Paddle blade P-47 and P-38J

Jank · 03-08-2006, 10:23 PM

Trying to compare the P-47 padle blade and the P-38J but don't know about the climb rates. The paddle blade P-47D that came out in 1944 had a climb rate of 3,120fpm at 5,000 feet.

The P-38J coulod reach 20,000 feet in 7 minutes flat.

Does anyone have any data for each aircraft at the same altitude?

Twitch · 03-09-2006, 10:26 AM

P-47D-35-RA hit 20,000 feet in 8.5 minutes

Sal Monella · 03-09-2006, 03:01 PM

Twitch, can you share where that data came from? I have some interesting data that I will post.

Sal Monella · 03-09-2006, 04:46 PM

As you can see, time to climb at combat power to 20,000 feet is right at 7 minutes. The P-47D with the paddle prop blade was a very different animal indeed. Francis Gabreski said that after the paddle blade was installed, the Germans found that they could no longer just climb away from the Thunderbolt.

Jank · 03-09-2006, 05:27 PM

Wonderful chart Sal

Magister · 03-09-2006, 11:49 PM

Yes, as you say, the paddle bladed Thunderbolt was a different airplane. She she got a 400fpm boost in climb which is clearly borne out by the chart you have provided.

Very impressive climb for a 14,500lb airplane in 1944.

Thanks for the info!

Aggie08 · 03-10-2006, 12:06 AM

I've never heard of a paddle blade. Anyone have pictures?

Sal Monella · 03-10-2006, 12:12 PM

I believe it was fitted on all the D-22 and later series starting early in 1944. It had a broader chord and more bite. It really helped out with the P-47's rather anemic low altitude performance.

I don't have side by side comparison pictures.

Twitch · 03-10-2006, 02:51 PM

Sal- the climb figure is typically found in about any aircraft stat book. Initial climb rate is about 3,200FPM. Time to altitude is more meaningful since initial climb rate can and does fall off by differing amounts depending on the plane.

The insight from Gabreski is dead similar to Bob Johnson's. While us little kiddies fart around with the magic of specification comparisons in the real world guys like Zemke, Gabreski, and Johnson capitalized on things like the new prop and the Jug's high roll and dive rate to dominate the battles they were in regardless of what any book says about performance.

wmaxt · 03-10-2006, 03:55 PM

The Paddle blade props also had a more sensitive control mechanism that was more effective, the same type of system added a lot to the P-38K too.

The Paddle blade P-47D was also faster than the P-38J (421mph @ 25,800ft) but about the same as the L, I think.

The P-38J/L could get to 20,000ft in 5-5.4min in WEP here is data from AAF Flight test 47-1706-A, Randomly picked P-38J # 42-67869

Altitude - Cl Rate - Time
0 -------- 4,000 --- 0
5000 ---- 3960 ---- 1.25
10000 -- 3860 ----- 2.54
15000 -- 3550 ----- 3.89
20000 -- 3190 ----- 5.37
25000 -- 2665 ----- 7.o6
30000 -- 1830 ----- 9.32
35000 -- 985 ------ 12.99
40000 -- 100 ------ 25.14

Heres a graph for an in house test of an L model

wmaxt

Magister · 03-10-2006, 07:08 PM

Whoa!

4.5 minutes to 20,000ft with a full load of ammo and internal fuel? That's an average of 4,444fpm over the entire climb. No way. Sorry. I don't buy it.

Jabberwocky · 03-10-2006, 10:21 PM

Its more like 5 minutes to 20,000 feet for an L in full War Emergency Power.

Tis really not that remarkable for a plane with 3,450 hp pulling it along.

Standard Spitfire L.F. Mk IXs were tested to 20,000 feet in 4 3/4 minutes at +18 lbs. That droped to about 4 1/2 minutes at +25lbs. Some A&AEE testing had them pulling upwards of 5,700 feet/minute for the first 1,000 feet or so and better than 5000 feet/minute until 10,000 feet.

Magister · 03-10-2006, 10:36 PM

Its more like 5 minutes to 20,000 feet for an L in full War Emergency Power.

Not according to that chart!

Tis really not that remarkable for a plane with 3,450 hp pulling it along.

It is when you figure that it weighs in at 17,500 at combat load! (full ammo and internal fuel)

Standard Spitfire L.F. Mk IXs were tested to 20,000 feet in 4 3/4 minutes at +18 lbs. That droped to about 4 1/2 minutes at +25lbs. Some A&AEE testing had them pulling upwards of 5,700 feet/minute for the first 1,000 feet or so and better than 5000 feet/minute until 10,000 feet.

Yeah well a P-38 at combat weight weighs in at over twice that of the Spitfire!

The P-38K model had a broad chord propeller. Not the J and L series.

the lancaster kicks ass · 03-11-2006, 02:11 AM

Quote:

Standard Spitfire L.F. Mk IXs were tested to 20,000 feet in 4 3/4 minutes at +18 lbs. That droped to about 4 1/2 minutes at +25lbs. Some A&AEE testing had them pulling upwards of 5,700 feet/minute for the first 1,000 feet or so and better than 5000 feet/minute until 10,000 feet.

Yeah well a P-38 at combat weight weighs in at over twice that of the Spitfire!

what's your point? does the spit's climb rate suddenly become void because the P-38's heavier? if the P-38 was the same weight as the spit would she climb the same? if the Queen had balls would she be the King?

FLYBOYJ · 03-11-2006, 09:45 AM

Quote:

Originally Posted by Twitch

The insight from Gabreski is dead similar to Bob Johnson's. While us little kiddies fart around with the magic of specification comparisons in the real world guys like Zemke, Gabreski, and Johnson capitalized on things like the new prop and the Jug's high roll and dive rate to dominate the battles they were in regardless of what any book says about performance.

YEP!!!!

Folks - been reading this thread and observing interesting discussion, but I'm gonna throw my 2 cents in here...

I know its probably been said before but these tests were done under the best circumstances, maybe with "line" aircraft but never the less under somewhat controlled conditions flown by very experienced pilots. For my money stick with the POH - its probably the best representation of performance gathered based on factory and government tests designed for combat operations.
In my P-38 manual recommended climb performance is listed at 54"MP, 3000 rpm at a combat weight of 17, 400 you're going to get 7 minutes to 20,000 feet at best rate of climb (Vx) - period. Of course more boost and less weight may get you up there quicker but the charts are formulated for a reason with those numbers and be rest assured a WW2 combat pilot is going to go with those numbers posted, not data gathered from Wright Patterson or anywhere else that is not part of the "official document," that being the POH or in USAAF terms the -1.....