questions about a damaged Merlin engine trailing white smoke

[Flyingkag]

Hey guys,

today some questions I have about the damaged engine a crashing P-51D Mustang.

One WWII witness gave a written statement, saying the plane was "trailing white smoke" as it flew over him; it crashed in the mountains one minute later; that "white smoke" would mean "coolant" I guess.

Facts and other statements let me understand that this Mustang slowly had lost altitude in it last minutes of flight, probably flying down with an about 5% ratio, so that as it came in front of a mountain, with no possible escape, it hit the trees...just some meters under the top of the mountain.

It seems it had NO reserve of power, because the crash happened just 5 meters under the hill top! He just was not able to pass over...No luck...

Can someone maybe explain to me what is the relation of the white smoke and the lack of power of the engine?; I understand nothing on mechanics.

would maybe such a smoke have come inside of the cockpit (plane was hit about 4 minutes earlyer), so that the pilot maybe had choosen to open or jettison the canopy because of the toxic (?) stuff of this smoke?

Thanks for sharing your opinion, guys!

Mathias

[RSwank]

Loss of coolant means that the engine would start to overheat and eventually seize up, i.e. stop running.
Depending on how much or fast the coolant was leaking would cause the the engine to seize sooner or later.

This example ran for about 15 minutes before the engine seized. Book page 54.

https://books.google.com/books?id=oU...engine&f=false




This one says only a few minutes, but goes into some detail on what is happening. Starts on book page 143.

https://books.google.com/books?id=OP...engine&f=false

[Tony Kambic]

Aerobatic shows drip a special oil on hot exhausts to produce the white smoke trail. I wouldn't doubt that oil leaking from a cracked line or block on a hot seized engine could produce the same. For that matter, coolant could also be leaking.

The P-51 was a fairly good glider with a ratio of 4 miles per every 1,000 ft. according to the pilot's manual.

[Flyingkag]

thanks guys! interesting answers, ...as usually!

I know that in that history the Mustang just flew about 4 minutes after having been hit by Me109s. Seems the engine was still running, but with few power, as it hit the trees.

And what is your opinion about the possibility that such a white smoke should have been coming inside of the cockpit? is there some possible internal communication between engine and cockpit letting imagine that white smoke coud have invaded the cockpit, so that the pilot had to open/jettison the canopy? Or is a cockpit an isolated/closed area in a Mustang plane?

I guesss that if some smoke would come in my cockpit, my personal reflex would be to "open the windows" for searching fresh air...but I'm not a Mustang pilot...and not pilot at all! Maybe a stupid reflex!

[Revi16]

The white smoke (or steam) from coolant can enter the cockpit.

It also depends where the plane is hit. A hit in the radiator, behind and below the cockpit, will trail steam, but most likely not enter the cockpit.
A hit in a coolant line under the cockpit or in the engine bay, may allow smoke into the cockpit. It all depends where the hit took place.

http://usautoindustryworldwartwo.com...-51-107w-2.jpg

http://www.enginehistory.org/Allison...ysteminp51.jpg

[Flyingkag]

Thanks Revi16

I didn't realize that the radiator is behind the cockpit; that explains why the air intake is located there on the plane's belly, so far from the engine. I better understand with your attached documents.

Mathias

[ArtieBob]

A broken line in the engine compartment could blind the pilot. A KYANG TF-51 had a line break on takeoff at summer encampment in ?1953?, blinding the pilot and having lost engine power, he had little option but to crash-land straight ahead with no visual reference, destroying the aircraft and badly injuring the pilot. He did survive and later became CO of the ANG unit.

Best Regards,

ArtieBob

[Kutscha]

Had a radiator line blow in a car once. The white 'smoke' produced was as thick as a London fog. Lucky there was no accidents.

[John Beaman]

IIRC from my "shade tree" mechanic days, white smoke is oil or coolant and black smoke is petrol or fuel problems.

[MarkRS]

Black smoke: burning rubber or carbon from badly mixed fuel burn.
Blue smoke: burning oil.
White smoke: steam from coolant leaking into engine.