a332 APU FL320?

[LukeA346]

Hello everyone, So I thought I'd test out my new camera on this lovely Saturday morning since there is hardly a cloud in the Sky and snap snap some Planes. (Apologies on the quality)

I captured this Monarch a332 just before leveling off at FL320 from Gatwick to Sanford and I noticed that "3rd trail" upon cropping. I was under the impression that there were certain rules regarding the use of the APU over certain flight levels? I've seen a few threads from Google but nothing exactly getting to my question.


Picture -> Monarch A332 Contrails (http://i48.tinypic.com/x5ziur.jpg)

Edit, It dose appear after looking at more pictures the 3d trail isn't visible so it was either switched off it it wasn't the APU as I was snapping away or some other momentary trail.

Thanks!

[Hotel Tango]

Ah yes, the pilots have deliberately broken the rules and you've caught them out. Quick send your photo to the Mail.

I don't think that's your intention here but just look at your post. Might it not be better phrased so that it reads as a question of interest?

Maybe it's just me ;)

[Emoclew]

Luke346,
I operate on the N.Atlantic Track system and regularly see a weak centre contrail behind most heavy jets. It is definitely not from the APU, and I have assumed it's a low pressure vortex coming off the aft fuselage.
However I am not an aerodynamicist, and would be interested to read a reply from whoever can explain it.
Emoclew

[LukeA346]

It wasn't intended to read as, "omg look they are doing something Illegal" However I can see it from your point of view but that wasn't my intention.

I just want to find out about it, If it the APU, what are the rules regarding it, Why might it be still running, and if it isn't the APU what is it? Water draining off or something.

Hell I don't really care if its running or not to be honest with you let alone go running to the mail as you put it, But Cheers for your really help full insight! :D

[LukeA346]

Thanks for the response Emoclew!

I'm looking though a few more of the pictures I snapped of the same A332 and its only Visible in a couple of them and the rest its not (Over 1-2 minuet time span of pictures) So it seems what ever it exactly is was only momentarily visible.

Thanks!

[jtr]

APU can operate up to A/C certified limit of 41,100 on the 330 (If memory serves)

What it is most likely to be is the fine mist created by waste water leaving the drain masts on the A/C belly. This is where the water from the galley drains (and I assume the hand basin drains from toilets) is sent overboard.

[anne747380]

Interesting photo,I also have photos like that in my collection and it is the grey water coming out of the drain mast.Someone emptied the sink or poured water in the sink in the galley.The plane is having a wee:)

[LukeA346]

Thanks for the responses!

Ive came across much more detailed picture of a 777: Foto United Airlines Boeing 777-200 (http://www.flugzeugbilder.de/show.php?id=806977)

clearly showing the origin of the water, Damn I gotta get my self a better lens, maybe a telescope for that matter :ok:

[Irish_Avro_Driver]

Ah yes, the pilots have deliberately broken the rules and you've caught them out. Quick send your photo to the Mail.

I don't think that's your intention here but just look at your post. Might it not be better phrased so that it reads as a question of interest?

Maybe it's just me

Yes, its just you.

[Hotel Tango]

Ah, OK then IAD, thanks.

[anne747380]

Boeing 777 drain mast
Boeing 777 drain mast | Flickr - Photo Sharing! (http://www.flickr.com/photos/zipsyjets/7183161072/)

[scudpilot]

Chemtrails?

:)

Chemtrail conspiracy theory - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Chemtrail_conspiracy_theory)

[750XL]

I don't know the exact reasons why an APU may be kept running during the flight, but I've done a flight before where the capt decided to keep the APU running (A320 iirc) due to extreme temperatures at destination airport (in excess of -30c) and he was a bit concerned whether or not they could get the APU working again in them temps.

[FLCH]

Some days on the 757, we have to run the APU up at altitude on an ETOPS verification flight going across the Atlantic.

Just a start up let it run for a minute or so then log the results.

[spannersatcx]

It is an ETOPS requirement to operate and start the APU at cruise altitude once a month, as it is an ETOPS requirement to have a certain number of generators available, the APU being one of them.