Battle stations. Did anyone watch it tonight????
Battle stations. Did anyone watch it tonight????
Author
Discussion

andytk

Original Poster:

1,558 posts

294 months

Thursday 20th February 2003
quotequote all
This is a first for me. (I think) an off topic post but its bugging me.

On channel 4's Battle Stations program tonight they were doing the potted history of the P-38 Lightning.

Charles Lindengburg (of atlantic crossing fame) flew with a Lightning squadron out in the pacific for a while. While he was there he suggested a modification to the plane that massivley improved its range.

Unfortunatley I went to the bog at this bit so I missed them saying exactly what the modification was.

Now it's annoying me.

How the hell did they massively increase the range with a simple engine tweak??

Andy

sadoksevoli

1,232 posts

285 months

Thursday 20th February 2003
quotequote all
Reducing the rpm and increasing the "mercury" - whatever that means - anyone else enlighten us/me?

Niggle

600 posts

294 months

Thursday 20th February 2003
quotequote all

sadoksevoli said: Reducing the rpm and increasing the "mercury" - whatever that means - anyone else enlighten us/me?

The 'mercury' probably refers to the air pressure (those two puppies were supercharged) going into the engine, from that and the other comment the 'engineers' made I'd guess he was advocating leaning the engines right out.

What else could he do to double the range from 900nm to 1800nm?

andytk

Original Poster:

1,558 posts

294 months

Thursday 20th February 2003
quotequote all
Hmmmm.

So jack up the supercharger pressure, lean the engines riiiight out and reduce the engines rpm?

Presumably you'll also have to fiddle with the propeller pitch to enable the engines to run slower and the airplane to fly at the same speed.

I guess that fits. Pilots today still have control over their carbs and can lean engines out to improve range at the risk of melting valves etc etc.

Any pilots out there care to comment on the validity of this theory.

Andy

apache

39,731 posts

312 months

Thursday 20th February 2003
quotequote all
I too missed the main part of this but I caught the bit where he said "drop to 3 inches of mercury" which is about 1.4psi, the engineers were saying it would burn the engines out. Hope that helps, another brilliant/beautiful design from Kelly Johnson.

I noticed the earlier jobs seemed to have different engines, was this another case of Allison to Rolls Royce?

andytk

Original Poster:

1,558 posts

294 months

Thursday 20th February 2003
quotequote all
hmmm
Don't see how dropping the charger pressure could burn the engines out.
Also I don't think the lightning ran merlins, I think it always ran the allison engine. Makes it one of the few V-12 engined planes during WW2 not to run the merlin. (I could be wrong about this though)
Where is eric when you need him...

Andy

eric mc

125,343 posts

293 months

Thursday 20th February 2003
quotequote all
I was participating in my other "passion" - being a member of an operatic society (we're rehearsing "Chess" at the moment). I set the video on timer so hopefully I'll have something interesting to watch tomorrow night.

P-38s only used Allison V12s which were both supercharged AND turbocharged (although the early versions weren't turbocharged). The P-38 also could reach very high Mach numbers in a dive and a number were lost when pilots couldn't exercise enough elevator authority to pull the nose up at high subsonic speeds.

apache

39,731 posts

312 months

Friday 21st February 2003
quotequote all
ahh, is that what they call compressability?

HarryW

15,982 posts

297 months

Friday 21st February 2003
quotequote all
Maybe totally wrong here, but didn;'t they fit a merlin engine to it, modify a few other bits and call it the P51 mustang

harry

mybrainhurts

90,809 posts

283 months

Friday 21st February 2003
quotequote all
No, Harry.......totally wrong.

mybrainhurts

90,809 posts

283 months

Friday 21st February 2003
quotequote all
They took a P51 Mustang, put a Merlin in it, and called it a..........P51 Mustang.

apache

39,731 posts

312 months

Friday 21st February 2003
quotequote all
you may laugh, but there was a Mustang variant with radar that consisted of two fuselages joined by a stub wing that could be mistaken for a P38.........well, maybe..........er not at all actually

eric mc

125,343 posts

293 months

Friday 21st February 2003
quotequote all
The North American F-82 Twin Mustang - used as a night fighter in the Korean War.

apache

39,731 posts

312 months

Friday 21st February 2003
quotequote all
aaaaaaaythangyew

andytk

Original Poster:

1,558 posts

294 months

Friday 21st February 2003
quotequote all
So back to the origional question. How did they extend the range??

Any pilots know.

Andy

Niggle

600 posts

294 months

Friday 21st February 2003
quotequote all

apache

39,731 posts

312 months

Friday 21st February 2003
quotequote all
"In a pleasant manner Lindbergh explained cruise control techniques he had worked out for the Lightning's: reduce the standard 2,200 rpm to 1,600, set fuel mixtures to "auto-lean," and slightly increase manifold pressures. This, Lindbergh predicted, would stretch the Lightning's radius by 400 hundred miles, a nine-hour flight."

that'll be it then

HarryW

15,982 posts

297 months

Friday 21st February 2003
quotequote all

Niggle said: c/o google www.475thfghf.org/Lindbergh.htm


That doesn't look like a mustang

Amazing isn't it, that not flying at full throttle gives you greater range

H

williamp

20,291 posts

301 months

Friday 21st February 2003
quotequote all
Eric Mc (and others)

Wasn't there a night fighter version called the Black Widow???

I agree- its a great aircraft. Totally unique piece of original thinking. Who could have thought if doing something so amazingly different (especially when their current aircraft were Biplanes)

ATG

23,571 posts

300 months

Friday 21st February 2003
quotequote all

HarryW said:

Niggle said: c/o google www.475thfghf.org/Lindbergh.htm


That doesn't look like a mustang

Amazing isn't it, that not flying at full throttle gives you greater range

H



I think the point was that the engineers and pilots all assumed that if you ran the engines this lean it would destroy them within the space of one mission. They'd underestimated the abuse the engines could take.