How The Spitfire Mk XIV Compared to the K4 and Other Questions

[GregP]

Thanks Biff.

 

[stona]

The typhoons had stripes......simples

That's why they had stripes

Cheers

Steve

 

[stona]

Buck Casson couldn't tell Bader's Spitfire from a 109, Doh !

Malan, Byrne and Freeborn couldn't tell a Hurricane from a Bf 109 between them as Frank Rose could testify. Sadly Montague Hulton-Harrop could not, the first British pilot to die in the war, killed by his own side.

Cheers

Steve

 

[Koopernic]

Those variants will have better climb and straight line speed, but did they offer better manoeuvrability?

In other words, will the tactics of the Spitfire pilot have to be changed much?

The manoeuvrability of all of the versions of the Me 109 with MW50 (about 30% more power) was better since a higher power to weight ratio means higher amounts of lift can be generated before the aircraft looses speed and altitude. The versions with the larger superchargers were particularly more manoeuvrable at altitude. The Spitfire's turning circle is often attributed to the efficiency of its large area wing. A large wing simply generates less drag for the same lift in heavy turning flight. Usually this is associated with reductions in speed in level flight due to the greater weight and parasitic drag of the larger wing. However the Spitfire got around this by simply having more power, it always had more power, and this I put it was the real source of the spitfires performance. Even when the Me 109 got its over boosted engine 150PN fuel became available to the Spitfire. The low shock drag of the thin wing was another.

 

[rochie]

Malan, Byrne and Freeborn couldn't tell a Hurricane from a Bf 109 between them as Frank Rose could testify. Sadly Montague Hulton-Harrop could not, the first British pilot to die in the war, killed by his own side.

Cheers

Steve

Battle of Barking Creek ?

 

[pbehn]

That's why they had stripes

Cheers

Steve

Sorry steve I think I went into over subtle mode there, it was meant as a joke for the reason you said.

 

[GregP]

You know Biff, I was thinking about your answer and I wonder if maybe things were very different in WWII. You tell me.

When you were blasting through the skies in an F-15 on Uncle Sam's dollar you had a rather wonderful radar in the front and the back. So your SA was coming from a knowledge of what was around you BVR. In WWII, I think (could be wrong here) that if they were escorting bombers then maybe they knew generally from where the enemy would come. But if the fighter pilots were on a mission not involving escort, they were probably faster and might or might not have a idea where the enemy might show up from and might or might not have info from radar.

If they were high up and in contact with home radar, maybe they knew in general. If they were low and sneaking in, then the good old Mark I eyeball might be all they had for warning, and SA started when bullets started hitting the plane in the case of an ambush or when they spotted the enemy in the case of a frontal approach. I wonder what percent of the time they had any information from gound-based radar and what percent of the time they were "on their own," but I'm not sure anybody knows for sure.

I may be wrong here, but SA is a modern invention of words for the sttae of being aware of what is going on around you, and I'm not too sure such a concept was ever taught to WWII aviators. They might have had to develop that on their own by combat experience and the luck of surviving it.

Any thoughts on that? Do you know when SA was first taught? I thought it was a John Boyd thing, probably about the same time he developed his OODA loop.

 

[drgondog]

Gents,

Here is another log on the fire with this climb rate comparison. Yes, an ideal way to compare aircraft is at the same weight (max fuel load, with weapons, etc.). However, the reality of combat doesn't really arrive at the beginning of the "test" with two aircraft with similar load outs. Reality I would think would be the Allied fighters arriving over X with quite a bit of fuel burned down, then engaging in combat with Axis aircraft that were just arriving at fight height, or still in the climb (depending on early warning systems).

What I think is a valid way of looking at things using the similar load out basis is how much of a performance advantage does one aircraft have over another. In the case of the Spit I would think in most scenario's over Europe it would be at the advantage versus Me-109 (both full load out) and or would be greater after having been airborne for longer (having burned out a larger percentage of total fuel than the his opponent).

Also lets not forget that the for the most part the 190 and 109 are both relatively short legged compared to late Spits and the US A/C. There lies one of the few advantages of being on the defensive, you can have better performing aircraft due to not needing to fly very far to get to the fight. But then again you are not very far from the fight, nor is you airfield, nor your family, nor most if not all things you find important...

Yes, the Mig-29 is a hotrod, and performs in many arenas better than the F-15, however he didn't get very far from the flag pole and would not be of much use in an offensive war. It had no legs.

Cheers,
Biff

Not that Biff's comments need reinforcement but here is possible food for thought

The P-51B-15 was equipped with a 1650-7 qualified for 75" MP which yielded significant improvement over 67" - for example a fully loaded P-51B-15 @9880 pounds GTOW with full 269 gallons internal fuel, draggy bomb racks (~13mph delta), full ammo.

Wing Loading at 1G = 42. ROC at SL 75" = 4350 fpm, ROC at 10,000 = 3700 fpm, ROC at 25,000 = 2400 fpm with two bomb racks.

For the Spit XIV with full 112 Imp Gallons (134 US), the GTOW = 8488 with full loading. No bomb rack for speed and climb tests.

Wing Loading at 1G = 35 ROC = according to RAF reports for 18 pounds boost was 5500 at SL, 4700 at 10,000 3500 at 25,000.

But here is what the immediate impact is when you reduce the internal fuel load from 269 pounds to 134.5 gallons..

The GWTO for the P-51B reduces from 9880 to 9073 pounds. The WL drops from 42 to 38.6

As Weight is a major factor when considering ROC = (T*V-D*V)/W then there is already an increase in ROC by a factor of 1/(92%)

Without even looking at an equally consequential dramatic reduction in Induced Drag the 'new P-51B' ROC's for 5K, 10K and 25K
increases to 4350/.92, 3700/.92 and 2400/.92 or 4730 at SL, 4021 at 10,000 feet and 2600 fpm at 25K.

While the P-51B still falls short of the Spit XIV, the differences narrow just on internal fuel equality, whereas the difference in drag for the Mustang vs the Spit XIV are huge and would narrow the differences even more.

Further, at the 9073 pound GW without bomb racks, the P-51B with 1650-7 at 75", clean - would approach the performance of the P-51H at 80" which was also very close in climb, superior in speed and acceleration and much closer in turn to the Mark XIV. As Turn radius is directly proportional to WL, the 92% factor applies here also

Back to get closure on Biff's point. If a high performance FW 190D or 109K engages a P-51B well on the way home and operating on internal fuel for a couple of hundred miles, they will find a FAR more agile foe than they would if they had engaged while the externals were still on.

 

[Mike Williams]

Interesting post Bill. Keep in mind that Mustang IIIs and IVs in RAF service operated at 80" hg./+25 lbs boost and that the Spitfire XIVs operated at +21 lbs. boost.

To give an idea of performance at these powers (V-1650-7 - 1,940 HP; Griffon 65 - 2,220 HP):

Spitfire XIV Climb at +21 lbs. boost (extrapolated from A.F.D.U. data)

Spitfire XIV JF.319 Climb at +21 lbs. boost (extrapolated from A. A.E.E. test)

Spitfire XIV JF.319 level speeds at +21 lbs. boost (extrapolated from from A. A.E.E. test)

Spitfire XIV JF.319 level speeds at +21 lbs. boost (extrapolated from Vickers Armstrongs test)

Spitfire XIV at +21 Lbs boost; Mustang III (V-1650-3) at +25 lbs boost; and P-51B (V-1650-7) at +25 lbs boost - Level Speeds, Rolls-Royce test

Mustang III climb at +25 lbs. boost, 9,260 lbs take off weight (Merlin 100). I don't think the powers of the Merlin 100 and Packard V-1650-7 were much different with both operating at 80" hg./+25 lbs.

Mustang III level speed at +25 lbs. boost (Merlin 100)

Mustang IV V-1650-7 level speed at + 25 lbs. boost

I'll leave it to you to sort out the math

 

[BiffF15]

You know Biff, I was thinking about your answer and I wonder if maybe things were very different in WWII. You tell me.

When you were blasting through the skies in an F-15 on Uncle Sam's dollar you had a rather wonderful radar in the front and the back. So your SA was coming from a knowledge of what was around you BVR. In WWII, I think (could be wrong here) that if they were escorting bombers then maybe they knew generally from where the enemy would come. But if the fighter pilots were on a mission not involving escort, they were probably faster and might or might not have a idea where the enemy might show up from and might or might not have info from radar.

The F-15 has only a radar for what's out front. We have a radar warning receiver for 360 degree coverage (it tells us when we are being locked up). I'm sure in WW2 as now, before you stepped for a mission you received an intel report with what they expected you would see. I'm sure ours are more accurate now, but the general flow I think remains the same. As for cruise speed, we tend to be faster in the high threat areas, and slower when outside those. I would think the fighters cruise speed in WW2 would depend on fuel, distance, and expected land time. Faster when time was tight, slower when time or fuel were not a problem.

If they were high up and in contact with home radar, maybe they knew in general. If they were low and sneaking in, then the good old Mark I eyeball might be all they had for warning, and SA started when bullets started hitting the plane in the case of an ambush or when they spotted the enemy in the case of a frontal approach. I wonder what percent of the time they had any information from gound-based radar and what percent of the time they were "on their own," but I'm not sure anybody knows for sure.

I may be wrong here, but SA is a modern invention of words for the state of being aware of what is going on around you, and I'm not too sure such a concept was ever taught to WWII aviators. They might have had to develop that on their own by combat experience and the luck of surviving it.

While they might not have called it SA back in the day, it is what it is. The SA they had came from the radio / bombers / other fighters / GCI if they had it, or from the Mk 1 eyeball. What you do with the SA you have can or will effect mission success.

Any thoughts on that? Do you know when SA was first taught? I thought it was a John Boyd thing, probably about the same time he developed his OODA loop.

I do not know when SA gained it's label. However, I would think that teaching a guy to employ a weapon (a fighter in this case) you would teach, fly, and debrief to an individual or groups "awareness" of his aircraft, his flight, and opponent or opponent's.

Cheers,
Biff

 

[GregP]

Thanks again, Biff.

 

[Mike Williams]

I do not know when SA gained it's label. However, I would think that teaching a guy to employ a weapon (a fighter in this case) you would teach, fly, and debrief to an individual or groups "awareness" of his aircraft, his flight, and opponent or opponent's.

Cheers,
Biff

Fwiw:
P-51 Formation Combat Tactics, by Lt. Col. Irwin H. Dregne, 357th FG
P-51 Squadron Tactics, by Capt. John B. England, 357th FG
P-51 Squadron Tactics, by Major Edwin W. Hiro, 357th FG
P-51 Individual Combat Tactics, by Major John A. Storch, 357th FG

 

[BiffF15]

Mike,

Thanks for posting those! They are by todays standards a little light on detail, but do convey what they were doing in general.

Major John Storch said it well, "The preceding and following statements are completely dependent on the circumstances and no hard and fast rules can be set down". That's another way of saying "it depends". It's funny to see that some things never change!

Cheers,
Biff

 

[Spacefire]

Fwiw:
P-51 Formation Combat Tactics, by Lt. Col. Irwin H. Dregne, 357th FG
P-51 Squadron Tactics, by Capt. John B. England, 357th FG
P-51 Squadron Tactics, by Major Edwin W. Hiro, 357th FG
P-51 Individual Combat Tactics, by Major John A. Storch, 357th FG

Thanks for those. Basically answers what I was wondering.

Also, I apologize for my comment about you I made on one of the first pages. I wrongly assumed what Kurfurst claimed was true.

I appreciate the work you do.

 

[GregP]

Here is John Boyd's OODA Loop explained:

http://www.jvminc.com/boydsrealooda_loop.pdf

 

[parsifal]

im not sure that some of the starting assumptions about fuel loads would be correct in all situations. defending CAP would often be airborne from the earliest point of detection and then might take some time to vector the defenders onto the incoming streams. Often the defenders would be out of fuel by end of mission and be forced into a deadstick landing or ditch the aircraft. its a major decision for someone trying to decide about the use of his CAP assets, whether to use it until it could not return safely or whether to bring it down for refuelling and re-arming often with the enemy pressing onto a vital target unopposed.

Im not challenging or questioning the logic behind the idea. German aircraft weights are one thing, lack of maintenance and engine wear is another. Aircraft in wartime situations seldom operate to spec and for the losing side they are going to push their defences to the limit.

Just a thought guys.

 

[GregP]

Hey Biff,

You probably have this, but: Fighter Combat Tactics

http://www.imagery.vnfawing.com/PDF-Archive/Fighter-Combat-Tactics-and-Maneuvering.pdf

 

[gjs238]

Yes, the Mig-29 is a hotrod, and performs in many arenas better than the F-15, however he didn't get very far from the flag pole and would not be of much use in an offensive war. It had no legs.

Cheers,
Biff

If the Mig-29 is a hotrod, than what is the Su-27 Flanker series?

 

[GregP]

If the MiG-29 is a hot rod, the Su--35 has to be a serious threat. Biff, you probably flew against German MiG-29's huh?

Did you ever get to fly with or against any Russian fighters or Russian pilots other than maybe in formation at an airshow? If so, what were your impressions?

Upon thought, I realize this is well outside WWII ... I'll move to to modern after this post with anything about modern jets.

 

[Glider]

A comment on SA. I was always taught that it couldn't be taught. You could and did what you can to emphasise the importance of looking and being aware of what is going on around you but at the end of the day that's all you could do.
Its something that you had to a certain degree or you didn't, as your mind either automatically picked up the clues, stored and processed them so you just knew where people were around you or you didn't to the same degree.

Another way of thinking about it is the difference between looking and seeing. How many times when driving has a car pulled out in front of another one with out looking. The probability is that he did look, but he didn't see.

A side observation as a glider pilot I had zero faith in the ability of a pilot in a powered aircraft to know what is going on in the sky around them. I once had to make an emergency landing because a display team came right over the airfield when I was on a cable launch. Fortunately I saw them as they didn't see me as I was right in front of them. On a second occasion at the Midland Gliding club two of the Red Arrows did a similar thing and went either side of the cable and below the height of the glider. If they can get it wrong anyone can.