British/European wing location on single seaters vs most US aircraft.

[BarnOwlLover]

I've noticed that most British/European aircraft have their wings mounted further forward on the fuselage than planes like say the P-51 and P-47. Also, I know that planes like the Spitfire and Hawker Tempest and Fury have their main fuel tanks mounted between the engine and cockpit. Is this an accurate observation or an illusion? What could be governing this positioning?

 

[MiTasol]

Putting the fuel tanks on the centre of gravity (cofg) means no trim changes as fuel is burned off.

Putting the pilot in that location, and the fuel in the wings as near the cofg as practical, results in better visibility for the pilot and a minimal change of trim as fuel is burned off.

 

[BarnOwlLover]

Is that why most European aircraft had their wings mounted so far forward compared to several American types? Not all these aircraft (such as the Hawker Typhoon) did have the main fuel tank in the front fuselage. However, even it had the wing mostly ahead of the cockpit, while on the Mustang the cockpit was largely over the wing.

 

[GrauGeist]

Wing placement has alot to do with the aircraft's design, size of the engine, fuel storage locations and such.

The key factor is maintaining the aircraft's Center of Gravity (CoG).

 

[Shortround6]

The P-36/40 had the main fuel under the cockpit in the wing, fuselage sat on top of the wing. Mustang did the same thing.
You want a skinny fuselage you have to

The Typhoon was sort of a special case. You had a 2400-2500lb engine instead of a 1400-1700lb Merlin. You need to keep that engine near the center of gravity.

Engine actually goes past the forward spar.
As mentioned by others, you want to keep most of the fuel on/near the center of gravity.

With an Allison the whole engine was out ahead of the wing leading edge.

Sometimes it was just a different way of solving a puzzle .

D. 520 put fuel ahead of the cockpit

main part of cockpit was behind the wing trailing edge. Great if you are looking down, not so good for deflection shooting

 

[pbehn]

The P-36/40 had the main fuel under the cockpit in the wing, fuselage sat on top of the wing. Mustang did the same thing.
You want a skinny fuselage you have to

The Typhoon was sort of a special case. You had a 2400-2500lb engine instead of a 1400-1700lb Merlin. You need to keep that engine near the center of gravity.
View attachment 700367
Engine actually goes past the forward spar.
As mentioned by others, you want to keep most of the fuel on/near the center of gravity.
View attachment 700368

With an Allison the whole engine was out ahead of the wing leading edge.

Sometimes it was just a different way of solving a puzzle .

D. 520 put fuel ahead of the cockpit
View attachment 700366
main part of cockpit was behind the wing trailing edge. Great if you are looking down, not so good for deflection shooting

When the Typhoon had to adopt thinner Laminar flow type wings they had less volume, so the re design Typhoon II which became the Tempest had fuel moved from the wings to the fuselage, according to wiki a 21 inch 70 gallon fuel bay was added in front of the pilot. The Hawker Tornado and Typhoon were very similar prototypes, but the Tornado was 12" longer, with the difference entirely due to the different engines.

 

[Shortround6]

When the Typhoon had to adopt thinner Laminar flow type wings they had less volume, so the re design Typhoon II which became the Tempest had fuel moved from the wings to the fuselage, according to wiki a 21 inch 70 gallon fuel bay was added in front of the pilot. The Hawker Tornado and Typhoon were very similar prototypes, but the Tornado was 12" longer, with the difference entirely due to the different engines.

The Mustang also arranged it's landing gear different with the wheels going into the wing root extensions (?). the landing gear was in front of the main spar and not behind it which freed up space for the fuel. Just a different way of doing things.

 

[pbehn]

The Mustang also arranged it's landing gear different with the wheels going into the wing root extensions (?). the landing gear was in front of the main spar and not behind it which freed up space for the fuel. Just a different way of doing things.

Also, with the Spitfire I read that special tyres and wheels were developed for it, I dont know about the Mustang but I would think it benefitted also because new developments quickly become the norm, so in terms of the OP the volume needed for something as mundane as a wheel changed, or the same sized wheel could cope with a massive increase in weight.

 

[thunderbird]

Center of gravity relative to the average wing chord is the primary design condition for whether a plane is flyable. Its a balancing act of equipment location, consumables location and wing location and is affected by many factors. Counterintuitively, the later Griffon spitfires had a longer nose despite using a much heavier engine. i suspect power affects meant the nose needed to be longer to maintain the aircraft's neutral stability. or that a more complex control system reduced the affect of the change in center of gravity location. Or that dead weight was added to maintain the center of gravity location.

Typically, one wants to have a positive static margin, which means, pulling back on the stick increases wing lift, and generally at a constant, modest increase in stick force per increase in gee loads, and pushing the stick forward acts conversely.

And maintaining the center of gravity location as fuel and weapon loads changed was critical. There are some hints that the P-39s, and likely the P-63 reduced their static longitudinal margins, possibly into the unstable range as the machine guns and cannons were discharged, considering the stories that the P-39 would tumble.

The P-51, with its fuel tank behind the pilot was either unstable or very neutral until that tank was discharged. Hence, directions to burn that fuel first, and then drop tanks.

The late griffon powered spitfires might have had their nose lengthened so that another fuel tank could have been added behind the pilot, as the early spitfires were already neutrally stable, and would possibly have been unflyable if a fuel tank was installed behind the pilot. A cutaway would help to get some idea what is going on.

 

[tomo pauk]

I've noticed that most British/European aircraft have their wings mounted further forward on the fuselage than planes like say the P-51 and P-47. Also, I know that planes like the Spitfire and Hawker Tempest and Fury have their main fuel tanks mounted between the engine and cockpit. Is this an accurate observation or an illusion? What could be governing this positioning?

Are there any numbers,or percentages to compare?

 

[BarnOwlLover]

XP-51F illustration:

Spitfire III Merlin 60 engine test bed:

Look at the wing leading edges, which seems (though these are illustrations instead of photos) on the Spitfire to be a fair bit further forward compared to the cockpit vs the Mustang. However, the Spitfire had its main fuel tank between the engine and the cockpit, while the Mustang had it in the wings between the main spars.

 

[GrauGeist]

The P-51 had two main tanks that spanned the width between the port and starboard landing gear with a small gap beneath the cockpit. It also had a fuse tank behind the cockpit.

 

[pbehn]

No one would design the Spitfire the way it ended up, it had a substantial weight placed in or near the tail to maintain CoG. Between the Spitfire original design and the Mustang MkI original design the Merlin (and Alisson) had already grown substantially in power output. With a 1936 Merlin and prop the Mustang would struggle to get off the ground.

 

[BarnOwlLover]

The Hawker Typhoon (which used an engine much larger than the Merlin), the Tempest (a re-winged Typhoon with a longer front fuselage to take up displaced wing tanks and increase fuel capacity overall) and the Fury/Sea Fury (related to the Tempest and Typhoon lineage but foreward of the rear cockpit firewall was mostly a new aircraft) used a similar wing placement scheme. As did the likes of the Macchi C200/202/205.

So I question if there's anything wrong with that philosophy of design. Though it should be noted that the Merlin Mustangs and later Merlin-powered and Griffon powered Spitfires had fuselage tanks that did play havoc with CG and directional stability if they were filled beyond a certain point.

 

[Shortround6]

I don't know what they moved in the Mustang but the rear tank problem seems to a bit overblown?
Post war manuals (different radios? moved O2 tanks?) do want the rear tank be the first one used after take-off.
But then they want the tank to only be filled to 65 gallons to prevent the rearward CG problem and they want 25 gallons to left in the rear tank to preserve the right CG for landing.
So 40 gallons separates dangerous aft CG problem from dangerous forward CG problem?

 

[pbehn]

The Hawker Typhoon (which used an engine much larger than the Merlin), the Tempest (a re-winged Typhoon with a longer front fuselage to take up displaced wing tanks and increase fuel capacity overall) and the Fury/Sea Fury (related to the Tempest and Typhoon lineage but foreward of the rear cockpit firewall was mostly a new aircraft) used a similar wing placement scheme. As did the likes of the Macchi C200/202/205.

So I question if there's anything wrong with that philosophy of design. Though it should be noted that the Merlin Mustangs and later Merlin-powered and Griffon powered Spitfires had fuselage tanks that did play havoc with CG and directional stability if they were filled beyond a certain point.

The only philosophy is to maintain the CoG. The two types you quoted in your OP the P-51 and P-47 had equipment in the rear that wasnt there on other types, the cooling system on the P-51 and the Turbo system on the P-47. The USA produced other types like the P-40, F2A(Buffalo) F4F(Wildcat) with proportions similar to the Spitfire etc.