HazelNuts39

It seems Takata is right this time. The Air Caraibe memo states that about 30 minutes after the UAS event the crew reset both FMGEC to get rid of the SPD LIM red flag and to regain VLS indication on the PFD.

RE 5°/CLB: The Air Caraibe crew used GPS altitude and groundspeed to maintain trajectory and speed. Prior to UAS they had disconnected the A/THR and set cruise N1 for the weight and altitude.

PJ2

Fully agree with you, AZR. This condition seems to have been introduced and incorporated into the memorized drill portion of the UAS response, around 2006.

In its "Unreliable Speeds; Latest Improvements" document from September, 2006, it is indicated that the memory drill qualifying condition, "Safe Conduct of the Flight Affected?" will be "Defined in Training". But the guidance remains, if the safety of the flight is not affected, first step is to level off and troubleshoot. Prior to 2006 the drill had "Immediate Actions" and then "Immediate Pitch and Thrust Guidance" and then a "When Flight Path Stabilized" section which required the Probe Heat to be put ON and "Attitude/Thrust - Adjust".

The December, 2007 edition, (#5), of Airbus' "Safety First" an article entitled "Unreliable Speed" was published. The article is quite thorough and well-written, making clear many points. It states, in part:

The question, as always when such changes occur and the distribution and incorporation of infomation is involved is, how are these changes incorporated into training by airlines operating Airbus equipment? As with most editorial changes, these changes were ordinary in the sense that most changes in procedures, SOPs, checklists and so on go through a pretty thorough vetting process even at the airline and are then published, incorporated into SOPs and training scripts and regimes, all of which take time to make their way to flight crews.

Here again, as this is the way almost all changes to SOPs work, we have to be mindful of hindsight bias. We can see now, that there were at the time of these changes, already UAS & ADR events occurring. The 2006 documents speak to awareness and addressing of the issues.

According to BEA IR#2 Appendix 7, "List of events on A330/A340 attributable to the blocking of at least two Pitot probes with ice, identified by Airbus as of 3 November 2009" there were ten UAS events prior to 2007. So the information would have been "out there".

Since most crews appeared to have kept the aircraft level while troubleshooting, (we don't know this for certain but it appears so), it would be interesting though likely difficult to determine given the passage of time, if crews who had one of the listed UAS events had had either training in the changed procedure or were at least aware of the changes and knew how to do the updated drill.

TTex600

When? When Airbus intro'd an airplane that required the FD's be followed. If the FD's are not followed, it sometimes confuses the Autothrust system, etc. The only real way to "fly" the bus requires one to turn the A/P, A/T and F/D's all off. Otherwise, you're mixing things up and confusing both the co-pilot and FiFI/Henri/HAL.

CONF iture

AP is also lost if ADR DISAGREE, could it have been reengaged to also follow the reappearing FD bars ?
But the Air Caraibes memo shows AP can be reengaged when VLS are not even computed ...

CONF iture

But the Airbus procedure is quite clear : If you choose to NOT follow the FD, turn them OFF.

OK465

HN39 (or CONF or A33Zab):

If I might ask (without going to the memo), how did they reset the FMGEC's and how did they know, procedurally, to do it?

(BTW: saw your earlier question, and yes you can get the same 'latched' SPD LIM situation by inputting two airspeed discrepancies with no failure. Using a single offside ADR failure is just quicker than typing on an IOS keypad, but at least one side must incorporate the speed discrepancy, 2 or 3 ADR 'failures' and revivals will not do it. Once on the ground, you can reset both the SPD LIM & FC law by cycling the generators off and on.)

HazelNuts39

OK465;
Sorry, I don't know more than the memo says: warnings "AUTO FLT FN1(2) FAULT" are recorded, and these are explained by the reset of the FMGEC's.

OK465

Very important.

And a 'normal' op where this required is a PRM breakout.

It's interesting that if the PNF deselects both FD's first (as required) and then the PF elects to use TOGA rather than CLB on the breakout, the FD's reappear in TOGA (due to flaps extended) and must be again deselected by the PNF.

Making radio calls, watching a TCAS target, reconfiguring, resetting the FCU by the PNF, and hand flying raw data for the PF can all be quite challenging and must be a very disciplined drill.

When the FD's are reselected after the breakout, care must be taken to not fly them until proper FMA mode indications are verified, some modes not being selectable until after re-engagement.

(edit: BTW for B44, the same requirement to turn off the FD's on a PRM breakout exists in the automated Boeing's also, because sometimes people inadvertantly do dumb things, even in Boeing's. )

CONF iture

I think they would use the RESET OF COMPUTERS procedure from the QRH and were probably in touch with their maintenance through the ACARS. That reset was done 30 minutes after the initial event. 3 hours later ... PRIM1 was also reset, maybe in an attempt to go back to Normal Law.
It is also possible the maintenance was directly in touch with Airbus.

Lyman

In the initial discussions re: BUSS, I believe that once it activates, no more NORMAL LAW, til she's on the ground and tended to....

A33Zab

Someone knows if this memo is translated into english?

From the available documentation: (AMM FMGEC / EFCS)

AP Operational Conditions:

Quote:

(2) AP engagement inhibition and disengagement logics



(a) Pitch and roll angle limits

• - Roll angle
• . AP engagement is inhibited when abs(phi) > 40°
• . AP is automatically disengaged when abs(phi) > 45°.
• - Pitch angle
• . AP engagement is inhibited when theta < -10° or theta > +22°
• . AP is automatically disengaged when theta < -13° or theta > 25°.

(b) AP engagement is inhibited in flight when CAS < VLS or CAS > (VMO/MMO or VLE/VFE).

(c) AP engagement is inhibited when the FMGEC receives the "pitch angle protection active" information from the FCPC.

HazelNuts39

No translation I'm afraid, but I converted it to a
WORD document. Hope that helps.

A33Zab

FCOM Procedures 22-10

Quote:

MANUAL FMGES RESET

MANUAL RESET OF FMGCS

On rare occasions, the FMGS may require manual resetting.
If this occurs in flight, reset one FMGC at a time.
The aircraft has two reset breakers per FMGC:
‐ The FM reset-breaker C/B resets the flight management part of the FMGC.
‐ The FMGEC reset-breaker C/B resets the flight management, flight guidance, and flight envelope parts.

Resetting the FM reset-breakers C/B or FMGEC reset-breakers C/B disconnects the onside autopilot.
The FM further resynchronizes to reset one or both FM.
Resetting the FM or FMGC reset-breaker does not increment the reset counter: There is no limitation to the number of reset-breaker resets.

bubbers44

I still think setting the attitude to what it was at FL350 and doing what the autopilot was at about 2.5 degrees nose up attitude and maintaining cruise power around 90 percent N1 or what ever your cruise power is with your conditions would be prefered to busting through altitudes because of a bad checklist. If the altimiters work, use them. Just get out the unusable airspeed checklist and don't repeat this error again. The 5 degrees nose up and climb power is still taught in some airlines. Pray for the airliners above them opposite direction. That procedure is only to be used in an emergency when control of aircraft was in doubt, not loss of airspeed.

OK465

Thanks once again A33Zab & CONF.

Using reset-breakers for a procedure makes it sound a little more like an 'old' Boeing.

Although, in the past, if you put breakers (reset type or not) on any flight deck (even as few as there are in a 330), some flight engineer would eventually figure out a valid operational reason for 'using' 'some' of them.

AlphaZuluRomeo

Hi VGCM66,

No subtitled version exists that I'm aware of.
But as there were questions about Mr Rosay's interview, I translated two parts where he can be seen:

On the loss of speed indications and the procedure to follow:
On the (non) reaction to the stall warning:
Hope it helps, and my english is not too bad...

NeoFit

Mr Rosay @ 29:15
Easy to say, i hope everybody is aware of this. But in really life ...

Unfortunatly, the reptilian brain has sometimes a snooze.
BEA wrote (1994 Tarom YR-LCA serious incident report):
Terrifying, is'n it.

bubbers44

I know hundreds of pilots and not one would pull back in a stall. The only pilots that pulled back in a stall are the AF new hires and one Bonanza pilot who lost an engine out of Burbank trying to return after an engine failure in front of my eyes. Of course all died in that crash too. None of my hundreds of students died by pulling up in a stall. Rethink your 80% theory.

Lyman

bubbers44, that appears not to be NeoFit's theory at all, but statistical data published by BEA.....Oddly, I am speechless.

sevenstrokeroll

I agree with bubbers.

I was also very lucky in flying...I read, reread, and reread again "STick and Rudder" by Langweische. In it, his constant refrain was , in trouble? push forward on the stick.

and its important not to say: lower the nose...pushing forward on the stick reduces angle of attack (ok, maybe not in inverted aerobatic flight).

I drummed this into my students and one of my proudest moments was when one of my students came up to me saying he had a near midaircollision with someone at Truckee Airport (near lake tahoe california usa)...the other plane was on the wrong side of the depicted traffic pattern...they were head on converging on base leg. Mind you field elevation is 5900'msl...he avoided traffic , got the stall warning and PUSHED forward even though the mountains nearby were filling the window. an incorrect thing to do would be to pull up to avoid the mountains...but not when you are stalled or near a stall.

He landed safely, having recovered from a stall in a difficult situation.

he told me I saved his life and the lives of his family. I told him to thank Wolf gang langweische, the author of 'Stick and rudder".