HazelNuts39

Not just a consensus, but a feature of all jet engines, not just high-bypass engines. The very reason for having a flight idle higher than ground idle is the spool-up time. Since the adoption in 1958 of Special Civil Air Regulation Nr. SR-422A for Turbine-Powered Transport Category Airplanes of Current Design, the 'baulked' landing climb requirement must be met with:

Turbine D

Lyman,

The year was 1988. What you are "seeing" is neither a "stall" or a "surge". It is a result of a throttle burst from minimum idle to max thrust. In those days, when you did that, even on a test stand, you would see unburned fuel vapors out the tailpipe. It had to do with the state of design knowledge in those days regarding the combustor and fuel insertion into the combustor. With today's combustor sophistication and knowledge rarely would you see this.

Anyhow, both engines performed as advertised, with power application being just a little late.

Dozy,

Without getting into a lot of detail, I am sure. It was a warning and reminder of the spool up time required on this engine from minimum flight idle to TOGA thrust, whether it takes place at 50 feet or 250 feet from the ground, much more critical than at or near cruise altitude.

thermostat

I believe that we all as pilots knew very well that jet engines took about 8 seconds to spool up. That was the case on the B727 when I flew them back in the 70's. I am quite sure it was a lack of knowledge and experience that caused that accident. The A320 was new and no one quite understood it's idiosyncrasies. When I started my training on the A320, I realized how complicated the technology was and understood then why they lost that first one at the show. Remember too that the A320 of today is very different to the one that crashed. Many mods over the years. I don't fault the pilots. The technology was new, difficult to understand and the training possibly inadequate. It's so easy to point fingers after the fact.

thermostat

First of all that :
(1) Pilots understand and respect high altitude flight into thunderstorms
(2) Radar must be properly setup at Top of Climb.
(3) Pilots understand "supercooled water" and how it behaves.
(4) Respect SOPs and apply them
(5) Better training on high altitude manual handling
(6) More use of GPS info. A separate GPS readout of speed (GS), altitude (true), and track, would have saved the day. I carried a handheld unit and it made me feel sooooo good. It was all I needed to land the thing if all was lost.

It's hard for me to accept the loss of a perfectly good airplane due to all of the above. Hope we all learn from it.

DozyWannabe

This statement:

and this one:

are logically incompatible with one another. Either you believe that the BEA are involved in an ongoing effort to shield Airbus from blame by fudging information or you don't. You cannot claim to be agnostic and hold the viewpoint in the first statement.

Don't you dare put words in my mouth - I "buy" nobody's "perfection". I just don't believe the BEA are any less independent than any other international accident investigation body you care to name.

@thermostat and Turbine D:

I'm happy to bow to those more knowledgeable, but I'm having a hard time reconciling the idea that the A320 had any specific "idiosyncrasies" regarding engine spool-up time that the crew would have been unaware of if the guidelines regarding spool-up time were known of in the B727 days.

The captain of AF296 was AF's second most experienced pilot on type - he was well aware that the aircraft would limit alpha-max if there was not sufficient airspeed to initiate a climb. I believe that he simply became so goal-focused on getting to 100ft at the runway threshold, that he didn't factor in the side-effect of expediting his descent (by throttling back to spool-down) to do so. "There but for the grace of God" is one thing, but to blame the aircraft for being inscrutable is a cop-out.

Clandestino

Since appointment of BEA as investigating authority for both Habsheim (which definitively is not another name for "Paris" or "Le Bourget") and AF447 disasters is perfectly IAW Annex 13, it is either completely normal or we are all doomed because ICAO is part of conspiracy to cover-up the fatal design flaws of FBW Airbi.



If your desire is to increase informational value of the thread, read and understand reports before posting something brutally at odds with them, without source of reason why you disagree. If you are participating in discussion for entertainment purposes only, keep up the good work.

According to DFDR readout, no penetration of storm cell occurred. Discussed to death but the notion keeps re-spawning.

jcjeant

Hi,

Something certain about the crash at Habsheim :
Both flight recorders (CVR and DFDR) disappear the evening of the event, transported by air by the Director of the DGAC Daniel TENENBAUM without any judicial seal there is affixed by the Prosecutor of Mulhouse, Jean WOLF.
It is therefore by an illegal act that begins the investigation
I am not surprised, therefore, of the controversy that followed and which is still not closed for some
BTW ... there is good reason for all the publicity that was made during the sealing of the black boxes of AF447 .. it was even filmed and shown to public

DozyWannabe

Or a mistake.

A lot of that "controversy" was manufactured by a private Swiss investigator who was paid to come to the conclusions he came to.

The BEA were so horrified by the accusations levelled at them that they (and the local gendarmerie) wouldn't touch the recorders from the subsequent Air Inter crash until the NTSB team that they had brought over were able to confirm that no tampering with the CVR and DFDR had occurred. The NTSB team were genuinely worried that the data would be lost due to remaining in the burning wreckage for so long.

jcjeant

Mistake or not .. it's illegal act .. turn it how you want !
What followed I don't bother anymore .. it's history ..

DozyWannabe

Maybe so, but the DGAC is *not* the BEA. What followed was an honest attempt on the BEA's part to prove to the doubters that whatever happened with the boxes from AF296 would not be repeated on their watch. The people who won't let the aftermath of AF296 go conveniently forget about those efforts, and do themselves no favours by doing so, because it doesn't suit their agenda.

KBPsen

Perhaps it was, but that was completely irrelevant to the investigation just as it is completely irrelevant to AF447.

Turn it how you want, it was said. Another oblique swipe at BEA seems to be the favoured direction

Mr Optimistic

And where exactly are we going now?

Linktrained

SAFETY FIRST issue 11 Jan 2011 page 8

Under STALL WARNING and STALL

A340-600 " performing a low altitude level flight deceleration at idle until SW is triggered and then push the THR levers to TOGA...

The thrust actually reaches TOGA (20 seconds later), the aircraft stalls ... "

Others may know whether this information is helpful - or relevant.

I had a new Captain nearly do this unintentionally with a very empty Britannia freighter, where the time would have been less but still seemed an age. It was night time... I learned from that example... I didn't copy !

jcjeant

BPBsen
Sorry for return on this subject .. but if this is not revelant to an investigation .. why the boxes must be sealed ?
What is the exact purpose of affixing seals ?

DozyWannabe

Round in the same old circles until new information comes out.

@jcj : The seal is for the judicial inquiry, not the accident investigation.

jcjeant

Thank you .. so it's a very important matter of the judicial inquiry ( Pièces a conviction - exhibits ) like a gun discovered on a crime scene ...

KBPsen

It is the usual attempts by the usual suspects to cast doubt on BEA's credibility with the usual Have-you-stopped-beating-your-wife type of questions.

A form of early insurance in case the contents of the final report is not liked, I suppose. Or perhaps just a case of disliking anything French and having a dig any which way.

jcjeant

Hi,

Voss Says Pilots Must Back Up Automation
http://www.ainonline.com/aviation-ne...ack-automation

thermostat

Clandestino. Have you heard the saying "Doctors differ, patients die" ?
I watched an informative video in 4 parts with a pilot. 2 investigators (one English and one American) and an expert in weather matters. They showed a segment on supercooled water and how it reacted when disturbed. This video was extremely well done and all the ppruners should watch it. My experience in aviation spans 32 years, and I do my own thinking thank you. Common sense mixed with experience on different jets allows me to draw my own conclusions.
It's very clear to me (as I have posted many times before) why the accident happened.

Turbine D

thermostat,

Do you really think they encountered supercooled water? Wouldn't ice crystals clogging the pitots be a more likely scenario? I think they finally saw what was ahead on the radar (somewhat late) and started to skirt around the worst of the CB. I am of the impression that CBs in the ITCZ are different than those over land in that the updrafts around the edges of the CBs are warmer (ocean warm water effect) and wouldn't produce supercooled water at the altitude they were cruising at. In fact, they couldn't climb because of the warmer temperature. Am I wrong here?