BAC 111 over Dorset last week

[India Four Two]

I was recently in the UK, staying near Shaftesbury (about halfway between Boscombe Down and Yeovilton) and during one of the brief periods when it wasn't raining, I hear some very loud jet noise. Being a Total Aviation Person, I went outside to see what was causing it and was surprised to see what I assume was the RAE BAC 111 (chubby fuselage, twinjet, dayglo on wings and tail, and lots of noise) climbing out westwards at medium level. What interested me was that there was a continuous white vapour trail coming from the left wingtip.

Was this fuel dumping or some kind of test procedure? Anyone know?

[ICT_SLB]

IIRC - and it's been several decades - the fuel dump on 1-11s is about one third out on the wing from the centre line. It was not a common option plus I beleive it could only be done symmetrically - dumping from both sides at the same time. My guess is that you just saw a wingtip vortex - sometimes the light's only just right to show one not both.

[India Four Two]

ICT,

Thanks for the info on the fuel dump location. What I saw was clearly coming from the wingtip. The aircraft was almost directly overhead, so I don't think lighting would have been an issue.

I've seen lots of wingtip vortices and this one looked completely different. Puffy, white and completely opaque and quite wide. It looked exactly like a mini-contrail and it stretched back about 10 fuselage lengths.

I presume it had just departed Boscombe Down. Can anyone from RAE (or Q whatever it is nowadays) provide any info?

Edited to say on second thoughts, and after some research, I must have seen ZE432 from EPTS: http://www.airliners.net/open.file/0935844/M/

I don't see any special equipment on the wingtips in the photo, so ICT is probably right - an anomalous wingtip vortex. There certainly was an anomalous amount of moisture in the atmosphere that week!

I42

[ICT_SLB]

India,
The EPTS 1-11 definitely doesn't have fuel dump - the nozzle was formed into the inboard flap fairing - looking a lot like an old-fashioned fire hose about 4 inches long - and as you can see there is no such thing in your picture.