Responses to Original Swissair Accident Article


Don Ames Responded

There have been 3 major accidents in recent years which have been at least partially attributable to high tech systems and a lack of basic manual back up capabilities.( South America-757, Florida-DC-9 and Canada-MD-11) It appears that the aviation industry has come to rely too much on digital electronic instrument and flight control systems; and with insufficient thought given to how to quickly evacuate smoke from modern pressurized aircraft with a MANUAL system (whilst remaining pressurized).

We need to be sure all aircraft, and especially airliners, have a capability to:

1.  Manually operate pressurization and outflow valves to quickly evacuate smoke that is in the cockpit and/or cabin

2.  Be flown on instruments and communicate and navigate on battery powered emergency equipment

3.  Be flown with all other electrical power disconnected

Additionally, aircrews need to be proficient in operating the aircraft on their back-up systems.

Attention given to these areas should save a lot of lives.

Don Ames


        Comment (by IASA Safety)

  1. It would be nice to be able to remain pressurized and early on commence exhausting the smoke (or at least curtail its build-up). Present practice has crews making a rapid descent to 10,000 feet before depressurizing, however little adverse effect would be felt by most passengers if, in an emergency, the cabin was allowed to rise to 15,000 feet for a short period as crews dumped cabin pressure early. There may be a little discomfort and passenger concern. The need to depressurize is also related to the possibility that smoke in the cockpit may be from engine driven compressors (EDC’s) through the aircon. The requirement to dump fuel can, in some aircraft, be in conflict with the configuration for rapid or emergency descent. In some aircraft there are strict boundaries on  speed and configuration for fuel dump, particularly for rear-engined aircraft. The need for a manual outflow valve and ram air vent goes without saying.
                                                              The Virgin Bus
  2. An entirely separate (virgin) electrical system containing the rudimentals for IFR flight in IMC should be selectable. The ability to immediately select such a system, fundamental though it may be, is infinitely preferable to the contrasting, existing, interminable checklisting situation. At present crews have to allow any electrical fire to continue and develop whilst they trouble-shoot it and the situation worsens. The fact that it can rapidly deteriorate and compound was shown graphically by the Swissair accident. Fire-in-the-air stories abound as does the fact that in many cases crews survived by the narrowest of margins. If you look around you, at the fire notices in whatever building you happen to be in now, you will notice that the overpowering imperative in case of fire is to alert everyone and evacuate. There are many instances of what panicking passengers will achieve if alerted, at best distracting trim changes – at worst total pandemonium. And, of course, evacuation isn’t an option. The only way to sensibly combat electrical fires airborne is to immediately inert the normal electrical system and fall back on manually deployable air-driven generators or ram-air turbines. These will maintain charge to batteries that are powering inverters (for three-phase and single phase AC requirements) and DC instrumentation (required flight and engine instruments and avionics only – no weather radar, FADEC, EICAS etc). Such a package may add 800 kgs to the average long-haul RPT airliner’s zero fuel weight but that is a small price to pay for passenger security and confidence. Crews would also be relieved of the concern that, unlike the travelling public, their exposure to the fire risk is every day of their working lives. If the bean-counters throw up their arms aghast at how much this modification would cost in the airliner of the future I urge them to consider the following points:

    3.    What we should see as a result of the Swissair accident may well be somewhat cathartic for the industry, but it will be necessary as a result of Valujet 592, TWA800, sr111, Silkair (and all the non-notorious others) superimposed upon the outcome of whatever is to be the next latest tragic accident. Whether we will see it in the report is the question.   But because Swissair has such abiding respect within the industry and the Swiss have always been prime instigators of ab initio technology I think you can expect to see the first developments from that neck of the woods. To paraphrase Neville Shute: "There is no byway in that highway called the sky."


hylander Responded (to the original article)

A very good article with many good suggestions for

future design progress. I hope the authorities read this.


R. Jollis Responded (to the original article)

John Sampson's article, "Swissair Flight 111, The

Accident that redefined CRM" is right on!

As long as the FAA and it's constituency, the airline

and aircraft industries, continue to measure safety in

terms of financial Return On Investment, we can expect to see more air

disasters like sr111 and TWA800. Better CRM

procedures and training can only marginally improve

our chances of survival. For a brutally straight

forward insider's look, read former US DOT

inspector general, Mary Schiavo's book, "Flying Blind,

Flying Safe"

R. Jollis

Manage Your Outcomes

Comment (by JRS): I’m not a visionary but when it comes to applying my imagination to what happened in the Swissair accident I have no trouble conjuring up two entirely separate theories:- of what did transpire - and what might have been  (in different circumstances). In the first instance I see the innocent low-key beginning of the happenstance, the advice to ATC and cabin crew, the follow-up R/T, the descent checklist and then its rapid escalation through donning of masks and goggles and serious checklisting. Then come the profoundly disturbing staccato images – an atmosphere of great urgency (anxiety, concern but no fear), awareness of the deteriorating environment and restricted peripheral vision, unexpected autopilot disconnect, frustration about having to wait until over-water before commencing the dump, denser smoke, upgrading the emergency, deploying the ADG, fuel starvation flame-out of number two tail engine with many resulting warnings and cautions, sudden cockpit darkness, CRT's blank out, floodlight reflections, misting goggles, instrument power failures and an alarming realization that your partial panel attitude-flying instrument scan and control inputs are very haphazard -even chaotic, eyes streaming with tears, the annoying ceaseless audio of uncancelled system alerts and warblers, intercom and R/T mistakes and confusion, ATC distractions, EICAS announcements, unanswered cabin staff queries, a pervasive and growing feeling of consummate helplessness, breathing and vision difficulties; a Flight Attendant invades the cockpit, evidently distraught - then disappears, total uncertainty as to where the checklist is at. Then, as a vaguely discerned finale ..... seeing the collapse of the other pilot with no-one to help, a feeling of immense solitude, the agony of hot molten plastic dripping from above, difficulty in concentrating, total loss of attitude and altitude awareness and eventually, on the threshold of unconsciousness, the sensation and increased noise levels as the aircraft is accelerating under g and entering its terminal unusual attitude - but peaceably, a final ethereal dissociation from recovery (as a task) because of the mental detachment that stems from the asphyxiating ingestion of toxic smoke. A last poignantly dutiful but pointless pull on the control column as the MD11 tightens into its final graveyard spiral into the waters off the cove. Declaration of a final Mayday and any thought of external succour is totally irrelevant to such a scenario. No apologies for graphic depictions, you’ve got to see the word-picture distinctions I’ll now try to make.

In my second apparition I see a three man crew undergoing the same initial conspiracy of circumstance. In this scene the smoke detector alerts them and the captain declares: "activate the smoke checklist". After the (memory recall items), immediate action preliminaries of full-face masks, ATC and cabin staff alerting, the next step is dependent upon captain’s discretion. However, as with the Swissair instance, visible confirmatory smoke and fumes are evident and this is where the outcomes based approach makes the difference: the Captain orders "select the Flight Essential Bus, you have control". "Deploy the EVAS" (i.e. the inflated plastic aid to instrument vision). They feel a thump as the ADG slips down and locks into place in the slipstream and a charging light illuminates on the CIWS. The first officer is now responsible for ATC comms and flying the aircraft – nothing else, so he begins a gradual descent as per his edicts to ATC. He’s declared a Pan, he’s squawking emergency and he automatically has priority, so ATC must divert other traffic and clear levels below him. It’s called "take control of your destiny", it’s not an apologetic approach. It's no longer the polite "request" - it's "require". The aircraft is now on its "virgin" bus, previously isolated from the normal electrical system and presumably having 100% integrity because of that. The captain and the flight engineer commence the challenge/reply portion of the checklist actions. It is evident that despite his killing the normal electrics, the smoke build-up is continuing, that there is a self-sustaining conflagration behind one of the overhead panels. He orders: "Call Mayday, Hold 230 knots, commence fuel dumping to 50 kilo and Inert the flight deck". The FE pulls a lanyard on the bulkhead-mounted nitrogen canister and grabs the foam extinguisher from its bracket. The FE, in anticipation, has already (per the checklist) shut off both EDC’s so that there is no inflow to the cockpit but he doesn’t open the outflow valve – so there is only a gradual depressurization. The flight deck door is already closed so, for their purposes, the cockpit is hermetically sealed and the flame-retardant nitrogen-rich atmosphere dampens the fire. In the absence of oxygen, and with no stoking electrics, no materials fire can take hold. The FE then sprays the adhesively congealing and sealing foam spray onto the overhead panel and the smoke emanations cease. It is now up to the captain. After a pause, he considers the danger is past and orders: "Depressurize and vent smoke, continue with the smoke elimination checklist". Flight is continued, masks off, to their divert field in their significantly reduced (but not crippled) configuration. They have no weather radar, airframe or engine anti-ice but at the lower altitudes they’re not likely to need it. Flight instruments, hydraulics, avionics and comms are sufficient for recovery. There is no point in further tempting fate and trouble-shooting as the Nitrogen and foam operation was a one-shot affair. A two-man band working fate or a three-man consortium with a game-plan? Given the alarming scope and urgency of the task, vive le difference.

It is possible with today’s technology to change the outcome of the in-fuselage fire-in-the-air challenge. To date it’s been a mish-mash apathetic and disorganized approach to resolving an unidentified issue. I’m advocating both a CRM and multi-disciplinary, technical, take-charge/outcomes-based methodology. I readily concede that there are more forms of inflight fire than one confined to the cockpit or electrically initiated. However, if the cargo despatchers and security are doing their jobs we are probably talking about the worst case scenario here. Cabin fires outside the cockpit ( or wing events for that matter) make it more important that there is a third man with the technical know-how to go aft, look into it and keep the captain properly informed.

However there’s a lot of inertia out there. Many CEO’s just have their fingers crossed that the Swissair report will be couched in terms that enables it to be dismissed (like Valujet, TWA800,Silkair, ...) as just another "one off".... but casualty figures will probably  mount as jets get older and electrics continue to be the silent servant but also tragically, sometimes, the swift unseen suffocating savage.

If you feel that there is something missing from this argument (or have something to add) please feel free to comment.

Gordon Donaldson Responded (to the original article)

This is an outstanding article. The author's

experience and passion for the subject come through

in his writing. He brings up a very important

question: Have we gone too far in assuming we can

replace a third aircrew member with electronics?

Gordon Donaldson

Peter P. Goldstern Responded:

Very thought provoking. Using the FE position as a pilot

training function sounds sensible but the chances are

that the unions would find a reason to object. There is

however the option of letting the customer decide.

Advertise your flights as 2 or 3 crew flights and set the

fares accordingly. If the customer would rather fly for

less with more risk, the decision is his?

Peter P. Goldstern

If anything simply cannot go wrong, it will anyway

Original responses   

Nothing is as easy as it looks.

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