Concorde

[U of I Tweak]

Did anyone happen to see the special on the Concorde accident that was on TLC a couple of days ago? They presented a number of different theories as to what caused the accident beyond the strip of metal.

Now I hate to disagree with pilots with thousands of hours and former crew members on the Concorde, but some of the stuff they were saying just didn't add up with me.

One theory was that there was a spacer missing inbetween the wheels on the left main gear that allowed the tires to wobble and fail. They indicated that they think the tire burst well before it struck a piece of metal based on where the metal was found. It also stated that the pilot took off at 180 KIAS or so, when normal liftoff was 198. The idea was that they were skidding off of the runway towards a 747 holding short. It was also stated that the plane was overweight and had a "dangerously aft" CG.

It seems to me that if there was a significant problem early in the take off roll (due to tire wobble) and the aircraft was drifting that an abort would have been prudent. I would imagine that they were well below V1. Does anyone happen to know what V1, Vr, and V2 are in a loaded Concorde? If they lifted off 20 knots shy of Vr, wouldn't that in most airplanes then be below V1 as well? I also have a very hard time imagining that a professional pilot, especially one flying the Concorde would consider trying to fly overweight.

I realize that the media is poor at covering aviation, but many of the interviewees were Concorde FEs, and Captains.

I'd find any insights anyone has interesting.

 

[ILikePlanes]

I didn't see the special but a tire WILL wobble if the bearing spacer isn't installed or isn't installed correctly. If I remember right, there was a Fokker at MDW that one of the nose tires came off on. Cause was a missing spacer for that tire.

Anyway, that's my 2 cents,

Peace out

 

[Snoopy58]

Very interesting bit on the Concord -- I saw most of it. A while ago, AW&ST had an article with some of the numbers from the accident report. I don't remember too many specifics, but some of the numbers were pretty high. I have to think that with a rotation speed of almost 200 knots, you get quite a V1-Vr split. Also, most high performance jets do NOT reject for a tire all the way up to V1 -- it's safer to keep going & land on it & try to stop from 1500 or 2000' down the runway at touchdown speed (and time to think through what's going on) after having burned down or dumped gas to reduce weight, rather than to stop with the bad tire from a lot farther down the runway. Also, who knows when in the takeoff run they'd have detected the tire problem?

Granted, nobody wants to take a jet four-wheeling through the grass, but rotating 20 knots early isn't the normal response to a directional control problem! (Not unheard of, though -- same response crashed the C-130 testbed aircraft several years ago.) Especially when you have better performance & better control the faster you're going!

Interesting that the jet was overloaded & out of CG (according to the TLC show). Also interesting that the FE shut down the offending engine without direction by the Captain! Shutting down an engine that's still producing thrust too soon can bring down a lot of jets! With enough speed, I'm sure the Concord could fly okay on 2 engines out, but behind the power curve it's a whole different ballgame! The AW&ST article referred to a Concord-specific performance number (at least I'd never seen it before), a Vzrc -- a "zero rate of climb" speed. Slower than that (at whatever configuration -- 1 engine out maybe), the jet couldn't climb. Faster than that, it could.

In the general case, I have to think that, with so much power but no thrust reversers and only so many tires with brakes on them, the Concord would be a very "go-oriented" aircraft instead of a "stop-oriented" one, which tends to drive large V1-Vr splits. The T-38 would go for a lot of things the C-130 would stop for -- a slick, high-powered "go-oriented" jet vs a tank with great brakes -- stop for almost anything right up until rotation in a Herk. Splits in V1-Vr were common in the T-38, rare in the C-130.

I have no reason to doubt the suggestion that the Concord was past V1 when the crew realized that something was wrong.

 

[bobbysamd]

Mr. Concorde

That's "Mister" Concorde to you.

Said day for aviation. Today was the last day of scheduled Concorde service. Here's a BBC story. Back to the future with subsonic air travel.

This BBC link has pix and articles.

This link should be of particular interest to our former Mr. Concorde.

 

[T-Gates]

I was listening to the narration on the BBC page and I found it funny how the CP says "when we fly Condorde....."

Like it has a first name....

I'm going to start doing that with the RJ.....

"Welcome aboard RJ, today you will be travelling at eighty precent the speed of sound....."