APU Starting

[haughtney1]

Had an interesting chat with an engineer about starting the APU whilst refuelling...he was not keen, I was aware of the issue, but more to the point have seen nothing written down in 2 company Ops manuals specifically prohibiting it (happy to be proved wrong and shown it exists somewhere BTW)

Anyone care to add thoughts or opinion?

[hetfield]

What does your company SOP say?

[haughtney1]

Hetfield, please re-read my post please...the answer is there:ok: or should I say the lack of answer in itself, is an answer to your question.

[hetfield]

Ooops,

sorry, too fast, too sloppy.

In my company you may start the APU during refueling on A300/320/330/340

Kind regards

[BOAC]

H1 - PPRune email on its way.

[spannersatcx]

Ours state APU must not be started or shut down during refuelling, but the APU may remain running during refuelling This covers the 747/744/330/340/777.

Also be aware that although your SOP's may allow it local airport rules override them!

[A Very Civil Pilot]

Ours say can be on, but not started during fuelling. I guess it's in case the apu has a hor start or similar with all that fuel vapour in the air.

[mutley320]

Our company ops manual the same. Apu "should" not be started during refuelling.
Airbus, 330,320. Can't find airbus reference. Recall it may have been a Boing sop we have held on to.

[Alpine Flyer]

F70/100 APU starting prohibited during refueling (and IRS alignment), may be on if started prior to either.

[jettison valve]

haughtney1,

I remember that this Airbus rule - don´t start or stop the APU during refueling - was changed several years ago (at least for the A330/A340). I´ll dig around a bit tomorrow.

Anyway - in these days, rather beware of A330/A340 APU generator pieces exiting the tailcone and hitting you when the APU is running (regardless of refuel ops)... :}

Cheers,
J.V.

[donjovi]

For some years now(with 2 different operators) ,on Airbus, the restriction on starting has been lifted, however, electrical power transfer is not authorised.
donjovi

[Bolty McBolt]

I understand the need for SOPs about fuelling and APU use, loading pax etc
All flammable fuel should be treated with respect and procedures but....

I have had a few experiences with aircraft fuel and sparks or flames that I may share . I am not recommending disobeying any SOPS but sometimes other peoples experiences can paint a different picture or perspective.
Disclaimer :- we are talking about aircraft that only ever use Jet A or A1

As youth worked in the local fuel farm, (Storage tanks) every day the Jet A1 was tested for S.G and flash point. Flash point is an excellent indicator for quality of product ie if the flash point is lower more wide cut fuel in the mix.
From memory the min temperature that Jet A1 was allowed to flash was around 50 deg C. Flash point is lower than flame point which is the temp the fuel has to be to sustain fire.
The flash point test is a small amount of fuel is heated and temp monitored with an ignition source above, when the fuel vapour "flashes" the temp is recorded. In my time never saw anything below 80 Deg.
Long and the short Jet A1 needs to be fairly hot to sustain a flame if its in a puddle but an atomised spray is a different matter.

As above in my halcyon days I was slim enough to easily fit inside Boeing aircraft fuel tanks a fact the other members of my crew relished. ( An attribute I quickly changed with beer)
I quickly gained many hours of fuel tank experience and trouble shooting.
A defect that needed rectification required the removal of a component and its mounting bolts were rounded and seized. Normal spanners would not do the job.
The tank I was in was still freshly opened, fuel puddled everywhere, myself with breathing apparatus on. There was no way a high speed cutter would be deployed as the shower of sparks was to scary to contemplate.
So the mark 1 shiny sharp cold chisel and hammer were deployed.
The head of the bolt was dispatched with ease and caught in a plastic bag tapped into position but I did not notice this for my attention was fixed on the spark that flew off the bolt and sailed 4-5 feet across the tank to extinguish in a tiny puddle of fuel. I will admit it was unnerving.

Just a few experiences amongst many with jet fuel, some of which may explain why different airlines have different SOPs regarding operations when fuelling.

:ok:

[King Muppet]

Airbus A319/20/21/30

see FCOM 2.1.30 - it's allowable subject to a couple of conditions

In the UK your company should have carried out a risk assessment in accordance with (I think) HSE guidelines and a CAA CAP (can't remember which one - sorry) that specify minimum distances from the refuelling point or fuel vents - the 'fuelling zone'; 6 metres rings a bell, but your company can, of course, choose a bigger distance. As long as your APU and its exhaust are outside that then no problems. You should have it published somewhere - if not, ask. As stated above, it's possible that there may be local regulations in force or restrictions for other aircraft types...