Some Myths are true:P-51 range speed

[HoHun]

Hi Flyboy,

>whats a wet wing?

This is a term (I believe it's actually a proper technical term, but I'm not sure on that) for a wing that acts as fuel tank, instead of having a fuel tank mounted inside.

That means the wing skin is the fuel tank skin. The advantages are that you don't have to carry a fuel tank (lighter weight) and that you can use even the last small corner of the wings' internal volume to carry fuel (small plane, little drag).

The disadvantage is that if your plane gets hit, fuel spills out immediately, so it's not really well suited for military aircraft. (I have to admit that I don't know whether modern combat jets use wet wings. Tradeoffs might be a bit different nowadays than they were in WW2.)

Another disadvantage is that it can be difficult to keep the tanks tight even though the wings bend under aerodynamic loads, and have hundreds or thousands of riveting points. The P-35 apparently was a continous maintenance problem due to that.

It's also near impossible to make a wet wing self-sealing, at least with WW2 technology.

However, if it comes to pure range, it's a great thing to have a wet wing! :-)

Regards,

Henning (HoHun)

[niklas]

Are u sure that it serves as a fuel tank? Couldn´t it be the term for the water cooling system ? The 209 V1 did not have afaik a pressurized water cooling system, so the water vaporized in this high performance engine. The steam was led into the wing where it condensed (wet wing?). The cool water was collected and brought to the engine back.

niklas

[straffo]

Henning I remember reading of the trial of a 109 with a 2nd wing acting as tank and so being a wet wing .

It's exact or was it a fake ?

[Guppy35]

Regarding the Wet wing.  Paul Mantz who raced P51Cs after the war used the wet wing in his P51s for the Bendix.  It essentially meant sealing all the cracks in the wing and using all that available space for fuel.

Both his 51s still survive.  One, now owned by Kermit Weeks has been completly restored to stock military P51C status and flies as "Ina the Macon Belle" in Tuskegee Airmen colors.

The other is in the NASM.  When they restored it, they had to replace the wing due to the damage done by the use of the wet wing.  corrossion etc, really wrecked the insides.

Jackie Cochran did not use the wet wing,  She carried 165 gallon tanks under the wings.

The P51B/C was the preferred mount of the air racers as it was considered the faster and more streamlined of the Merlin Mustangs.

Top photo showing Mantz's wet wing P51C.  The blankets on the wings were to keep the fuel from expanding in the heat.

Bottom photo is Jackie Cochran's P51C

Dan/Slack

[Guppy35]

Originally posted by straffo
Henning I remember reading of the trial of a 109 with a 2nd wing acting as tank and so being a wet wing .

It's exact or was it a fake ?

A Hurricane was tested this way too.  Not a wet wing in the true sense of the word.

Dan/Slack

[HoHun]

Hi Niklas,

>Are u sure that it serves as a fuel tank? Couldn´t it be the term for the water cooling system ? The 209 V1 did not have afaik a pressurized water cooling system, so the water vaporized in this high performance engine. The steam was led into the wing where it condensed (wet wing?). The cool water was collected and brought to the engine back.

Hm, the term "wet wing" definitely describes the fuel tank concept. The Me 209 was mentioned in this thread only conincidentally, though the surface condensation cooling certainly got wetness into the wing, too :-)

Regards,

Henning (HoHun)

[HoHun]

Hi Straffo,

>Henning I remember reading of the trial of a 109 with a 2nd wing acting as tank and so being a wet wing .

>It's exact or was it a fake ?

I'm convinced it was a fake. On the site where it came from, it appeared harmless as it's fictional character was evident, but I've got to say that I'm a big fan of marking modified photographs as such because once off this site, the photo is going to cause a lot of confusion.

A few years back, (m) was suggested for such a marking, similar to the copyright (c). Maybe we history buffs should try and convince the photo wizards to start using that before they drive us around the bend ;-)

Regards,

Henning (HoHun)

[HoHun]

Hi Dan,

>The other is in the NASM.  When they restored it, they had to replace the wing due to the damage done by the use of the wet wing.  corrossion etc, really wrecked the insides.

Roger that, I got the NASM book on this one - Excalibur III it is, with a wet wing (corrosion photos included). Great book, quite different from the usual Warbirds stories but fascinating all the way :-)

Just reading: "Winds aloft chart used by Charles Blair for the Atlantic speed crossing. At near midpoint, the helping winds were giving Excalibur III a ground speed of 600 mph." Wow! 8-O

>The P51B/C was the preferred mount of the air racers as it was considered the faster and more streamlined of the Merlin Mustangs.

Makes sense! :-)

Excalibur III (when restored) had a V-1650-9 engine - do you know the characteristics of this one? I've found a claim this engine type was used in the P-51M prototype (with water-injection), but I don't know anything about full throttle height etc.

Regards,

Henning (HoHun)

[Guppy35]

Originally posted by HoHun
Hi Dan,

Excalibur III (when restored) had a V-1650-9 engine - do you know the characteristics of this one? I've found a claim this engine type was used in the P-51M prototype (with water-injection), but I don't know anything about full throttle height etc.

Regards,

Henning (HoHun)

In "Mustang-Story of the P51 Fighter" by Robert Grunhegan, he lists engine details.  He has the V-1650-9 as used in the P51H with the V-1650-9A in the P51M prototype

Quoting from the book:

"The equivilant British rating of this engine was the R.M. 16.S.M.  This series was developed from the Merlin Mark 100 and featured heavier construction for sustained operation at higher boost pressures.  Main castings were strengthened and the crankshaft used end to end oil feed

Max power for take off     1380 BHP at 3000 RPM at 61" hg(dry) fuel flow 160 GPH
1830 BHP at 3000 RPM at 80" hg, (wet) fuel flow 210 GPH
War Emergency (wet) low blower  1930 BHP at 10,100fet  3000 RPM at 80"hg
High Blower   1630 BHP at 23,500ft"

There's other bits and pieces on it in the book as well.

Dan/Slack

[Kurfürst]

Are 1650-9 figures rammed or static figures, dan?
can`t find my 51H curves to make it clear..

[gwshaw]

Originally posted by HoHun

Excalibur III (when restored) had a V-1650-9 engine - do you know the characteristics of this one? I've found a claim this engine type was used in the P-51M prototype (with water-injection), but I don't know anything about full throttle height etc.

Regards,

Henning (HoHun) [/B]

It was basically a -3 strengthened to allow it to use 80+ in Hg manifold pressures vice 67 in Hg for the -3. "Vees for Victory" has some unrammed figures for it, that match the figures in Guppy35's posting.

Greg Shaw

[HoHun]

Hi Greg,

>It was basically a -3 strengthened to allow it to use 80+ in Hg manifold pressures vice 67 in Hg for the -3. "Vees for Victory" has some unrammed figures for it, that match the figures in Guppy35's posting.

Ah, thanks, the V-1650-3 seems a good choice for long-range flight because of its high-altitude design point. Combining that with Dan's information that the -9 is a 100 series Merlin (which I believe was a series that had a reputation for excellent reliability), I'd say Excalibur III had the perfect engine for the job :-)

Regards,

Henning (HoHun)

[kreighund]

Yes all fighters today use wet wings and bags in the fuselage or wet fuselages....big circle back to the A6M Zero...of course most fighters use a Halon bottle to fill the tanks with halon once guns are selected.......