Just curious about the P-51 FM

[Mustang]

Chronicling the history and development of the P-51 Mustang through a timeline


http://p51h.home.comcast.net/~p51h/time/time.htm

[Mustang]

I found data, Maybe not good for P 51 D's

FM:

One problems with the P51D was that on take-off with a full load of fuel (with drop tanks and ammo) the plane at maximum weight AND was tail heavy.
Instructors in the US trained the new pilots to burn off their drop tanks FIRST, then begin burning off fuel from the tank behind the pilot in order to get maximum range.
The problem was that if a problem came up that meant returning to the field o land, the plane could not be landed in the tail heavy condition: it would flip upside down on its tail on approach.
Many green pilots were killed.
The experienced pilots quickly retrained the green kids to take off on the wing tanks, then at about 2000 feet switch the tank behind the pilot to burn off the 85 gallons that was making the plane tail heavy during the remaining time it took to climb to 30,000 ft plus. That way if they did have to drop the wing tanks to go after BF 109s for FW 190, the Mustang would not have to fight in a tail heavy configuration, which would mean sure death.
Landing the Mustang had some Do's and Don'ts. The plane required itself to be flown onto the runway with ample power. Too many green pilots would find themselves "short" of the runway and at just above stall speed, trying to add a big burst of power from the Merlin. The Merlin is not a high rev engine, but it IS an extremely high torque engine. Opening the throttle would cause an immediate increase of torque to be applied to the massive bladed propeller which reacted slowly causing reaction torque causing the plane to roll in the opposite direction of the propeller rotation, usually causing a stall and crash since there was no time to apply opposite stick to correct. Most experienced Mustang drivers landed well above stall speed and slightly long to assure that they would not be caught with this problem.
This high torque problem showed up on the F6F Hellcat and the Corsair which used the same design prop. Both Navy and Marine pilots reported the problem which was very bad on flat top landing where there was no margin for error.

When the D model became available in quantity in the summer, cases of the aircraft losing its tail surfaces in flight began to be reported.
Flight restrictions were placed on the aircraft and the tail surfaces were beefed up. Wing failures were also reported due to control stick force reversal in high-speed dives.
The bobweight was added to the elevator control system to fix this problem. But for the aircraft to be even marginally stable, the fuselage fuel tank had to be less than half full.
The Mustang still had problems a year later when the 7AF began B-29 escort missions to Japan. Incidences were reported of tail surface failures in
dogfights.


History:

The first combat unit equipped with Merlin-powered Mustangs was the 354th Fighter Group, which reached England in October of 1943. The 354th FG consisted of the 353rd, 355th and 356th Fighter Squadrons, and was part of the 9th Air Force which had the responsibility of air-to-ground attacks in support of the upcoming invasion of Europe. However, they were immediately ordered to support the bomber operations of the 8th Air Force. The 354th flew their first cross-Channel sweep mission on December 1, 1943, and scored their first victory on a mission to Bremen on December 16. However, inexperienced pilots and ground crews and numerous technical problems limited operations with the P-51B/C until about eight weeks into 1944. From the early spring of 1944, the Merlin-powered Mustang became an important fighter in the ETO.

The 357th Fighter Group, also initially assigned to the 9th Air Force but was quickly transferred to operational control of the 8th Air Force for bomber escort. It flew its first P-51B escort mission on February 11, 1944.

The 363rd Fighter Group became the third P-51B operator in Europe on February 23, 1944.

Most of the P-51B/Cs were assigned to the 8th and 9th Air Forces in England, with a lesser number with the 12th and 15th USAAF in Italy. The P-51B/C remained the prime Mustang variant in service from December 1943 until March of 1944, when the bubble-topped P-51D began to arrive. However, P-51B/C fighters remained predominant until the middle of 1944, and remained in combat until the end of the war in Europe even after the arrival of large numbers of P-51Ds. Even as late as the l ast month of the war, 1000 out of the 2500 Mustangs serving in the ETO were of the P-51B/C variety.

However, many pilots regarded the Malcolm-hooded P-51B/C as the best Mustang of the entire series. It was lighter, faster, and had crisper handling than the later bubble-hooded P-51D and actually had a better all-round view. Its primary weakness, however, was in its armament--only four rather than six guns, which often proved prone to jamming. Some of the modifications applied to the P-51D to improve the ammunition feed were later retrofitted into P-51B/Cs, which made their guns less prone to jamming. With modified guns and a Malcolm hood, the P-51B/C was arguably a better fighter than the P-51D, with better visibility, lower weight, and without the structural problems which afflicted the D.

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WWII 8thAAF COMBAT CHRONOLOGY
JANUARY 1944 THROUGH JUNE 1944

http://www.8thafhs.org/combat1944a.htm

???

XLS spreadsheet showing all the 8th Air Force missions and targets with losses by date throughout the war. The 8th flew Mission #1 17 August 1942 when 12 B-17s attacked Rouen Marshalling yards and the last mission on 8 May 1945 Mission.

http://www.taphilo.com/history/8thaf/8thaf-missions.xls

???


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[MiloMorai]

The fuselage tank was used first as this is what caused the tail heaviness. Then the drop tanks as the wing tanks were required to get home.

[Mustang]

Originally Posted by MiloMorai

The fuselage tank was used first as this is what caused the tail heaviness. Then the drop tanks as the wing tanks were required to get home.

No!

You have the main fuel tanks inside the wings





It all depends on the distance of the mission..

Maybe you need keep full the 85 gallons fuel tank behind the pilot on fight in order to get home.

[MaxGunz]

The tanks in the wings are the wing tanks, same as the ones you shoot for.

[JtD]

Really can't be bothered to reply to all of your chitchat here horseback, as most of them are unrelated to what I said anyway, but as you mention JG 26 as the unit who "easily won" the air war in the west in 1943, JG 26 had to write off 400% of their average operational strength in 1943. And as losses are not the only thing indicative of winning, lets look at other aspects as well:
- it was tasked with protection of Germany and territories against bombing raids, which were conducted more frequently and more destructively by the end of 1943 than at the beginning of 1943
- it was tasked with the destruction of the enemy air forces, which by the end of 1943 were a lot stronger than they were at the beginning of 1943

Those are the facts. "Winning easily" looks different. By any rational standard.

[horseback]

Originally Posted by JtD

Really can't be bothered to reply to all of your chitchat here horseback, as most of them are unrelated to what I said anyway, but as you mention JG 26 as the unit who "easily won" the air war in the west in 1943, JG 26 had to write off 400% of their average operational strength in 1943. And as losses are not the only thing indicative of winning, lets look at other aspects as well:
- it was tasked with protection of Germany and territories against bombing raids, which were conducted more frequently and more destructively by the end of 1943 than at the beginning of 1943
- it was tasked with the destruction of the enemy air forces, which by the end of 1943 were a lot stronger than they were at the beginning of 1943

Those are the facts. "Winning easily" looks different. By any rational standard.

You’ll want to explain all that to the men of the 91st, 96th and 100th Bomb Groups, each of which suffered over 400% casualties over Europe from spring 1943 to VE Day (there were 48 bombers in a Group). There were about 20 Heavy Bomb Groups in the 8th AF that suffered a minimum of 200% casualties and several among that number had around 300% casualties. The groups that took the highest casualties lost most of their numbers at a disproportionate rate in 1943. What the JGs and ZGs in the West prior to the spring of 1944 were doing looked an awful lot like ‘winning easily’ to them.

I tend to differ with you about the tasking of the JGs on the Channel Front; I used JG 26 as a well-known example, but let’s examine the war aims of the two sides. My contention of the LW’s campaign being easily successful at the end of 1943 is based on the understanding that the German leadership at that point in the war believed (regardless of whether it was rational to do so) that once the Allies got tired of banging their collective heads against the Atlantic Wall, they would at worst, recognize Germany’s hegemony/de facto control of Europe and go the hell away, or at best, join Hitler and the volk in the effort to crush the Communist threat embodied in the Soviet Union (somewhere in the middle of all that they were hoping for at least the suspension of Lend Lease to Stalin). They believed that the Casablanca declaration that the Allies’ primary war aim was unconditional surrender of the Axis Powers was all show.

On that basis, the goal of the LW in the Channel was to continue to do what they had been doing very well in the second half of 1943—bleed the American and British air forces as they crossed into Europe and hammer the bombers once their escorts had to turn back from lack of fuel. Inflicting maximum casualties on the enemy meant that their weak and effete democratic system would eventually turn on Roosevelt and Churchill and the new elected leaders would sue for peace. For Hitler and his followers, it was a classic demonstration of German will and that was how they sold it to the German people.

"Just hang on a little bit longer, and they will give up and go back to making refrigerators and razor blades. Once we've settled with Stalin and consolidated our holdings in Europe, then we'll deal with them on our terms," they were saying.

On the other side, the requirement for unconditional surrender was not show, but they were working to a schedule; FDR and Churchill were committed to opening a ‘Second Front’ in Europe in 1944, which meant a major amphibious assault on the French coast, and the best time for amphibious operations is when the weather is reasonably good and the tides are low near dawn. That meant no later than August, and if they needed a moonless night before the morning of the invasion in order to maximize the effectiveness of airborne assault to ‘prep’ the area behind the beachhead, you only had early June.

All of that required (according to the Admirals whose ships were going to be stuck close to an enemy held coast and the Generals whose soldiers and equipment were going to be bottlenecked on the beachhead for the first couple of days) that the Luftwaffe be seriously cut down in size and effectiveness, and that was the responsibility of the Allied air forces. In late 1943, there was serious doubt that they could accomplish that task.

The heavy bombers had been expected to be able to protect themselves and to penetrate Germany’s airspace to bomb German aircraft production out of existence; there were other industries targeted but aircraft production was the main target. It turned into a massive failure, because the bombers were taking unacceptable losses in the absence of effective fighter escorts. Heads rolled at 8th AF Command and in its Fighter headquarters in late 1943 as a direct result, and major efforts to get the new Mustangs under 8th AF command were made. It is a fact that all Merlin Mustang production not committed to the RAF went to the 8th Air Force (or its control) until late spring of '44, when production finally allowed for groups outside the ETO to transition into the type.

That's why I said what I said.

cheers

horseback

[JtD]

Originally Posted by Mustang

No!

You have the main fuel tanks inside the wings.

If you start with two 110 gallon drop tanks you have a fuel total of 489 gallons. Lets say you use 225 gallons each way, and keep 39 reserve. If you use up the 85 gallon fuselage tank first, you'll still have 80 gallons at the far end of your trip in the drop tanks. If you happen to be engaged there, you can't drop them if you want to return to your base, as you'll need 225 gallons, but only have 184 internal.

Practice was to use half the rear tank first, then the drop tanks. In this case, you'd have OK control characteristics and could always drop the drop tanks and make it home.

[MiloMorai]

Originally Posted by Mustang

Maybe you need keep full the 85 gallons fuel tank behind the pilot on fight in order to get home.

You wouldn't get home as the a/c would become VERY tail heavy. That would be ~600lb behind the CoG.

From the Pilot manual:

more than 48gal in the fuselage tank - a/c restricted straight flying and gentle maneuvers only

aerobatics and spinning permitted with no more than 30 gal in the fuselage tank

kind of hard to have combat with these restrictions

http://www.avialogs.com/viewer/avial...er.php?id=3851

[Bearcat]

Originally Posted by MiloMorai

The fuselage tank was used first as this is what caused the tail heaviness. Then the drop tanks as the wing tanks were required to get home.

Originally Posted by Mustang

No!
You have the main fuel tanks inside the wings




It all depends on the distance of the mission..
Maybe you need keep full the 85 gallons fuel tank behind the pilot on fight in order to get home.

Generally what they did was use drop tanks first then use up about 1/2 - 2/3 of the fuel in the fuselage tank then they would alternate between wing tanks to make sure the aircraft was balanced. From what I was told by P-51 pilots in the chapter of TAI that I belonged to they kept that fuel for a reserve and once it got past @ 45 gallons it was less unstable.. but they then went for the wing tanks.