PPRuNe Forums - View Single Post - Jet goes down on its way to Medellin, Colombia
Old 1st Jan 2017, 04:48
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Passenger 389
 
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On 31st Dec 2016, 21:17, broadreach wrote:

Having just read the report - and seen the earlier PowerPoint presentation - I’m beginning to think the captain may actually have decided, when the engines began to quit, that they'd never make Rio Negro, that a crash was inevitable and that his only option was to drop all the anchors and do so at the slowest possible speed.
Respectfully, I'm unable to discern the basis for your conclusion, having carefully reviewed the detailed chronology in the Preliminary Report that combines FDR data (until it stopped recording) with the radio communications between LaMia 2933 and ATC.

Everything in that chronology seems to point to the opposite conclusion - that they "drop[ped] all the anchors" in an effort to descend rapidly to reach the glideslope (the one for 'powered' planes, not gliders).

The chronology indicates they set flaps 18, reduced thrust, extended speedbrakes, lowered the landing gear, then set flaps 24 and eventually 33.

All that was done before the FDR stopped recording, approximately 3 minutes prior to the crash, when it showed "a CAS of 115 kt, a ground speed of 142 kt and a pressure altitude of 15,934 ft msl."

And it was done at a time when they needed to maintain sufficient altitude to clear the mountains between them and the airport (or even to reach the flatter terrain beyond the mountains).

And most of it was done as they were requesting from ATC (or undertaking) an immediate descent toward the localiser and final approach.

Even while they were losing engine power -- and continuing after they lost engine power entirely -- they appeared to have been fixated on trying to reach the glideslope, and kept urgently requesting "vectors" to the runway.

11 seconds before the final recorded communication, they were still requesting "vectors."

Experienced pilots and/or accident investigators may see something I have overlooked. And the Report lacks (and will lack) the benefit of a CVR for the relevant time window.

However, I see nothing that suggests they were looking for a place to set the plane down short of the runway, and that is why they 'drop[ped] all the anchors' (as you put it.)

On the contrary, the timing seems all wrong for such a scenario. The "anchors" already had been dropped by then.

Last edited by Passenger 389; 1st Jan 2017 at 04:51. Reason: correct typos
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