Re: Air Brakes?(Fokker-100 crash in Brazil)

Date:         10 Nov 96 05:29:12 
From:         Stephan Stephany <stephan@lac.inpe.br>
Organization: INPE
References:   1
Followups:    1
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Mark A. C. Wilson wrote:
>
> I would like some information about the probability of a cellular or any
> kind of transmitter being able to mess up the air brake system of a Fokker
> 100. I am a High School student taking flying lessons, and heard about the
> accident down in Brazil last Thursday, October 31st, where this Aircraft
> fell into a residential neighborhood after take off due to a passanger's
> cellular phone. The phone (somehow) opened the air brakes and reversed the
> troutle of the right engine, slaming the aircraft into a residential
> building couple minutes after takeoff. The pilot of the aircraft behind...
> claims to have seen the right air brake open couple times during takeoff.

The deployment of the right reverser was seen by an aircraft mechanic
(used to perform maintenance in Learjets). He said to the officials
that the right reverser opened during take-off and closed and opened
again a couple of times and tried to call the control tower. Nobody
knows if something else happened (spoiler deployment or some problem
with flaps).

The plane took-off, but couldn't climb above 100ft, stalled and crashed
over houses after hitting a three store building with the wing. Most
passenger were found as expecting an emergency landing and most of
them probably died due to the fire. The plane was at least at 100 knts
(take off is at something like 130-150 knts, I don't know exactly).

The throtle of the right engine was cut because this is a "standard"
(if we could say such a problem is standard) procedureif an accidental
deployment happens.

The Fokker 100 belonged to TAM, an airline with a very good safety
record (until last Thursday), but currently growing very fast. The
crashed plane was painted as "number one" (due to the award given to
TAM as world best commuter airline - or something). As far as I know,
TAM had only one plane crashed before: it was a Fokker 27 that tried
a touch and go (after the crew realized the plane was too fast to
stop) and stalled over a car, nobody on board was killed, but two
persons died in the car and the plane was a total loss).

Concerning the crashed Fokker 100, it was the "flagship", painted as
I said as "number one" (due to that award that TAM won) and the pilot
had 12,000 hs of flight (almost 10,000 flying TAM planes). The 1st.
officer had 3 or 4,000 hs. The TAM fleet of Fokker 100 was mostly
purchased in 1993 and I never heard here in Brazil of maintenance
problems.

The plane reached only 90 ft and there was little the pilot could do.
It was amazing that only 3 or 4 people was killed on ground. The plane
missed a school with hundreds of kids. Some people say the pilot
intentionally cleared the school, but nobody knows if he had time to
realize it after the 1 mile "flight". The 95 people on board died
(crew of 6 plus 89 passengers).

I'm not an expert, but I don't believe it was something like the
problem that downed the Lauda-Air 767 few years ago (it was some sort
of software error that attempted to close a closed hydraulic valve or
so and opened it?). I thing there was many reports of incidents
realted to accidental deployment of the thrust reversers concerning
Boeing airplanes, but I believe that never happened with Fokker-100's
(please, I'm *not* saying Fokker is better or not...). For sure the
F-100 is not fly-by-wire and is less complex than a 767. A faulty
design is maybe unlikely. Perhaps a maintenance mistake (TAM was
growing very fast and under these conditions sometimes safety
standards go down) Some people even think on sabotage (TAM was
conquering the commuter/regional market and indeed is strange that this
happened with the "number one" airplane over S. Paulo and in a flight
full of high officials of several companies (that flight, the  402 was
inbound to Rio de Janeiro, as part of a "shuttle" service between the
two largest Brazilian cities). Who knows? It was quite sad for
everybody.

Concerning celular phones (again, I'm not an expert, just Cessnas and
Pipers amateur driver) I don't believe it. There was confirmed reports
of illegal FM broadcasting (we call pirate radios, they broadcast
without licence and use equipment that do not comply the standards)
interfering in the ILS of planes landing in Congonhas, but just a few
and without any consequences. Of course the press is saying that, but
without any "solid" assumption to support it.

Due to this crash, FAA already requested an inspection on all American
fleet of F-100 (it's only American Airlines that have F-100's?).

Anyone has news on this subject? There is a board of DAC officials (our
FAA - actually DAC belongs to the mi litary), plus Rolls-Royce, Fokker
and FAA/NTSB experts working on that. The records on the voice-recorder
are being analysed, but contain things like "pull, pull,..." and nothing
could be concluded until now. The FDR was shipped to the USA/NTSB
because it was badly damaged by the fire.

It's too early to know for sure what happened, but the accidental
deployment of (at least) the thrust reverser is a strong hipothesis.

Stephan Stephany
stephan@lac.inpe.br
(National Institute for Space Research, Brazil)