Single-skinned fuel pipes
AC Ovee, before he disappeared out of sight posted this;
"Well, I have conducted AAR on different aircraft throughout the years; tanking and receiving. While different aircraft types route the pipes differently, the same principles and materials are generally used. But, I have heard that there are some types that have double-skinned pipework. The MR2 has the same where the pipe passes through the crew compartment. I agree that the Nimrod is far from the the latest design in AAR, but that doesn't make it unsafe just because of that. What makes it safe, if safe means that it will not suffer a fire, is answered below."
I have already outlined recent civilian airworthiness directives and I was under the impression that Nimrod was part AAR pipe double-skinned. Not according to this.
"The AAR pipeline ran from the former escape hatch just above / inboard from the Air Eng. Station and was routed to the rear of the Capt and then into the bomb bay area. There was a solid connection at the point of entry into the flight deck, thereafter, it was a conventional refuelling pipe as seen on a refuelling vehicle. The pipe was covered with a protective skin, but was not "double skinned" in the context we are discussing. It was then routed underfloor below the toilet with a series of tubes, for want of a better description, where the flexible pipe passed through frames and stringers (to prevent fretting and chafing ) en-route to the pipes in the bomb bay and the No1 tank (I think). The confusion may have arisen re the protective rubber coating over the main pipeline...but it was not, and never could be a second skin as such. It would have contained a leak I suppose, but not for long."
OK, so we have had several major fuel leaks in the AAR pipework, engineers have not been able to re-create these leaks on the ground and the RAF refuses to comply with engineering fuel pipe best practice. Crews have been sent up time and time again on AAR missions, just waiting for yet another dangerous fuel leak.
Someone is playing with the lives of aircrew. Tri-Jet has double skin, MRA4 does not. Why is that then, money??