For all you P-38 Drivers.

[Chalenge]

I realize parasitic drag is usually thought of as drag caused by air friction. However parasitic drag is also defined as a combination of air friction across surfaces as well as interference drag. Interference drag would be the interaction of two aerodynamic bodies and yes that includes the junction of fuselage with wing as well as engine/tail booms with wing that required fillets to correct.

Parasite drag is the "turbulent drag" that was causing the problem and was further aggravated by the inadequately stiffened booms.

[Chalenge]

Oh... by the way.

The P-51 was the first laminar flow design ever implemented. You are correct in saying that it did not experience laminar flow... but only if you mean over the entire wing. Yes the P-51 was designed for laminar flow and yes it did experience laminar flow over 40-50% of its airfoil by design. Yes there were problems with reduced performance over theoretical and design potential... but to say that the P-51 never experienced laminar flow over any portion of its airfoil is not an honest statement. If the Mustang never experienced any form of laminar flow then it would never have the performance it did and does.

[Brooke]

but only if you mean over the entire wing.

Yes, that's what I mean.

[Chalenge]

In that case it doesnt matter. In having laminar flow over 40-50% of the surface area you are eliminating that much effective drag (turbulent) and because the layers are not separated until the point of minimum pressure the effective profile drag is much less whereas on an aircraft with turbulent drag over the entire wing surface (99.9%) the profile drag can in effect be as much as doubled. Also... the laminar airfoil of the P-51 eliminates the increase of the coefficient of drag for the majority of the effective AOA. What that means is that as a pilot increases the AOA the coefficient of lift increases but the coefficient of drag remains constant for 65% (approximately) of the effective AOA. This is why a P-51 can raise its nose as much as eight degrees (or a little more) and the drag remains the same as if the wing were level and the P-51 can use its E to zoom to great advantage. No P-51 should ever zoom straight up unless the pilot is willing to give up a great deal of his E to do it (the coefficient of drag will climb at a greater rate than on a Spitfire for instance).

[Brooke]

If you want to talk about P-51's, why not make a new topic instead of continuing to post such things in this P-38 topic?

[Brooke]

Here, I created this:

Topic: The P-51 and its laminar-flow wing
http://bbs.hitechcreations.com/smf/index.php/topic,296622.0.html

Now, this P-38 topic can be left in peace to talk about P-38's instead of getting contantly derailed.

[Chalenge]

Brooke I was talking about airflow and correctly your misinformation. Like I said... you were looking for the word parasite/parasitic.

Dont get your panties in a bunch for not knowing the subject very well. 

And on subject... P-38s were never as good as their press. War propaganda you know... cant afford to waste efforts on a technically complex aircraft thats difficult to manufacture and kills its own pilots after all! 

[Brooke]

Brooke I was talking about airflow and correctly your misinformation. Like I said... you were looking for the word parasite/parasitic.

No, that is the incorrect term.  See above.

Dont get your panties in a bunch for not knowing the subject very well. 

I seem to know it better than you do.

And on subject... P-38s were never as good as their press. War propaganda you know... cant afford to waste efforts on a technically complex aircraft thats difficult to manufacture and kills its own pilots after all! 

You can certainly have your opinion.

[Chalenge]

I seem to know it better than you do.

Not at all. You dont understand that interference drag is just a component of parasite drag and your argument against laminar flow is generated by someone else who is arguably in the dark on the subject.

[Brooke]

Not at all. You dont understand that interference drag is just a component of parasite drag and your argument against laminar flow is generated by someone else who is arguably in the dark on the subject.

This from the guy who thinks the P-38 issue was just tail stiffness.

[Ack-Ack]

And on subject... P-38s were never as good as their press. War propaganda you know... cant afford to waste efforts on a technically complex aircraft thats difficult to manufacture and kills its own pilots after all! 

LOL!  It wasn't? 

ack-ack

[Captain Virgil Hilts]

I think the word you are searching for is 'parasite' since most of the flow this airplane ever saw (99.9%) was turbulent and only about 2-3mm was ever laminar beyond the stagnation point. I have said before... the tail buffeting of the P-38 was brought on by inadequate tail boom stiffening.

Maybe thats why 38 pilots need viagra at an early age.   

You have no idea at all what you're talking about. What you know about a P-38 would fit on the head of a sewing pin and leave room for a medium sized herd of elephants to tango drunk.

The problem with the P-38 was that air accelerated to the speed of sound over the high aspect ratio wing that created the superior flying characteristics. That buffeted the tail. The tail actually did not flex, Lockheed proved that in the NACA wind tunnel in 1941 and in 1942.

The P-38 had a better than 6-1 kill ratio in Europe, and even better than that in the Pacific. It was the P-38 and the P-47 that kept the strategic bombing campaign going before the P-51 reached Europe, despite the P-38 facing 10-1 numerical superiority by the Germans deep in enemy territory because the 8th AF was stupid enough to send the P-38's they needed to the Mediterranean, and so short sighted as to not fit the P-47 for the correct drop tanks. It was the P-38 that was the first Allied fighter over Berlin, twice, when every other aircraft had to turn back. The P-51 showed up after the P-47 and P-38 had cut the Luftwaffe up and faced Germans who were not as well trained, had less experience, beat up aircraft, and not enough fuel. It was the ground work of the P-47 and the P-38 that helped the ground troops take ground, the ground work that the fragile P-51 handled poorly.


I suggest you take a couple of doses of scorpion venom for your paranoid dementia, and call somebody who cares in the morning. It's the P-51 pilots that need Viagra, the P-38 pilots can get it up easily, since the P-38 out climbs the P-51 to 20k.

[Treize69]

You have no idea at all what you're talking about. What you know about a P-38 would fit on the head of a sewing pin and leave room for a medium sized herd of elephants to tango drunk.

The problem with the P-38 was that air accelerated to the speed of sound over the high aspect ratio wing that created the superior flying characteristics. That buffeted the tail. The tail actually did not flex, Lockheed proved that in the NACA wind tunnel in 1941 and in 1942.

The P-38 had a better than 6-1 kill ratio in Europe, and even better than that in the Pacific. It was the P-38 and the P-47 that kept the strategic bombing campaign going before the P-51 reached Europe, despite the P-38 facing 10-1 numerical superiority by the Germans deep in enemy territory because the 8th AF was stupid enough to send the P-38's they needed to the Mediterranean, and so short sighted as to not fit the P-47 for the correct drop tanks. It was the P-38 that was the first Allied fighter over Berlin, twice, when every other aircraft had to turn back. The P-51 showed up after the P-47 and P-38 had cut the Luftwaffe up and faced Germans who were not as well trained, had less experience, beat up aircraft, and not enough fuel. It was the ground work of the P-47 and the P-38 that helped the ground troops take ground, the ground work that the fragile P-51 handled poorly.


I suggest you take a couple of doses of scorpion venom for your paranoid dementia, and call somebody who cares in the morning. It's the P-51 pilots that need Viagra, the P-38 pilots can get it up easily, since the P-38 out climbs the P-51 to 20k.

Isn't there a quote attributed to Gerald Johnson along the lines of "The P-38 and P-47 pilots took out the Luftwaffes best, the the P-51s handled the rest"?

[GtoRA2]

Not at all. You dont understand that interference drag is just a component of parasite drag and your argument against laminar flow is generated by someone else who is arguably in the dark on the subject.

Yeah it's not like our two tops scoring aces flew it...

[CAP1]

Isn't there a quote attributed to Gerald Johnson along the lines of "The P-38 and P-47 pilots took out the Luftwaffes best, the the P-51s handled the rest"?

hhmm...i dunno, but if you don't mind, that looks like sig material to me.