Groundhog Thread Part Deux - P-39 Fantasy and Fetish - The Never Ending Story (Mods take no responsibility for head against wall injuries sustained) (2 Viewers)

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Dude, there is no doubt to me you are trolling now, if I had any previous doubts you've removed them with this response to drgondog
 
P-39 Expert said:
Please, I have never said that a P-39 was a "Super Escort". The question was could it escort bombers in Europe. I have proven that many times by using information from the pilot's manual.
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The Mustang Mk II/ P-51A if fitted with a rear internal tank would have more internal fuel than your P-39 has in total, it could also carry external tanks. It did 410MPH at 10,000ft and was, at the time, one of if not the fastest at that altitude. 1,500 were made 50 went to the British/RCAF, it our performed the P-39 in every way but was not considered for long range escort, why cant you consider you just got it wrong.
 
Did not outperform the P-39N in climb, ceiling or turning radius. Speed was about 10-15mph difference.
 
P-39 Expert said:
Did not outperform the P-39N in climb, ceiling or turning radius. Speed was about 10-15mph difference.
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You need to remember your P-39 has a 110gal tank on, and when it drops it it still has the shackles, the difference in performance is in the tests I posted but which you havnt read. This was mentioned in Drgondogs post but you didnt read that either.
 
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P-39 Expert said:
I guess I don't know what trolling means. Can you enlighten me?
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Internet troll - a person who intentionally tries to instigate conflict, hostility, or arguments in an online social community.

Common characteristics include:
- Continuing with a line of argument even after it's been thoroughly debunked.
- Ignoring posts that contradict the argument being made.
- Changing the scope of the argument when contradictory evidence has been provided.
- Making statements without providing evidence to support the assertion.
 
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FLYBOYJ said:
For the sake of discussion here are the charts. Colors were added by me.

View attachment 632925

View attachment 632926

View attachment 632927

LET THE GROUNDHOGGERY BEGIN!
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While you are at it, get your red pen and circle "At 12000 Ft Only" at the top of column 1 of the Flight Operation Instruction Chart (range chart).

We're still figuring range and combat radius, right? On the Specific Engine Flight Chart you have the Fuel Flow column circled in yellow. Those numbers are for 14000'-15500'. What does that have to do with cruise or combat fuel flow at 25000'? Absolutely nothing.

Then on the Takeoff, Climb and Landing Chart you have Time From SL and Fuel Flow From SL circled in red. What does that have to do with range? Absolutely nothing. In the 8000lb row (drop tank) the 25000' column shows 29.9 minutes and 31.2gal from SL. The 31.2gal figure is a misprint when compared with the other figures in that column. Probably meant 42gal or so like the P-39N chart. Anyway, how far is this plane traveling in the 29.9 minutes that it takes to climb to 25000'? Since the plane climbs at about 170mph IAS then the average TAS is about 220mph. In that 29.9 minutes the plane has traveled 110mi. Unless of course the plane is climbing AWAY from the target, or somehow helicoptered up to 25000' without moving toward the target. These figures are worthless when figuring range.

Go to the Flight Operation Instruction Chart. This is the range chart. Go to any column. Divide the gallons available by the U.S GPH (gallons per hour) to get flight time. Multiply that by the IAS then convert that to TAS. As an example use column III at 15000'. 145gal divided by 70gph = 2.07hrs. 2.07 hrs x IAS 206mph = 426mi. Convert to TAS = 554mi. Now go up the column to the Range In Air Miles at 145gal. It says 499mi, not 554mi. The very smart AAF officers who put together this chart have already factored in the total fuel used and the miles gained while climbing to 25000'. They did this so the pilot can simply deduct the 20gal for warmup and climb to 5000' from total fuel and the range values work for any altitude and power setting. The pilot doesn't need to worry about the actual fuel used or the miles gained while climbing. It's already figured in the chart.

Don't use figures from the Takeoff, Climb and Landing Chart or the Specific Engine Flight Chart. They are not for figuring range. Use the Flight Operation Instruction Chart. Deduct the 20gal Takeoff and Climb allowance from total fuel. The rest is done for you.
 

This is absolute bollocks. Every mission...repeat EVERY mission involving long-range escort would factor in weather, particularly winds, to ensure that the required range could achieved. Apply any headwind and your range will be reduced because you have to use more fuel to overcome the additional drag...oh, and winds change during a long mission so it's entirely possible to have headwinds in both directions, or to have tailwinds in both directions. All of that has to be planned into the mission. Pilots didn't just read off a chart, climb into their jalopy and commit aviation.

As has been pointed out many times (but you keep ignoring it) the range for a single aircraft is not the same as the range for a squadron of aircraft. You can't take off an entire squadron all at once, which means some amount of time will be spent forming up in the air. This was typically done by flying circuits around the home airfield until all the aircraft were in formation, and only then setting course for the target. All that time circling will use up fuel that can't be used on the mission. Then you have aircraft within the formation offering differing performance or being unable to maintain a constant throttle setting due to formation keeping. All of that will burn more fuel per aircraft than the case for a single aircraft.
 
I posted the charts for the P-39 N and Q and both sets of flight operation instruction chart contain this statement, varying with configuration:



So that chart tells me that there is a 20 gallon allowance for warm up and climb to 5000'.

BUT on the climb data chart we have this:



it also says this on the bottom of the same chart;



If you look at the climb chart and flight operation instruction chart. they are in conflict with each other as the climb to 5000' is more than 20 gallons (depending on weight)




So let me put this out there to my fellow pilots, especially Wes, Bill and Biff (if you wish to partake in this groundhoggery) who are all ATPs and have way more time in the air than this Commercially Rated CFII who only flies SEL aircraft - how would you interpret this?

 
P-39 Expert said:
Did not outperform the P-39N in climb, ceiling or turning radius. Speed was about 10-15mph difference.
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You have never answered this question which has been put a number of times.

If the P39N (the one you always quote) was so good, why did they produce thousands of the P39Q?

I mention this :-
a) Because I would like to know
b) Every other combat aircraft I can think of improved with the exception of the P39, why was that?
 
SaparotRob said:
I don't think you are getting in the spirit of the thread.
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He loses me as soon as he mentions heading straight to a target, they took off, formed up as a group then formed up with others and headed straight to a rendezvous at a certain time an place, then did what they had to do until someone else did it at another RDV. Even PR pilots flying alone didnt head straight to anywhere, they avoided flack and fighter bases and changed course regularly to avoid being intercepted. If you always head straight to where you want to go you give your opponents hours to prepare an attack. Oh and if you head straight to Berlin from most US bases in South East England you fly over all the heavily defended areas of Netherlands the Ruhr and Hanover. Duisburg, Mulheim, Essen, Dortmund, Hanover and Berlin are aligned pointing to England like the stones in Stonehenge.
 
The P-39 just flies higher than the flak. D'uh.
 
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