With regard to the HS146 conversion I am curious to know how it has been certified, are the changes embodied in the aircraft drawing set, is it referenced in all the other aircraft clearance documentation such as the safety case, and is it underwritten by the aircraft design authority, presumably now BAe Systems? Maybe I am unnecessarily concerned that someone might have decided its a quick easy option, the aircraft is soon going out of service, we don't need to document it with the full modification procedure etc.
I am always slightly nervous when something is adapted from another aircraft, in this case apparently some stanchions that attach to the floor on the Voyager. The cause of my nervousness goes back to the Buccaneer S Mk 2 cold weather trial in Fort Churchill in the early 70's. On the first trial the fuel flow proportioner hydraulic motor leaked from a garter seal after the aircraft had been cold soaked. Dowty, who made the motor, said we have an easy fix, use a carbon face seal as used on the Viggen proportioner motor. We don't need to test it, its already cleared down to -40 or some such figure. The mod was done on a couple of units and the following winter the aircraft went for a further cold weather trial. I can still remember my fellow systems engineer Graham Armitt, who was one of the HSA reps on the trial, ringing me up and ranting that the Effing proportioners leaking far worse than before, the effing floor is covered in effing hydraulic oil and everyone here is really pissed off. It turned out the Buccaneer proportioner motor had more end float and the static O ring held the carbon seal away from its mating face as the system started up, resulting in a massive hydraulic leak. The problem was subsequently fixed by a stronger spring and different seal material but we made sure Dowty cold chamber tested it before we fitted it to an aircraft. I learned about clearing things by analogy from the experience.
Walbut