Simviation Forums

.........tried simulating the BA biff at Heathrow? I got past the perimeter fence just once out of five attempts. I think they were incredibly lucky!!

I tried both with engines at no power and idle thrust. It certainly doesn't seem possible with zero power and just possible with idle JUST!!!
Vololiberista

Try adjusting your fuel load, the 777 would have been at a fairly light weight (for a heavy) while doing an approach to EGLL from Hong Kong due to fuel use.

Not yet.. but it does bring up some questions..

Last report I heard was 2 miles out at 600agl...

That's an 18:1 glide ratio... so I'm guessing that whatever power setting they were at before not being able to increase it again..  was a good bit above idle. I know, just like flying a C172, every approach is different... but I'd imagine that on short final, they'd have been pretty darn close to idle.

What is a power off glide ratio for light-fuel / high-passenger load in a 777 ?  Maybe 7:1 ?

Something isn't adding up..   :-?

I'm not convinced that;

1. You have enough reliable information to attempt this.
2. The MSFS flight model is accurate enough to simulate it.

Media reports vary considerably & are based on speculation & unofficial witness statements which are not known for their accuracy. Captain Burkill & his crew have made no official comments on events leading up to the crash.
Captain Burkill speaking at today's BA press conference

Hagar is right,, this is really speculation on specualtion..  ::)  But that's OK because we're not trying to solve, condem or praise.. we're just talking about it. The MSFS flight model might not be exact, but it's pretty darn close  ;)

I did a little research though.. 'cause it got me to thinking. A 777 is capable of nearly 18:1 gliding.. BUT  that's at 220kias.

In order to get a 777 to do 18:1 at approach speed, would require some combination of flaps and thrust... And at approach speed WITH flaps but NO thrust.. it glides like a boat anchor ..

You don't even know the power settings on the engines. One witness reported that they were making more noise than usual which made him think something was wrong. If both engines had lost all power they would hardly have been making a noise.

The Gimli Glider, anyone?  ;)

http://en.wikipedia.org/wiki/Gimli_Glider

It all depends on the airspeed at the time things started to go wrong!!  Vat would probaly be around 140kts. This is an assumption obviously. At 2DME the 777 would already be slowing down from 170/180 knts  in order to achieve Vat. Probably full flaps would already have been set. My estimation is that the engines were working at say 10-15% above idle and didn't respond when more power was requested.
Look here for the initial report
http://www.aaib.dft.gov.uk/latest_news/index.cfm
Also this website will eventually publish the full report.
They were lucky they evidently hit the ground very hard which suggests  the a/c stalled in say from 20feet. If they hadn't been able to get over the hedge who knows what would have happened!!
Vololiberista

Let's not forget wind or density altitude... two important factors.

And according to John Wayne in The High and the Mighty, murmuring "...and now I lay me down to sleep..." helps a little.

Let's not forget wind or density altitude... two important factors.

EGLL is 70ft above sea level!!!!! Wind was moderate 15knts i believe
From a historical aspect here is the last BOAC accident in 1966
http://www.pilotfriend.com/disasters/crash/boac911.htm
This one "cannot" be reproduced in FS9!!!!!!!!!!!!
Vololiberista