The High Yo-Yo

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Right on - I also understand that this was a common manuever for the P-61 as well!
 

Early model P-38s, specifically the E and F model were not fitted with "maneuver flaps". This is a setting incorporated to improve turn rate and radius without a severe drag penalty. These first appeared on the P-38G. Using flaps, the P-38 could out-turn anything in the luftwaffe inventory with relative ease. Indeed, even the Spitfire IX and XIV were hardpressed to hang with a Lightning under those conditions. Those Fowler flaps really improved agility and the absolute lack of torque made flying on the edge far less dramatic than in single-engine fighters.

Vertical performance was the best of major USAAF fighters (Rivaled by the P-63).

I've spoken with many P-38 pilots over the years. Most of those who served in the ETO also flew the P-51. To a man, if forced into a low-speed, slug-it-out brawl, they would rather be flying the P-38. However, at 30,000 feet, chasing German fighters, each would rather fly the Mustang. This is simply due to the problems P-38s suffered with compressibility and a relatively low critical Mach of 0.68 (P-51 was 0.75). While dive recovery flaps would later make the P-38 much easier to fly at high-speeds, few later models (P-38J-25-LO and P-38L-1-LO) fitted with these were in service when the last 8th AF P-38 group transitioned to Mustangs (only the 56th FG would be flying anything but P-51s at the surrender, these being P-47Ms). By the fall of 1944, the only Groups flying Lightnings were in the 9th Tactical AF, and they spent most of their time well below 15,000 feet.

Over in the MTO, 15th AF fighters were generally divided between P-38s and P-51s. Flying from Italy, the P-38s units had a much better combat record than the 8th AF Lightning groups, which suffered serious engine reliablity issues (usually blamed on lousy fuel, rectified by Doolittle's order to blend custom fuel for the P-38 units).

As to the High Yo-Yo... It works well when the enemy cooperates. If E states are nearly equal, the enemy can work the vertical too. Where the High Yo-Yo really helps is when you have a lot more speed than the enemy. Pulling nose-high, burns off that speed, while storing potential E. A series of High Yo-Yos bracketed around slashing attacks will cause the enemy to burn off more speed maneuvering to avoid you. Eventually, he will have no E in the tank and becomes an easy target for the fighter hovering above like a starved hawk. You may find that the enemy is using nose-low turns to retain his speed. That will work until he runs out of altitude, which is the same place his luck runs out too.

Roll rate comments: Roll rate is important, but superior roll rate can be offset by superior flying. At low speeds, a bootful of rudder can substantially boost roll-in. Naturally, there's a downside. The yaw associated with large rudder displacement will eat up airspeed. So, you have to balance gains against loss and that requires experience. At low speeds, the P-38 was not a good roller, due to smallish ailerons and the issue of momentum. Getting those outboard engines and associated hardware rolling takes time.

Most WWII fighters suffered a loss of roll rate as speed increased. There were aerodynamic reasons (wing twist and such), but the largest factor was extreme control forces. Simply stated, the pilots lacked the strength and leverage to obtain large control surface deflection. This was not the case with the P-38J-25-LO and the P-38Ls. Hydraulic boost meant that the pilot could get full deflection at almost any speed. As mentioned by someone else, differential throttle and rudder could be used to speed up low-speed roll, but were not needed above 200 mph.

Oddly enough, the P-38's ailerons were more effective at low speeds than several well known contemporaries. This was due to the P-38's wing stalling from the root on out as opposed to stalling from the tips on in. For example, at 100 mph the ailerons of the Typhoon were all but useless, with roll being more a function of rudder (and torque). Not so in the P-38, which had good rudder authority and aileron effectiveness right through complete stall. Rudder authority came from the rudders being in the propeller slip stream and ailerons that were still biting the air even after the main span of the wing had stalled. P-38s could be rolled around their longitudinal axis, nose up, hanging on the props, with zero forward velocity. Not a common practice to be sure, but it could be done and was frequently demonstrated at post-war air shows.

My regards,

NAVAIR
 
wmaxt said:
This is off a graph so the numbers are approximate and of course aircraft trim/load will vary the numbers a bit. Also the P-38 was credited with much better roll/turn rates when differental throttals were used.

Did you get them from NACA Report 868?
 

No, I don't have access to that one. These were from Lockheed and can be accessed through the Planes and Pilots of WWII. The statement about turn radii was from the Warren Bodie and he didn't mention the report number.

wmaxt
 
FLYBOYJ said:
Great stuff NAVAIR and welcome! Are you former Navy?

Thanks for the welcome!

Yes, I was a Naval Aircrewman crewing the Grumman C-1A, C-2A, HU-16 and the Douglas C-118 and Convair C-131. Logged 332 traps.. every one an adventure. I left the Navy in 1979.

You guys may know me from my websites (Plane and Pilots of WWII being but one), my magazine articles or from Aces High, where I'm a Trainer and go by the handle Widewing. That user name was already taken here..

My regards,

NAVAIR
 

Very cool and welcome again! I'm a former AD, spent 6 1/2 years with VP-65. In the 1980s worked for Lcokheed and built 130 P-3Cs.

lesofprimus is a former seal, good guy, right now he's dealing with Katrina, but he's a great guy!

You'll enjoy it here, lots of real good folks, enjoy!

FBJ
 
the lancaster kicks ass said:
excuse me FBJ, you forgot to introduce me

Sorry Lanc, ole buddy, I thought my introduction was all inclusive, but I figured heavy bomber talk would soon transpire enabling you to make your Grand Entrance! \/


lesofprimus said:
I see atleast he warned him about me..... Minister of Whoopass....

Yup - the WMD of Aviation Forums
 
the lancaster kicks ass said:
that aint no introduction-fool!

"Ladies and Gentlemen, boys and girls, children of all ages, allow me to introduce the incomparable, Master of Lancaster, the legacy of ARVO, the Wizard of Merlin - Powered Bombers, the one and only Mr.,"

LANCASTER - KICKS - ASS!

hows that?
 

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