Lightning - dangerous for some....
Guest
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Lightning - dangerous for some....
Four days back in GVA, a string of thunderstorms transited overhead the field. Lightning strikes very adjacent to and possibly on the field occured.
The airport ruled that the use of headsets by groundstaff would be forbidden during the predicted time of storm activity. (due to discharge risk)
So far so good - however, the refuellers were hard at work and looked strange when
asked to stop refueling for a while: "we've got other customers waiting..."
Two points here - firstly excellent radio mic-tel socket to headset connections are available and in continuous use in Japan for instance - eliminating the discharge risk - secondly despite a good search on and off the web, I have been unable to turn up rules or recommendations about fueling in thunderstorms. Anyone got relevant info or comments to back up my nagging memory?
The airport ruled that the use of headsets by groundstaff would be forbidden during the predicted time of storm activity. (due to discharge risk)
So far so good - however, the refuellers were hard at work and looked strange when
asked to stop refueling for a while: "we've got other customers waiting..."
Two points here - firstly excellent radio mic-tel socket to headset connections are available and in continuous use in Japan for instance - eliminating the discharge risk - secondly despite a good search on and off the web, I have been unable to turn up rules or recommendations about fueling in thunderstorms. Anyone got relevant info or comments to back up my nagging memory?
Guest
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If nothing else is forthcoming you may want to try here and fire off an e-mail or give them a ring -
Greater Orlando Aviation Authority
Orlando is allegedly the lightning strike capital of the world. They are most definately well-versed in coping with the problem. If they are unable to provide a definitive answer I'm sure they'll steer you in the right direction.
Greater Orlando Aviation Authority
Orlando is allegedly the lightning strike capital of the world. They are most definately well-versed in coping with the problem. If they are unable to provide a definitive answer I'm sure they'll steer you in the right direction.
Guest
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R H Golde in his textbook ‘Lightning Protection’, reports on an explosion caused by a direct lightning strike to a fuel installation. The identified cause was ignition of the fuel air mixture, and he comments that to prevent such an explosion it is necessary to prevent emission of a fuel air mixture while an active thunderstorm is overhead. I would (and this is possibly showing my ignorance of the refuelling apparatus used on aircraft) expect it is impossible to prevent emission of fumes during refuelling and reports of refuelling during a thunderstorm are therefore surprising.
I am fairly certain that the British Army has standing instructions to prevent vehicle refuelling during a thunderstorm. It would be very surprising if the RAF does not also have the same instructions.
Interestingly enough, also in the Golde’s book there is a section on lightning strikes to aircraft, and the protection built into aircraft fuel tanks to prevent lightning induced sparks inside the tanks.
(Should explain that the dissertation for my first degree was on the probability of lightning strikes and, besides an interest in the subject, it serves me professionally to keep up to date so the comments already made on this thread are very interesting.)
[Edited for a typo.]
[This message has been edited by Evening Star (edited 23 May 2001).]
I am fairly certain that the British Army has standing instructions to prevent vehicle refuelling during a thunderstorm. It would be very surprising if the RAF does not also have the same instructions.
Interestingly enough, also in the Golde’s book there is a section on lightning strikes to aircraft, and the protection built into aircraft fuel tanks to prevent lightning induced sparks inside the tanks.
(Should explain that the dissertation for my first degree was on the probability of lightning strikes and, besides an interest in the subject, it serves me professionally to keep up to date so the comments already made on this thread are very interesting.)
[Edited for a typo.]
[This message has been edited by Evening Star (edited 23 May 2001).]
Guest
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Evening Star, the refuelling hose couplings to refuel valves (underwing) are vapour tight and would not pose any risk in TS activity and the bowser is also grounded to aircraft structure. Overwing refuelling on small aircraft however, would present a certain element of risk in those conditions.
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HotDog
And when the fuel goes into the wings, what does it displace? Fuel vapour that is vented from the wings to atmosphere. Have a look at UK CAP 74, 'Aircraft Fuelling: Fire Prevention and Safety Measures". Both precautions, no push back headsets and no refuelling, are eminently sensible, but then we can't let safety impede punctuality and profit can we?
[This message has been edited by Hew Jampton (edited 22 May 2001).]
And when the fuel goes into the wings, what does it displace? Fuel vapour that is vented from the wings to atmosphere. Have a look at UK CAP 74, 'Aircraft Fuelling: Fire Prevention and Safety Measures". Both precautions, no push back headsets and no refuelling, are eminently sensible, but then we can't let safety impede punctuality and profit can we?
[This message has been edited by Hew Jampton (edited 22 May 2001).]
Guest
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It's not just the risk of a direct strike that creates a hazard; there is also the matter of 'induced potential' (ever felt your hair stand on end in a storm - I have, on top of a Scottish mountain... all metalwork, ice axes etc also started buzzing... no fun at all if you are fueling, and really quite glad I wasn't flying that day! Made a very rapid descent...)
Also even a relatively distant strike to ground can cause a ground current sufficient to raise a spark... covered some of this stuff in explosives training, the same risks apply to fueling I guess.
Also even a relatively distant strike to ground can cause a ground current sufficient to raise a spark... covered some of this stuff in explosives training, the same risks apply to fueling I guess.
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I saw someone mention Central Florida as the lightning capitol. This is probably true. MCO has a policy of clearing the ramp due to multiple deaths due to lightning strikes sveral years ago. Most airlines operating in the state have policies against fueling during a storm. Also, I'm will to bet that SFB has the same policy in place.
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Few, from Hew!
My issue of CAP74 is slightly out of date, but it says
"The aerodrome authority - Air Traffic Control should issue guidance, depending on local conditions, as to when fuelling operations should be suspended due to the proximity of severe electrical storms."
I gather that the latest issue expands on this and places more of the responsibility on the aerodrome authority rather than ATC.
My issue of CAP74 is slightly out of date, but it says
"The aerodrome authority - Air Traffic Control should issue guidance, depending on local conditions, as to when fuelling operations should be suspended due to the proximity of severe electrical storms."
I gather that the latest issue expands on this and places more of the responsibility on the aerodrome authority rather than ATC.