Lack of trims and pitch in 109

[Fishu]

I have read often about some negative G maneuvers of Hartmann, but I can't figure out how to do that in AH enough effectively.

1) Almost every plane follows 109 who pushes nose down, because it does it so slow

2) Can use trims to make it quicker, but it takes time to move trim and when you want to pull up... oh well

3) Barely can wish for redout in 109, with decent trims with what you can also pull up

4) Also pulling up is slow in 109, again faces problems of trimming.

Bf109 seems to be either a bus, push only or pull only plane.
Lets try to look for this for next release, i don't know that much of 109s that i know how much you can push / pull it without trims, but it doesnt seem right with the maneuvers ive heard. (other planes does pitching well without having to trim for seconds)

Also 109s have problems keeping level on autopilot with less than a. 170mph IAS.

[This message has been edited by Fishu (edited 01-20-2000).]

[MiG Eater]

The -109 was widely regarded as having poor control harmony.  This is from the many after war reports from test pilots flying the 109.  There is even a recent article in Flight Journal that profiled a pilot's recent experience in one.  Roll was good and could be effected with relatively light force.  The elevator forces, on the other hand were quite high requiring the use of both hands on the stick for maneuvering above  400kph (240 knots).  The low pitch rate in the 109's in AH seem to model this trait well.  It physically takes more time to move the stick with the high forces.  Compare bench pressing a heavy weighted barbel with both hands to a light dumbell with one hand. You can move the light one a lot faster.
 
Hartmann's example of using negative G bunts more likely took his followers by surprise rather than displaying a superior pitch rate in his airplane.  He reported banging his head into the canopy on these occasions.  VERY few pilots use or used push overs for a lot of reasons (airframe stress, engine performance, etc.) but for one significant reason:  It HURTS!   At best its very uncomfortable and disorienting.  Its hard to push on the stick as you are being pushed the opposite way out of the airplane.  The blood pressure builds rapidly in the head and especially the eyes.  Can't model that stuff too well into the flight model.  Also, its likely that Hartmann had a high tolerance for negative G's.  

MiG

[Fishu]

I am talking more of low speed pitching..
At 200mph or less, it seems to take forever to pitch nose down.. but at 250mph it even does redout.

Forces increases when going slower?  

[ra]

I don't know if this is the same manuever, but I remember reading of Harttmann using negative G's to get out of a turning fight.  When he had an enemy on his six during a turn, he would push forward and roll out of the turn the opposite way.  So it really wasn't a manuever that required a particular kind of plane to execute, just a tactic for disengaging.

Speaking of 109 trim though, I believe most versions of the 109 had no rudder trim, so technically we shouldn't have it either.  Of course without rudder trim the autopilot wouldn't work, and how can you go fetch a beer without autopilot??    

--ra--

[leonid]

To elaborate on MiG Eaters post.  When I read about Hartmann's negative G maneuver, the first thing I pictured was a Russian pilot trying to keep his/her bullseye on the 109, following Hartmann into a negative G pitchdown, then physically lifting off the seat (yet held in place by his straps) while blood rushes to his/her head.  By this point the bullseye is totally lost, since the Russian pilot's head is banging against the canopy.  Yeah, it would be difficult to replicate that in a flight sim.

------------------
leonid, aka grisha
129 IAP VVS RKKA

[spinny]

If I'm not mistaken, Hartmann's maneuver was this: As he was turning, he would kick down rudder, and the nose would dip and dig, he would then pull in the direction of the down rudder and go out the other way.

As was mentioned above, pilots did not like negative g manuevers. I read an account by a Spit pilot who said that one thing that made the neg g move so unpleasant was that the floor of the plane always had dirt and crap on it; if he pulled a neg g move, all this stuff would float up and get in his eyes...not very nice at all, he wrote.

------------------
Spinny, VF-17, The Jolly Rogers 8X

[juzz]

I've heard the turning escape was used when the enemy pilot pulled lead to shoot, and Hartmann knew he was unseen "under the nose" of the enemy pilot, he would roll level and escape with a negative G dive.

[lemur]

You're all partially right...

Except the main reason he did it was that his plane was fuel injected. Their's weren't.

What does this mean? Fuel injection doesn't require gravity on order to function since fuel is squirted into the motor via pressure from a fuel pump.

Carberators on the other hand, require gravity to function properly.

The point of all this was that he could pull a zero-negative g dive and his motor would keep working. His opponents on the other hand, would have their motors quit on them! And in some cases would actually have to work at restarting them!

Mind you, most late-war planes were fuel injected so this isn't really modeled in WB.

-Lemur

[ra]

lemur,

Neg G cutoff is modeled in WB, but this an AH thread.    

I don't think any planes modeled currently in AH had carberators.

--ra--

[MiG Eater]

 

Originally posted by lemur:
You're all partially right...

Except the main reason he did it was that his plane was fuel injected. Their's weren't.

What does this mean? Fuel injection doesn't require gravity on order to function since fuel is squirted into the motor via pressure from a fuel pump.

Carberators on the other hand, require gravity to function properly.

Mind you, most late-war planes were fuel injected so this isn't really modeled in WB.

-Lemur

The advantage enjoyed by -109 drivers was mostly in the Battle of Brittain where British Spits and Hurri's used gravity fed float type carburaters.  It was pretty early in the war when allied aircraft started sporting the new pressure fed carbs negating the effectiveness of the bunt over manuever used by the Germans.  

Pressure fed carberators were the norm for American airplanes.  I used to work on R-2800 carberators, which were/are almost the size of some 4 cylinder car engine blocks.  Their design has the airflow going up since the carb was mounted on the bottom of the engine.  Using a series of bellows to measure airflow through a venturi, the fuel was metered and sprayed into the intake manifold.  Same thing for Merlin engines. Those little scoops just below and behind a Mustang's spinner or on the underside of a Spit's nose section are the carb intakes.  

German pilots were able to time the negative G bunt over, I suspect, right when it would cause the most disruption to the enemy pilot's aim.  They had the benefit of learning from the many experten that used the maneuver and survived the early war years to teach others of the technique.  Hartmann described an example in his book, pp 166-168 of "The Blond Knight of Germany" in an action against American Mustangs in late June of '44.  

Trivia:  Hartmann flew 19 combat missions before scoring his first kill and didn't get his second until his 41st mission, 3 months later! (Nov 5, 1942 and Jan 27, 1943)  Had he been an American pilot he'd have been rotated out of action with only 2 kills at 50 missions.

MiG

[This message has been edited by MiG Eater (edited 01-25-2000).]

[funked]

Ra - All the planes in AH had carburetors except the German ones.

[combat23]

All the carbs in Ah worked in neg situations.
The manuaver as I understand it can work. Was in a 109 the other nite and got a bit low and slow in front of a spit. Rolled left and pushed forward on the stick. got red out and then pulled back on stick. spit overshot(he was rolling back to see where I was) Went for a shot at him and got killed by someone else I didn't see.   But He didn't get me

see ya on line

[Hristo]

A bit longish, but you can see how the pushover saved me from the dweebfire on the deck.

film

And when he started rolling to see where I went, he started to lose the fight  

Even if the 109 has poorer negative G elevator than the Spit (and P 51, IMO), it is not neg G performance, but neg G timing which makes it a good move.

It is a very effective move if the opponent is faster than you, and approaching from behind. Too bad dweebfires discovered Split S only.

[funked]

Combat23 - Not all Spitfire Mk. IX had the modification to the carb. to prevent cutout.