I posted this just before that thread got locked...
I seem to remember you saying that 26 planes lost their tails due to this effect AFTER strengthening? Well, I happened to have a book delivered last week; 'Hawker Typhoon: The Combat History'.
It says that there 26 pilot deaths due to SEVERAL defects including:
1) Seepage of carbon monoxide into the cockpit due to the deterioration of the engine bulkhead seals - pilot unconsciousness as a result
2) Engine failure through wear on the valve sleeves causing a jam that would blow up the cylinder
3) Breaking off of the tail-unit
So the 26 deaths were due to ALL three effects and not just the tail plane problem. This issue was partly cured by riveting 20 fish plates around the fuselage.
The book also includes the notable history of all 3317 typhoons built (the last one being delivered to the RAF in November 1945). A cursory glance through these reveals that more typhoons were shot down by spitfires, P-51s and P-47s than by losing their tail.
The breaking of the tail is explained here:
"The cause turned out to be a manefestation... [of]...compressibility. Aircraft react to its effect in various ways, according to the shape of their wings. On the Typhoon, the effect was to force its nose down beyond the vertical. This a pilot could not rectify until he had reduced speed. The conclusion was that the pilots had simultaneously throttled right back and brought the nose up by using the trimming gear; thus, when speed dropped enough for the controls to act normally, the nose, under full trim, rose so violently that it imposed a breaking strain on the tail unit. It was also found that at high speeds elevator flutter often made the tail section break at the rear fuselage transport joint."I always throttle back and use the trim to recover from compressing - I wonder how many other aircraft would experience the same thing?
Anyway, I hope that clears it up, RAM.
I should be getting 'La-5 in Action' by signal/squadron publications soon - anyone got that?
[This message has been edited by Dowding (edited 05-15-2001).]
