Groundhog Thread Part Deux - P-39 Fantasy and Fetish - The Never Ending Story (Mods take no responsibility for head against wall injuries sustained) (3 Viewers)

[pbehn]

[Emphasis added -- Thump]

Forming up takes both time and fuel. I don't understand why our friend here doesn't seem to take that into account.

Unusually for me I was trying to be fair. Parks instructions were for pilots and squadrons and wings that had to climb to high altitude above their airfields, not to some RV point over the N Sea, that may be done more economically, I dont know. But the general point is the same, you cant do the same with a lot of anything that you can with one or two. Ask a school teacher about going on a walk with 30 children or their own 2 sons/daughters. To me the significant thing in Parks instructions was reference to a "good squadron", he was no longer a pilot he was a commander, in statistics he would refer to a good squadron and in his other work try to turn a bad squadron into a good one, thereby upping the average, in this case by decreasing time taken.

 

[Thumpalumpacus]

To me the significant thing in Parks instructions was reference to a "good squadron", he was no longer a pilot he was a commander, in statistics he would refer to a good squadron and in his other work try to turn a bad squadron into a good one, thereby upping the average, in this case by decreasing time taken.

[Emboldening added -- Thump]

You're right that that is an unusual qualifier. It's not a word a commander puts into a report without drawing significance to that modifier.

 

[FLYBOYJ]

From the Manual for P-39N-1-BE. Gross weight at startup: 7,967 lbs. So, use the figures for 8,000 lbs.

I was likely being kind when I called the P-39N a loggerheaded, swag-bellied, hedge pig ... uuhhh ... groundhog.

Try the same calculations at 20 or 25,000 feet! We beat this horse to death several dozen pages ago of course to no avail.

 

[pbehn]

Try the same calculations at 20 or 25,000 feet! We beat this horse to death several dozen pages ago of course to no avail.

After "proving" that the P-39N could have been one of the periods best interceptors, we are now seeing the proof that it could also have been the second best long range escort fighter, if only the fools could have seen it at the time.

 

[Thumpalumpacus]

[...] To throw some gasoline into the fire, we haven't even brought up this fact during our range/ fuel calculations, let alone not flying in a straight formation, constantly making shallow turns within the flight while not only making yourself a harder target but scanning for enemy aircraft.

And now the planes on either outlier of the formation are having to horse the throttles around even more as the formation turns to and fro' doing the escort weave. This in a plane that might not get me to the bathroom without a refueling stop.

 

[FLYBOYJ]

And now the planes on either outlier of the formation are having to horse the throttles around even more as the formation turns to and fro' doing the escort weave. This in a plane that might not get me to the bathroom without a refueling stop.

If you maintain a V or finger 4. The Germans had a good technique (I think developed by Molders) where the wingman would move up while the lead tightened his turn, this was done simultaneously within a 4 plane formation.

 

[33k in the air]

And now the planes on either outlier of the formation are having to horse the throttles around even more as the formation turns to and fro' doing the escort weave. This in a plane that might not get me to the bathroom without a refueling stop.

Hence why the relay escort method came into use. Rather than staying with the bombers all the way, greatly reducing escort range, now the fighters flew at their own cruising speed to the rendezvous point, met up with bombers, escorted them for about 100 miles or half an hour, at which point they were relieved by the next escort fighter group.

 

[Shortround6]

. Assume we allow for 10 minutes of combat. Combat would be at 44.5 MAP and 147 gal per hour per 8,000 pound chart, top left. 10 minutes at 147 gph burns 24.5 gallons, leaving 102.3 gallons of fuel.

This only applies if combat was at around 15,000ft.

At 25,000ft the Allison is making about 770hp while in flat out level speed or about 740hp when climbing (less RAM).

Of course even a fuel burn of 94 gallons a hour means 31-32 gallons for a combat allowance for 20 minutes and not 25 gallons.

If the plane descends to 20,000ft the power goes to about 900 hp (higher in level flight, lower in climb) but the fuel burn goes from about 1.5 gallons per minute to about 1.9 gal per minute.

Power figures from the P-39Q test.

The "expert" seems to think that the P-39, which is starving for air and thus can't burn any more fuel, is going to get both good gas consumption and good performance.

 

[nuuumannn]

Wasn't that the problem with Bader's Big Wing during the BoB?

Pretty much, a wee snippet from my well-thumbed copy of Bungay's The Most Dangerous Enemy:

"Assuming it climbed at its optimal speed [I'm assuming he means Best Rate Climb here], a Spitfire would take about 23 minutes to cover the 70 miles from Duxford to Canterbury. It could take off about five minutes after the first radar warning of a build-up over Calais. A bomber travelling at 180 mph would reach Canterbury in 14 minutes. Even without adding in time for forming up, and assuming the Wing used Spitfires rather than the slower Hurricanes, which would take longer, a German bomber formation would be over Canterbury in half the time it would take a single fighter from Duxford to get there. The whole thing was absurd."

PO Tom Neil of 249 Sqn had this to say about the Big Wings, "All too frequently, when returning to North Weald in a semi-exhausted condition, all we saw of 12 Group's contribution to the engagement, was a vast formation of Hurricanes in neat vics of three, steaming comfortably over our heads in pursuit of an enemy who had long since disappeared in the direction of France. Our reactions on such occasions, though mostly of resigned amusement at first, grew to be more harshly critical later on."

There were pilots who were critical of the practice who took part in it, Flt Lt Douglas Blackwood of 310 Sqn stated that it was often chaos at the back of the formation with people being left behind, but Bader up front never saw that side of it. Another pilot, 19 Sqn's Frank Brinsden recalled that the Big Wings were a disaster that achieved nothing because they broke up during combat at any rate.

And in my truck, cruise control is near-useless in traffic because I must consistently adjust throttle to "fly" with traffic. It's great on open highway when everyone is doing the same speed. It follows that I get better mileage driving an empty road than stop-and-go through a freeway jam.

Same in my V8 Commodore, smooth fuel consumption on the open road when I reach the engine's sweet spot, but in traffic around town it's a whore of a thing.

 

[Thumpalumpacus]

If you maintain a V or finger 4. The Germans had a good technique (I think developed by Molders) where the wingman would move up while the lead tightened his turn, this was done simultaneously within a 4 plane formation.

View attachment 632579

I had larger escort formations in mind when I wrote that, and I should have made that plain. My apologies for not being as clear as I should have. And if I'm not understanding escort protocols right, that's on me. I'm thinking 24 fighters or so weaving above a formation of bombers. Am I missing something? Did sections stay in specific sectors over the bombers?

 

[FLYBOYJ]

I had larger escort formations in mind when I wrote that, and I should have made that plain. My apologies for not being as clear as I should have. And if I'm not understanding escort protocols right, that's on me. I'm thinking 24 fighters or so weaving above a formation of bombers. Am I missing something? Did sections stay in specific sectors over the bombers?

What I showed was just a basic maneuver for fighters, no apologies required. You got it right.

 

[nuuumannn]

If you maintain a V or finger 4. The Germans had a good technique (I think developed by Molders) where the wingman would move up while the lead tightened his turn, this was done simultaneously within a 4 plane formation.

A Kette, which was based around the Rotte, which was a fighter and his wingman, two Rotten made a Kette, [and two Ketten made a Litter ] which was eminently more flexible than, say the British Vic, which was cumbersome and required the guys inside to be throttling back while the guys on the outside would be powering up to maintain formation with the leader. I believe the British later adopted the Finger Four too. The Vic was adopted as the standard formation because a Vic of three made up a Section, of which two Sections made up a Flight and two Flights made up a Squadron.

 

[Thumpalumpacus]

A Kette, which was based around the Rotte, which was a fighter and his wingman, two Rotten made a Kette, [...]

I got that from Caldwell's book on JG26, yeah.

I always loved the term rottenfuhrer -- god knows I've had enough of those!

 

[Shortround6]

I had larger escort formations in mind when I wrote that, and I should have made that plain. My apologies for not being as clear as I should have. And if I'm not understanding escort protocols right, that's on me. I'm thinking 24 fighters or so weaving above a formation of bombers. Am I missing something? Did sections stay in specific sectors over the bombers?

Drgondog would be the expert but my understanding is that the fighter formations did a series of S turns over the bombers to keep their airspeed up while remaining over or near the bombers. Trying to accelerate form bomber cruise speed to combat speed for fighters could take 2 or more minutes, at which time the attackers have come and gone.

 

[nuuumannn]

rottenfuhrer

"Herr Oberst, the Rottenfuhrer"

"Yes, I believe he is..."

 

[Thumpalumpacus]

Drgondog would be the expert but my understanding is that the fighter formations did a series of S turns over the bombers to keep their airspeed up while remaining over or near the bombers. Trying to accelerate form bomber cruise speed to combat speed for fighters could take 2 or more minutes, at which time the attackers have come and gone.

Thanks for that. I think where my thinking might be faulty is whether all the fighters did a weave over the bomber formation, or whether fighter sections performed individual weaves over an assigned sector of the formation?

 

[Milosh]

Iirc there was close escort and extended escort. The extend (not sure this is the correct word) flew some distance out in front of the bomber formation. The close escort, one group on each side and one trailing the bombers.

edit: this might have come one of the Mighty Eighth books

 

[33k in the air]

Thanks for that. I think where my thinking might be faulty is whether all the fighters did a weave over the bomber formation, or whether fighter sections performed individual weaves over an assigned sector of the formation?

The document Development of the Long-Range Escort Fighter on pages 70, 93, and 119 has illustrations showing the way the escorts were positioned and flew.


ETA: There is also this from Target Berlin regarding the 6 March 1944 mission (p.14):

When fully assembled, the bomber stream for a large attack could be more than 90 miles long. Because they cruised somewhat faster than bombers and had to zig-zag to maintain station on them, individual fighter groups could not cover bombers for much more than 30 minutes at a time before fuel began to run low and they had to break away. As a result only a small proportion of the available escort fighters would be in position to cover bombers at any one time. On 6 March only rarely would there be more than 150 escorts in position; if these were distributed evenly along the length of the bomber stream there would be an average of only three fighters for every two miles of airspace. Such a split force would obviously have been ineffectual and easily overwhelmed by the enemy; so it was usual to position about a third of the fighters near the head of the bomber stream --- that part most vulnerable to head-on attack --- and distribute the remaining fighters in 8-aircraft units along the length of the stream. It was inevitable, therefore, that from time to time some combat wings would have no fighters covering them.

 

[GregP]

I was assuming the drop tank got used up before engaging in combat, but it actually could happen any time. Good call.

 

[pbehn]

A bomber travelling at 180 mph would reach Canterbury in 14 minutes. Even without adding in time for forming up, and assuming the Wing used Spitfires rather than the slower Hurricanes, which would take longer, a German bomber formation would be over Canterbury in half the time it would take a single fighter from Duxford to get there. The whole thing was absurd."

And on the other side of the coin, when Goering tried his first massed raids on London headwinds dropped the bombers speed down to around 110MPH which screwed up all calculations about escorting them. These headwinds gave the big wing time to form up and put in a spectacular late show.