B-52 with black smoke in the takeoff

[Jenisch]

View: https://www.youtube.com/watch?v=Cq6Hpxyrhyo

Hello,

Watching this video, which I guess is from a movie, I was wondering why the B-52s left a trail of black smoke in the take off. Could this be a consequence of the water methanol mixture that was sprayed in turbojets in order to increase the thurst in the takeoff?

 

[pbehn]

A lot of early jets were dirty in military jets they probably didnt care so much. Concord was a dirty minx.


View: https://www.youtube.com/watch?v=B7wK0cSsJRU

 

[mikewint]

You are looking at 3,334 gallons per hour of Jet fuel (essentially kerosene) being burned. The 52s did have water injection to boost thrust but all that black is just like any black exhaust, (like a car under hard acceleration) i.e. unburnt fuel mostly carbon.
The movie is Gathering of Eagles, circa 1963 and you are looking at Rock Hudson and Rod Taylor. Curtis LeMay had allowed the film crews almost total access to SAC bases

 

[T Bolt]

All the old jet engines belched smoke pretty good, even the airliners like the DC-8 and 707. The Air Force just kept using those older type engines long after the airlines went to cleaner burning engines. I was working out at O'Hare field around 15 years ago when the Air Force Reserve still had KC-135's there. You'd be driving around with the windows open and go behind an airliner and just get a strong smell of karosene. You'd drive behind one of those KC-135's and start choking and gaging

 

[pbehn]

All the old jet engines belched smoke pretty good, even the airliners like the DC-8 and 707.

There was a time when no self respecting movie or drama was complete without a 707 trailing 4 black exhaust plumes into the sky, it was the modern world.

 

[GrauGeist]

Best time to get "black lung" is during an "Elephant Walk" (with or without the MITO)

 

[Vic Balshaw]

And I thought they were all coal burners………………………..Ok I'm out of here!!

 

[mikewint]

Vic, twas wood, (renewable fuel) but too many crew were lost trying to add an arm-load to the engines while in flight

 

[Airframes]

Yep, the aircrew brevet (half wing) was 'St'. - for Stoker, and you could always tell which one it was, by the blackened face, with white area where the goggles had been, and long leather gauntlets !
In flight re-fueling was a bit of a problem, as sometimes a log got stuck in the boom ..................

 

[mikewint]

Terry-

 

[Token]

A lot of early jets were dirty in military jets they probably didnt care so much. Concord was a dirty minx.

They did care, but probably not for the same reasons many people think.

Energy out is related to fuel in, and a percentage of that fuel is not efficiently used, resulting in smoke. And jet performance has improved in efficiency over the years. Eventually the big smokers of the day, like the B-52 and F4 Phantom, were re-engined specifically to reduce smoke, but not for concerns about pollution.

Smoking engines simply make it much easier to visually acquire aircraft in flight. I can't count the number of times that smoke has helped me visually acquire a Phantom or a Buff that was low level and maybe indirectly terrain masking. Just find the smoke and follow it to the end, then even if you still can't see the aircraft itself you just follow the end of the smoke until the contrast changes and the aircraft can be seen.

When the F4 and the B-52 were re-engined in the mid-late 70s there was an immediate increase in difficulty sighting them.

T!

 

[pbehn]

They did care, but probably not for the same reasons many people think.

Energy out is related to fuel in, and a percentage of that fuel is not efficiently used, resulting in smoke. And jet performance has improved in efficiency over the years. Eventually the big smokers of the day, like the B-52 and F4 Phantom, were re-engined specifically to reduce smoke, but not for concerns about pollution.


T!

I can believe it
Watching planes come in at Heathrow out of the stack you can see the exhaust plume of the most distant aircraft before you see the plane itself even with modern airliners.

 

[Airframes]

And I always thought the smoke from the B-52, and the J-79 engine Phantom, was due to the crew frying bacon ......................

 

[Vic Balshaw]

You mean singing the hairs off the rind!!