15 June 2015

This is Not as Impressive as it looks

Boeing has released a video of the Paris Air Show routine intended for its 787-9.  (Facebook followers, click through to see it)

It is pretty impressive, but it is not as impressive as it appears:

First, it's not climbing vertically. That is a function of camera angle and a long lens which creates a forced perspective that makes it look that way.

Also, the pilot is keeping the aircraft on the runway longer than is normal for the pull-up.

First, some facts:
  • The 787-9 has an MTOW of 557,000 lb, and a operating empty weight of about 304,000 pounds. (Probably less, because they probably haven't installed the passenger seats, etc. to make the aircraft handle more spiritedly.)
  • It has about 142,000 lbs of installed thrust, and at sea level and the engines specific fuel consumption is somewhere in the 0.3 lbs fuel/hr-lbs thrust.
For the airshow display, the aircraft will have 2-4 crewmen and perhaps about an hour's worth of fuel, which means that it has a weight of about 350,000 lbs, and a thrust to weight ratio of 0.4:1, which is similar to that of a fully loaded F-4 Phantom on taking off.

I would also note that for this flight, the fuel is almost certainly not in the wing tanks, to keep down the rotational inertia so that it can roll more aggressively.

Still, I wish I were in Paris to see it.

Hell, I wish that I was in Paris right now.

H/T Firedoglake.


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