Multi Engine checkride tomorrow

[Mark815]

Congrats!!



Hell, I'll write you a check if you want some multi piston time. How much you want? 500? 1000?

(Seriously, it comes quick...don't sweat it)

haha thank...i'm still sweating it though I need to find a job that lets me fly something multi!

 

[WacoFan]

But digging one's own grave is fun!

I fully agree with the last, as I posted previously......it's one of those "which religious camp" are you in? Same with pitch/power vs speed/altitude religious arguments.

Ok...but I've always wondered why the P-38 was made to operate with props like that? Inward rotating props are easier aren't they? Why did they make the P-38 that way?

 

[MikeD]

Ok...but I've always wondered why the P-38 was made to operate with props like that? Inward rotating props are easier aren't they? Why did they make the P-38 that way?

Stability, I imagine. With the outward rotating props, you have a longer arm on each wing, providing a more stable aircraft roll-wise when both engines are operating. However, when single engine, both engines become critical in the sense of having to counteract that long moment arm. Plus, with its unique boom design, I remember reading that there was a problem with disturbed airflow and downwash between the booms and the center fuselage/wing area and affecting the horizontal stab. The original XP-38 had inward rotating props and all subsequent models went with the outward rotating.

 

[Guy]

Ok...but I've always wondered why the P-38 was made to operate with props like that? Inward rotating props are easier aren't they? Why did they make the P-38 that way?

I had wondered that same thing and when I went through the Champlin Fighter Museum, I asked the guide that very question. The answer was he had never noticed that the props did that.

However, for a better answer, there is a post here:

http://www.ww2aircraft.net/forum/technical/why-propellers-p-38-lightning-rotate-outwards-10566.html

from a fellow who references and quotes a book on the P-38.

Interestingly, the "prototye" P-38, the XP-38, had inwardly-rotating engines (before it crashed). However, all subsequent P-38's (including the first batch of YP-38's) had outwardly rotating propellers; Warren M. Bodie, in his book The Lockheed P-38 Lightning: The Definitive Story Of Lockheed's P-38 Fighter, states that, "Engine rotation was changed so that the propellers rotated outboard (at the top), thereby eliminating or at least reducing the downwash onto the wing centersection/fuselage juncture. There was, by then, no doubt that the disturbed airflow, trapped between the two booms, was having an adverse effect on the horizontal stabilizer. No problem was encountered in reversing propeller rotation direction; they merely had to interchange the left and right engines."

From Wikipedia:

http://en.wikipedia.org/wiki/Lockheed_P-38_Lightning

 

[WacoFan]

Stability, I imagine. With the outward rotating props, you have a longer arm on each wing, providing a more stable aircraft roll-wise when both engines are operating. However, when single engine, both engines become critical in the sense of having to counteract that long moment arm. Plus, with its unique boom design, I remember reading that there was a problem with disturbed airflow and downwash between the booms and the center fuselage/wing area and affecting the horizontal stab. The original XP-38 had inward rotating props and all subsequent models went with the outward rotating.

I had wondered that same thing and when I went through the Champlin Fighter Museum, I asked the guide that very question. The answer was he had never noticed that the props did that.

However, for a better answer, there is a post here:

http://www.ww2aircraft.net/forum/technical/why-propellers-p-38-lightning-rotate-outwards-10566.html

from a fellow who references and quotes a book on the P-38.



From Wikipedia:

http://en.wikipedia.org/wiki/Lockheed_P-38_Lightning

Gracias!

I will add that for those of you that are interested in reading about a full-on aviation bad-ass that probably doesn't get enough attention, Tony LeVier would be an interesting google for you.