A330 Flight Test Crash
 

It's been a long time since I read about that one in Aviation Leak (week), but wasn't stall protection disabled in Flight Level Change mode, or whatever it was called? What kind of a design problem was that? How deep into the software was that hidden?

As you all must know better than me, the A-320 Air Inter was a failure called modality: the same knob selected glide path angle in degrees and tenths, or rate of descent in thousands and hundreds. Did a real pilot design these things?

Like an old 727 driver told me, "Sometimes I WANT to hurt that airplane, if that will save it."

GB

Not just rudder hard overs, 411A.


08/28/1973 21:50

LOCATION: Thirty-five miles west of Los Angeles, California

CARRIER: Trans World Airlines FLIGHT:

AIRCRAFT: Boeing B-707-331B

REGISTRY: N8705T S/N: 18916/455

ABOARD: 152 FATAL: 1 GROUND:

DETAILS: The plane porpoised while descending to LAX. The

aircraft was subjected to 2 minutes of peak acceleration forces of 2.4

g A combination of design tolerances in the aircraft's longitudinal

control system which, under certain conditions, produced a critical

relationship between control forces and aircraft response.

On Norbert Jacquet’s website, we can find a page pointing out that the Airbus 320 would be much more dangerous than the Boeing 737 NG (-600 to -900).

Here : http://jacno.com/am5300.htm (May, 5th 2006).

Extracts :

On this same Norbert Jacquet’s page, there is a link towards a page confirming that Bernard Ziegler, father of the “Airbus technology”, in 1961 cut a teleferic cable with his plane ( http://www.time.com/time/magazine/ar...872735,00.html ).

Was Bernard Ziegler the right man to conceive the Airbus cockpits?

What can we think about the differences on the crashes’ rates for the A 320 and the B 737 NG? (the B 737 NG fleet is 40% inferior to the A 320’s one)?

Ladies and gentlemen, before we return this thread on its tracks, I'd like to give my comments on some accidents mentioned here.

Regarding the Roselawn ATR-72 crash: there were two accident reports, one by NTSB and another by its French counterpart, BEA. They were pretty much the same in their factual information and analysis sections, but they differed wildly when it came to probable causes. NTSB blamed the airplane designers and inadeqate regulatory oversight during ATR certification. BEA accused the flightcrew of being negligent for continuing the flight in icing conditions when there were escape routes available. So who got it right? No one - both were seriously wrong.

NTSB claimed that ATR knew that their airplanes' ailerons are prone to hinge moment reversal, especially with ice contamination, and should have been redesigned. Problem is that aileron moment reversal on uncontaminated wing occurs at 26° AoA - deep into stall so it was considered to be a non-issue. Another problem is that atypical icing over Roselawn was caused by supercooled large droplets (SLD). At the time of crash, they were largely unknown fenomenon outside some narrow meteorological circles and even worse, they cannot be created by water spray tankers during icing certification. So ATR and DGAC sprayed and sprayed and sprayed ATRs from tankers and never had problems with ailerons. Also SLD tend not to create large ice deposits on leading edges, they flow chordwise and then freeze. Lack of ice on leading edges can lead one to conclude he's flying through light icing, while ice builds up out of sight.

However, it's absolutely wrong to blame our deceased coleagues for improper operation of their ATR. Sad fact is that they were faced with unknown phenomenon and so became test pilots without ever realizing it. While their actions preceeding loss of control were somewhat unusual, they were far from unreasonable. They did turn on de-icing level 3 (i.e. boots) but were never concerned about icing because there was not much ice on the airplane. Also there was argument that 'since it brought down the airplane, icing was severe'. Well gents, if ATR had powered ailerons, or if they were better designed, if there were brazilia or SF 340 instead of ATR, pax and crew would land happily at KORD and SLDs would be still be unheard of. Biggger de-icing boots, ice evidence probe, increased speeds for tkof/ldg, stick shaker that fires earlier with anti-ice turned on and whole bunch of procedures for dealing with icing are all legacy of Roselawn. It's very improper to chastize the crew for not adhering to procedures that were developed as result of their mishap.

Back to airbus. Halbsheim flypast. Airplane was too low. Then it was too slow. On the top of it, idle thrust comes into equation (comanded, not as result of failure). I apologise for not having the nerve to explain why flying low and slow can be health damaging with any airplane.

Strasbourg crash was caused by misseting 3300 fpm instead of 3.3 degree flight path on FCU (that's autopilot control panel in airbusspeak). FCU has been redesigned since to prevent similar occurences, and i don't know whether it was designed by real pilot, but by my definition, real pilot always check if the autopilot does what it's commanded. With the speed they had, they shouldn't have descended with more than 1000 fpm and they hit 3300. Also PFD have shown unusal nose down attitude, yet they missed all the clues and there was no GPWS to save them.

Belle Harbor crash wasn't caused by excessive rudder deflection. Yes, rudder has some design issues but what tore off the tail was rapid rudder reversals. For the time being, they seem to be commanded and not caused by control unit failure. For those unimformed: you never, ever cycle any of your flight controls rapidly during flight - dangers involved are: PIO, control failure or even airframe failure. So this crash wasn't really type specific.

Toulouse A330 crah is here: I'd just like to add that there are claims that crew went out flying after long day in the office, so fatigue could also be the issue.

Regarding the Gibson dive: crew was blamed for trying to fly with flaps extended and slats retracred, to improve cruise performance. Couple of years later test flight in this configuration was atttempted to prove the theory but it only disproved it, as so rigged 727 was unable to climb to high twenties, let alone cruise above FL300. This claim comes from Stanley Stewart, and while I couldn't verify it, I wouldn't mark mr. Stewart as unreliable source.

To sum it up: FBW or no FBW it's still subject to aerodinamic forces and gravity like any other airplane. I'll just repeat what wileydog3 said: "do the same thing with the 'bus as with any other airplane.. play to the strengths, respect the weaknesses".

Well done, whoever you are. A very good post; very good indeed.

Funnily enough my Software Engineering professor, Peter Mellor was brought in when that happened and when he spoke about it, he said that it was an area of human-computer interaction that was in its infancy in the late 1980s. Now we know that in safety-critical applications, multi-function dials (push/pull for secondary functionality) are a big no-no.

I was an aviation nut long before I became a computer geek though, and in those terms I think that the introduction of the A320 and its brethren were similar to the Comet in the way that they were guinea pigs for a new level of aviation technology. Boeing admitted in the '50s that were it not for the Comet, it's likely that the 707 would have suffered similar problems. This is why I think a lot of the AvB argument is pointless. As a software guy, I can understand the frustration of having a layer of abstraction between the nuts and bolts and their human controller, and I can understand the worry that some pilots had of being rendered superfluous by the new technology. But it was and remains an unfounded fear, because there are no fewer flight deck crew on an A320/30/40 than on a modern Boeing.

I did hear a strong rumour the probs with the A380 is the horizontal stab test strain gauges are off the clock and they have tried to beef up the stab, but that has thrown the weight and balance out.......... anyone else heard this?, curiously someone else has mentioned there are 380's parked outside at Tolouse minus the backends? again anyone heard this or seen them?

Hey gents isn't it Norbert Jacquet himself under the cover of a pseudo (the shrimp) who is lighting the fire of all these very polemical threads? He is well known on the french forums (radiocockpit) to appear with several pseudos,funny guy!!

319 Beer Ad
 

Back to the general thread I hope.

Most of us have probably seen the bouncing 319 beer ad so there is no need to post it.

Whilst we could debate it's credibility, I'd suggest and have read it's caused by a dual radalt fault which results in a 'normal' out of range signal comming from the radalts antennas caused by possible water ingress.

Accepting this is possible, then the normal pitch law does not transition to flare law at 100 feet and reverse & spoilers are locked out until either sufficient ground speed or main gear time on ground is achieved. Likewise if the speed decays to Alpha floor, before the aircraft knows its on the ground, then Alpha Lock is activated and TOGA is commanded unless the Autothrust instinctive disconnect is held for 15 seconds prior to this occuring.

As an operator my company SoP's call "RadAlt Alive" at 2500, is this standard with other companies and is it generally recognized that should the Radalt indication not appear then it's a lot more significant than such a failure on the other Brand of A/C.

This could probably be in Technical but seems to follow this thread?

Recall an old story of an Ansett 320 doing "Auto" go-arounds possibly due to Alpha floor activation and we had a Foreign A330 Radalt incident about 5 years ago in Melbourne. Does anyone know of other instances?

BTW

For any follies, it's still great gear in my book.

Just got to work with what you've got and try to understand what that is:O

Load of bollocks, dual rad alt failure gives you direct law on gear down.

The Heineken beer advertisement featured a model aircraft, nothing about that advertisement comes close to reality. Are you this gullible to other advertisements produced by beer companies ?

Likewise another load of bollocks. No such thing as "Alpha Lock".

Another load of bollocks, the calls and FMAs are for low vis operations, the Airbus assumes each and every landing is CAT III. The aircraft does not know the visibility and cloud base.

Rad alt failure on a 777 will not do wonders for an autoland either. No aircraft I am aware of that is currently in production can do an autoland or low visibility approach to a DH without a rad alt.

My but aren't we a little condescending. The "Rad Alt Alive" call is for more than just low visibility operations. It is a situational awareness call, as a reminder to the crew that they are approaching the ground. Anyone worth their salt should be verifying that the call is coming at the expected time and place, and not at a point where it is unexpected, thus being a possible indicator that they are much closer to terra firma than they think.

Load of bollocks???
 

Sorry Zeke,

I should have known not try and be tech on this forum..... but now I've started.

Yes, Dual Radalt Failure gives Direct Law on gear down, autopilot disco... no argument.
There are known cases though where water ingestion at the radalt antenna has resulted in a no return signal. ie the A/C doesn't know the RadAlt has failed and so will not recognize the Dual RadAlt fault.

Along a similar line I've had a Radalt ramp up whilst cruising at FL330 and RA1(Amber) took over both sides indicating -5 feet and a host of ECAMS.... it's just a machine and will always find new ways to break.:bored:

If you believe that fine, I hope you never find yourself in such a situation.

Anyone with something constructive to add it would be appreciated.

Flamers move on thanks.:\

Sorry should have said FLARE MODE at 100' not law.... pedantics count?

The full add is at http://www.aviationexplorer.com/a319...commercial.htm

As they say on that other site it is "AIRBUS A319 BUMPY LANDING - (TELEVISION COMMERCIAL FOR HEINIKEN) - TRICK AVIATION VIDEOGRAPHY"

The first part of the advertisement shows a real aircraft, just after the "cabin crew prepare for landing" it cuts to the fake video.

If you were to review the landing you would notice that none of the gear struts compress, no thrust reversers or spoilers, no strobes or landing lights.

Just after passing the control tower in the background and saying "captain speaking" you will see where they morph the model back to a shot of a real aircraft. You will notice after the morph the spoilers are deployed.

I would like to nominate you for the most gullible ppruner of the year.

OK Zeke, what ever, I was looking for discussion not abuse.

Has anyone else had any experiences with passive Radalt failures or anything constructive to add?

I'm on the A330, suspect laws are similar but I don't know!

Is wheel speed (>72kts) an OR logic question and what constitutes an on ground LGCIU signal for the engines (FADEC) on the 319?

Radalt Failures
 

The radio altimteter was designed as a landing aid, and has been adapted for uses beyond, such as GPWS. The signal bounced from the ground gets weaker with the square of the distance, so funny things can happen. Other aircraft, and even heavy rain clouds can reflect the signal, giving a false lockon with a perfectly operating system. Ice without a wet surface is nearly invisible to it, however. Since you are using a computer, you are conversant with speeds/frequencies. The radalt sends and receives on 4.35 GHz, +/- 100 MHz, Frequency Modulated, Continuous Wave.

Most radalt installation failures are due to such simple things as corrosion between the antennas and the fuselage, and coaxial connector fittings at the back of the transceiver mounting tray. Symptoms are almost always a lock onto a false signal at altitude, where the ground return signal is weak, and therefore the transceiver reception is at full volume. Back below 300', most quirks disappear, making them difficult for Sparky to confirm.

I spent a month one week in Auk chasing authrottle retards as 250' on a fleet of 747-200. The pilots were concerned, of course... Lack of electrical bonding between the radalt antennas and the flame sprayed belly panels, and a signal switching inside the radalt at 250' conspired to cause one radalt to go to near 0 feet briefly, triggering A/T retard.

Every radalt anomaly should be reported to maintenance, before it gets worse. Since it is a vital part of a Cat IIIb Autoland system, any altitude indication higher than correct should be reported to authorities.

For dual autoland, of course, at least two radalts must be operating and indicating near identical altitude. Glideslope signal is washed out of the autoland equation by 50', as the radalt indication has been brought in. Below about 40', in widebodies at least, the approach is ballistic.

GB

WAGM
 

Hi WAGM,

I see that you're a new prooner so you may not know, posters here tend to say exactly what they think ...

Mate regarding the Heineken Beer ad, all I have ever heard on any forums worldwide, is that it is a fake (it certainly looks like a fake and Zeke's breakdown of it fits perfectly) so, I wonder ...

a) are you giving us the wind-up?

or

b) has somebody been giving you the wind-up? (You know, your captain flaming the new guy a little?)

Don't know, only guessing.

In any case I wish you a long and happy association with proone.

Cheers,

ABX

Greybeard, ABX,

Thank you for a reasonable reply.

No, this is not a wind up and I don't believe I've been wound either.

This link;

Aviation Safety Investigation Report - Final Airbus A330-341, PK-GPC

or this link;

www.atsb.gov.au/publications/investigation_reports/2001/AAIR/aair200104399.aspx


report and my own experience with radalt failure got me interested in the area and made me wonder if just perhaps at least some of that video was based on fact. I believe it would be lazy or stupid just to dismiss it as a fake because that's what was the view of someone else with no specific credentials.

Perhaps there is a PPruner who was involved if the original footage or alternatly the construction of a the fake?

Just to be pedantic (I couldn't sleep a couple of nights ago and cracked open a textbook on radar), the signal gets weaker with the 4th power of distance, not the square. It turns out that the signal from the plane falls off with the square of the distance, as you'd expect, but in addition to that, the return also falls off with the square of the distance, causing an overall loss proportional to the 4th power of distance.

Which, of course, makes your comment all the more relevent.:)

WAGM & Zeke
 

I ask as someone who has little knowledge of this a/c.

Does the A319 (I assume it is a A319 in the Heineken ad?) have brakes on the nose wheel?

I ask because in the beer ad the FLG brakes lock and the wheels smoke, yet the mains do not.

Maybe someone can tell me?

Cheers,

ABX

Ps. I remain to be convinced that the ad is real and tend to believe Zeke's description earlier. :}

There are no brakes on the nosegear of the A319 (or on any other aircraft that I am aware of).

JO

Try the 727!

Heineken Ad:

Just after the captain says "This is the captain speaking ..." the front of the plane dips down and the nose wheels smoke (as if being locked up by the brakes), something that would be pretty hard given J.O.'s reply...

Sorry WAGM (I truly am not having a shot at you mate) I can't see that video as being real, unless someone has more info not yet shared.

Cheers,

ABX

This is what you may be looking for:

Bulletin 812 for 320/1

To paraphrase: If you are in heavy rain the radalts can sense an incorrect height.

If both radalts are affected at once:

If the value detected is greater than 150' spurious autocall out and spurious ECAMs or GPWS warnings.

If value between 150' and 80'

During auto approach:
degradation of the guidance, glideslope no longer flown, excessive deviations can occur.
Variation of londitudinal pitch and or vertical speed leading to GPWS warning.
During Manual approach:
No adverse warnings but GPWS or autocall out warning may be triggered.

Had it once in very heavy rain on descent. Numerous ECAMs and a flash of GPWS.:ok:

In all honesty, the quality of the beer advert video reminds me a lot of flight sim....

I would perhaps cautiously offer this as the possible source of the "false" video...

Regards,

Shuttlebus

Forget the ad please
 

Moving on from the ad debate thanks.

Has anyone else with airbus experience had problems with the Radalt system and/or informed thoughts on it's effect on flight laws/air ground logic etc

Non pilot speaking: If I read some of these posts correctly, some people think that the Heineken advert shows a real video of a real a/c??? Shurely shome mistake. Anyone can see that it's been frigged in the video suite.

Back to the original thread.
Doesn't matter if it be 'bus or boeing. The Mode control panel or what ever the manufacturer choses to call it is The Fiction Panel. If you don't know what your mode annunciators say then you can bet the aircraft will be flying you!! FPA 3.3 or V/S 3300 would have been a non event if they'd only checked the FMAs after making the selection.

Zeke, Back to the FCOM for you, Alpha Lock lives

It is possible that you will find some 727's with nosegear-brakes fitted.
I've got 1000's of hours on the 727 and none of them had brakes up front.

Clearly fake, not even a Bus can do that. :}

Can you prove your accusation?

Therefore, as you seem to follow this file in France, I have a few questions to ask you and it seems more important to take an interest on this.

First question. In what he reports, Norbert Jacquet refers to false licenses pilot:

This story of these false licenses is really unbelievable. What do you think about it? Is France a banana republic? Could a banana republic build aircrafts worthy of the name?

If you do find one (most likely a 100 series) and are planning a max brake landing I recommend using the locking lever on the shoulder harness!

Tree an Phil H

The 200's delivered to Australia had them. I can't recall whether the 100's did. Time was mainly on 200 but initial type was 100, many moons ago.

From memory they activated after about 2/3 pedal travel, so did not factor in normal ops.

M

Tree, I had thousands of hours on the Convair 880M which had nosewheel brakes fed by No.1 Hydraulic system. (Definitely showing my age.:} )

1. The a/c can be flwon like any others
2. Fly,navigate,comunicate
3.One head up all times
4.Cross check the accuracy of the FMS
5. KNOW YOUR FMA ALL TIMES
6.WHEN THINGS DON'T GO AS EXPEXTED TAKE OVER
7.Use proper level of automaton for the task
8.PRACTICE TASK SHARING AND BACK UP EACH OTHERS.

Errors are human and we all do them, we shouldn't blame the A/C if we don't know its systems..

I don't think the Airbus is perfect but I am sure it doesn't have any more defects than others...

All the modern fighters are fly by wire (some fly by light)..
Get used to it...
Speevy

I certainly do agree that in that kind of automated airplanes, the AIR/GND logic can play many tricks, and engineers or certification process can not imagine or produce all that before airline pilots will have to experiment by themselves ...

It is quite common these days to get an "LDG MEMO" at FL370 over the NAT tracks associated to a RAD ALT showing 1000... just because you're not the only one out there...

Regarding your link, they don't talk about pilots experience and background, and as a RA FAULT implies using MANUAL PITCH TRIM, they may well have forgotten how to use that after flying the bus for too long ... witch could explain the too many bounces!?

What can I say... you probably report the commonly accepted official version, but did you go further... ?

Have you ever seen at Farnborough one of these Airbuses demonstrating its capabilities of very slow flying... did you notice the resulting attitude?
Now, do you believe that Habsheim 320 was showing that typical attitude... or there were still many nose up degrees to extract before staling!?

Do you know that no more than 3 days after the crash, all the trees on the airplane path have been cut, before producing any clues?

Do you know that flight recorders have been hidden from Justice during the first... 10 days?

Do you know that brand new 320 technology was allowed only 1200 hours certification ... when Airbus decided to implement a 2000 hours program for the later 340?

Reading out of the box can teach all of us many things...

All our 727's in our Micronesian operation had working nose gear brakes at one time (-100's and -200's)

They worked very well.

To 'second' somebody's 'motion' up there, when something does not look, sound or feel right, take over.
The computers might be flying most of the time-but they can not override your authority.


Easy for me to say- how to take over will be the problem.

My first Airbus ground school begins in 4 weeks, however the company produced what appears to be an excellent CD-ROM to study in advance. So far the info seems to be structured in a very clear, logical manner.

you want to take over:
simple revert to Speed Heading V/S or any other selected modes (op clb,etc) if that doesn't help there is a red push button you usually use to disconect the automatics isn't?

For CONF iture: The accident you refering to, I don't knw all those details, but did you know that the captain was trying to show how smart was the a/c demostrating Alpha Floor but forgot this:
ALPHA-FLOOR PROTECTION
Alpha-floor protection automatically sets the thrust at TOGA thrust, when the aircraft reaches a very high angle of attack.
The Flight Augmentation Computer (FAC) generates the signal that triggers the alpha-floor mode. This, in turn, sets TOGA thrust on the engines, regardless of the thrust lever positions.
The FAC sends this signal when the angle of attack is above a predetermined threshold, that is a function of the configuration.
In CONF3 and CONF FULL, this threshold decreases as a function of the aircraft deceleration rate (down to - 3°).
Alpha-floor is available from lift-off until the aircraft reaches 100 feet RA in approach.

I repeat, errors tend to be uman in any case...

If you comand Toga the A320 will go around!!! Look at the Tap video (the one about the xwind) they applyed Toga almost when they were already on th GND if there is any delay is caused by the Spool up time common to all A/C (the 737 and the A320 got almost the same CFM)...

If I am flyng the a/C and something doesn't look right I would take over no matter which a/c we're talking about..
Speevy

Old Joke
 

Sorry:
What's the difference between an A-320 and a chainsaw?
About a hundred trees a minute...

GB