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Yesterday I was watching a show about Air Crash Investigation, the Air France flight 447 case involving an Airbus A330-200.

I was watching it with Spanish voice dubbing and the weird part is that the narrator said the plane...

  • reached a final speed of 13,000 km/h
  • started falling at 7,000 km/h
  • crashed at 200 km/h

The only speed value that makes sense to me is the last one: 200 km/h.

My guess is that something was missed in translation. What is usually the speed measure for aircraft in the US?

I also thought about the 7,000 figure, and perhaps instead of speed in km/h it meant altitude in feet?

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  • $\begingroup$ This could be in reference to vertical feet per minute that the aircraft was falling. $\endgroup$ – Dave Oct 20 '15 at 16:45
  • $\begingroup$ you mean vertical speed of 13,000 feet per min? $\endgroup$ – Juan Carlos Oropeza Oct 20 '15 at 16:54
  • $\begingroup$ The last recorded vertical speed was 10912 ft/min = 199.6 km/h, so that matches the last value. Not sure what the others are referring to. Max altitude was 38,000 ft = 11582m, which doesn't quite match the first. $\endgroup$ – fooot Oct 20 '15 at 16:55
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I think there is some information lost in translation.

The speeds of 13000 kmph are associated with reentry vehicles. The aircraft won't have had time to accelerate to that speeds in the first place, even if there is no atmosphere.

The (forward) speed is usually measured in mph in US (to the best of my knowledge). The vertical speed is given usually in feet per minute. Note that the aircraft speed is usually given in knots (or its Mach number) by convention.

Now, the numbers you've quoted:

  • 7000 When the autopilot disconnected, the roll angle increased in two seconds from 0 to +8.4 degrees. In response, the Pilot Flying (PF) applied nose-up sidestick inputs, which the Investigation termed as abrupt and excessive. As a result, the aircraft started to climb at 7000 ft/min.

  • 200 The (vertical) speed at impact was around 108 knots (10,912 ft/m), which is around 200 kmph.

  • 13000 I'm not sure about this one. The maximum altitude reached was less than this value (~11500m actually), so doesn't make sense. The only thing that is related to this number for that flight was the depth at which the wreckage was found- 3,980 metres or 13,060 ft.

Note: Most of the data is from the Final accident report of Air France 447.

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  • $\begingroup$ Thanks your answer at least answer two of three. I will give some chance and maybe someone watch that episode too. $\endgroup$ – Juan Carlos Oropeza Oct 20 '15 at 17:36
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    $\begingroup$ I think I found it dailymotion.com/video/… at min 33:30-33:50 say falling at 12,000 feet per minute $\endgroup$ – Juan Carlos Oropeza Oct 20 '15 at 18:19

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