No, you had fast climbing hard hitting short range interceptors because they only had 85G of internal fuel.
Wasn't the P-51 the best escort fighter of the war? (1 Viewer)
- Thread starter Jank
- Start date
No, you had fast climbing hard hitting short range interceptors because they only had 85G of internal fuel.
Shortround6
Lieutenant General
Ah, no.
You ALWAYS need climb performance. Why did the Allies have so much trouble with the Zero? not only could it out turn the early US planes (and the later ones) it could outclimb them at combat altitudes, which it could not do to the later Allied planes. Any number of other examples could be picked including why did they fit the Merlin XX engine to the Hurricane?
Answer is to improve the climbing ability at combat altitudes. The Spit could outclimb the Hurricane using the same engine and the Spit was already getting the Merlin XII, The Hurricane needed the Merlin XX in order to be competitive with the Bf 109E at altitude.
Service ceiling is usually defined as the altitude at which a plane can climb 100fpm. and this number is totally useless for most operational purposes except as a general indicator.
What matters is the altitude at which a plane (actually group of planes) can climb at 500fpm as this is the performance needed for the small group of planes to maintain formation as they perform somewhat gentle maneuvers, liking changing direction of flight. Plane on the outside has to use more power (speed) to stay in formation.
What matters even more for fighters is the altitude at which the plane can still climb at 1000fpm as this was considered the minimum climb rate needed for actual combat or combat maneuvering. Put your slow climbing fighter into even a 3 G turn (70.6 degree bank and and increase of 70% in stall speed) at over 20,000ft and you won't get very far into the turn before you either have to reduce the bank angle and turn rate or start losing altitude as the speed bleeds off. A faster climbing plane has more surplus power to maintain speed, it may not be using it's surplus power to climb but it is using the power to maintain speed in the turn and keep it's turn rate up.
This is the whole argument against trying to build escort fighters in years before WW II and in the first few years. The more heavily burdened "escort" fighter would not be able to effectively fight a short ranged fighter using a comparable engine.
The MK II Spit with that tank on the wing was hardly a useable solution but it does show, even if you cut the difference between the two test planes in 1/2 that the weight of the extra fuel (and tank and I don't believe this tank was self sealing? open to correction) cut several thousand feet from the service ceiling, the operational ceiling and the combat ceiling.
The MK V Spit was caught by several things, yes it got a better engine than the MK XII Merlin, but then they added more equipement (the 20mm guns and ammo) and increased the weight of the plane by several hundred pounds, build quality was a bit iffy at times (fit and finish) and performance (speed climb) didn't increase by very much, in some case not at all, snow guards and air filters?
Now if people would be satisfied with either eight .303 guns (or even six?) on the escort fighter to make up for the increased fuel load then it becomes a somewhat more doable.
Kevin J
Banned
That was exactly what we needed. The only long range fighter we had was the Hurricane II with 2 x 45 IG drop tanks. We used them for close escort on our raids into France. The Spitfire Vb with its single 45 IG slipper had to drop it before entering the danger zone. They were top cover. So 12 squadrons of fighters would escort 1 Squadron of bombers. Obviously, there's withdrawal support too. Spitfire Vb's with 30 IG combat capable slipper tanks?
Last edited:
Shortround6
Lieutenant General
Hurricane needed extra fuel because it needed more fuel per mile than the Spit even without drop tanks, carrying two drop tanks ups the drag a bit more.
Not saying the Spit had more range but the difference might not be as much as it appears.
The Merlin 60 series engines were game changers because they gave a lot more power at the higher altitudes (over 20,000ft) for not that much of an increase in weight.
Yes we can add up all the weights it it comes to hundreds of pounds BUT the alternatives were (in the design phase in 1939-41) the RR Vulture, the Sabre and the Centaurus for engines that would give you 1000hp in the upper 20,000 ft range, for the Americans it was the R-2800 with either a two stage supercharger or turbo.
Compared to those engines the Merlin 60 was a lightweight.
Anybody want to build a Typhoon with 250-300imp of internal fuel and use it over Germany in daylight in1942/43 against Bf 109Gs?
Not saying the Spit had more range but the difference might not be as much as it appears.
The Merlin 60 series engines were game changers because they gave a lot more power at the higher altitudes (over 20,000ft) for not that much of an increase in weight.
Yes we can add up all the weights it it comes to hundreds of pounds BUT the alternatives were (in the design phase in 1939-41) the RR Vulture, the Sabre and the Centaurus for engines that would give you 1000hp in the upper 20,000 ft range, for the Americans it was the R-2800 with either a two stage supercharger or turbo.
Compared to those engines the Merlin 60 was a lightweight.
Anybody want to build a Typhoon with 250-300imp of internal fuel and use it over Germany in daylight in1942/43 against Bf 109Gs?
And they developed tested and fitted 85G auxiliary 75G drop tanks to the P51 to escort it, in about 18 months.
The British specified climb performance because their planes had short range, they took off at the last minute to intercepted incoming aircraft, if the Spitfire had another 30G of fuel it could be at 20,000ft waiting for the enemy instead of climbing like a rocket. A Spit at 20,000ft with 85G of fuel instead of 60G is still going to have adequate performance.
drgondog
Major
Internal fuel remaining after a fight, sufficient to return home at cruise speeds - combined with the agility to battle the opponents interceptors were the two factors required for long range escort. If the aircraft under discussion had these two attributes, then it met the primary design objectives.
BTW, as discussed before, the F6F and F4U met these criteria for carrier based bombers but were inadequate for sustained operations for AAF medium and heavy bombers at extent of their range envelopes. Just different missions between USN and AAF.
BTW, as discussed before, the F6F and F4U met these criteria for carrier based bombers but were inadequate for sustained operations for AAF medium and heavy bombers at extent of their range envelopes. Just different missions between USN and AAF.
swampyankee
Chief Master Sergeant
- 4,306
- Jun 25, 2013
One rather obvious advantage of carrier operations is that one can move carriers to someplace where the aircraft's range is sufficient. One related disadvantage is that this could put one's carriers in range of land-based aircraft. Early in the war, carrier aircraft were generally significantly inferior in performance to comparable land-based aircraft (exception: Zero), but by 1944 this was largely no longer true (there was not sufficient air combat between F4Us or F6Fs and FW190s or Bf109s to definitively answer this question. Regardless of this, I strongly suspect no Luftwaffe pilot would be chortling in his beard after meeting either).
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Surprisingly enough, the F4F and the P-36 had comparable range - roughly 850 miles.
Reluctant Poster
Tech Sergeant
- 1,776
- Dec 6, 2006
Where are you getting the additional warning time? They weren't being held on the ground, taking off at the last minute to save fuel.They were launched as soon as the information was sufficiently processed to result in a successful interception.
When the Spitfire was being designed radar was not in existence, warning time was very short indeed. The British had conducted exercises before the war and concluded that standing patrols were not practical due to wear and tear on men and machines. Rate of climb was obviously very important If not the most important paramete.
Sinnotts "The Royal Air Force and Aircraft Design 1923-1939" has a lot of information on the thinking that went into the parameters guiding pre war aircraft design in Britain.
Tactically rate of climb was extremely important. Read Lundstroms "The First Team" for a discussion of how the poor rate of climb of the Wildcat allowed Japanese bombers to slip past.
The British had developed by far the most sophisticated air defense system in the world by 1939. It is difficult to imagine how it could have been done better without the 20-20 vision known as hindsight.
Last edited:
Was that before or after they put a Merlin engine in it? You cant put and 85G auxilliary tank in a Spitfire and even if you do you dont get the range of a P-51, because its main tanks are larger and it uses less fuel while cruising.
With a 1000HP engine and about 660HP available at take off with a twin blade wooden prop the last thing a Spitfire needed was extra fuel. Twin pitch props were only introduced in 1940. There was very little loitering about at 20,000 ft in the Battle of Britain unless that was the intention. Park used to put squadrons up covering areas in case of a change in direction of enemy raids.
You have me scratching my head wondering when I've proposed that a slightly modified, armed Spitfire can do 1800+ mile range while escorting something. Data sheets are response to the statement: The things that were within reach of UK bombers with fighter escort were mainly French farms, very little that the Germans felt obliged to defend.
...that was patiently false (as proven by data sheets and simple geography): for example, a whole Ruhr area is well within 300 mile radius for RAF flying from Kent and East Anglia.
For bombing the Ruhr, the bombers don't need to fly at most economical speed (for max range), but can use max lean mixture power. Gets them to 190-200 mph at 15000 ft, with a lot of range to spare.
Having fighter escort relays against a target 300 miles away is a far easier affair than doing that against a target 600 miles away. It also allows for 'target escort' to come under umbrella of 'last part of sortie escort' on the return leg.
When Spitfires were used to escort US bombers in the very early days of the campaign how far did they take them before handing over to US P-47s?
LW aircraft were picked up on radar and tracked before they crossed the channel, the ground controllers kept the planes on the ground until the raids bearing and then possible target were established, only after that were the fighters ordered up because they didn't have the fuel to chase them if they got it wrong. The Spitfire sacrificed fuel for performance based on the power available at the time, under 1,000hp, by 1941 it had another 300-400HP available and MkII PR Spits had been using 30G rear 20G underseat tanks for 12 months by that time.
No they were not. A raid picked up 100 miles away travelling at 200mph presents a huge number of possibilities. The object was not to chase them but to stop them hitting their targets and to fight over land.
Did Spitfires have twin blade wooden props in 1940?.
Yes and if they got it wrong the fighters did not have the fuel to change direction and chase which is the reason they stayed on the ground until the very last minute and climbed hard into the attack once the raids target was identified, because of the 85G of fuel,
During Dunkerque they had fuel to fly and fight over the beaches. Once crossed the coast RADAR couldn't be used so the forces had to be in place beforehand.
The Spitfire IX was supposed to have 175 miles of combat radius when covering US bombers.
