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Recent content by DavidLeyman

  1. DavidLeyman

    sealant removal from a blind fuel tank

    In retrospect I have a niggle in the back of my head that says 'scratched surfaces'. Granted that the case in point may be stainless steel but if the practice of flailing about with sharp blades becomes endemic then the surface finish of the structure could be impaired. Scraping sealant off is...
  2. DavidLeyman

    sealant removal from a blind fuel tank

    I'm with thruthefence on this. There is also a teensy worry about what happens to the shaved off bits. Can we guarantee that they are all out? Et aussi, je ne suis pas un Dieu en Francais, malhereusement
  3. DavidLeyman

    Qantas 747 oxygen tank rupture

    Mike Halloran: Good idea in theory. We were fishing Findhorn Bay in Scotland and found a WWII tank on the sounder (they used this place for practicing the D-Day Landings - lots died there!). We immediately marked it and subsequently failed to find it again. Right! We were inept, no doubt...
  4. DavidLeyman

    sealant removal from a blind fuel tank

    thruthefence: Ye Gods. Really? Are you living in third world country, perhaps?
  5. DavidLeyman

    747 Takeoff and cruising power comparison

    rb1957 and j79guy are right. Someone has decided that you are the pigeon on the branch ready to be shot down if it all goes wrong. Get the risk assessment team and the insurance people involved. Get everybody you can find involved. On the face of it, any engine that has to be run at steady...
  6. DavidLeyman

    Qantas 747 oxygen tank rupture

    Valujet Flight 592 was carrying several pyrotechnic oxygen generators as cargo, was it not? This is what we understood in UK about it. "....and is therefore unavailable for inspection." How convenient for 'them' and frustrating for 'us'. Prost is right but standardisation is a good thing. The...
  7. DavidLeyman

    fuel additive

    Diethylene glycol monomethyl ether is added as an icing inhibitor. It doesn't do anything to the fuel but lowers the freezing point of the water, I am told. It has limited capability as a biocide but anything that helps prevent fungus can only be good. We took many pounds out of a C130 in...
  8. DavidLeyman

    Fuel tank wire testing - best practices

    Field Team: 20% LEL. Seems a bit high even for the military. Eng3000: almost nobody has a TDR. They are soooo expensive - but sweet. You are right about the tank wiring. People have a bit of a cavalier attitude towards fuel tank - we burned out two aircraft in a hangar because we didn't...
  9. DavidLeyman

    sealant removal from a blind fuel tank

    Is not MEK an illegal substance in many countries now? I am thinking about COSHH legislation and its equivalent elsewhere. Turco might do it but it is a bit of a long shot. Practically speaking I go with WKTaylor. That is undoubtedly my route though this problem. Dry powder? Tank? You have...
  10. DavidLeyman

    Thrust to power

    Oh, dear. This comes up often. The old 'D' Licence guys used to do measurements of airflow corrected to ISA SL. This was on engines post major servicing that were bolted to the back of a lorry (truck) and pointed into the wind - for which a graph was available. They would then do a...
  11. DavidLeyman

    Bleed Air Leak Detection Systems

    I am, by nature, a propulsion specialist but persons such as I look at fire protection and detection devices so this is appropriate. Firstly: B52? Plasgear - you should crawl down the leading edge of a Beverly to change the generator in flight or top up the oils. Damn great Centaurus sleeve...

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