What can you say about an accident like this?

Not a lot.

It’s a tragedy on a scale Western Europe hasn’t seen for years. It was the sort of accident we thought we’d seen the last of in this part of the world.

But Boeing MD-80 series aircraft crashed fatally twice last year: once in September at Phuket killing 90 people, and the other at Isparta, Turkey in November killing 56.

Among aircraft of its design period it has a safety record which does not differ significantly from its peer airliners, but there is no doubt that it cannot match the safety record of the succeeding generations of narrobody, notably the Airbus A320 series and the Next Generation Boeing 737 series. Aircraft and flightdeck design have moved on, and the MD-80 series and its successor - the MD-90 later designated the Boeing 717 – have been out of production since 2006. The aircraft that crashed had been in service 15 years – not a long time for a jet airliner.

Referring to this accident, it occurred in daylight and good weather. The aeroplane was full or nearly so, and would have been heavy. Although that may turn out to have been a factor in the accident it would not have been the cause.

There is much talk of a No 1 (left) engine fire, but no official source has confirmed it. If a single engine power loss and engine fire were all that had occurred, the pilots would have been able to control the aircraft, so the investigators will be looking for more than that. They will also be looking for why the aircraft caught fire so fast and so completely that only a few passengers were able to survive.

If the flight data recorder and cockpit voice recorder have survived the fire, and yield good data, we will have information very soon. But the early information is likely only to be a series of facts. Using the data from the boxes, what happened in the accident is normally fairly easy to establish; why it happened will take longer.

Here is my video analysis of how the investigation such as this usually develops:

7 Responses to What can you say about an accident like this?

  1. Iliya Maximov 21 August, 2008 at 1:21 pm #

    It’s obvious that engine failure is not the direct cause for the crash. It would be interesting to me what are your guesses about the cause on prima vista. Do you think that a stall followed by a roll to the right could be a possibility?

  2. David Learmount 21 August, 2008 at 1:35 pm #

    It’s always a risk wandering off down the road that leads to speculation. But if there was an engine failure, the risk of airspeed loss exists. If airspeed loss takes place just after take-off, a stall becomes a risk.

    But we don’t know any of this actually happened. We could play “what if” scenarios forever and a day, but it’s best to wait for a few facts first. The story about the engine failure/fire has not been confirmed by any official source yet. That doesn’t mean it didn’t happen, but we can’t assume it did until the data that proves it has been made available.

  3. David Nicholas 22 August, 2008 at 10:19 am #

    The fire theory is already becoming discredited, following security video film.
    I was thinking yesterday (the day after the accident) that we don’t hear much these days about density altitude. The airfield elevation is 610 metres above sea level (not far off 2000ft in old money), it was the heat of an August day (probably 33/34 degrees C) and with an anticyclone W of Spain a light northerly wind. Add to this a heavy aircraft and,as Iliya and DL agree, the performance margin becomes slender. We don’t know exactly what the temperature sensor defect was. If it was simply the outside air temperature sensor, then I would have thought there would have been more than one input, and perhaps more than one gauge. Whatever it was concerned the crew sufficiently to return to the stand, where the problem was not rectified. If this had been a problem with an Air Data Computer then perhaps we have the makings of an underlying problem with (on the ramp) only one symptom.
    This might prove to be a blind alley, but something led to sudden loss of control after V1 (do we know if the aircraft ever left the ground?), and in these hot and high conditions whatever margin of performance existed was insufficient.
    Much will be revealed by the CVR and data recordings, although how much will be published prior to the enquiry remains to be seen.

  4. nelson court 26 August, 2008 at 1:51 pm #

    If the engine failure was uncontained could it not be that the rudder and/or elevator controls were damaged and the pilots had no directional or pitch control? c

  5. Simon Rochester 28 August, 2008 at 2:37 am #

    One of the first things the investigators should find out is, what was the exact weight of te aircraft at the time it commenced its take off roll. Were they tankering fuel, with the average male passenger supposed to weigh 78 kgs, including 6 kgs of cabin baggage. My thinking is perhaps the aircraft may have been over weight. It will then NOT fly on one engine.

  6. David Nicholas 28 August, 2008 at 10:41 am #

    Simon, we will never know (exactly), which is one of the problems with average passenger and bag weights, but these are determined with a margin of safety in hand. However, it was hot and high and the stabiliser trim setting is based upon proper weight and balance procedures including any freight. Freight weights can sometimes be optimistic and are often declared by the shipping agent, with occasional check-weighing, so that might have been an issue affecting the trim. Fuel tankering (likely to be “up to mtow”) is another possible area. The heavy weight is not in doubt, but the aircraft may have been close to the trim limits at takeoff weight. Any MD80 load controllers out there?
    What exactly was the defect that caused the delay (some two hours I understand) during which time the temperature may have increased? Did the crew do their takeoff performance calculations again? Were the numbers correct to begin with (back to weight, balance and stabiliser trim)? Rotation at too slow a speed, or over-rotation followed by a low-speed stall would be a scenario fitting with the high-incidence, tail-first impacts after loss of control.
    This continues to be speculative, of course, but my feeling is that the underlying cause of this tragedy might eventually be found in this area…..

  7. Philip Hutchison 29 August, 2008 at 7:17 am #

    I live in Madrid and took off on a flight an hour before the accident. In our case we used almost the entire runway, rotating just before the zebra lines and would question if we would have been able to continue in the event of an engine failure. The temperature increases here at the rate of 2/3 degrees per hour during the day in summer, it would be interesting to know when they had carried out the payload calculations and if they had taken into consideration the temperature changes.