June 2009 Archives

The incident at Johannesburg last month in which a British Airways crew very nicely avoided a potentially catastrophic situation on take-off has resulted in an airworthiness directive on the Boeing 747-400.

The AD finally confirms precisely what happened. Prior to V1 a thrust-reverser amber warning was generated and a few seconds later, after V1, a second warning was received. (It's not specified, but I think the warnings must have been either both outboards or both inboards because of how the logic works.)

The flap control unit (FCU) is designed to to retract the [updated] inner and central leading-edge flaps when the reversers are deployed in order to avoid "impingement of efflux air" from the reversers (ie FOD damage). It worked as advertised, but of course the aircraft was taking off not landing and the warnings were spurious. Result: aircraft rotates (at hot 'n' high Jo'burg remember) with no only outboard leading-edge flaps. The AD confirms that the crew experienced pre-stall buffet and stick-shaker activation.

Once the aircraft lifted off, the air/ground logic system re-commanded extension of the L/E flaps after five seconds, and the deployment took 10-15 seconds during which there was more buffet and stick-shaker before it climbed away, and the crew dumped fuel before returning to land for tea and medals.

What the FAA's AD does is to mandate a Boeing service bulletin which has already been issued which "describes procedures for modifying certain thrust-reverser control system wiring to the FCU in the P414 and P415 panels. The modification includes re-routing and re-terminating one wire for each engine and replacing the wire if necessary."

It affects only aircraft with Rolls-Royce engines. Ho hum....

The FAA adds without comment: "In addition, one operator reported 12 single-engine REV indications during take-off over the past three years, leading to seven rejected take-offs. The incident described above was the first known simultaneous two-engine event."

Obviously nobody has any idea how the Yemenia Airbus A310 crashed at Moroni in the Comoros, but pilots familiar with the airport are cheerfuly admitting that it's a challenging place to go. In particular the approach to runway 20 at night, in poor weather, is not great - although obviously it doesn't in itself explain the accident.

Here are a couple of charts, the first showing the visual procedures just to help orient yourself, and the second showing the procedure for the 20. Given the strong south-westerly wind, gusting to 37kt, at the time there's not much doubt that it was in use. You can see the uncomfortable manoeuvre over the dark sea and potential use of land-based lights for visual guidance with all the known potential for disorientation that it brings. May turn out not to have anything to do with it of course.

France's transport minister Dominique Bussereau has said that there is talk of the flight having made one approach followed by a go-around and then the accident on a second approach. But he stressed that the information wasn't confirmed. Local reports talk of wreckage within eight miles of the coast.

Visual chart.

Runway 20 procedure.

Let me say first that I have no doubt that the floor in Lufthansa Technik's new Malta hangar is a truly fabulous example of its kind. And also that I do sympathise with poor Jane Shepherd whose job it is to create press releases on, well, floors. (Inasmuch as I ever sympathise with the PR industry, which is rarely.)

But in all forms of writing there is such a thing as knowing when to stop. Like before you write this sentence for example.

"The new development was officially inaugurated by Maltese Prime Minister Lawrence Gonzi, who walked all over Flowcrete's floor to applaud Lufthansa Technik for its investment towards achieving excellence in high value added manufacturing."

You remember the Air New Zealand body-paint ad based on the "nothing to hide" tagline - as opposed to low-cost carriers who hide extra fees in their booking conditions - well they've, er, extended the concept to the flight-safety announcement. (Once you start writing about risque stuff, everything sounds dodgy.)

Great videos.
More videos in the series, including bloopers, below. Great stuff.

Happily the February loss of a Bond Helicopters EC225 Super Puma in the North Sea was non-fatal, and now it turns out that luckily it was in benign conditions for the survivors. That's because of three serious and unsuspected phenomena that led to the search operation being much more difficult than you'd imagine in the circumstances. The AAIB reports on them today.

The helicopter, you may recall, descended fairly gently into the sea in darkness, visually observed by individuals on the rig to which it was heading. It floated and the 18 occupants quickly got into the liferafts. Between the aircraft, the liferafts and the individuals they had plenty of locator beacons. Nevertheless, it took a 27 minute search to find the survivors.

Here's why.

What if they put out a press release and nobody believed it? Slightly surreally the NTSB issued a press release last night giving brief details of two AF447-like incidents of which they've become aware, but because of how they did it some people are very sensibly questioning if it's real. Quite right too.

The problem is that although the press release was e-mailed via the NTSB's automatic notification system, it wasn't, and still hasn't been, placed on their website. So if you weren't on the e-mail address list then you had to rely on news reports for the information. And the news reports, as is sadly the way these days, carry no additional information or quotes from the NTSB confirming the authenticity. So given the reputation of the media, people are doubting the press release's provenance.

A couple of people are even saying the grammar is so lousy on the press release that it can't be authentic. A lovely thought, but it's hard to think of a public document that would survive that test in 2009. (AAIB report maybe??)

Anyway I've come in to find this situation this morning. I've got the release direct from the NTSB overnight myself in the usual way that I do and I'm happy that it's for real. (Though I confess I don't know that for a fact, so I'm adding to the problem.)

Below is the text, followed by the text of an informal document circulating on the internet via email and websites before the NTSB document emerged, and is purportedly from a pilot on the Northwest flight mentioned by the NTSB. There's no proof of its authenticity of which I'm aware, but please leave a comment if you can help with that.

The TAM incident is interesting in that the crew reported a sudden drop in outside air temperature rather than the real or indicated increase that has been associated with other incidents (such as Air Caraibes). The NWA incident recorded in the supposed pilot report includes an account of a sudden increase too.

The French BEA investigators have just announced that their next press conference will be in Paris at 15:00 local (13:00GMT  09:00EST) for up to two hours next Thursday 2 July. There is an entirely unconfirmed story around that the preliminary report will be issued next Tuesday 30 June.

A company in Lafayette, Louisiana called C&C Technologies has added some important detail to the way the black-box pinger behaves at the end of its battery life, but more importantly it describes the unmanned submarine that it may use to help the search for the FDR/CVR and sunk debris. C&C say they've already been contacted by the investigators to that effect.

The first key fact, which addresses something I've been wondering about, is that once the 30-day specified duration of the pinger is reached, it's expected to die very quickly. It's a feature of the lithium batteries used. That's in a week's time.

The submarine (or autonomous underwater vehicle - AUV) it turns out is a pretty capable beast. It's untethered, has sonar and camera, and an acoustic link to transmit the sonar and video images to the surface in realtime. Crucially, the most advanced version is rated to 4,500m (15,000ft) depth which is what we're potentially talking about in the crash area. (Earlier ones to 3,000m)

Full details and pictures below.

French newspaper Le Monde this morning reported that the pinger from one of the AF447 flight recorders may have been found, but the report has just been denied by the commander on the scene interviewed by French radio station Europe 1.

English translation of the Europe 1 report follows: The black boxes of the Airbus A330 that crashed at sea on 1 June have still not been located. Contacted by Europe 1 Tuesday morning, Philippe Guillemet, the commander of the ship "Pourquoi Pas?" in the search area has categorically denied the information published earlier by The Monde.fr that the signal box Black was found.

To the question "Very clearly, you have not spotted any of the black boxes?" Guillemet commander replied: "Absolutely. What we have read in Le Monde, I regret that this is not correct. I shall not validate any of this information, I do not know where it comes from. It is still under investigation."

"A signlal was received but nothing is confirmed unfortunately. We receive signals nearly every day and afterwards they must be considered. That is a false information that is passed. "

A document that appears to be a detailed Air France briefing to its pilot workforce from four days ago (ie just after the BEA press conference last week) has turned up. Seems pretty clear that it's genuine.

You can see the original in French here, or the same thing here where it was originally posted. And read on for a translation into English.

It was pretty obvious from soon after the BA038 accident at Heathrow 18 months ago that the investigation was going to be long and difficult. But I think what's become even more obvious is that the whole question of fuel-icing is a lurking beast that is not easily going to go away.

The UK AAIB and NTSB (because of the Delta Air Lines incident that may or may not be linked) have already recommended that EASA and the FAA conduct a much wider investigation of fuel-icing.

Before returning to London after the Paris Airshow this week I was lucky enough to be invited to visit a place where they know a great deal about this sort of thing, and also know what they don't know. What's interesting is that they think that understanding the issue better is going to be tough.

In about an hour and a half France's BEA is due to hold a briefing on what it's found so far in the AF447 investigation. Ironically it's being held at their HQ which is just down the road from the Paris Airshow here at Le Bourget where Airbus, Thales and just about vendor with systems on the A330 are camped out in force. Plus practically the entire world's aerospace media. Whatever else, there's no excuse for the event not being properly reported.

I rather wonder what they will be able to usefully say. Hard to see what else can be known by now, apart perhaps from knocking down the last lingering possibility of a bomb.

Meanwhile, a useful EASA briefing document has surfaced, after a surprisingly long time actually, explaining nicely what pitot icing is all about and the sort of thing that has happened in the past. Courtesy of this Pprune member. I encourage you to take a quick look.

Imagine being caressed by the hands of the first officer in this video (easy gentlemen, I mean if you were an aeroplane.) I'm really, truly not being sexist here. If you're a QFI trying to explain to your early-hours students how to handle an aeroplane, just drop the patter and show them this movie. There is a moment at just about 2:52 when the hairs stood up on the back of my neck watching that left hand.

So, on to Hyeres and the navy. We're promised two CN235 flights during the tour and one C-130H. I'm absolutely gutted that what is probably my last chance to fly in a C-160 Transall is not going to happen. There's even one on the tarmac at Hyeres when we arrive to taunt me.

Tomorrow morning I'm off to the Paris Airshow where I may or may not have a good time. But I doubt I'll have as good as a time as I just did in France when I was on the end of the full fiery breath of France Inc's marketing machine in all its glory.

Like other nations, France has a plan to look after its key industries for the duration of the current crisis, and normal rules are pretty much suspended. And so I, and a large group of competitors, found ourselves on a seriously full-on tour of everything that is rotary in the French military and paramilitary over three days.

Here's a quick run-through of how it went. I've written about it some of it here and here already, and we're publishing more of that kind of thing during the show.

Adding to the evidence of earlier failures is this Air France memo to its pilots from last November. It's in French but it warns of a significant number of similar incidents involving unreliable airspeed indications. It cautions pilots to be vigilant in conditions involving "high altitude, icing, turbulence" and and urges them to try to avoid being surprised and to fly gently if they end up in manual control.

Meanwhile French TV station TF1 has found an Air France mechanic who talks on air about the history of events, also in French. They've come up with some documents relating earlier incidents which you can see parts of below.

United, which took most people by surprise last week when CEO Glenn Tilton revealed that it was shaping up for a big aircraft buy, also made clear that it won't be taking A380s or 747s. No real surprise there of course.

Anyway, meanwhile it's putting lie-flat seats and some decent IFE in its remaining widebodies, including the 747 in the timelapse movie below. Gershwin fans should turn up the volume.

This post is mainly about A330 pitot tubes and in particular the educational story of two nasty icing incidents at A330-operator Air Caraibes which I relate below. There's no getting round the fact that the pitot issue has to be a major focus of the investigation until proven otherwise - but I would say now that in the long term it may not be the primary issue. That, I suspect, is more likely to be the question of how this aircraft came to be in the middle of a storm in the first place. We shall see.

Anyway, meanwhile back to pitot tubes, which it's now reported that Air France is going to replace within days rather than weeks following pressure from its pilots' unions SNPL and the much smaller ALTER. Seems there may be EASA action too.

Sources in the unions are putting it about that there have been quite a few pitot icing incidents on A330s, which I don't think is disputed by anyone. And it turns out that two of them, in August and September last year, are unusually well documented.

Not exactly the kind of headline to grab the reader's attention I realise but must come as a huge relief to the poor battered folks at Alitalia to be able to put out this kind of thing, complete with a pic of a Boeing 767 with Skyteam branding. But no winglets!!!!

A lot of information, and some terrific analysis, has turned up overnight after French television station France2  produced the ACARS messages from the last minutes of the flight of the A330. The data was clear on screen and has since been reproduced here and analysed by some very knowledgeable people on Pprune, here for example, but also here and here.

At the same time, Airbus has come out with its guidance to operators, which is substantially based on the ACARS messages.

About 19s I reckon. (The link below no longer works, but you can see it here.)
 

Easy to say with the benefit of hindsight I know but, really, even so..

Compare with this for example.

France's BEA has said what it so far has to say about AF447 and has probably wisely not taken the discussion much further forward. Agency head is Paul-Louis Arslanian, who's going to be a pretty busy guy as he's still in charge of the ANZ A320 investigation, and he's once again being exceptionally open about what's going on. Today's press conference was lengthy and conducted in both French and English.

Some points. Obviously an exceptionally difficult investigation lies ahead but the ramifications of an unsolved mystery are pretty horrendous for Airbus and I have little doubt that France Inc will move heaven and earth to pin down the cause.

And what might that be? Well, as I've been saying on umpteen TV and radio shows all week, we really don't know if weather caused this.

Personally I don't think it can have been the primary cause, but it will be a surprise if it's not a factor of course.

Meanwhile I'm curious about this airworthiness directive which mandated operators to insert information in the A330 flight manual about what to do if you suffer double pitot tube heat failure (or radome failure - and in fact unreliable airspeed indications for any reason.) It was issued after several reports of aircraft suffering exactly that situation in heavy icing.

Here's what is claimed, plausibly I think, to be a report of what was experienced on one A330 when exactly that happened. Not a happy situation.

And here's French magazine Le Point, which has been doing a good job on this story, citing Air France sources as saying AF447 did in fact experience icing on the probes. As many of you will have seen, here's a superb analysis of the weather at the time by one Tim Vasquez, who's new to me but maybe not to you.

I'm frankly surprised to hear of that problem affecting a current generation widebody, but that's aviation I suppose. If you can shed light on this issue then please leave a comment.

Finally I think Arslanian was fairly deliberately playing down the chances of finding the recorders and/or substantial wreckage. In fact the precedents are pretty good - you have to look hard for instances in which recorders are not found, even in oceanic water. 

Examples:

• South African Airways Boeing 747 Combi 'Helderberg' lost in deep water in 1987. CVR found, although not FDR, after a markedly less than perfect salvage operation.
• Birgenair Boeing 757 FDR found by US Navy in 7,000ft of water
• TW800 - OK, not deep, but big wreckage field and the pinger had broken off the FDR
  
• China Airlines 747 in 2002 - both found
• TransAsia ATR 72 in 2002 - both found ...and there are others.

I realise this water is very deep indeed, but technology has moved on quite a bit since some of those earlier ones. And I don't think money will be an object.