View Full Version : Dominie "Smog"

28th Feb 2012, 22:24
In light of the recent Doncaster "donkey derby" thread, I thought perhaps some learned gents (or otherwise) might be able to help clear up a long held headscratcher. Once upon a time I rode shotgun in a Dominie T1, medium level, we ferried an F-4 crew between Colt and Wattisham I recall. I think it was upon each successive takeoff that the old girl seemed to leech smog through the floor vents which partially filled the cabin. As a novice aviator at the time I did my duty by querying my imminent demise with the boys up front, at which they smiled heartily as if it happened de rigeur. :ok:

Well, wossup? Was this "design feature" typical of the Dom? And did it occur aboard other types? And by the way, when you were flying empty, how did you manage when the only VOR/DME was up the back?

Pontius Navigator
28th Feb 2012, 22:32
not smog, condensation through the airvents. You get it on some civvie jets if the conditions are right.

28th Feb 2012, 23:05
Well I sort of guessed it was benign, but would anyone care to explain the science? What system do small jets lack that the big jets have? It was no small beer, like firing off a CO2 extinguisher

28th Feb 2012, 23:19
Normally water separators get to it, but yes it's just condensation. If you tweak the cabin temp up a bit, it disappears.

28th Feb 2012, 23:29
Mid July 1986. I'm guessing it was a bit of a scorcher! :p

29th Feb 2012, 00:02
They had Decca in 1974 ...:)

29th Feb 2012, 00:18
Well how come I got pestered for the DME reading every time they needed a course change?

29th Feb 2012, 17:39
As a RHS stude (AEOp) for a short while on Doms, I'd take VOR fixes regularly - can't be sure this late in life whether DME was available.... I vaguely recall that it was, but probably not used by stude. (They liked to see how small a triangle our fixes produced, rather than a simple line with a tick mark being drawn)....so VOR available at least whilst up the pointy end.

29th Feb 2012, 18:21
That brought back a few memories.

I thought the Dominie was bad until I moved onto the F4. It was a case of max chat on the heater before any descent. Anything less resulted in a barrage of high velocity icecubes.

Pontius Navigator
29th Feb 2012, 19:42
daveJB, DME was controlled and displayed to the nav studes alone. The ADF was also controlled by the nav but the pilots could see the display.

On the pilot's resettlement course - Civil IRT - they had to take a nav along to tune the ADF. The pilot had to check the beacon coding but was wholly reliant on the nav on speed of tuning etc. As I could do it pretty quickly and was not otherwise involved in teaching studes I got a good number of jollies out of it with Berlin a few times etc. :)

Courtney Mil
29th Feb 2012, 22:28
Steamfrom the leaky boilers.

Gehovah, nice one. That brought back an F4 memory.

1st Mar 2012, 07:08
Did my civil IRT 21/9/88 in XS738. Wasn't you down the back per chance was it Pontious? Finningley - Stansted - Bedford - Stansted - Finningley. Positioned the aircraft to Stansted to pick up CAAFU examiner, IRT on 1 pilot Stansted - Bedford, my IRT Bedford - Stansted, pay cheque, drop off CAAFU examiner, fly back to Finningley where the barrel was waiting in the crew room. Happy days.:ok:

1st Mar 2012, 07:23
Brings back memories of my first ever flight in a jet. I was at Air Cadet camp at Stradishall in '66 and was taken up on a night flight in one of the shiny new Dominies. Shorty after take off someone shouted "smoke in the cockpit," and before anyone could react it had gone.

Pontius Navigator
1st Mar 2012, 07:36
BB, no, I don't remember the beer.

I still had a course then. My jollies were a year or so later so you don't owe me any :)

India Four Two
1st Mar 2012, 14:07
Here is a "ground fog development" I saw in a Do 228 (un-pressurized) during the departure from Manila:

It almost became IMC in the cockpit a few minutes later ;)

1st Mar 2012, 17:59
Wow, never heard of this phenomenon before. Must make the pax a bit nervy!!
Add one wipe rag to the pre T/O checklist.

Leaves me wondering, do such jets have a windscreen demist just like in a motor?

Pontius Navigator
1st Mar 2012, 18:44
Cooch, often experienced in Airbus as well, quite spooky seeing the 'smoke' pouring from the overheads.

aw ditor
1st Mar 2012, 18:51

Vampire 9' had the same problem. The "Godfrey Cold Air Unit" fitted for MEAF and not removed on return to UK, fired high-speed-slush' when descending through Lincolnshire cloud on a QGH. Very cooling!


1st Mar 2012, 19:58
Well apart from the obvious cockpit visibility issues(!), I would have thought that corrosion/electical problems might eventually ensue.

Also brings to mind an immediate conflict of interest whereby airlines try to save fuel by short heating the cabin air. Or is that just a myth?

Any thoughts/anecdotes?

Pontius Navigator
1st Mar 2012, 21:11
Coochy, not heating but conditioning. I believe where 4 conditioners are fitted only 3 might be activated thus giving a slightly reduced, but acceptable, air quality.

1st Mar 2012, 21:26
Bit of thread drift creeping in here but I remember the first time my parents flew the (brand new) 777, they complained of unaccceptably cold temperature in the aft cabin. They raised it with the CC but to no obvious avail.

Do you think its quite common practice to treat "cattle class" like cattle in that respect? With ever increasing fuel costs, are we to expect a new culture of short changing pax on cabin air quality?

Occasional Aviator
1st Mar 2012, 22:30
Coochy, you're right.

There were serious corrosion issues on the Dom - caused by condensation collecting on the inside of the fuselage and dripping down to the bottom centreline.

I remember three ac awaiting assessment in the hangar when I was at Finningley; don't know if some wag had arranged it that way but the three were lined up by tail number in the order Q, R, A....

1st Mar 2012, 22:38

Doesnt half encourage thread drift though.

Can you imagine kitting these up with a brace of AIM-9s and sending them off up north to escort the Reds? Might have been worth it just for the value in confusing their intel!

2nd Mar 2012, 05:30
No not a myth. On the TriStar and DC10 (for certain) it was common practice to shutdown 1 of 3 ECS packs in the cruise and to close the louvres to save fuel. Some aircraft also had Recirc Fans to abet this.

2nd Mar 2012, 09:50
Seem to recall making a goodly amount of smog in the Nimrods once we'd finished cabin pressure runs (on the ground) with a max rate de-pressurisation - the old ear drums took a bashing that's for sure:\
Note - only done with the approval of all on board!

Justin Cyder-Belvoir
2nd Mar 2012, 20:54
BananaMan, I think I may have authorised that trip!

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