Corsair and Hellcat in Europe

[Shortround6]

hmmmm.

Yep, 250 gph at 22-24,000ft "Normal Power (max. Continuous)"

except.

that max continuous (Normal) power would have you "cruising" at over 380mph according to this chart.
I wonder what the fuel burn was if cruising at 310-320mph true??

 

[P-39 Expert]

hmmmm.
View attachment 502778

Yep, 250 gph at 22-24,000ft "Normal Power (max. Continuous)"

except.
View attachment 502779
that max continuous (Normal) power would have you "cruising" at over 380mph according to this chart.
I wonder what the fuel burn was if cruising at 310-320mph true??

You are fast. Remember you have at least one 150gal drop tank to knock about 40mph off your speed. Still nowhere near the range for ETO.

Odd how normal power is faster then military power on that chart.

 

[Dawncaster]

hmmmm.
View attachment 502778

Yep, 250 gph at 22-24,000ft "Normal Power (max. Continuous)"

except.
View attachment 502779
that max continuous (Normal) power would have you "cruising" at over 380mph according to this chart.
I wonder what the fuel burn was if cruising at 310-320mph true??

'AUTO RICH' consumes more fuel than 'AUTO LEAN'.

'AUTO RICH' for power or better cooling and 'AUTO LEAN' was usually used for cruising.

Eventually, Both F4U and F6F were offically cleared to use 30 minutes military power and unlimited normal rated cruise with 'AUTO LEAN'.

The F6F's handbook was 1 May 1946 version and the F4U-1's handbook was at least revised after 1 June 1944.

Odd how normal power is faster then military power on that chart.

F4U-1 was first fighter with production model R-2800, so it suffered from various initial problems. One of them was high-altitude performance, Birdcage Corsairs just after deployment were not allowed to fly above 29,000 feet. Due to early Corsair's operational experience, the R-2800 has been improved for battle. Hellcats and rised cabin Corsairs, which were able to appear on the battlefield with most problems resolved, were lucky.

 

[DarrenW]

hmmmm.
View attachment 502778

Yep, 250 gph at 22-24,000ft "Normal Power (max. Continuous)"

except.
View attachment 502779
that max continuous (Normal) power would have you "cruising" at over 380mph according to this chart.
I wonder what the fuel burn was if cruising at 310-320mph true??

First off, that chart is for the Corsair, not the Hellcat. P-39 Expert lumped them both together in his original post. I have three Hellcat pilot manuals and none of them show figures for that sort of fuel usage. Here's the source for my figures:

Secondly, what pilot would elect to fly at max continuous power settings while cruising to the target area (whether ETO or otherwise)? That's a great way to run out of fuel. That's what the cruise settings are used for. As you can see with the Hellcat example, the fuel burn rate is basically cut in half by dialing down manifold pressures, RPMs, and running an auto lean mixture. Speed is still a respectable 283 mph.

But again, I'm not advocating that the Hellcat could have been used for high altitude bomber escort, you and others have already convinced me otherwise. I'm just talking range and radius in the general sense and what effects them.

 

[DarrenW]

'AUTO RICH' consumes more fuel than 'AUTO LEAN'.

'AUTO RICH' for power or better cooling and 'AUTO LEAN' was usually used for cruising.

Eventually, Both F4U and F6F were offically cleared to use 30 minutes military power and unlimited normal rated cruise with 'AUTO LEAN'.

View attachment 502780 View attachment 502781

The F6F's handbook was 1 May 1946 version and the F4U-1's handbook was at least revised after 1 June 1944.



F4U-1 was first fighter with production model R-2800, so it suffered from various initial problems. One of them was high-altitude performance, Birdcage Corsairs just after deployment were not allowed to fly above 29,000 feet. Due to early Corsair's operational experience, the R-2800 has been improved for battle. Hellcats and rised cabin Corsairs, which were able to appear on the battlefield with most problems resolved, were lucky.

Sorry Dawncaster, seems that I stepped on your toes a bit here and repeated some of what you already stated. We obviously were responding at roughly the same time...

 

[Dawncaster]

First off, that chart is for the Corsair, not the Hellcat. Here's the source for my figures:

Secondly, what pilot would elect to fly at max continuous power settings while cruising to the target area (whether ETO or otherwise)? That's a great way to run out of fuel. That's what the cruise settings are used for. As you can see with the Hellcat example, the fuel burn rate is basically cut in half by dialing down manifold pressures, RPMs, and running an auto lean mixture. Speed is still a respectable 283 mph.

But again, I'm not advocating that the Hellcat could have been used for high altitude bomber escort, you and others have already convinced me otherwise. I'm just talking range and radius in the general sense and what effects them.

If only consider the range and cruise speed Corsair may be slightly better than Hellcat, even without auxiliary fuel tanks in the wing, the Corsair has equivalent range and faster cruising speeds. Well, both models were not capable at ETO as escort fighters, but they can be good low and medium altitude fighters. Tempest and Typhoon which had similar operational altitudes would fight together.

Sorry Dawncaster, seems that I stepped on your toes a bit here and repeated some of what you already stated. We obviously were responding at roughly the same time...

Like many confused dogfights!

 

[DarrenW]

...... Remember you have at least one 150gal drop tank to knock about 40mph off your speed.....

From what I can tell from US Navy documents, the 150 gallon centerline tank used by the Hellcat decreased top speed anywhere from 10-20 mph, depending on altitude (greater loss at height, due to increased speeds). 40 mph deficits at any height/speed sound excessive to me.

Are you sure you're not talking about two tanks used on the Corsair and lumping the two aircraft together again?

 

[DarrenW]

If only consider the range and cruise speed Corsair may be slightly better than Hellcat, even without auxiliary fuel tanks in the wing, the Corsair has equivalent range and faster cruising speeds. Well, both models were not capable at ETO as escort fighters, but they can be good low and medium altitude fighters. Tempest and Typhoon which had similar operational altitudes would fight together.



Like many confused dogfights!

agreed!

 

[Shortround6]

the

First off, that chart is for the Corsair, not the Hellcat. P-39 Expert lumped them both together in his original post. I have three Hellcat pilot manuals and none of them show figures for that sort of fuel usage. Here's the source for my figures:

View attachment 502784

Secondly, what pilot would elect to fly at max continuous power settings while cruising to the target area (whether ETO or otherwise)? That's a great way to run out of fuel. That's what the cruise settings are used for. As you can see with the Hellcat example, the fuel burn rate is basically cut in half by dialing down manifold pressures, RPMs, and running an auto lean mixture. Speed is still a respectable 283 mph.

But again, I'm not advocating that the Hellcat could have been used for high altitude bomber escort, you and others have already convinced me otherwise. I'm just talking range and radius in the general sense and what effects them.

I am actually on your side.
He was right, the chart does show the gph he said, however the the power setting and thus the fuel flow he claimed would never have been used and did not need to be used in when cruising either the F4U or F6F at the speeds/attitudes in question.

As to drop tanks and loss of speed. Using the loss of max speed with tank/s to compute the loss of speed when cruising is also wrong. the penalty of carrying the tanks at 300mph is going to be less than at 400mph. It will be proportional. not a flat loss of 40mph regardless of speed when clean.

 

[P-39 Expert]

the

First off, that chart is for the Corsair, not the Hellcat. P-39 Expert lumped them both together in his original post. I have three Hellcat pilot manuals and none of them show figures for that sort of fuel usage. Here's the source for my figures:

View attachment 502784

Secondly, what pilot would elect to fly at max continuous power settings while cruising to the target area (whether ETO or otherwise)? That's a great way to run out of fuel. That's what the cruise settings are used for. As you can see with the Hellcat example, the fuel burn rate is basically cut in half by dialing down manifold pressures, RPMs, and running an auto lean mixture. Speed is still a respectable 283 mph.

But again, I'm not advocating that the Hellcat could have been used for high altitude bomber escort, you and others have already convinced me otherwise. I'm just talking range and radius in the general sense and what effects them.

Same engine in Corsair and Hellcat.

You flew at normal/max continuous when escorting B17/B24 over Europe. LW had you on radar from the time you took off and know exactly where you are. So likely they are above you, if only barely.

Now there may be times or situations where you can back off the throttle a little, but you certtainly better PLAN your mission at normal/max continuous.

 

[DarrenW]

You flew at normal/max continuous when escorting B17/B24 over Europe....

Is this really true guys? I hail to the other "experts" here on the subject because I'm more of a PTO fella....

 

[DarrenW]

I

As to drop tanks and loss of speed. Using the loss of max speed with tank/s to compute the loss of speed when cruising is also wrong. the penalty of carrying the tanks at 300mph is going to be less than at 400mph. It will be proportional. not a flat loss of 40mph regardless of speed when clean.

Gotcha! So we can expect even less of a penalty while flying at the slower cruising speeds....

 

[Shortround6]

Same engine in Corsair and Hellcat.

You flew at normal/max continuous when escorting B17/B24 over Europe. LW had you on radar from the time you took off and know exactly where you are. So likely they are above you, if only barely.

Now there may be times or situations where you can back off the throttle a little, but you certtainly better PLAN your mission at normal/max continuous.

No. You did not. you flew at a speed that allowed you to accelerate up to combat speed in a short period of time without burning up all your fuel in the meantime.

If the bomber stream is moving at 180-200mph true and you are weaving above at 300-320mph you are actually flying over 50% further than the bombers.
If you are blasting around at 360-400mph at max cruise then you are flying twice as a far as the bombers for each mile the bombers make towards the targets in Germany and nobody had enough fuel to do that.
Usually what was wanted was max lean or close to it NOT max continuous.

 

[wuzak]

Odd how normal power is faster then military power on that chart.

Not really.

Firstly, military power is faster at the same altitudes, up to about 23,500ft, except fro a small part around 20,000ft due to gear change.

Secondly, the extra boost and rpm shows in a shift to lower altitudes.

I suspect that over 23,500ft the supercharger can't make as much boost as normal power at that rpm and/or the drive power requirements have gone way up.

 

[P-39 Expert]

No. You did not. you flew at a speed that allowed you to accelerate up to combat speed in a short period of time without burning up all your fuel in the meantime.

If the bomber stream is moving at 180-200mph true and you are weaving above at 300-320mph you are actually flying over 50% further than the bombers.
If you are blasting around at 360-400mph at max cruise then you are flying twice as a far as the bombers for each mile the bombers make towards the targets in Germany and nobody had enough fuel to do that.
Usually what was wanted was max lean or close to it NOT max continuous.

Bomber stream is more like 220-240mph and with drop tank you are going 340-350mph and weaving to stay with the slower bombers. Maybe after mid '44 after the LW had been beaten down you could cruise at lower than normal power, but in late '43 and the first half of '44 you better plan your mission at normal power.

In any event, range (actually internal fuel capacity) would have precluded the Corsair and Hellcat from long range bomber escort duty in Europe.

 

[Shortround6]

You have, of course, some sort of documentation to back that up?

It is contrary to what the the planning charts called for. Granted they are guidelines and individual missions would vary but using your standards would mean very short ranges/radius indeed. An early P-47 (clean) burned 190-210gph at max continuous and at 25,000ft it did 360mph true using 190gph. Since it burned 91 gallons take-off and climbing to 25,000ft that sure doesn't leave much fuel for reserve let alone combat.
We know that early P-47s were short radius but this is ridiculous. 15 minutes at military rating (and not including 5 minutes at WEP) will burn about 68 gallons.

However using the planning charts 210mph IAS at 25,000ft (around 310-315 true) the P-47 burns about 120 gallons an hour. That is is estimate as the flight instruction chart has no listing for that speed, however 200IAS at 25,000ft burns 95 gph and 225IAS burns 145gph.

A P-38G with underwing tanks burned around 220gph to do 360mph true at 25,000ft. at max continuous At 215IAS at 25,000ft it burned about 110gph.
That extra 40-45mph cost an awful lot of fuel.

 

[Milosh]

B-17 manual, B-17 Pilots Manual.pdf

 

[Shortround6]

So about 143 IAS at 25,000ft when running at 55,000 to 60,000lbs but that is not formation flying which is slower ?

Bombers sure aren't doing 240mph true.

 

[P-39 Expert]

So about 143 IAS at 25,000ft when running at 55,000 to 60,000lbs but that is not formation flying which is slower ?

Bombers sure aren't doing 240mph true.

Janes listed the B-17 cruising speed at 220mph and B-24 at 237mph. That's about 150mph indicated. They were slow.

You can fly at whatever speed you want, but only a fool would fly over occupied France or Germany at less than normal power at minimum 25000'. You could not hide from radar and you were already a sitting duck with that big drop tank. If you had the chance to save fuel of course you would take it, but you had to plan your mission for normal power.

Your (clean) Thunderbolt example right out of the manual: 305gal internal
- 45gal reserve for take off and climb to 5000'
- 70gal reserve for 15min combat (275gph)
- 27gal reserve for landing (20min at 80gph)
163gal available at 190gph normal power = .86hr x 225mph (bomber speed) = 195mi or call it a 100 mile radius. Not quite to the German border.

 

[DarrenW]

Janes listed the B-17 cruising speed at 220mph and B-24 at 237mph. That's about 150mph indicated. They were slow.

What is the point that you're trying to make? The cruise speeds of the Fort and Lib at bombing altitudes are still far lower than the cruise speeds of the majority of American fighters in service at the time (save for the P-39). I believe the points that SR6 has made thus far are still valid even while using your sources.