Originally posted by AquaShrimp
Widewing, my analysis of the P-47 is wrong? I'm proved right by later prototype and production models of the P-47! If anything, you are confused.
I said the P-47 had too little range to be an escort plane. So did Republic, thusly the P-47N was developed.
I said the P-47 was too heavy and needed a lightweight version. So did Republic, thusly the P-47J was developed.
I said the P-47 had too low of a critical mach. So did Republic, thusly diveflaps were added, AND a laminar flow wing P-47 was tested (P-47K).
Ok, it's obvious that you are unwilling consider that you were in error. So I'll merely point out where you have been wrong so far and present facts that disprove your conclusions.
You stated:
"I think the P-47 was far too heavy"
Fact: While heavy, the P-47 was not "far too heavy". It out-performed the fighters of the enemy. It's power loading at altitude was better than the P-51D. Its weight was mitigated by its enormous horsepower. At around 14,000 lbs, it was only marginally heavier than the Typhoon and Tempest, neither of which could match its performance above 20,000 feet (where the ETO air war was fought). It was 3,000 lb lighter than the P-38L.
You stated:
"had too low of a critical mach to achieve the potential that it had."
Fact: P-47s were the fastest, best climbing fighters at the altitude they were engineered to fight at. Late models were the fastest prop fighters to see combat in WWII, up to 40 mph faster than the P-51s. The P-47 had the exact same speed restriction as the P-51D; 500 mph IAS. We have data that shows the P-47 being capable of 600 mph TAS in a dive. Dive recovery flaps were installed because they made recovery easier. The P-51 was not fitted as it would have required a major redesign of the wing structure. Instead, North American changed the angle of incidence of the horizontal stabilizer on later models to reduce high Mach tuck. The F4U and F6F didn't have them because they seldom flew high enough to get into high Mach issues, meaning that they were not needed. As it was, neither the F4U or the F6F demonstrated severe tuck under at high Mach anyway.
Dive limitations for US fighters:
P-47D: 500 mph IAS
P-51D: 500 mph IAS
P-63A: 500 mph IAS
P-40E: 480 mph IAS
P-39Q: 475 mph IAS
F6F-5: 449 mph IAS
F4U-1D: 443 mph IAS
P-38L: 440 mph IAS
P-61A: 430 mph IAS
FM-2: 425 mph IAS
Recent testing by the Society of Experimental Test Pilots established that the military's ratings were accurate. They dive tested the P-47D-40, P-51D, F6F-5 and FG-1D. Their conclusion was that they ranked in the order I have listed them.
You stated:
"Stressed Aluminum skin- Would have saved weight."
Fact:
The P-47 was a stressed-skin, flush riveted monoplane, as advanced in structure as any aircraft of its time.
You stated:
"Remove machine gun armament and replace with two 20mm cannons."
Fact:
The USAAF did not want 20mm cannons on their fighters. Moreover, the eight-gun installation on the P-47 was more than adequate for the job it was designed to do. It simplified logistics and the Browning MGs were utterly reliable.
You stated:
"Thin, laminar flow wings- High altitude escort fighters needed to be able to fly and dive fast."
Fact:
There is much disinformation about the advantages of the laminar flow airfoils. Even North American admitted that there was no significant decrease in overall drag over 90% of the speed range. This was due to the air flow not remaining laminar as was originally thought. If you examine the wings of both the P-47 and P-51, you would notice that the chord to thickness ratio of the Thunderbolt's wing was less than that of the P-51D. That means that relative to the width of the wing, the P-47's wing was thinner than that of the P-51. Max dive speeds are limited as much by drag rise of the propeller as by the drag rise of the wing itself. At Wright Field in July of 1944, a shiny new P-51D was dive tested at gradually increasing speeds. Initial buffeting began at Mach .75 and gradually increased as speed went up. Eventually, they dived it to Mach .83, but did such damage to the plane that it was written off. In contrast, the immensely strong P-47 could survive repeated dives to Mach .83 without injury to the airframe.
You stated:
"Squared off wingtips- Improves roll rate"
Fact: Neither of the two fastest rolling fighters in the US inventory, the P-63 and F4U, had squared wingtips. Aileron design is the greatest factor, not whether the wingtip is squared or radiused. Read this NACA test report:
You stated:
"The P-47 was relegated to ground attack work because of its short-commings."
Fact:
Already mentioned that this statement is uninformed. General Elwood "Pete" Quesada commanded the 9th AF in the ETO. Originally, the 9th AF was to be assigned P-51B fighters (based upon the out-moded idea that the A-36 was very effective...It wasn't). However, the 8th AF wanted the Mustangs. That suited Quesada just fine. He asked for every P-47 he could get. Why? Because Quesada saw that the A-36 loss rates were 4 times that of P-47s in MTO operations. After the war, Quesada was asked why he preferred the Thunderbolt over the P-51. He replied, "because we knew that without a shadow of a doubt that our losses would have been far greater had we been flying the P-51. P-47s brought my men home."
P-47s were assigned to this role because it was the best aircraft for the job.
Now, you just made these statements:
"I said the P-47 had too little range to be an escort plane. So did Republic, thusly the P-47N was developed"
You were wrong... Now you sound like your opinion somehow enlightened Republic and they built the P-47N just to prove you right. Had you bothered to educate yourself prior to making your initial post, you would have recognized that the P-47 had adequate range by 1944 and was the longest ranging single-engine fighter of the war by late 1944. You can't backtrack like that and expect to get away with it.
"I said the P-47 was too heavy and needed a lightweight version. So did Republic, thusly the P-47J was developed."
Again, you are backtracking.... LOL.. The XP-47J was a prototype, basically a technology demonstrator. It was rejected by the USAAF as not meeting their needs. In addition, it was actually
heavier than the P-47C-5 and had a greater fuel burn rate. With the same fuel capacity as the C models thru the D-23, it offered no improvement in range. As an interceptor, the XP-47J would have excelled, but it was no improvement as an escort fighter.
"I said the P-47 had too low of a critical mach. So did Republic, thusly diveflaps were added, AND a laminar flow wing P-47 was tested (P-47K).
"
Dive flaps were added, but not because the P-47 had a low critical Mach. They were added because the P-47 flew extremely high, where compressibility was a major issue for ALL fighters. Due to the P-47's extreme dive acceleration, pilots could get into compressibility trouble very quickly. These flaps were installed on the F8F, and not because it had a low critical Mach, but because they reduced the risks associated with high speed dives. Not all designs could readily accommodate the flaps. The P-51 couldn't and a different approach was taken by North American as stated previously.
Finally, the XP-47K did not fly with a laminar flow wing. This fighter was modified to test the new "bubble" canopy. Later, it was used as the second test bed for the enlarged wing eventually used on the P-47N (with internal fuel tanks). This wing used the same Republic airfoil section as previous P-47s.
Now, you can keep insisting you are correct, but we have established that you are lacking in the facts. Arguing in circles won't reverse this. Had you gone back to 1941 and XP-47B, some of your points would have been viable. However, by late 1943, the P-47 had established itself as the premier high alt fighter on the planet.
My regards,
Widewing
