View Single Post
  #36  
Old September 10th 09, 10:29 PM posted to rec.aviation.piloting
Flaps_50!
external usenet poster
 
Posts: 117
Default Twin take off on one engine?

On Sep 11, 1:02*am, "Peter Dohm" wrote:
"Clark" wrote in message

...



"Flaps_50!" wrote in news:2ce85d20-5c84-4425-a1bf-
:


On Sep 4, 8:47 am, Clark wrote:
"Flaps_50!" wrote in news:d7b4faf4-4167-46cd-8692-
:


According to the data I can find, the 747 can't climb on one engine so
how can it take off?
Cheers


Hmmm, empty weight is about 360,000 lbs plus a little fuel and 50,000
lbs
*of
thrust. It aught to work. I suspect your data are in error or perhaps
you
're
considering a loaded 747.


It comes from the certification requirements of a commercial 747
climbing on 3 engines. The excess thrust is calculated from the rate
of climb in that condition and knowing that 1 HP is 33,000 ft lbs /
rminute. Perhaps my math is wrong but I don't calculate an excess
thrust of 120,000 lbs... What do you get?


Cheers


What I get is that I suspect your numbers are at gross weight. I suggest
looking at the problem as stated rather than making up your own
conditions.


--
---
there should be a "sig" here


What I get is the latest successfull troll: *please ignore him.


I see, discussion using physics and aeronautics about real aircraft
performance is a troll to you. You clearly prefer BS.
The 747 figures I used: empty weight 403,000 #, MTOW 870,000 #.
Minimum fuel 70,000 #, thrust available 60,000 #. That gave me TOW of
473,000 # which is quite a bit more than Clark 'estimated' so the drag
would be proportionally higher. In the absence of any ref to the
claimed actual takeoff on one engine, it sounds like urban piloting
myth.