Elddis and Hymer

[PTA]

2026 Crusaders utilise ABS for rear panels only. Side and front are GRP.
I'll keep you posted.

 

[Dustydog]

It wasn’t the windows that caused failure it was square cut outs of the ADF, and escape hatch combined with a very flexible lightweight structure. These findings came from tank tests and further examination of the remains recovered from the sea. The windows were changed during the aircraft’s re-design following the two major crashes from altitude.

There’s a good programme on the investigation of the crashes “ A great British air disaster”

I think it went a lot deeper Clive.
The cause of two of the accidents were as you describe.
But the real lesson was a number of factors.

Aluminium skin too thin.
No understanding of repeated stress cycles.
Square windows cause stress concentration, exactly like the radio radar domes that failed.All punched and screwed holes building in an inherent crack propagater.
No crack stoppage system.

Sadly by the time us Brits revised the air frame, discarding all square orifices , thicker alloys, the Boeing 707 was airborne , learning all the engineering pitfalls from us😢

Worth a read like your suggestion

https://www.bradyheywood.com.au/wp-content/uploads/2020/04/52fa7d_26c0a4ff1a5448cbbab972f169a764d9.pdf

 

[otherclive]

I think it went a lot deeper Clive.
The cause of two of the accidents were as you describe.
But the real lesson was a number of factors.

Aluminium skin too thin.
No understanding of repeated stress cycles.
Square windows cause stress concentration, exactly like the radio radar domes that failed.All punched and screwed holes building in an inherent crack propagater.
No crack stoppage system.

Sadly by the time us Brits revised the air frame, discarding all square orifices , thicker alloys, the Boeing 707 was airborne , learning all the engineering pitfalls from us😢

Worth a read like your suggestion

https://www.bradyheywood.com.au/wp-content/uploads/2020/04/52fa7d_26c0a4ff1a5448cbbab972f169a764d9.pdf

An interesting article, but your comment wrt the 707 learning the lessons isn't strictly aligned with events. The 707 went airborne almost exactly at the time of the two major Comet losses and had circular windows. On one test flight the test pilot even barrel rolled it! Notwithstanding the Comet's accidents, Boeings success was down to economics with a higher passenger load, ease of maintenance, especially engine access and swop out. It was more attractive to airlines. When I was in Canada I used the Canadian Forces 707 shuttle a number of times. A great feeling as Anne Murray's "Snowbird" can over the PA system as the pilot hit the throttles, and that thing rocketed down the runaway and up. Almost as good as the RAF's VC 10s and you sat facing forwards in the 707 too.

View: https://www.youtube.com/watch?v=Ra_khhzuFlE