View Full Version : Unserviceabilities with Unusual Symptoms ..

2nd Jun 2007, 12:22
Compressor Stall has suggested this thread and my guess is that all our Tech Log folk will support it.

Aim is for PPRuNers who have seen odd symptom U/S situations to put them here with the outcome. That way all who fly that Type can benefit ie -

(a) nominate aircraft type

(b) describe the symptoms observed

(c) describe what the problem and/or fix was.

Stallie gives the first example which I have copied to the body posts -

(a) B200

(b) airborne ASI drops by 50 knots but returns to normal on landing

(c) leaking ASI face.

Clearly this would apply generally so I'll have a general U/S post as well.

We'll see how the thread progresses but my idea at this stage is to collate posts on the one Type/Model so that it is easy for those on Type/Model to find material relevant to their interests. As with the URL sticky, I'll have no hesitation in pinching examples from other places ...

If a given post needs to lead into more detailed discussion, I'll leave the basics here and split the discussion off into another thread .. that way this thread becomes a reference information thread only.

As there are post length limits, I'll set up several dummy General posts to reserve the first few posts for non-specific problems and do likewise with a dummy post for each Type/Model so that we can delay the inevitable of having to leapfrog through the thread to track all entries for a given Type/Model.

Unfortunately there is no way of which I am aware to reorder posts periodically (and simply) so we will need to use the index post to keep track of multiple entries for a given Type/Model as the thread develops .. shouldn't make it too terribly difficult for folk to follow. Occasionally, when I'm bored to tears .. I might just reorder the posts to approximate an alphabetical listing.

As with the URL sticky, I'll delete individual posts after the content is transferred to the Type/Model post and, periodically, remove empty posts from the thread to keep things a bit tidier.

Please be patient if there are delays in this latter part of the gameplan .. we mods also have our day jobs which occasionally divert and distract us from our real work of PPRuNeing ...

Caveat: PPRuNe does not warrant the correctness or appropriateness of any post, or post entry, in this thread. Posts are provided as information only for PPRuNer background and familiarisation. PPRuNe does not recommend nor encourage any procedure which is not specified in approved operational or maintenance documents.

Credits: A4, bugg smasher, Compressor Stall, craig freier, IFixPlanes

2nd Jun 2007, 12:28
Post Subject Aircraft

003 General

020 Airbus A320 Series (318/319/320/321)
008 Beechcraft B200
010 Boeing 737 Classic
012 Boeing 737 NG
014 Boeing 747
016 Boeing 757/767
018 Boeing 777
022 MD10/MD11

2nd Jun 2007, 12:30
ASI - reading airborne drops by 50 knots but returns to normal on landing.
U/S: leaking ASI face.

2nd Jun 2007, 12:33
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2nd Jun 2007, 12:37
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2nd Jun 2007, 12:37
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2nd Jun 2007, 12:38
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2nd Jun 2007, 12:42
ASI - reading airborne drops by 50 knots but returns to normal on landing.
U/S: leaking ASI face.

2nd Jun 2007, 12:46
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5th Jun 2007, 22:15
Speed trim fail light illuminates with master caution and flt ctl. Speed lim amber warning on captain's PFD. Left N1 gauge fails.
U/S: N1 C/B tripped

5th Jun 2007, 23:23
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5th Jun 2007, 23:27
Trouble shooting on gear retraction after lift off - Trip C/B "ALTN EXTEND SOL" (P6-3 D16). If gear now will retract, the microswitch has defectively switched to "access door open" (normally caused by dirt). Make a log book entry and finish your flight. Donīt forget to reset the C/B or move the gear lever to OFF before manual extension. For further detail refer to this thread (http://www.pprune.org/forums/showthread.php?p=3235452)

Note only

5th Jun 2007, 23:31
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5th Jun 2007, 23:34
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5th Jun 2007, 23:35
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5th Jun 2007, 23:37
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5th Jun 2007, 23:38
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5th Jun 2007, 23:39
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5th Jun 2007, 23:40
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5th Jun 2007, 23:41

After 2nd engine start, ECAM HYD BLUE SYS LO PR. HYD Page shows 3000 PSI (normal) but F/CTL Page shows B for all BLUE system components (abnormal). So contradictory indications for BLUE system.

Previous night the engineers had tested the RAT (BLUE system..) and had left the leak measurement valves in the open position i.e. selected "ON" on the maintenance panel (on the o/head panel towards rear of flightdeck). The aircraft had then been depowered with valves in the maintenance position. On power up the lights on the panel were not noticed (apparently they will be on).

Fix: Deselection of LMV returns system and all indications to normal.

5th Jun 2007, 23:41
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6th Jun 2007, 21:07

DEU 2 fails in flight. Subsequently, slats fail to extend - multiple occurences.

note only

bugg smasher
8th Jun 2007, 06:34
Reserved for expansion

tubby linton
4th Jul 2007, 17:35
Flight director disagree.
I have never seen this before on an airbus!
AP2 engaged.Modes are v/s and loc with gs armed. Aircraft is cleared to 2000ft and further with the glide.
F/o PFd GS* as glideslope captures at approx 2300ft.Ap1 engaged as plan is practice autoland.
Capt Pfd Alt* as approaching fcu altitude as GS* not annunciated.
AP1 now master autopilot so aircraft attempts to acquire fcu alt and not the glideslope.
Glideslope is now showing fly down so both autopilots and fd disengaged and a manual approach and landing flown.
Does anybody have any ideas as to why this happened?
Double rad alt fail will cause neither fd to arm in gs on the minibus but never seen it as a failure just on one side!

4th Jul 2007, 19:20
012 Boeing 737 NG

Symptom: No nosewheel steering after tug has disconnected.

Reason: Steering bypass lever has not fully returned to the vertical. This is a known problem on the NG, make a tech log entry and get the engineers to service the lever.

Immediate Solution: Call groundcrew back to move lever back to correct position and continue flight or return to stand and get engineering fix.

15th Sep 2007, 23:36
This is for the B757 unusual symptoms section (No16).
Just finished Centre Tank feeding. One wing then lost fuel rapidly (100kgs every 2 mins). Daylight, but no visual cues. Will the aircraft fly with one wing tank empty and the other with 6 tons? I was not really prepared to experiment. When 1 ton lost, decided to make an emergency landing at a major airfield just below us. On stand, one wing had lost 1.2 tons. Inspection and engine run produced no fault. Refuelled and prepared to continue, when a junior mech came to me and said he had seen this once before. Origin was Turkey. Fuel density is measured at only one point (so I am told) - unlike the quantity. He suggested that water had come to rest over the density measuring point and the auto refuel cut-out had operated when 6.5 tons was registered. Further - he said - fuel from Turkey often had a higher than normal water content. (I have operated from there for several years and had not noticed this.)
When the wing tank started to feed, the water rapidly movd from the measuring point and the correct density prevailed. Difference in water/fuel density = 20%. Difference in full wing tank contents (6.5t) and 'lost' fuel (1.2t) = 20%. When I suggested this to Quality Control, they flew into a rage - but my shoulders are broad.:{

22nd Sep 2007, 10:34
Best one I know of was a Shed ( Shorts 330) at Cranfield used for para dropping....

During very rapid descent after dropping said load, the pilots watch glass "popped" :}

7th Dec 2007, 16:47
:ugh:john .....half the area is reserved for expansion. most ordinary people dont have the patience . talk sense and make it more reader friendly

Dream Land
7th Dec 2007, 17:52
Again, seperate the airframes. :ok:

17th Dec 2007, 20:38
After take-off, F/O's F/D fails, all three A/Ps unable to select. Flaps retracted normally.

Solution: Arm alternate flaps for 30 seconds, then disarm.

26th Dec 2007, 17:49
When releasing park brake for taxi, L & R ANTISKID cautions on EICAS.

Cause: Setting Park brake too soon after A/skid test (while test not fully complete)

Solution: With Park Brake released, re-do A/skid test. When cautions go out, problem should be solved.

22nd Aug 2008, 07:19
020 A320-232 IAE V2500 A5

During cruise F340 E/WD started displaying rapid and continuous ecam warning messages....rud trim2 fault..fws sdac2 fault..air pack2 regul fault..nav ils2 fault..yaw damper2 fault..nav adr2 fault..and the list goes on ...with no failure message nor ecam action being required by the system.
SYS. DISPLAY ELEC page consulted..GEN2 voltage observed to fluctuate btn 5 to 103v
APU started and when avail. GEN2 switched off without IDG disconnection,problem disappears...continue to base as such
maintnance reports a socket change or upgrade ( if there is such a thing )
in FADEC 2 as per airbus tech bulletin after numerous reports to airbus about similar occurences..as per company techies

22nd Aug 2008, 07:25
For those who wonder why I haven't tidied this thread up .. all a case of time .. and it takes quite some time to move this and that here and there to get a reasonable presentation.

What I request is that you just post your comments and, periodically, I'll find time to slash and burn to put the comments into some sort of semblance of order ..

22nd Aug 2008, 07:40
Being a mark 1 mode zero lazy person, the only thing i do wonder about is where do you get the stamina to do it all, much less tidy up this thread
any personal APU?......any suggestions is more than welcome by yours truly :eek:

22nd Aug 2008, 08:12
It's a simple situation ...

moderator = masochist :hmm:

For some inexplicable reason, we all get a buzz out of modding in PPRuNe ... hopefully, at least most of the time .. we do a passable job ..

9th Sep 2008, 23:10
I'm not flying the A310/A300 for some time now (I'm on A340/A330) but it just might happened that:

Once LAND mode has been armed and one AP engaged in CMD, the DC bus tie contactor (connecting the DC NORM BUS and the DC ESS BUS) automatically opens in order to assure an independent electrical power supplies for the AP/FD 1 and AP/FD 2.
In case of DC bus tie contactor failure to open, the landing capability does not change from CAT 2 to CAT 3 after the engagement of the second AP (but no audio alert is provided).

As you know FD1 receives info from FCC1 and ADR1 and FD2 from FCC2 and ADR2. In case of a slight difference of info one FD goes for the GS* and the other just acquired ALT*.

Anyway that was just a little bit strange...
Just may be one of your pax was phoning to his girl friend and the cellular interfered...

14th Dec 2008, 03:24
3 points:
1. On 767/757, fuel densitometers are very moisture critical;
2. During our Fuel Leak simulator training, we demonstrated that the 767 was controllable with one wing FULL and one wing EMPTY.
3. The Flight Crew Training Manual (FCTM) states that the fuel imbalance limit is NOT for controllability reasons, but for long term structural reasons.

Sorry Mr Moderator, this belongs with #26 (757 fuel problem)

6th Jan 2009, 12:10
737-300 CFM engines
Spin engine inspect blades on walk round. Hear sound similar to ball in roulette wheel as fan slows to a stop. Didn't accept suggestion to ferry to major service depot. Possibly should have.

Head sheared from tie bolt and floating around engine internals. Light to moderate blade fir trees' damage.

(p.s. This the style you are looking for?)

14th May 2009, 14:25
Both Eng bleeds inop after take off in short succession couple off resets carried out with no success. ECAM did not sense the second Eng Bleed inop. No ECAM associated with losing pressurisation. No ECAM except the fault light on the overhead panel on second eng bleed. Used the APU bleed to land...

V1... Ooops
17th May 2009, 20:04
Problem: 400~ caution light is illuminated, but all AC services work normally.
Cause: 400~ fuse in AC fuse panel is open circuit.

23rd May 2009, 20:02
Seen Quite A Few A320, A330 And A340 Return To Stand Due Leak Measurement Vlv Left Engaged

And that was that
15th Jun 2009, 01:16

On ground HYD EDP selected to OFF to check on another matter, notice HYD system remains pressurised at 3,000PSI??? Re-cycle and check C.B, still remains pressurised.

Cause : The HYD EDP Solenoid shut off valve fails to operate and remains open!

MEL raised (C) !

When asked what does one do in flight, when HYD SYS OVHT occurs? Airbus answer, "10x-9 and that the HYD box will overheat and shear off the HYD drive mechanism, with no further damage", when pressed for more info, nothing cameback.

Therefore, didn't take MEL! 4 hour flight over water at night, problem with this particular HYD system, could only become worse in flight! don't get paid enough money to take that one !

15th Jun 2009, 01:27
.. which is why the MEL/PUS systems are permissions, not coercive directions. The pilot is expected to consider the facts ON THE DAY and moderate the MEL permission as appears appropriate. ie the pilot can require more restrictions up to and including not accepting the aircraft.

.. all depends on the operator being reasonable and honourable as well, of course.

low n' slow
2nd Sep 2009, 22:00
Symptom: Overhead panel black after engaging external power after engine shutdown.

Cause: Fault in WEU

Solution: Momentarily hold "Lamps Test" in "1", this will break through the WEU glitch and allow signals through to the panel lights.

Symptom: Ailerons heavy and stick at full deflection (on ground with no aerodynamic load, this is often dismissed as normal!).

Cause: May be pulleys slipping off their main bearings causing the retaining washer to become conical, in turn causing friction.

Solution: Ask tech to look at aileron pulleys and their retaining washers.

Symptom: "Avionic Smoke" when powering up avionics in very cold and humid environment. (verify that there is no actual smoke or fire situation).

Cause: Humidity or frost build up in avionic smoke detector.

Solution: Start one engine, open pressure dump valve and apply maximum heating until the warning goes out, may take a few minutes.


25th Sep 2009, 06:21
Something to remember about these flying computers.
I have read of SWLT inputs that do not work in this forum.
Take time to positively push each switch and ensure light msg appears or clears. I have demonstrated to junior mechanics that by pushing a SWLT quickly no msg appeared then selecting again but slowly and positively the msg will appear.
When doing soft resets on the o'head panel ensure a reasonable time lag (10-15secs) before reseting not a nano sec. This is a (Ctrl/Alt/Delete) function for your computer not a c/b.
Something to remember when the cockpit goes black.....

Cosmo Beauregard
3rd Nov 2009, 00:39
God I love Twin Otters! Smoke rolling out from the floor boards with Airconditioning on, getting passed by canadian geese in flight & Greyhound busses on the ground... The only fixed wing aircraft in the world to take off in a nose down attitude... those wacky DeHavilland guys!

22nd Jan 2010, 00:11
Well done not to accept the aircraft. This is not a MEL C item. Acc. Mel 29-23-01 "PTU may run continously when selected AUTO provided operation of the PTU in both directions is checked before first flight of the day."
That also means that in OFF the PTU must stop! Hence this item is a NOGO.

3rd Feb 2010, 16:35
I hope this in the right place.

FMC all loaded properly with PERF INIT and TAKEOFF data loaded.

Message shows MAX ALT FL XXX, if you go to clear it in the scratch pad your initial fuel will show, but no fuel calculations will show up on LEGS or PROG.

In order to get the calculated fuel back you have to change the cruise altitude on the VNAV page to something it will accept, if the cruise altitude up link was more than what the FMC allows.

This was not taught to me in school nor passed to me on the line, the engineers couldn't figure it out either, I know it seems obvious now, but forgive me I'm a slow learner.

8th Feb 2010, 14:59
problem: uncommanded prop feathering after t/o.
action: shut-down as per emergency checklist.
cause: T.B.C, suspected fault in beta sys, will update when I know

Cause : Beta-backup system failure, now Modding to remove the system as it apparently causes more problems than it protects from.

28th Mar 2010, 06:54
"Flight director disagree.
I have never seen this before on an airbus!
AP2 engaged.Modes are v/s and loc with gs armed. Aircraft is cleared to 2000ft and further with the glide.
F/o PFd GS* as glideslope captures at approx 2300ft.Ap1 engaged as plan is practice autoland.
Capt Pfd Alt* as approaching fcu altitude as GS* not annunciated.
AP1 now master autopilot so aircraft attempts to acquire fcu alt and not the glideslope.
Glideslope is now showing fly down so both autopilots and fd disengaged and a manual approach and landing flown.
Does anybody have any ideas as to why this happened?"

My guess is one ILS receiver in a failure mode not understood by the FWC. What about the GS and LOC indications?
Just my 5 cents!

10th May 2010, 15:44
After tuning ILS 1 & 2, setting up for approach in marginal weather, noticed that ILS 1 tuning was intermittent (indications switched between freq/course to IDENT/course)...and ILS 2 was rock solid IDENT. This situation prevented a dual autopilot autoland and also NO AIII capability...only the ILS 2 was available for an instrument approach. Next day, after talking to Maintenance regarding the writeup...come to find out that a failure of MMR 1 had occurred...according to them, this never happens! There is no comparator between these and you wouldn't know you suffered this problem until on final and no Cat2/Cat3 capability.

tubby linton
10th May 2010, 15:53
Heavy airbourne,I posted the original problem and after a lot of digging in the fcom I discovered that if the aircraft FDchanges to ALT* and at the same time it is in a position to capture GS it will not capture the GS!

21st May 2010, 02:15
Thanks, tubby linton! :D

"It's not a bug, it's a feature." :ugh:

5th Aug 2010, 11:26
Sometimes when in the cargo aircraft during loading they drop a heavy box in the forward door area a couple seconds later the ELEC SMOKE warning comes on with the MASTER WARNING.

Check for electrical fire evidence first! You want to make sure it is really a nuisance and not a real thing. You have time btw. as we are on the ground and all doors open.

You may select OVBD VALVE to OVBD position and wait. Normally it goes away. May be reproduced by jumping up and down again in the door area.

Cause: Dust risen by the falling parcel or jumping
Solution: MX entrance for cleaning up with vacuum ;)

P.S. I've never seen it been done (cleaning up I mean)

5th Aug 2010, 11:34
Problem: One fuel tank quantity indicator may be INOP.

According MEL A/C can be dispatched after dipstick. No problem with that, but:
FMS has no more performance page, no speeds, no predictions on fuel etc.
This is a logical consequence but nevertheless a nuisance.

Back to manual fuel checking etc. Not a problem with this contraption as everything to do this is at hand.

Rises the question - how is this handled in e.g. A320 or 737? More problems with the performance page, speeds etc.?

14th Sep 2010, 03:18
If the FQIS is giving an erroneous indication, it is a simple matter, after starting one engine, to go to the FMC INIT page - FUEL, and deselect FQ (fuel quantity).
By doing this, the FOB is calculated only from the original (blocked) FOB - FF (fuel flow) (as determined from the FF sensors at each FCU (fuel control unit).

By using this method, there should be no incorrectly computed GW, thereby giving erroneous performance/speed data to/from the FMC.

However, your questions asks specifically of the B737/A320 FMCs; I would like to think those FMCs have a similar capability.

Dan Winterland
26th Oct 2010, 01:28
Airbus GS Capture.

I have also seen it myself. It's a known fault and the subject of the "No Loc or GS Capture in Approach" OEB. It's corrected by a new standard of MMR.

Dan Winterland
26th Oct 2010, 01:50
A320 legacy FMGC retention of previous VAPP in secondary flight plan.

Here's a good one which I have seen several times and which could catch someone out badly one day. If the previous flight has had the VAPP increased for any reason in an A320 with the of style "legacy" FMGCs and the active flight plan has been copied into the secondary, sometimes it can retain the selected VAPP on the next flight in the secondary flight plan. It should be checked, but one day it will be missed.

9th Dec 2010, 09:29
During takeoff/initial climb the left engine lost power. The flt crew attempted to continue the climb-out, but following the application of water-methanol, the pilot lost directional control. Subsequently, the aircraft banked to the left, entered a descent and impacted between the parallel runways. Injuries: 2 Fatal

Never arm the water-methanol system when already at takeoff power.

3rd Apr 2011, 10:01
Good day, maybe someone now this. During flight and especially landing hydraulic fluid transfer from B to A. It became 100 A and 85 B. No leak found.

3rd Apr 2011, 17:03
A more detailed description would be helpful. :ok:
Classic or NG?
During final approach (select LG down) or during landing roll (brake system in operation)?
Is the system pressure A and B the same?

AMM 29-15-00 PB101

FIM 29-10 TASK 807 (Fault Code 291 080 00)

3rd Apr 2011, 22:56
It is classic but ok i will try to find by myself, thank you

4th Apr 2011, 07:38
...but ok i will try to find by myself...
What do you expect without giving details. Garbage in leads to garbage out. :ugh:

low n' slow
27th Jun 2011, 13:07
The idea of having this thread going is great, but quite frankly, it's not very useful as long as all types are mixed like this. Pprune should really consider having a separate forum area (perhaps inside of techlog) with separate threads for each aircraft mentioned. That way, type specific discussions would be kept cleaner and easier to browse through.

4th Aug 2011, 00:11
vd8, re 737 Classic Hyd fluid transfer. A very common occurrence on the 73.In theory fluid transfer should be impossible,but a couple of leaking vlvs cause the problem. Speak to your local engs,there are two methods used on the ground to re-establish levels. If you can't get an answer,PM me & I'll dig the full info out.

26th Dec 2011, 09:24
Some more details?
Is this peculiar to the BE20 or does it affect the 90 / 1900 for example, is there something special about the system or could it potentially affect any pressurised/non pressurised aircraft? How does the error appear through the range, and is it only one ASI affected? I'm curious, sounds like a good one to try in the sim.

27th Feb 2013, 21:59
Good evening/morning/afternoon,

could somebody tell me what a ''control column/yoke jam'' means?

Thanks in advance

17th Mar 2013, 21:53
Blue and Green or Blue and Yellow HYD fault light flashing on OVHD with no associated ECAM.

Cause: Associated engine oil pressure switch fault. That's right OIL pressure switch.

17th Mar 2013, 23:43
Blue and Green or Blue and Yellow HYD fault light flashing on OVHD with no associated ECAM.
Cause: Associated engine oil pressure switch fault. That's right OIL pressure switch.
Airbag uses signal from engine oil px to tell other systems when the engine is running.... So perhaps, no signal from switch meant the ptu was armed, but not running since the edp was doing just fine... hence fault light but no action required?

13th May 2013, 11:22
Interesting thread - only just looked at it.

Regarding PB switches not turning on/off with too brief a push: A lot of electronic circuits now incorporate "de-bounce" logic into their switching. A mechanical electric switch can obviously only be on or off, but sometimes as it is operated, the contacts can bounce, causing several on/offs to occur within microseconds of each other. This is not a problem with say a simple light or a fan, but now that many systems are computer interfaced, a rapid sequence of on/offs can totally confuse a system. Therefore, many switches use de-bounce logic which ignore rapid changes and only register longer term changes.

This is not such a problem with toggle switches, but can be with Airbus pushbutton types. My Airbus training reinforced this by telling me to make (relatively) slow , positive selections on the pushbuttons, and wait to see the integral caption light go on before releasing pressure on the switch.

Even so, I have recently had a yellow pump refuse to switch off via the push button until I tried slowly several times - think this was a fault though.

5th Aug 2013, 12:23
vd8 During flight and especially landing hydraulic fluid transfer from B to A. It became 100 A and 85 B. No leak found

I thought that was normal on 73 classic? Qty changes when gear position changes on A system.

On 73Ng a particular pseu fault can cause the gear transfer unit to operate and send B system fluid/pressure to drive the gear and "over flow" A sys to the point of it dumping the excess overboard.
In the case I saw the PSEU had incorrectly sensed an eng failure.

Black magic in that PSEU ! Be careful.

LAHSO 06/03
6th Sep 2013, 18:13
In response to VD8 his question, altough a bit late (only just read it now), maybe this is what you are looking for:

When accepting the aircraft and finding the hydraulic quantity indication over maximum (106% on the NG) in e.g. System A:

To transfer from system A to B:
ELEC A pump ON
ParkBrake SET
ELEC A pump OFF (pressure drop)
ELEC B pump ON
ELEC B pump OFF (pressure drop)

repeat as needed (usually 3-4 times suffice)

Although this was an overfull SYS B, an overfilled hydraulic system has at least once led to an evacuation after vacating the runway, putting the flaps to up, causing hydraulic vapor to enter the cabin (check valve failure). Bad press and very sick customers.

As correctly pointed out, quantity indications vary with configuration and with diff temperatures, and fluid does seem to travel from system to system.

Good thread!

Marcus Absent
7th Nov 2013, 10:49
Several years ago starting at SSH, right started normally and during the left engine start, the right just wound down. Both the EEC and ELC had failed. Trying to make any sense of the EICAS was not easy! Something to do with the small dedicated gen on the engine used just for the EEC, I think. No doubt someone will correct me if I'm wrong!

6th Feb 2014, 08:04

Dispatched with Engine 2 Igniter System A inop under MEL - requiring manual start. The flight was normal until landing.


During landing with full reverse, an ECAM ENG 2 REV FAULT occurred but the reverser operated normally with no asymmetry.

After landing the APU failed to start and gave an ECAM APU FAULT - APU AUTO SHUTDOWN

On stand, ground power was supplied but tripped off after shutdown and was restored a few seconds later. As the power came on a long series of cautions and warnings appeared on the ECAM, most of which we attributed to the power transfer.

Maintenance action:

APU igniter box fault was deferred and ENG 2 Reverser was locked out.

Departure Attempt 1:

An external air manual start was conducted to a stable idle condition, then a bunch of things happened.


Then an ECAM ELAC 1 PITCH FAULT occurred, followed by ENG 2 REV FAULT and Engine two Oil pressure indication was lost from the System Display.

Maintenance Action Two:

Engine 2 No4 bearing oil pressure sensor found to be U/S with C/B popped, it was deferred in the tech log.

All flight control power supplies were reset.

Departure Attempt 2:

Engine two started the same way to a stable idle condition then a series of ECAM warnings occurred,

ELAC 1 PITCH FAULT - pilot reset; then

MASTER WARNING ELEV L + R FAULT, ENG 2 REV FAULT, SDAC FAULT and a few others I can't remember - engineer guided resets carried out to no avail.

Maintenance action three:

ELAC 1 suspected to be faulty, deactivated and all other computers reset.

The engineers advised there would be a bunch of faults but they would be spurious and can be reset.

Departure attempt 3:

After start: MASTER WARNING ELEV L + R FAULT occurred but cleared after ELAC 2 and SEC 1, 2 & 3 resets carried out.

The flight control check was normal and the flight proceeded normally albeit 4 hours late with very angry pax.

Solution (finally found a few days later):

ELAC 1 was suspected and after deactivation stopped all of the warnings but after all flight control computers were replaced the problem reoccurred! Further investigation found a chaffed wire (IIRC between ENG 2 and ELAC 1) was shorting out the computers.

Piltdown Man
27th Mar 2014, 22:51
Type: F27-500

Symptom: Knocking noise heard in climb after cleaning up and thumping felt through control column. Frequency increased during cruise and reached maximum intensity during the descent. The instant the flap was lowered, the knocking stopped. Over a month or so, the knocking got worse and worse. Cabin crew continually complaining about the bumping.

Problem 1: There was a huge hole on the leading edge of the right hand horizontal stabliser (under the de-icing boot), big enough to stick your head and shoulders through.

Problem 2: Three of the bolts used to hold the tailplane had "gone".

Solution: Replace entire tailplane.

deefer dog
18th Oct 2014, 03:11
Seemed like a good idea, but is this thread really working as intended? Should it still be a sticky after so many years, with so few posts, and even less on the same topic?

11th Nov 2014, 07:09

Aircraft Type TECNAM:
Symptoms: Engine rough running and allegedly stopped in flight:
Reason: Fuel was found to be contaminated with brownish liquid which smelt unusual and looked like diesel.

What went wrong:
Allegedly the drum of fuel used to fuel the Rotex engine with the approved ULP was contaminated with diesel apparently incorrectly decanted into the service station tanks.
The fuel transferred to the aircraft was not noticed to smell wrong or the wrong colour and plane was allegedly flown and suffered engine failure.
Obviously the filter, drain, view and checks before flight did not flag the contamination.

How was it fixed
Engine strip and apparently fixed after suffering detonation issues.

A radio call stating Ï have an emergency was heard on the local frequ:
When police went to the ad no sign of anyone or any plane was found.

So all these events may not have ever happened...it is alleged.

Don't shoot the messenger.....

Fursty Ferret
27th Jun 2015, 13:39
Blue and Green or Blue and Yellow HYD fault light flashing on OVHD with no associated ECAM.

Cause: Associated engine oil pressure switch fault. That's right OIL pressure switch.

Associated faults:

* CVR ground control mode will not latch on
* Multiple and spurious probe heat fault cautions on ground (reset of all 3 PHC cures).

deefer dog
29th Sep 2015, 19:24
Un-used thread of zero value. Especially when considering the thread rules (another sticky) which state: It would be appreciated if folk could be a little discriminating in starting new threads and keep Tech Log for the more involved questions.

Sorry John, a great idea, but like Jeremy Corbyn, one that didn't work according to the plan!

13th Dec 2016, 16:25
AIR Wing BLEED LEAK during engine start

- Recurrent problem in hot condition (in spite Airbus recommendation to keep Flap1 at the gate)

- MEL is no go

- We selected Flaps 3 during the "After start Flow" ECAM disappeared a few minutes later during taxi

Willie Nelson
1st Jan 2017, 09:54
Our refuelling trucks will not fit under the aircraft when aircraft is a top config 1 and therefore this one creates all sorts of problems for us.

I've asked management about it on several occasions and got no formal response.

1st Jan 2017, 12:35
Solution is for the fuelling company to modify their trucks, or use a separate, towed platform or set of stairs to access the fuel coupling, while the truck is kept away from under the wing.

However, our company told us to retract flaps and slats when coming onto stand. Then, after refuelling, if the air temperature is above 30 degrees, they told us to extend to Config one using the Yellow pump and PTU. However, this requires one of you to be outside to watch that the wings are clear.

As if we haven't got enough to do during the turnaround.

I personally think that the problem only occurs if the air temp is above 30 degrees AND the sun is shining onto the slat surfaces. @ Feather44, does this alert happen at night?

Use of only the Blue electric pump would just extend the slats, preventing the problem with minimum incursion below the wings, but it does bring up a flap fault. This disappears when engines are started and the flaps move to position selected, but company obviously not keen on this method.

Loose rivets
30th Nov 2019, 03:17
Older, but funnier ones.

HP Herald, taking of on a seriously rainy day. After a while I felt sure I caught a glimpse of water in my horizon. Yep, there it is again. The vaguum system was hauling air in via an old penny sized wire gauze filter. Air and rain.

Believing my eyes was the first thing, especially when it started to foam. They'd just shampoo'd the aircraft.

The heavy brass giro, with its sculpted edges suddenly bit into the high water. It toppled in a crescendo of foam.

Loose rivets
30th Nov 2019, 03:22
British Eagle taxiing and losing fuel during tight turns. And I don't mean a cupful. Can't believe it now, but this aircraft always dumped fuel if it was 'tanked'. Gallons would slosh out. I hasten to add, I was a new sprog, and my opinion didn't count back then.

Fursty Ferret
22nd Dec 2019, 21:22
A320 series - on ground, different FMAs showing on each PFD (one side shows ALT blue, the other CLB). Changing the ND scale changes the FMAs.

Both FMGCs reset with no cure. Aircraft de powered to no effect.

In the end both SDACs (many CBs) were reset with the aircraft powered. Problem solved.

28th Jan 2020, 06:58
A320 series
Problem: Loss of Altitude Scale on one PFD and loss of one FD (we had 2FD2 on FMA). One AP, Autothrust and CAT 3 inoperative on ECAM status. No ECAM caution/warning generated.
Solution: Check Baro Reference setting on affected side. In our case the Baro Ref had reverted to 745Hpa due to a FCU failure mode. After re-setting the QNH everything went back to normal. For some reason this was not picked up by the FWC (apparently it was an intermittent fault, after a couple of minutes we got the ECAM caution 'FCU1 fault', which kept disappearing and reappearing until we used emergency cancel).

28th Nov 2020, 12:50
Cessna 152.
It used to yaw badly in flight, various attempts to cure it failed, eventually fault made itself apparent. It was a late 152 with the landing lights in the wing and the Perspex window had worked itself loose, at certain speeds the window would vibrate across opening the leading edge up and causing the aircraft to yaw, on landing it would do the reverse so all appeared normal, it was only when it decided to stick open was the fault finally identified and fixed.

22nd Feb 2021, 05:30
B777, at night over NOPAC. crew get a caution, more cautions, warnings, and more cautions, more warnings, APLT dies, ATR dies, stuff is dropping like flies to pyrethrum. The crew by now are quite awake, thinking of what malaise could cause the issues... Flt attendant calls up from fwd galley, asking if the crew are happy with the purser being under the floor in the E&E bay, pulling breakers.

Purser had been told by maintenance that to reset IFE system, he just had to cycle the 3 breakers under the IFE display. There were 3 breakers, within an inch of the display.... but "under" takes on new meanings in the mind of the recipient. Purser was confronted with a bunch more than 3 CBS. It was fortunate that he didn't get right through his CB smorgasbord, There were a number of breakers that were around a ways that would have been... bad to pull.

2 weeks later, having investigated this particular entertainment, I'm driving a night horror, and over the "water, big water, wet water..." to paraphrase a recent food stamp recipient prez, the topic comes up with my crew, as there is an IFE fault. I suggest politely that as I am going off to rest, please don't contact maintenance by Satcom for the purser on the IFE matter, it has recently ended badly. Purser has already asked to do so, and I have said, no, as other than the power cycling in the purser's manual there is no procedure that can be applied by maintenance. Relief crew nod understanding. I go to first class. to watch about 1 hr later the purser enter the cockpit, come back, and lift the hell hole trapdoor, and start to enter the hole. At which time I popped my own CB. I put a CC behind the door and to the right of the hole, had the Purser stay where he was, asked to enter the cockpit, and then got the relief guys to look at what the geek squad was up to. The purser was advised to stay at the rear of the aircraft and to think about his career prospects for the next 10 hours. Which is what he did. After landing there was a bit of a discussion on the law, on maintenance, and comms. Never happened again, the grapevine was pretty efficient if the message was clear enough.

I also brought my own coffee onboard for a while. :}

25th Jun 2022, 00:09
Flight director disagree.
I have never seen this before on an airbus!
AP2 engaged.Modes are v/s and loc with gs armed. Aircraft is cleared to 2000ft and further with the glide.
F/o PFd GS* as glideslope captures at approx 2300ft.Ap1 engaged as plan is practice autoland.
Capt Pfd Alt* as approaching fcu altitude as GS* not annunciated.
AP1 now master autopilot so aircraft attempts to acquire fcu alt and not the glideslope.
Glideslope is now showing fly down so both autopilots and fd disengaged and a manual approach and landing flown.
Does anybody have any ideas as to why this happened?
Double rad alt fail will cause neither fd to arm in gs on the minibus but never seen it as a failure just on one side!
Speed trim fail light illuminates with master caution and flt ctl. Speed lim amber warning on captain's PFD. Left N1 gauge fails.
U/S: N1 C/B tripped

4th Jan 2024, 09:03
After take-off, F/O's F/D fails, all three A/Ps unable to select. Flaps retracted normally.

Solution: Arm alternate flaps for 30 seconds, then disarm.

Same solution worked with triple flap control computer failure.