AFCAS Flashcards
How many flight control computers are there
3 FCC’s
Which FCC serves which side
Normally the FCC’s use onside data e.g. FCC 1 uses data from FMS 1 and FCC 2 uses data from FMS 2. FCC 1 serves FD 1 and AP 1, FCC 2 serves FD 2 and AP 2. Each FD provides display of steering commands at the onside PFD. The third FCC, (when installed), provides a fail operational AFCS capability in the most critical flight phases, which are take-off, go-around and landing
What is the effect of FCC failure
An FCC failure will cause the onside FD to fail. During manual flight with FD on, this condition is displayed to the pilot by: - Disappearance of the FD command bars - An amber FD flag at the PFD - An amber FAULT light in the onside FCC source select p/b - A level 1 alert at MFDS Steering guidance from the offside FD can be obtained (for display only) by depressing the onside FCC (FD) sources select p/b to ALTN. When AP 1 is engaged FCC 1 is in control. When AP 2 is engaged FCC 2 is in control. With both AP’s engaged (during take-off and auto-land) both FCC’s are in control. An FCC failure during flight with AP engaged will cause the onside AP to disconnect automatically. Engaging the offside AP remains possible. An FCC failure when both AP’s are engaged will cause both AP’s to disconnect automatically. Engaging the AP served by the operative FCC remains possible.
How many IRS’s are required for autopilot engagement
2 IRS’s
How can you disengage the autopilot
The AP can be manually disengaged by depressing the AP disconnect button at either control wheel. This action is accompanied by a single or double cavalry charge tone and flashing AP annunciation at the FMA. The flashing AP at the FMA can be cancelled by depressing the AP disconnect button again. Alternatively the AP disengages when the AP disconnect bar at the FMP is pulled or when one of the stabilizer trim switches on either control wheel is operated for more than 1.5 sec.
Automatic AP disengagement will occur in case of a system failure (e.g. the onside FCC) and is accompanied by a continuous cavalry charge tone and a flashing AP at the FMA. Both can be cancelled by the depressing either AP disconnect button
In HDG HOLD mode , how do you obtain a new heading
Rotate the HDG CONTROL knob to the desired heading and the pull the knob
How do you activate V/S mode
V/S is activated by rotating the V/S wheel
In ALT HLD mode how do you achieve a new altitude
Turning the ALT CONTROL knob to the desired Altitude and then either pulling the knob or pressing LVL CHNG push button
How do you activate LVL CHNG
LVL CHNG mode is activated by either pressing the push button or pulling the ALT select knob
What is the difference in aircraft reaction between V/S and LVL CHNG
V/S activation commands the aircraft to react fast and immediately, while LVL CHNG when activated takes into consideration pax comfort and does it slowly
In V/L mode when does VOR capture occur
VOR Capture will happen approx half dot
In approach mode when is the localiser captures
Localiser is captured at approximately 2 dots deflection
How can you set up a NAV capture
Upon Nav selection NAV mode Is armed , aircraft is still in HDG mode till the desired track is reached and NAV mode had captured
When cruising in PROF MODE , what must you do to initiate descent
When cruising in PROF the aircraft will not descend at the Top of Descent point in the flight plan unless the pilot lowers the FMP altitude to the clearance altitude.
In LAND mode, what is the difference between LAND and LAND2
In the LAND mode the aircraft will capture and track ILS localizer and glide slope and perform an automatic landing. Auto land capability is designated LAND 2. In aircraft equipped with three IRS’s, full auto land capability is designated LAND 3; reduced auto land capability is designated LAND 2.
How do you arm LAND mode
To arm the LAND mode, select ILS frequency and localizer course at the ILS control panel and select the APP/VOR p/b at the EFIS control panel to APP. Turn to the required intercept angle and select LAND
What limit is there to LOC and G/S capture
Localizer capture cannot take place if the intercept angle is more than 90 degrees. Glide slope capture can only take place after localizer capture.
How do you select GA mode? What should happen
The Go-Around(GA) mode is selected by pulling the TOGA triggers. In the GA mode, the aircraft will rotate to a safe climb-out attitude and maintain the heading existing at TOGA selection. ATS advances the thrust levers initially to TOGA thrust and after that controls thrust to maintain a rate of climb of 2000 feet per minute (1000 feet per minute for single engine operation) or 200 kt. The GA speed can be changed, after TOGA selection, via the FMP. In the TOGA mode the existing AP engage status will be maintained.
How do you engage T/O mode ? How should the aircraft be aligned
To engage the take-off mode the TOGA triggers must be pulled for approx. 1 second.
Before take-off the heading bug at EFIS is slaved to the actual aircraft heading and the FD command bars are centred. To ensure lateral FD guidance to maintain runway heading, the TOGA triggers must be pulled when the aircraft is aligned with the runway centre line as the FD provides guidance to maintain the existing heading at TOGA activation. When the AP is engaged after lift-off, the aircraft will maintain existing heading at engagement.
Which pitch angles will be displayed during take off in TOGA Mode
Before take-off, the FD pitch command shows 0 degrees pitch. Upon TOGA activation, 10 degrees pitch-up is displayed. During rotation and initial climb FD pitch commands (and, after AP engagement, elevator commands) are provided to maintain 18 degrees pitch or V2 +10, whichever comes first
How many Auto Throttle channels (ATS) are there and what do they drive
Two ATS channels are part of the Flight Augmentation Computer. Each AT channel drives its own thrust lever. If one AT channel fails the operative channel will drive both thrust levers via a tie-clutch
What happens if one channel fails
If one AT channel fails the operative channel will drive both thrust levers via a tie-clutch.
How is ATS engaged ? Disengaged
ATS can be armed or engaged provided at least one AT channel is operative. ATS is armed on the ground by depressing the ATS p/b at the FMP. ATS engages when the TOGA triggers are pulled. In the air ATS engages when the ATS p/b at the FMP is depressed. Automatic engagement in flight occurs when the alpha mode becomes active (see subsection Flight Envelop Protection), when the maximum speed is exceeded, or when the TOGA triggers are pulled. ATS engagement is shown at the FMA by AT when both channels are operative, or AT 1 or AT 2 when only the respective channel is operative. ATS can be manually disengaged by depressing either ATS disconnect button at the thrust levers. This is accompanied by a flashing AT indication at FMA. The flashing AT indication can be cancelled by depressing the ATS disconnect button a second time. ATS disengages automatically upon touchdown and when in the event of an aborted take-off reverse thrust is selected.
Can you override the ATS
The thrust levers incorporate force overrides which allow the pilot to override ATS, when necessary, with normal thrust lever forces
Why does the ATS declutch at 80 kts? How do you know it has done so
Prior to take-off ATS is armed by pushing the ATS p/b at the FMP. Upon pulling TOGA triggers ATS accelerates the engines to take-off EPR. In order to prevent possible thrust lever retardation, caused by a system failure during the critical part of the take-off, ATS declutches at 80kt. ATS declutch state is indicated by two white “D”s adjacent to the EPR tapes at MFDS
What precaution should you take with the ATS if taking off into a strong headwind
When taking off in a strong headwind it may occur that 80 kt is reached (and consequently ATS declutches) before the engines have reached take-off EPR. To ensure that take-off EPR is obtained before declutch at 80 kt, the engines should be manually accelerated to 1.30 EPR before pulling TOGA triggers.
How is the stabiliser trimmed automatically, manually and if both FAC channels fail
With the AP engaged, the stabilizer istrimmed automatically in response to APcommands. The stabilizer trim switches atthe control column are de-activated when theAP is engaged.
When the AP is not engaged the pilot has totrim the aircraft by means of the stabilizertrim switch at the control wheel. Trim rate is afunction of speed, i.e. trim rate is high at lowspeed and low at high speed.To achieve stabilizer trim movement, bothhalves of the trim switch must be operatedsimultaneously.A dedicated aural tone (whooler), is gener-ated when the trim switch is operated formore than 2.5 sec while airborne
If both FAC channels fail, the stabi-lizer can be trimmed by the pilot viathe stabilizer trim wheel
What is the effect of operating only one half of the stab trim switch
No trim movement takes place when the leftand the right pilot operate the trim switchessimultaneously in opposite directions.
Ifthe pilot erroneously operates onlyone half of the stabilizer trim switchfor more than 15 seconds, the moni-toring circuit will interpret this as afault in the trim switch wiring and willdisconnect the stabilizer trim switch.This condition will result in a nonresettable STAB TRIM 1 AND 2 faultthe next time that the stabilizer trimis operated normally
What happens if the pilots operate the trim switches in opposite directions
Trim will not work
