Bf109, "a flying brick"...

[707shap_Srbin]

Hi all!

Thought it will be interesting.

Interesting article on Falke-Eins Blog.

[Original_Uwe]

Sounds just about like the Kurfurst in DCS.

[216th_Lucas_From_Hell]

Good read, thanks!

 

".. incompletely trimmed ailerons and rudder ruin the feel of the aircraft to uselessness. Therefore, the aircraft must be carefully flown in.. "

 

This felt very, very relatable. I just can't get my head around the Bf-109 no matter how hard I try. It's a work of art in terms of engineering, but I can't connect with the monster and I feel that's a big part of flying. One needs to be one with the aircraft - if you're trying to tame it, or the aircraft is flying itself, it won't work. It's teamwork between you and the machine.

 

" ..The day was rounded off with a demonstration of captured American aircraft, in particular a P-51 Mustang – it was stressed that our Bf 109s and Fw 190s were generally superior to this type. We soon realised on our first combat sortie that this statement was not entirely accurate....”

 

Ah, good old cockiness. Reminds me of the Pokryshkin-Sapozhnikov vs. a new LaGG-3 model fresh from the factory in 1943.

 

 

The conditions for the battle were complicated: our “enemies” were to fly toward Sapozhnikov and me on unknown azimuths. Thus, even before the start of the fight in high-speed turns, they had favorable positions. But the bosses had decided, and we did not argue with them. We had to find a way out in the course of the fight.

The leadership arrived. I flew in the first pair. I gained the established altitude and by rocking my wings gave the command to initiate the fight in horizontal maneuvers. I energetically put my aircraft into a turning climb and, allowing the LaGG to approach to a dangerous distance, executed a sudden roll with decrease in altitude. The LaGG-3 passed by above me and I immediately set up on his tail and got him in my sight. No matter what way the LaGG turned, I kept him in my sight. Several minutes went by and the result was obvious.

Then we examined how the LaGG would handle itself in vertical maneuvers. I threw my aircraft into a steep dive and, having gained velocity, departed into a zoom. At the apex I placed my airplane on its wing. The LaGG was making a combat turn below me. It was relatively easy for me to catch him in the tail and fix him in my sight, parrying all attempts of this ‘enemy’ to avoid my attack.

Sapozhnikov also won his fight in turning and climbing, but fought to a draw in vertical maneuvers. After coming out of a dive, the LaGG-3 stayed close to me in a high-speed pass over the airfield, but the Spitfire, which had weaker diving capabilities, fell significantly behind us.

 

[Crump]

 

 

On the P-51 a light off-set of the vertical fin was built into the design which generated an aerodynamic force which helped to balance out the torque. 

 

But that is not what the Vertical Stabilizer filet is there for....

 

Torque is a low velocity phenomenon and a wings have plenty of natural dampening to eliminate it.  At the stall break however, the torque will roll the wing some 15 to 30 degrees in a typical world war II fighter.

 

 

 

On one takeoff my machine veered off to starboard without me being able to do much about it - my knees got in the way of the stick movement. 

 

 

Normal Left turning tendency of taildragger aircraft....actually all propeller aircraft with the prop turning clockwise.   Easily controlled in any viable aircraft design unless you physically cannot move the controls such as getting your knee caught.  I have to watch for this im my taildragger when taking passengers as the tend to pull their knees up high right where it will restrict my lateral control.

 

 

 

The tendency of the Bf 109 to swing badly on landing and take-off could of course be countered - but it required plenty of rudder. And if the tail was " lifted aggressively ", in the words of the late Mark Hanna (who also died at the controls of a Bf 109!), " the left swing tendency was difficult to stop and happens very quickly ". 

 

 

Torque is a very small contributor to the left turning tendencies of an aircraft.  It is a pure rolling moment and only translate to a directional moment by putting additional friction force on the tire. It takes a lot of force to turn the airplane that way and as such, torque is a very minor contributor to left turning tendencies.

 

P-factor (propeller effect) - The blade on the left side upswing has the wing and the ground interfering with its thrust production compared to the right side downswinging blade.  The right side produces more thrust and therefore pushes the airplane to the left.

Spiral Slipstream (Propeller effect) - the largest contributor is the spiral slipstream striking the left side of the vertical stab and pushing against the tail to move it to the right.  Tail moves right....nose moves left...

Gyroscopic procession (resultant force is experienced 90 degrees from normal force in the plane of rotation).  Because of the angle of the propeller on the gear, more force is experienced at the bottom front of the disc and the resultant is experienced on the left side of the disc turning the aircraft....ta da!!....to the left!

 

 

 

In February 1944 alone over one thousand Luftwaffe aircraft were lost in accidents, a good proportion of which were due to inadequate training (quoted in Isby 'The decisive duel' P361). As Bob Goebel points out, all fighter pilots - certainly all US P-51 pilots - could probably fly well. However only relatively few could shoot well. The Luftwaffe Nachwuchs at the controls of their high-powered and heavily armed Bf 109s could do neither. They didn't stand a chance. 

 

 

His conclusion is spot on, however.  It was not due to torque though.  It was due to the fact it takes skill and experience to fly any high performance taildragger.  The Luftwaffe simply did not ramp up a wartime pilot training program until too late nor did rotate their experienced pilots out to train the new ones.   The had no system to replace their losses and as such were forced to put a multitude of poorly trained "pilots" as grist for the mill. 

The filet added to the P-51 is placed their to increase directional stability at high speeds.  It actually makes low speed directional control slightly worse.  The spiral slipstream simply has more area to strike and influence.

[II/JG17_HerrMurf]

Use of the rudder is a fine art in the Bf. It becomes "normal" pretty quickly and you find yourself using about three positions without even looking at the ball (Climb, Dive, and Level). It has a significant effect on speed in both level and dive speed. This is most pronounced when attempting to extend from a Co-E enemy.

 

Switching between the Bf with multiple positons on the rudder and the Fw which has almost none is what screws me up. I don't usually under-rudder the Bf but when switching to the Fw, too much rudder at takeoff makes for an interesting departure on the first run. I find myself barking, "Get your foot off the damn pedal," inside my head.