressure to static pressure ie to pt ps /ps and this is exaclty what the machmeter measures thus any non standard temperature or density do not affect the accuracy of the machmeter and the only error worth considering is the pressure position error in addition to the usually small instrument error .a mach meter can be considered accurate to within +/ 0 01 mach in the normal operating range or to within +/ 0 02 at the limits of that range
Question 56-8 : Vno is the maximum speed ?
Not to be exceeded except in still air and with caution
Question 56-9 : Vne is the maximum speed ?
Which must never be exceeded
Question 56-10 : Vlo is the maximum ?
Speed at which the landing gear can be operated with full safety
Question 56-11 : The position error of the static vent on which the altimeter is connected varies substantially with the ?
Mach number of the aircraft
.the pressure errors on a pitot/static systems vary with aircraft speed but specifically with mach number
Question 56-12 : The density altitude is ?
The altitude of the standard atmosphere on which the density is equal to the actual density of the atmosphere
.the density altitude is the altitude in the standard atmosphere at which prevailing density occurs meaning your real altitude from the effects of height temperature and humidity and is used to establish performance as it is a figure that expresses where your machine thinks it is as opposed to where it actually is
Question 56-13 : The response time of a vertical speed detector may be decreased by adding a ?
Correction based on an accelerometer sensor
Admin .on a vertical speed indicator the pointer takes a few seconds to steady because of the time taken to build up a steady pressure difference on climb or descent there will also be a time lag on levelling out because of the time .to overcome the problem of lag the instantaneous vertical speed indicator i v s i incorporates an accelerometer sensor which responds quickly to a change of altitude .the figure below shows an ivsi at the beginning of a descent . 988.the piston in the vertical acceleration pump immediately rises in the cylinder and causes a temporary increase of pressure in the capsule the capsule expands and the pointer will give an instant indication of descent .as the initial acceleration is turned into a steady rate of descent the piston will slowly descend to its original position but by this time the correct differential pressure between the capsule and the case will have been set up and the correct rate of descent will continue to be shown
Question 56-14 : The pressure altitude is the altitude corresponding ?
In standard atmosphere to the pressure ps prevailing at this point
The altimeter is calibrated to standard atmosphere conditions .it is nothing more than a barometer which measures atmospheric pressure and relates it to the altitude at which that pressure is found in a standard atmosphere in a standard atmosphere the pressure at 5000 feet is 850 hpa so if the static pressure ps is 850 hpa the altimeter tells you that you are 5000 feet and this is your pressure altitude
Question 56-15 : The atmospheric pressure at fl 70 in a 'standard + 10' atmosphere is ?
781 85 hpa
Admin .7000 ft / 28 ft par hpa = 250 hpa.pressure at mean sea level msl in international standard atmosphere is 1013 25 hpa .1013 25 250 = 763 25.this answer is close to 781 85 hpa .lucastefanon .fl 70 ==> 770 hpa.true altitude .7x4x10= 280 ft.280/27=10 5 hpa.as it's warmer then must be added so .770+10 5= 780 5 which i think it's more precise value respect to the answer
Question 56-16 : Sound propagates through the air at a speed which only depends on ?
Temperature
Question 56-17 : The velocity of sound at the sea level in a standard atmosphere is ?
661 kt
Admin .the velocity of sound varies only with temperature .s = 39 x sqrt °kelvin.to get kelvin add 273 to the centigrade +15°c + 273 = 288°k.s = 39 x sqrt 288°k = 660 8 kt .sqrt square root
Question 56-18 : The limits of the yellow scale of an airspeed indicator are ?
Vno for the lower limit and vne for the upper limit
Img1034.
Question 56-19 : The limits of the green scale of an airspeed indicator are ?
Vs1 for the lower limit and vno for the upper limit
Img1034
Question 56-20 : The limits of the white scale of an airspeed indicator are ?
Vso for the lower limit and vfe for the upper limit
Img1034.white scale vso to vfe fe from flap extended .green scale vs without flaps to vno .yellow scale vno to vne .red line vne speed of never exceed
Question 56-21 : The reading of a mach indicator is independent of ?
The outside temperature
The mach number is a function of p s /s.where p = total pressure pitot .s = static pressure .indications on the mach indicator will vary with p s and p s which is the differential pressure measurement .tas will vary with temperature but not the mach indicator
Question 56-22 : After an aircraft has passed through a volcanic cloud which has blocked the total pressure probe inlet of the airspeed indicator the pilot begins a stabilized descent and finds that the indicated airspeed ?
Decreases steadily
Franck .the asi air speed indicator is provided by the pitot and static vent the pitot is blocked so the asi is going to react like an altimeter
Question 56-23 : The principle of the mach indicator is based on the computation of the ratio ?
Pt ps /ps
Admin .pt total pressure.ps static pressure.dynamic pressure = pt ps.mach number is proportional to dynamic pressure/static pressure
Question 56-24 : The mach number is the ?
True airspeed tas divided by the local speed of sound
Question 56-25 : Given . ts the static temperature sat . tt the total temperature tat . kr the recovery coefficient. m the mach number.the total temperature can be expressed approximately by the formula ?
Tt = ts 1+0 2 m²
Admin .this question is a little bit tricky .if you add the recovery coefficient to the formula you will have exactly the 'total temperature' without you only have an approximation
Question 56-26 : A blocked pitot head with a clear static source causes the airspeed indicator to ?
React like an altimeter
Question 56-27 : Given .m is the mach number.ts is the static temperature.tt is the total temperature ?
Ts = tt / 1+0 2 m²
Question 56-28 : The airspeed indicator of a twin engine aircraft comprises different sectors and colour marks the blue line corresponds to the ?
Optimum climbing speed with one engine inoperative or vy
Question 56-29 : The mach number is ?
The ratio of the aircraft true airspeed to the sonic velocity at the altitude considered
Admin .mach number formula .m = tas/a. a= local speed sound
Question 56-30 : In an adc air data computer the altitude is computed from ?
Measurement of barometric pressure from a static source on the fuselage static pressure
Question 56-31 : Indication of mach number is obtained from ?
Indicated speed and altitude using a speed indicator equipped with an altimeter type aneroid
Admin .the mach meter modifies the output from an airspeed capsule by using an altimeter aneroid capsule
Question 56-32 : The altimeter consists of one or several aneroid capsules located in a sealed casing the pressures in the aneroid capsule i and casing ii are respectively ?
I vacuum or a very low pressure ii static pressure
Question 56-33 : In case of accidental closing of an aircraft's left static pressure port rain birds the altimeter ?
Overreads the altitude in case of a sideslip to the left and displays the correct information during symmetric flight
Amassa .with a side slip to the left pressure will increase on the left side of the aircraft and decrease on the right .if both static ports are open the pressures are compensated this is why two static ports are used .so a lower static pressure will be sensed and the altimeter will overread the aircraft's altitude
Question 56-34 : The vertical speed indicator vsi is fed by ?
Static pressure
Question 56-35 : The altimeter is supplied with ?
Static pressure
Question 56-36 : Total air temperature tat is ?
Higher or equal to static air temperature sat depending on mach number and sat
Admin .tat = sat 1 + 0 2 x kr x m² . sat the static temperature in kelvin. tat the total temperature in kelvin. kr the recovery coefficient. m the mach number.if mach is 0 sat = tat .if sat is 0 tat = sat .absolute zero in kelvin is almost impossible to reach but from the formula tat will be 0 if sat is 0
Question 56-37 : An air data computer .1 supplies gs and drift angle.2 determines tat and true altitude.3 receives static pressure and total pressure.4 supplies tas to the ins computer.5 determines mach number and oat.the combination regrouping all the correct statements is ?
3 4 5
Admin .the adc air data computer uses as input data static pressure total pressure pitot pressure and tat . 1023
Question 56-38 : An aircraft is flying at flight level fl180 and mach number 0 36 its onboard thermometer reads tat = 5°c considering that the probe recovery coefficient is 0 84 the present weather conditions compared with the standard atmosphere are ?
Standard + 10°c
Admin .what is the oat outside air temperature at fl180 in standard atmosphere .15° 2 x 18 ° = 21ºc at fl180 .calculation . 997.oat at fl180 is 11°c instead of 21°c the present weather conditions compared with the standard atmosphere are standard + 10°c
Question 56-39 : An airspeed indicator displays ?
Ias
Img1034.ias for indicated air speed
Question 56-40 : The angle of attack transmitter placed laterally on the forward part of the fuselage supplies an electrical signal which can indicate the angular position of .1 a specific slaved pitot probe .2 a vane detector .3 a conical slotted probe .the combination regrouping all the correct statements is ?
2 3
.conical slotted probe the angle of attack aoa probe provides aoa or sideslip ss by sensing the direction of local airflow it is mounted on the fuselage with the sensing probe extending through the aircraft fuselage the sensing probe is continually driven to null pressure differential between the upper and lower slots in its forward surface these features sense the direction of air stream flow local aoa or ss the angular position of the sensing probe is converted to an electrical output by an angular sensor . 998. 999.vane detector the angle of attack sensor is of the wind vane type its sensing element is a small wing which is positioned in the direction of airflow the small wing is mechanically linked to a free turn shaft which drives the devices transmitting the local angle of attack signal . 1000.
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