F4U in Europe
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I needed google, but I got there.
fubar57
General
Wasn't that from the Wild
Yes, rumor / legend has it during WW Nam a new guy was brought into the squadron and when someone explained their mission that was his reply. It then became part of their lore and adorned many of their patches.
I did several deployments / TDYs with them. The Snacko (the guy who keeps the snack bar and beer fridge stocked) was a Major. Usually it's the newest guy in the squadron (a 1st Lieutenant), but when rank is top heavy then the lowest rank gets the nod. It was a very senior squadron, and every one of them I dealt with was a great guy.
1994 timeframe I take off from Dhahran as number #2 of 2 Eagles, tasked with protecting 1 AWACs, 1 KC-10A, and 4 F4Gs, aka Geasels. We go fly the sortie arriving over Iraq just after the sun has come up, call it MacAir appreciation day and 4.5 hours later come home. I run into the F4G snacko (previously mentioned Major) and he and another guy are giggling like school girls. So senior guys yucking it up means some classic prank has been executed. Come to find out they formed into an echelon formation, went full burner as high as they could go (low 30s - 2 drop tanks, 2 HARMs, 4 AIM-7 and 4 AIM-9) and flew into the SA-2 ring around Tallil, Iraq. They then peeled off one at a time and did a full burner dive down to 10k over the town, obviously supersonic, and as a flight probably kept the local glass guy in business for years. It was Saddam Hussein's birthday...
Cheers,
Biff
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GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
My Uncles were retired Navy Chiefs - I knew that from a tender young age
FLYBOYJ
"THE GREAT GAZOO"
Along with drinking really strong black coffee and about 20 horrific curse words that could set a nun's habit on fire!My Uncles were retired Navy Chiefs - I knew that from a tender young age
wuzak
Captain
I wonder why the P-39 burns less fuel at 25,000ft than at 12,000ft?
What is "minimum power"?
Are you talking about most economical cruise?
What cruise setting was the B-17 using for 225mph at 25,000ft? I'm betting that cruise speed was dictated by formation flying, rather than aircraft capability.
What speed could a B-17 at 25,000 cruise using maximum continuous?
Not sure if the ratio between max continuous and combat power works the same at 25,000ft as it does at 12,000ft.
What rpm does max continuous use at 25,000ft? Is it different to combat power?
There is more than one cruise setting. Which ones are you using for this comparison?
Noting that the P-51, for one, could cruise at 300mph+ at 25,000ft.
A Spitfire PR.XI could cruise at 397mph @ 31,000ft, and 378mph @ 38,000ft. These are maximum continuous cruise speeds.
How does this all compare to the F4U-1 cruise performance?
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
It's great when things get back to normal.
wuzak
Captain
So I had a look for myself in the
To try and calculate range.
Full internal fuel (87 USG) and external tank (75 USG) is 162 USG (which the manual rounds up to 165 USG?). This gives a t/o weight of ~8,100lb.
In the Take-off, Climb and Landing Chart the following numbers are given for climb to 25,000ft.
That is, allow 39 USG for the P-39Q to climb to 25,000ft*. The note at the bottom says "fuel includes warm-up and take-off allowance".
That leaves 126 USG for cruising, fighting and reserve. The manual does not specify a reserve, either in USG or time.
The Flight Operation Instruction Chart says that at maximum continuous the speed is 287mph TAS, fuel consumption is 62 USGPH.
That would give a cruising time of 2.03 hours, or 583 miles. But that does not give allowance for combat or reserve. I can't find an actual fuel consumption for combat power either.
Maximum speed for the P-39Q at 25,000ft is 361mph from 772hp. If we use the ratio of speeds to calculate combat consumption at 25,000ft we get approximately 83 USGPH.
But the Note in the instructions for using the chart says that maximum continuous power is for Emergency Use Only.
That means that the bulk of the cruising will have to be performed at 20,000ft or lower.
179mph IAS ~ 250mph TAS.
Assume 30 minutes @ maximum continuous at 25,000ft, that gives 133.5 miles, used 31 USG.
Assume 5 minutes at Combat power at 25,000ft ~4 USG (don't count distance traveled as it could be further away).
That leaves 126 - 4 - 31 = 91 USG for cruise.
If we use the fastest cruise that we can for a sustained period, that is 250mph @ 20,000ft using 76 USG per hour, we get a total cruise time of 1.19 hours.
We may want a 20 minute reserve, which is 0.33 hours, gives remaining time of 0.86 hours. At 250mph that is 216 miles.
Total range is 216 miles + 133.5 miles ~ 350 miles.
Seems wrong. I must have messed up somewhere.
* The Flight Operation Instruction Chart gives 20 USG allowance for warm-up and take-off and climb to 5,000ft, but the Take-off, Climb and Landing Chart shows 25 USG for 8,100lb take-off weight.
To try and calculate range.
Full internal fuel (87 USG) and external tank (75 USG) is 162 USG (which the manual rounds up to 165 USG?). This gives a t/o weight of ~8,100lb.
In the Take-off, Climb and Landing Chart the following numbers are given for climb to 25,000ft.
That is, allow 39 USG for the P-39Q to climb to 25,000ft*. The note at the bottom says "fuel includes warm-up and take-off allowance".
That leaves 126 USG for cruising, fighting and reserve. The manual does not specify a reserve, either in USG or time.
The Flight Operation Instruction Chart says that at maximum continuous the speed is 287mph TAS, fuel consumption is 62 USGPH.
That would give a cruising time of 2.03 hours, or 583 miles. But that does not give allowance for combat or reserve. I can't find an actual fuel consumption for combat power either.
Maximum speed for the P-39Q at 25,000ft is 361mph from 772hp. If we use the ratio of speeds to calculate combat consumption at 25,000ft we get approximately 83 USGPH.
But the Note in the instructions for using the chart says that maximum continuous power is for Emergency Use Only.
That means that the bulk of the cruising will have to be performed at 20,000ft or lower.
179mph IAS ~ 250mph TAS.
Assume 30 minutes @ maximum continuous at 25,000ft, that gives 133.5 miles, used 31 USG.
Assume 5 minutes at Combat power at 25,000ft ~4 USG (don't count distance traveled as it could be further away).
That leaves 126 - 4 - 31 = 91 USG for cruise.
If we use the fastest cruise that we can for a sustained period, that is 250mph @ 20,000ft using 76 USG per hour, we get a total cruise time of 1.19 hours.
We may want a 20 minute reserve, which is 0.33 hours, gives remaining time of 0.86 hours. At 250mph that is 216 miles.
Total range is 216 miles + 133.5 miles ~ 350 miles.
Seems wrong. I must have messed up somewhere.
* The Flight Operation Instruction Chart gives 20 USG allowance for warm-up and take-off and climb to 5,000ft, but the Take-off, Climb and Landing Chart shows 25 USG for 8,100lb take-off weight.
wuzak
Captain
It seems to me that the manual is not set up to calculate range at 20,000ft or 25,000ft for the P-39Q.
FLYBOYJ
"THE GREAT GAZOO"
I think you've done well. If you take your total range calculation it gives a radius of ~175 miles, which sounds about right under the best conditions.
but our stubborn friend keeps making delusional statements:
You don't need to make this easier on the pilot and no where does it indicate that on the chart! That's why you have a climb chart and E6B! All this is taught in ground school, something that our friend doesn't understand!
I guess pixie dust will get you 20,000'!
It seems you understand this!
And this!
He refuses to acknowledge that you have to do climb calculations with the climb chart on the previous page. The cruise chart will give you the 20 gallon allowance to 5000' but you have to calculate climb depending on the rate of climb and power settings used.
If you factor that in the total range/ operating radius drops even further.
I have no problem with your query on this but I'm only going to allow this broken record discussion to go on for only so long.
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drgondog
Major
The primary reason is that no one was stupid enough to assume that a P-39 would be useful at those altitudes - not for interception, convoy protection, CAS or Short Range Escort of B-17s to French Coast befor turning back. Therefore, desiring to be held as reasonably agile-mentally, nobody prepared science fiction scenarios for their superior officers at Materiel Command.
The Legend in His Own Mind is hopelessly in love with the runt tart 'that couldn't'...
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
And never, Never clean their coffee mug!!
Regarding the recent reemergence of the Bell product, let's look at it in reverse.
During the Battle of Britain, what was the ONE single most short-coming of the Bf109?
Power/speed? Nope.
Performance at any altitude? No.
Armament? More nope.
Than what could it possibly have been?
Range. It lacked range.
You can have a world-beater (real or imagined) and if it doesn't have the range to get the job done, fix it or find something that can.
The Germans fixed their problem (sort of), the Americans found something else that worked (obviously).
Clayton Magnet
Staff Sergeant
- 912
- Feb 16, 2013
Good thing the British didn't get ahold of the P-51 first, and destroy its reputation with outlandish requirements like the P-39!
We could have lost the war
We could have lost the war
They tried, fortunately NAA were just too smart.
drgondog
Major
In all seriousness, the RAF/Air Ministry were exceedingly helpful in both analysis and demonstrated improvements beginning with NA-73 product improvement and extending through sharing knowledge gained operationally - such as cockpit layout, gun mounts and feed systems, camera installation, etc. Did I mention doing damn fool things like installing Merlin 61?
One of the very prominant members on this forum, Colin Ford, was exceedngly helpful in fleshing such important trivia for the Bastard Stepchild book.
BTW, NAA specifically developed the XP-51B (NA-101) as a letter extension to preclude Wright Field from getting their hands on a Spec writing engagement. ALL WWII Development through B-45 and F-86 were done without 'helpful' assistance of Materiel Command.
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SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Could you expand on "Spec writing engagement"?
wuzak
Captain
I apologize, I was more interested in the exercise of working through the range calculations for myself rather than reigniting that discussion.
I will have to look back in the thread to see if there were similar calculations made for the F4U in determining its suitability as an escort.
drgondog
Major
The MC wanted to dive into the XP-51B discussion and specify performance, etc. NAA told them 'hold my beer - we got this'. NAA suggested that breaking loose the Packard Merlin 1650-3 after Wright Bench tests Would Be Helpful, but once they showed Wright Field that the Mustang had been developed to EXISTING and Published AAC standards for Strength, etc they offered no real resistance.
Lee Atwood was a graduate Structures engineer from University of Texas - with first job at Wright Field and carried AAC 'standards' with him to Douglas, then to NAA. At one time the 'Echols Acolytes' tried to excuse ignoring the Mustang based on NAA using BAM/RAF design Limit/Ultimate Load standards - which are less but only slightly less than AAC/AAF in late 1930/early 1940s. The P-51H was desiged to Spitfire norm, and was ultimately stronger save the landing gear than P-51B/D at design Gross Weight,
Actually they did. As Bill will tell you the British suggested fitting the Merlin to the Mustang first and not for the Americans, but for the RAF. The British even expressed the view that the type should be licence built in Britain (by Gloster) with Rolls-Royce supplying the engines, all, again, for British use before the USAAF got hold of the type. It was Rolls-Royce who put a Merlin in a Mustang first and the information was shared between RR and various US agencies for their benefit, but originally it was for the aircraft to be supplied to the RAF.
