An Analysis of the Swissair Letter

Anything that can go wrong will go wrong

If everything seems to be going well, you have obviously overlooked something.

Subject: The KATZ Letter & the sr111 Update
Date: Mon, 28 Jun 1999 22:17:54 +0800




The first impression I get is that their PR Team has given the Board a "heads up" on the fact that the anniversary will be both a time of great emotion (and perhaps criticism) over the slow unraveling of the root causes of the disaster. Obviously this initiative is meant to both stave off criticism of Swissair and to reorient the emotions towards the memorial as a commemorative event. The more sombre, ceremonial and sanctimonious they are about the memorial events, the more that criticism will be deflected from the airline (in their view). It's one of those "we're all in this together" style of approaches (e.g. "we remain true to...."). I think that they are probably right. It will be a media feast and probably more than one book will hit the news-stands. However Swissair will "never enter into speculation of any kind". But they will be sending you "The Update" every few weeks.
It's a move designed to convey a sense of ongoing commitment and I suppose you'd have to say that it's a rational move on their part.

The Update
"......and Swissair has no free access to the information involved." The fact that they have their own specialists on the ground in Shearwater would indicate to me that they are as close to the investigation as anyone could be.
"internal investigations are being conducted at Swissair and Boeing" This could be anything from component teardown to an examination of CRM training techniques.

Examination of the Wiring
"Strong indications....." This paragraph reveals very little beyond the fact that, as everyone knows, electrical glitches that progress beyond simple component or system failure are very difficult, if not impossible, to analyse - either at the time or later.
"This means that the number of possible sources of any electrical malfunction is correspondingly large". I cannot resist saying here that while everyone concedes that an electrical short, fire, smoke, arc, flashover (let's call it an event) can happen anywhere in a system, no one is taking it that logical step further and saying: "That indicates to me that we're going to have to look at the whole question of wiring in aircraft. Beyond the question of the vulnerability of certain types of wiring insulation, there's the question of routing of system wiring and the loss of redundancy caused by bundling wires together" The latest FACT that has been uncovered is that there is one focal duct in the cabin/cockpit bulkhead through which all wiring must pass. Obviously any fire there (as in sr111) would have to have a catastrophic effect on aircraft systems. I think that Swissair is preparing itself publicly for these sorts of revelations, ones that bring into question the fundamental airworthiness of the MD-11

The Insulating Thermal/Acoustic Blankets
The Swissair exculpation has always been that HB-IWF had its heavy maintenance about two months before the McDonnell Douglas SB came out advocating that the blankets be replaced. However I believe that two types were found in the sr111 debris so perhaps this was partly underway. The catharsis for this as an issue was the FAA mandating their replacement, but I don't think that an absolute time-limit was specified. It has been conceded that the blankets are flammable but not that they caused/were involved in the sr111 fire. More significant is the fact that the FAA was forced eventually to accept that the flammability test itself was flawed. If they were forced into the same corner on wiring insulation tests then that would indeed be something.

Power Supplies for the Flight Data Recorder and CVR
In a way this has also become a bit of a red herring (like oxygen generators aboard VJ592). At the end of the day you have to belabour the odd point in an accident investigation report. You want to be able to do that:
a. Because you can't not say anything about a whole range of things you'd rather not alarm the public about and
b. Having a few fairly innocuous and believable focal points tends to concentrate the public's mind more.
c. If those focal points are (let's say) chafed wiring from R1 & L1 doors, a faultily-wired IFEN system and a poorly configured elec supply for the black boxes, well that's enough but they could throw in also that the blankets had to be changed because they fail the "more stringent" new series of tests.
Now this would be easily handled by both the NTSB and FAA because there's no focus on wiring insulation or any other potentially disruptive issues. They simply fine the IFEN installers, put it down to faulty wiring installation practices and everyone gets on with their lives. It becomes a historical "once off".

Examination Of Cockpit Procedures
"Checklists tell pilots exactly what to do in various inflight situations. Emergencies are dealt with using a series of special emergency checklists which are designed to ensure that the crew continues to work as effectively as possible, even in situations of extreme stress and pressure of time". Well, three observations here:
a. I guess Mr Katz's view is typical of a perception that most airline executives have of their crews - automatons marching to the beat of a checklist. Most airline execs don't really want to become involved in the nitty-gritty of operations. They have Ops, Training, Simulator and Standards Staff who can do that.
b. He concedes that pressure of time, extreme stress and working effectively are all considerations in possible outcomes. So too is cost-cutting, design deficiencies and poorly designed checklists.
c. When you design an operating system you should examine it closely for weak points and then redesign to eliminate those. The MD-11 never incorporated any re-design following on from a human factors evaluation. Once the pilots were committed to their course of action by the aircraft design (the checklist, the SEAsw and lack of a third man) they were also destined to die in their seats. Each confounding but inexorable development in the sr111 emergency was followed by another, even more perplexing and insoluble. It was quite apparently an escalating scenario that could only have been resolved by an escape system. In the military they have ejection seats. In an airliner it's called redundancy. The sr111 crew didn't have that option. There was no redundancy handle for them to pull in order to short-circuit the culmination of succesive systems failures. Simply
put, the power stayed on the wires and, not surprisingly, the fire worsened.

Outlook
This is quite a bland lapse into officialese that essentially says: "We've told you all we know and it's really out of our hands".
However unspoken in the statement: "Any technical or other improvements that emerge from the investigation will be implemented immediately"........is the obligatory rider "...that the FAA endorses and approves". Obviously there will be no unilateral Swissair incorporation of modifications or revision of procedures. And I'm also not sure that, in the absence of any FAA Directive, that they'd know just how to go about that. In fact they'd probably have to put new internal procedures in place.

It is a suitably pitched monograph, full of bewilderment and sympathy with a sprinkling of self-pity. You could almost believe that Swissair doesn't know why it should have happened to them. I hope that that is not genuinely the case.

regards
                                                               If you can't understand it, it is intuitively obvious.
IASA Australasia

sr111update3.jpg (50764 bytes)

Nature always sides with the hidden flaw.

If you perceive that there are four possible ways in which a procedure can go wrong, and circumvent these, then a fifth way, unprepared for, will promptly

Left to themselves, things tend to go from bad to worse.