F8F Bearcat rate of climb

[davparlr]

An interesting little sidelight comes from my youth. I grew up a couple of miles from Sherman Field at Pensacola NAS. As such, I was expose to many wonderful air shows. One beautiful, (but hot) summer day I went to an airshow at the base. They had both a P-51D and an F8F scheduled to do demos sequentially, the P-51 was first. It took off, flew for a few minutes and landed early. The Navy announcer took pride in saying that the P-51 had over heated and that this was an example of the superiority of the air cooled F8F engine. Next the F8F took off, flew for a few minutes and landed early. Quietly, the announcer said that it had overheated.

 

[fastmongrel]

Similar thing happened when I was at RNAS Yeovilton. There was a display by Firefly to be followed by a Corsair the commentator was telling us how reliable Corsairs were with round engines compared to the Fireflys V12 just as the Corsair blew its oil cooler and had to be towed off the runway by a Land Rover

 

[GregP]

I love the Hornet / Sea Hornet. Aesthetically, for me, it is a winner and far better-looking than even the Mosquito. Many might dsiagree but there is no "right" or "wrong" for what is a good looking plane.

Rate of climb-wise, it is very good, but would never maneuver with a Bearcat. The wing loading for the Sea hornet F Mk.III is about 57.9 pounds per square foot at 20,893 pounds and the power loading is 5.0 pounds per HP. For the F8F-2, the wing loading is about 39.3 pounds per HP at 9,600 pounds and the power loading is about 4.36 pounds per HP. So the wing loading is about 32% better for the Bearcat and the power loading is about 13% better, with both of these at normal takeoff weight. No dount this might change slightly at best combat weight.

Advantage Bearcat in both wing and power loading, as far as that goes. It means that to me, while not necessarily so, I would not be surprised if the Bearcat climbed slightly better, turned quite a bit better, and accelerated better.

The span loading is 268 pounds per foot for the F8F-2 and 464 pounds per foot for the Sea Hornet F Mk. III, meaning the Bearcat would be expected to be considerably more maneuverable as altitude increases.

That said, I have always been a fan of the Hornet / Sea Hornet, and both were near the end of the piston era, so they would likely not have been employed as first-line fighter aircraft except in a limited war anyway. Both would no doubt give a good account of themselves versus most of the available piston opposition in such wars while being somewhat on the defensive versus the existing jets of the late 1940's and early 1950's. No doubt both would have been a diffcult kill for the jets, just as the jets would have been a difficult kill for the two pistons. If the jets had made the mistake of slowing down for a fight, either of the pistons would likely have eaten them alive.

In any case, they are two of the best of the last of the piston era in real life. Some "what if" planes crop up occasionally, but these were real, live, service aircraft. We HAVE some Bearcats flying and I wish we'd see a Sea Hornet (or two) restored and flying today. If nothing else, it was magnificent. I bet the sound was unforgettable. The only thing close today might be hearing a Lancaster fly over. I haven't but surely wan to hear that. I heard a Shackleton fly past once and it MUST be at least similar.

 

[Jabberwocky]

I love the Hornet / Sea Hornet. Aesthetically, for me, it is a winner and far better-looking than even the Mosquito. Many might dsiagree but there is no "right" or "wrong" for what is a good looking plane.

Rate of climb-wise, it is very good, but would never maneuver with a Bearcat. The wing loading for the Sea hornet F Mk.III is about 57.9 pounds per square foot at 20,893 pounds and the power loading is 5.0 pounds per HP. For the F8F-2, the wing loading is about 39.3 pounds per HP at 9,600 pounds and the power loading is about 4.36 pounds per HP. So the wing loading is about 32% better for the Bearcat and the power loading is about 13% better, with both of these at normal takeoff weight. No dount this might change slightly at best combat weight.

Sea Hornet Mk XX and Mk XXI standard loaded weight (no external stores) was 15,682 lbs, not 20,893 lbs. Hornet F.1 standard loaded weight was 15,600 lbs. Data from FAA and RAF testing and data sheets.

Wing loading is thus 43.5 lb per sq ft, ~ 10% worse than the Bearcat. Power loading with Merlin 130/131 at 1,960 hp is 4.04 lb per hp, or about 7.5% better than the Bearcat.

 

[GregP]

C'mon Jabberwocky, the F.3 was the last Sea Hornet in regular RAF service and was the most produced. Somebody's leading you down the primrose path with the 15,682 pounds.

Empty was 12,502. 432 gallons of fuel add another 2,596 pounds. 760 shells adds 433 pounds plus the weight of the belt hardware. Call it 450 pounds. Call the pilot 200 pounds in flight gear with parachute. On the Gurmman there were about 150 pounds of oil and ADI. Call it twice that for the Sea Hornet due to two engines; 300 pounds. That alone adds up to 16,048 and I'm sure we forgot things like survival gear and a few other items.

At less than 16,000 pounds you're not adding full tanks, ammo, pilot, oil, and ADI. Sorry, it doesn't wash. And if you really want to get down to brass tacks, the R-2800-30W was 2,250 HP at Military, but 2,500 HP at Combat WER.

Sould you fight a Sea Hornet at 15,00 pounds? Yeas, with a lot of ful gone. You can do the same ina Bearcat and fight it at half fuel and you're down to 9,030 pounds. But I calculate at takeoff with full fuel, oil, ADI, 200 pound pilot, and normal incidentals. It makes comparisons easier since you're not fighting about where in the mission the fight took place. The absouilte best time for perfoamance is right before the thing runs out of fuel and ammunition ... but if you fight there, you usually don't make it home.

The Sea Hornet comes very close to the Bearcat, with the wing loading for the Sea Hornet still 12.65% higher and the power loading very close, but still 3% worse. The span loading at this weight is still 31+% worse.

I don't want to fight about it at all, but I won't buy a Sea Horent being better except in range, and can't find a reoported rate of climb that is anywhere near an F8F-2 at Combat WER power. The best I can find is about 4,560 fpm. An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?

Good thing they were on the same side, but they were both relatively short-lived. Wish we had a few Sea Hornets flying, as I said earlier. Since someone built a Mosquito, maybe we'll see a Sea Hornet sometine in the future. Both great planes that didn't quite make WWII.

 

[Jabberwocky]

Not my figures Greg, they're the RAFs and the FAA's. Argue with them, not me.

Sea Hornet Mk XX and Mk XXI weights (http://www.wwiiaircraftperformance.org/mosquito/sea-hornet.pdf)

Tare weight: 11,700 lbs
Gross weight: 15,682 lbs (permanent tanks full)
Mean weight: 14,362 lbs
Light weight: 12,570 lbs

Hornet F.1 weight (http://www.spitfireperformance.com/spit14speedchart.jpg)

All up weight (A.U.W): 15,600 lbs

I'll dig up the RAF Pilots notes as well

 

[wuzak]

An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?

It was, apparently, an F8F-1.

It was modified so that WEP could be used with the landing gear down (interlocks preventing this otherwise).

And it took off into a 40kt headwind.

Per Rich Leonard.

 

[Shortround6]

It also used 1/2 fuel I believe and I think (but could be wrong) one plane had ammo but the other didn't?

 

[GregP]

Sorry, don't buy it for an F.3. I havent researched an F.1 and probably won't, but the HP will certainly drop into the 1,770 or so range down from 2,030. The "light weight" above doesn't even allow for fuel weight, much less ammunition, pilot, oil, ADI, etc. Seems to be a plane with minimum fuel and no ammo. Sorry, don't believe it since it doesn't add up. I don't do comparisons at meaningless airshow weights, I do them at takeoff weight with full fuel and ammo for service planes and the Hornet is very good but not quite a Bearcat.

I find good references for the Hornet / Sea Hornet to be few and far between and have been in here long enough to have read Rich's account. I believe they were clean, no racks, and did the switch mod, too ... though that could be quite dangerous since you'd probably run out of rudder on takeoff if you stayed in the power. Probably had to reduce pwoer until the airspeed caught up with the rudder authority.

The Bearcat world records speak for themselves without my words, including the current and former world piston speed record plus the current and former world piston time to climb record. Seeing one perform in person makes one a believer. I'm not talking about an airsow takeoff at 1,700 - 1,800 HP, I'm talking about a max effort from a private strip. Never have seen anything do better ... but also haven't seen a Sea Hornet fly. The specs are enough to discount any rate of climb parity. I've never seen specs for the Sea Hornet that approach a Bearcat WER climb rate for a clean aircraft.

Please, no pissing contest. If you think otherwise, that's fine. I hope they make one and prove you right. At least then I could see and hear it fly. Maybe it could even set a world record.

 

[Jabberwocky]

To add further to the Hornet weight question.

The 1949 pilots notes for the F Mk XX gives a typical service condition weight of 16,100 lb. The 1950 pilots notes for the NF Mk XXI gives the all up weight of the aircraft in a typical service condition of "approximately 17,000 lb., i.e. with full internal fuel and ammunition". Given that the NF 21 was a two seater, with a radar in the nose, I'm not surprised there was weight creep.

The weight penalty for navalizing the Hornet, including the naval equipment and radio, is given as 550 lb. 280 lb of that was for the folding wing.

 

[GregP]

A pretty good plane regardless. I'd LOVE to fly one and still wish someone would complete one for flight. If they DO, it will likey be unarned and might be quite light.

 

[wuzak]

Sorry, don't buy it for an F.3. I havent researched an F.1 and probably won't, but the HP will certainly drop into the 1,770 or so range down from 2,030.

Why?

The F.1 and F.3 used the same spec engines - ie 130 series Merlins.

The "light weight" above doesn't even allow for fuel weight, much less ammunition, pilot, oil, ADI, etc.

Don't think Hornets used ADI. Thought that is a minor weight in the scheme of things.

In this chart the F.1 is listed as 16,145lb AUW.
http://www.spitfireperformance.com/spitfire14-afds-speedchart.jpg

 

[wuzak]

I believe they were clean, no racks, and did the switch mod, too ... though that could be quite dangerous since you'd probably run out of rudder on takeoff if you stayed in the power. Probably had to reduce pwoer until the airspeed caught up with the rudder authority.

That probably wouldn't be a problem with Hornets since they had counter-rotating props.

 

[GregP]

It was either ADI or WER boost. I'm leaning toward simple higher boost. They were 1,770 HP normal and 2,030 WER for a few minutes, however they got the "Emergency" rating.

Empty weight is not the same as basic weight. Basic weight is the weight that includes all fixed operating equipment, fixed furnishings, trapped fuel and oil, and water or other coolant in the radiator (if any), to which it is only necessary to add the variable or expendable load items, such as bombs, parachutes, and fuel for various missions. If basic weight typically adds about 1,000 pounds to a single engine Naval fighter aircraft, how much do you think it adds to a twin?

I might buy slightly under 16,000 for a Hornet, but not a Sea Hornet with arrester gear and Naval strangthening for carrier landings.

Figure the basic weight plus full internal fuel (432 Imperial gallons is 3,118 pounds, internal fuel [518.8 US gallons]), full armament (for the cannons only, I figure 450 pounds counting the cartridge band links), a pilot in a parachute and normal gear (200 pounds with parachute and charts, gun, water, food, etc. ... normal survival gear carried), radios and any other electronics that are not included in empty weight, and anything else required such as flares, etc.

Sure, you can FLY it under 16,000 pounds, but not at full capacity which was normal or even more for most combat missions. I do ALL calculations at full normal capacity, not max overload, since they flew that way or heavier almost all the time. You can calculate it anyway you like, but at least do it the same for both planes. Some people figure combat weight at basic plus pilot (in gear), plus 2/3 fuel, plus 2/3 ammo, plus radios and other gear. That's OK and even maybe desirable but the data aren't available for all planes, so I just use full internal capacity, without any external fuel to level the playing field.

If a bomber, I include a "typical" bomb load for the mission length, as gotten from references. For instance, the B-17 could lift a LOT of weight but, for London to Berlin and back, it "typically" carried 4,000 pounds. Sure there were 6,000 and 8,000 pound (maybe heavier) loads for shorter missions, but they weren't the norm.

So, under 16,000 pounds for a Sea Hornet? I think not if you use full internal capacity as I did for the Bearcat. It, too, gets lighter as the mission proceeds. For an airshow? Sure, you might fly the Hornet with no ammunition, 1/3 fuel, no survival gear or rations, flares, etc. and put dimunitive Eric Brown in it for a lightweight pilot to boot. You can do that with a Bearcat, too, but nobody did in combat service use. They loaded for a survivable mission, not a show. I bet they never launched at under 16,000 pounds for a real mission, especially if it happened to be a real combat mission, and they flew some of those. Probably had drop tanks and underwing bombs or rockets to boot. Mostly, I'd bet they launched at 18,000 - 19,500 pounds and came back to base at 15,500 pounds when they recovered.

The Bearcat usuaully launched at 10,000 - 12,500 pounds and probably recovered at 8,400 pounds or so.

 

[Hop]

An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?

I worked out the physics before and I'm pretty sure the only way a Bearcat could reach 10,000 ft in 94 seconds is at reduced weight (probably very little fuel and no ammo).

 

[fastmongrel]

Nice site about the Hornet

The de Havilland "Hornet" "Sea Hornet"

 

[krieghund]

Here is some more info on the Sea Hornet and Hornet Mk1

 

[Mike Williams]

Neil Stirling previously posted some nice performance comparison charts on this forum that are interesting: http://www.ww2aircraft.net/forum/av...ation-allied-fighters-35640-2.html#post977793

 

[Neil Stirling]

This from the the book The Grumman F8F Bearcat by Christopher Chant.

F8F-1

9,386lbs normal loaded.
12,957lbs maximum loaded.

Engine: R-2800-34W

Combat Power 2,750hp (70" hg ?) 2,750hp sl.
2,450hp 9,600ft. ( I would expect fth to be about 12,900ft)
1,850hp 15,500ft.


Max speed at sl 421mph.
Max speed at 18,800ft 428mph.

Initial climb 5,610ft/min.

Time to 20,000ft 4 mins 54 secs.

He doesn't give a source for this information, but it looks reasonable given 2,750hp.

Looks like a low altitude monster!!!



Neil.

 

[GregP]

Thanks Fastmongrel, Krieghund, and Mike! Appreciate it.

I see Neil used 58" for the Bearcat and estimated Hornet performance at 25 lbs boost (80" Hg). Considering they regularly ran the R-2800 on test benches at 150 inches (59 lbs boost), maybe 58" is a bit conservative. 58" was military power and 70" was WER. If you're going to use full boost (the 5 minute rating) on the Merlin 130 / 131, it makes sense to use full boost on the oither planes, too ... or restrict the Merlins to "Normal power."

That's why I tend to discount reports where one plane is being operated at the limit while an ostensible competitor is being restricted to less than full power. I've seen it happen from all sides. Anyway, there are several aircraft with very good climb, maneuverability, and acceleration. The Bearcat and the Hornet / Sea Hornet are certainly two of them.