Airbus A320/A330/A340 Electrical Flight Controls

[wsherriff]

The QUANTAS QF72 accident IS a result of the AIRCRAFT'S FLIGHT ENVELOPE MONITOR AND CONTROL COMPUTERS following their programmed instructions, exactly! See "Airbus A320/A330/A340 ELECTRICAL FLIGHT CONTROLS".

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From my experience in a pitchup in a Boeing 707 just on top of a building thunderstorm I report the following. Upon entering a strong updraft the swept wing aircraft design is mechanically transitoned into a nose high attitude, depending on the strength of the updraft and the length of the fuselage from the center of gravity to the end of the tail assembly. This mechanical nose high transition does not increase the G loading on the aircraft, as a normal pilot control input would. The aircraft continues, in this attitude, on its projected flight path for two to three minutes (NASA claims a fifteen mile diameter for an updraft). During this time there has been some mechanical lifting by the updraft and now when regaining normal relative wind conditions a return to cruising altitude is resumed.

[J.O.]

I am sure the Aussie investigators et al will be pleased to know that they no longer need to complete their investigation of the accident. Now having said that, what exactly is your point? Are you suggesting that a building thunderstorm caused the QF situation?

[NZScion]

Whats a Quantas?

[Gary Lager]

I am intrigued to learn how changing from straight and level flight to climbing flight involves no extra G loading.

Apart from that, wtf?

[Jimmy Hoffa Rocks]

MEDIA RELEASE

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2008/40a

ATSB Airbus investigation update

09 October 2008

The Australian Transport Safety Bureau investigation is progressing.
The aircraft's Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) arrived in Canberra late on Wednesday evening. Downloading and preliminary analysis overnight has revealed good data from both recorders. Data from the FDR has been provided to Qantas, the French Bureau d'Enquêtes et d'Analyses (BEA) and Airbus as parties to the investigation.
While the full interpretation and analysis of the recorded data will take some time, preliminary review of the data indicates that after the aircraft climbed about 200 feet from its cruising level of 37,000 feet, the aircraft then pitched nose-down and descended about 650 feet in about 20 seconds, before returning to the cruising level. This was closely followed by a further nose-down pitch where the aircraft descended about 400 feet in about 16 seconds before returning once again to the cruising level. Detailed review and analysis of FDR data is ongoing to assist in identifying the reasons for the events"


This investigation is ongoing!!

What's the connection ?

Wsheriff the Airbus 330 is a slightly differenlty animal ( to amke an unsderstatement ) than the 707 in regards to flight controls, I take it you know this ?

Have you really flown the 707 ?


There have been maintenance error made in the past causing flight control problems but this may not be the case ??

[wsherriff]

I am glad that you recognize there is no longer any need to proceed further in the investigation, as the true cause of the Quantas flight QF72 accident is the programming of the Monitor and Control computers in the Aircraft's Flight Envelope Protection System!

Paragraph 4.1, Page 619, AIRBUS A320/A330/A340 Electrical Flight Cntrols.

"One of the contributions of the electrical flight controls to the safety of the aircraft is the protections which are an integral part of the flight control laws. The structure is therefore protected during normal flying (G-load factor, speed). A third protection, called (High Angle of Attack Prevents the Aircraft from Stalling! These protections lighten the pilots's work load"

Upon entering an updraft the aircraft pitched up and gained 300 feet in the mechanical lifting force of the updraft. At this point the Monitor computer triggered the Control computer to shove the nose over into a steep dive attitude to protect the aircraft from a possible stall (high angle of attack protection) or the possibility of (exiting the Flight Envelope)

This radical pitch-over attitude transition, projected the unbelted passengers up into the ceiling of the aircraft, with serious head and neck injuries.

[bobrun]

The incident was caused by a faulty ADIRU. Nothing to do with the original post's suggestions and not related to weather at all.

[wsherriff]

The failure of an ADIRU will pitch up the aircraft for a gain of 300 feet and then perform a radical pitch over maneuver into a steep dive transition, without any pilot control input???? NO! But this is exactly what the Flight Envelope Protection System is programmed to do! The large increase in AOA upon entering an updraft triggers the AOA protection against a possiblle STALL or the aircraft exiting the ENVELOPE!

See: Airbus A320/A330/A340 Electrical Flight Controls

[bobrun]

wsherriff, have you read the news or the Airbus OEB? A faulty ADIRU was the cause of the problem, not an updraft!!:=


Investigations highlighted that at the moment of the event the ADR 1 was providing erroneous and temporary wrong parameters in a random manner. This abnormal behavior of the ADR 1 led to several consequences such as unjustified stall and over speed warnings, loss of attitude information on the Primary Flight Display, several ECAM warnings.
Among the abnormal parameters, the provided Angle of Attack value was such that the flight control computers commanded nose down movement.


Enough said, move on.:}

[wsherriff]

There were two normal ADIRU'S operating.

FDR reading, "aircraft climbed about 200 feet."

"unjustified"?, "stall and over speed warnings", are normal programmed responses of the aircraft's envelope protection system, upon entering an area of increased AOA.

Among the "abnormal"? parameters, the provided Angle of Attack value was such that the flight control computers, {triggered by the monitor computers), commanded nose down movement. Normal program response to increased AOA.

This abrupt, automatic, nose over maneuver projected the unbelted passengers up into the ceiling of the aircraft, with the resulting serious injuries! Without any possible pilot control input!

Possible use of the Auto Pilot computer, until the aircraft flight envelope protection system is reprogrammed?

[wsherriff]

We are considering not climbing flight but the mechanical lifting flight of the strong updraft.

[OutOfRunWay]

I beg to differ, sheriff, but manouveres with a negative G-load are neither "Normal" nor "Programmed". The Normal and Programmed behavoir of Airbusses is to smooth out turbulences, and not to paste the PAX across the ceiling.
Anyhow the debating the fulty ADIRU is senseless, because it has been established.

Cheers!

[wsherriff]

The two good ADIRUS consulted and over ruled the No.1 ADIRU! The normal programmed instructions! were followed. e.g. Shoving the nose over into a steep dive attitude to avoid a possible stall! (large increase in AOA in the updraft!)

[bobrun]

We are considering not climbing flight but the mechanical lifting flight of the strong updraft.
Again, there was no "updraft", but only a faulty ADIRU.

The two good ADIRUS consulted and over ruled the No.1 ADIRU!
No, not exactly, and that's why there was an upset.

What exactly are you trying to say here? Do you even fly an Airbus??

[wsherriff]

Quote:

"Again there was no "updraft", but only a faulty ADIRU".

The aircraft gained 200 feet and then pitched over into a steep dive attitude.

I have experienced a pitch-up in a B707. A swept wing aircraft WILL pitch-up in an updraft!

Page 619 Electrical Flight Controls, Quote.

"A third protection, called high angle of attack, prevents the aircraft from
stalling."

Did you ever fly the Airbus? It's just another aircraft.
I have flown the B707, CV990, B747, etc. etc.

[Bolty McBolt]

Upon entering an updraft the aircraft pitched up and gained 300 feet in the mechanical lifting force of the updraft. At this point the Monitor computer triggered the Control computer to shove the nose over into a steep dive attitude to protect the aircraft from a possible stall (high angle of attack protection) or the possibility of (exiting the Flight Envelope)


Up draft or ADIRU, The engineers changed an ADIRU and the aircraft flew home. Once home and a 100 odd trim and ceiling panels replaced, Aircraft back in service. Same FMGEC software etc etc


The two good ADIRUS consulted and over ruled the No.1 ADIRU!

This does not happen on a bus. 777 yes BUS no. BUS generates ECAM msg and crew kill faulty ADIRU. Crew input required.


At the time of the above incident, . S/O at the controls, Capt in the bunk, F/O also out of cockpit.
A/C pitched up due faulty ADIRU, Nose over caused by the person at the controls, NO software required

:ok:

[wsherriff]

"The enginers replaced the AIRDU, aircraft now back in service. Same FMGEC software."
Same potential exposure to an updraft!

The two good AIRDUS consulted and overruled the No. 1 AIRDU AUTOMATICALLY! (Immediate PROGRAMMED ACTION, prior to any crew action.)

"This does not happen on the Bus, 777 YES Bus NO."

Programs on Bus and 777 are exactly the same except crew over ride possible on the 777!

"Aircraft pitched up due to faulty ADIRU, Nose over caused by the person at the controls, NO software required."

SOFTWARE PROGRAM IS THERE AT ALL TIMES, REQUIRED OR NOT, IMMEDIATELY! NO OVER RIDE ON THE BUS!!!!!!!

[bobrun]

wsherriff,
looks like you're only trying to discredit the airbus, but brilliantly fail to do so. Although this is a rumor forum open to anyone, let's try to keep the propaganda out please. We're here to discuss real issues, thank you.

[B-HKD]

And he can't spell it right...:rolleyes:

Leo

[wsherriff]

Quote:

"Although this is a (Rumor Forum)?, (actually it is the Tech Log,) open to anyone lets try to keep the propaganda out please." "We're here to discuss the real issues, thank you."

Real issues, twelve passengers seriously injured, in an abrupt, aircraft nose, pitch over maneuver!

The software programmers have taken over the aircraft control initiative, from the pilots, as evidenced by the recent Qantas Flight QF72 accident!
The programmers do not know about pitch-ups in an updraft!

[wsherriff]

Poor typist and failing eyesight.

[Graybeard]

The ADIRU should have set FAIL WARN in its output data bus words upon sending out faulty data. This is a highly monitored unit whose output should be proven to a probability of on the order of 10 to -9 of no undetected failures.

Either the ADIRU (design) engineers need to fix that, or the Bus (design) engineers need to fix their lack of monitoring of Sign Status Matrix. That ADIRU should have been automatically taken off-line as soon as it reported Fail Warn.

Back in the pioneering days of Area Navigation, I remember an Inertial Sensor Unit in the KSSU DC-10 that had a stuck minor bit in its output word. The unit would flag Fail Warn in its output data bus when the bit caused checksum fail, and the Nav Computer would drop it from calculations. However, the Nav Computer would accept every good word. This caused the Nav System to miss the approach gateway by more than 60 miles after a long overwater flight. The fix was to merely change the logic in the Nav Computer to require six good words after receiving one word flagged bad before accepting the Inertial Sensor's data again.

GB

[wsherriff]

Quote from GrayBeard

"That Airdu should have been automatically taken off-line as soon as it reported Fail Warn!" (referring to AIRDU No1)