Concorde...Suggestions for modifications....
As in the war, fighting aircraft protected their fuel tanks with a layer of rubber mounted on the inside of all the surfaces of the tanks, thus when bullets pierced the tanks, the rubber allowed the bullets through but then sealed the holes behind them, thus preventing fuel from pouring out.
With Concorde, apparently most of the recorded piercings through the wings have been caused by small pieces of metal, bits of undercarriage etc. As the risk of tyre blowouts is ever present, what is needed is to significantly improve the fuel tanks ability to withstand the flying debris (or bullets) caused by the blowouts.
Tests need to be carried out to determine what thickness and type of rubber is required to perform this task. If the density of the rubber can be designed to match the density of the fuel (O.792), then installation would displace some fuel but should not significantly alter the C of G and balance calculations. It may be possible to replace the lost fuel by using the permitted maximum of overfill, or in the event a small loss of range might be the price that has to be paid for the necessary increased safety margin.
It would probably be the best policy to protect all the fuel tanks with a rubber base, as in the event we want the maximum margin of safety, and some debris piercing tanks 9 or 10 could still produce a disaster especially using the Murphy's law argument (ie: if you spend a fortune protecting most of the tanks in the area of perceived maximum danger then the next accident would be caused by something piercing the tanks you didn't protect) and let's face it, Concorde could not survive another major accident.
It might also be sensible to provide some additional (rubber) side protection for tanks 2, 3 and possibly 6 and 7 with maybe the inner sides of tanks 5a and 7a and the rear sides of 5 and 8 protected also.
Suggested Testing Conditions:
Test rigs need to be set up with tanks of the same type as used in Concorde, with the same panels underneath, ie: the same conditions as on the Concorde wing. Different types and thickness of rubber should be tested using a 12 bore shotgun (with the choke barrel which concentrates the pellets in a small area), the gunshot would be the best representation of the flying debris that might come from a tyre explosion, the gun should be fired from a distance of approx. 3 to 4 feet, this will be quite a severe test. One would be looking for the rubber to provide an almost perfect seal after the pellets from the shotgun had pierced through the aircraft skin and also the metal of the fuel tank. The fluid in the test tanks should be representative of kerosene in its fluidity and density.
The tests should be filmed (I can do this for you if you like!!), and the evidence submitted to the CAA to improve the chances that they will accept there has been a significant improvement in safety. It might also be worth releasing the tests to the media at some point, to demonstrate the improvements for all to see.
The modifications will involve substantial investment in both time and money, but hopefully should see all the Concorde's take to the skies again for the remainder of their natural lives.
Any feedback regarding this 25 th Sept 2000 article to: email@example.com
Note added 28 th June 2001:
Gordon Roxburgh's excellent Concorde site outlines the history and all the current events involving the 'Return to Flight' of the world's only supersonic passenger transport fleet.
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One of the important things when flying a Yak is not to let any possible spin that may suddenly develop get out of control !
Concorde, one of the greatest technological achievements in aviation history, has made good money for BA over the years and when you look at the original cost to the British and French taxpayer there is no doubt to whom the aircraft belong !
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We need to get a global campaign going to get Concorde G BOAF flying before Filton Airfield is redeveloped
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