Sir - Comparing notes is certainly a good idea (Letters, Flight International, 10-16 April, P41) - and not just between military and civilian organisations. Manufacturers should surely do the same, especially in matters relating to aircraft structure and integrity.
The industry appears not to have learned the lesson so dramatically demonstrated when a Vickers Vanguard crashed into the Belgian country side in the early 1970s. The aircraft's skin was torn off the horizontal stabiliser by escaping air which rushed into the empennage following the failure of the rear pressure hull. The direct cause was, I believe, toilet-fluid-induced corrosion.
The flightcrew's attempts, nearly two decades later near Tokyo Bay, to fly a Boeing 747 with a deskinned vertical stabiliser were therefore, unforgivably, doomed to failure. The design opportunity existed to allow for pressure relief through the empennage by careful placement of break-out panels. It is collective pride in an open-minded, well-run, industry which counts.
ALAN MASON
Red Beach, North Auckland New Zealand
Source: Flight International
