Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: funked on May 15, 2001, 05:56:00 AM
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Just because you can't make sense of it doesn't mean it's arbitrary.
Loss of wing area on one side (e.g. right side) of the aircraft does the following:
1. It reduces the drag on the right side of the aircraft. This results in a nose-left yawing moment which creates a nose-left slip angle unless countered by use of right rudder (rudder deflected trailing edge left). If the aircraft has dihedral, the slip angle will create a left-wing-down rolling moment. The right rudder deflection will also create a left-wing-down rolling moment.
2. It reduces the lift on the right side of the aircraft. This creates a right-wing-down rolling moment, which can be countered by reducing the lift on the left wing. This lift reduction is accomplished by "left" aileron, i.e. the left aileron is deflected trailing edge up.
Note that the required amount of this aileron deflection is reduced slightly by the the aforementioned rolling moments due to the dihedral and rudder deflection. And the reduction of lift on the left wing (due to aileron deflection) reduces induced drag on that side and thus balances some of the yawing moment. So the rudder and the ailerons "help" each other.
There is also a side-force equilibrium to consider. A nose-left slip and right rudder deflection both result in a side force which pushes the aircraft to the left. This can be balanced by a small right-wing-down bank angle. The bank angle means that a slightly higher lift coefficient is required for level flight, which is obtained by deflection the elevator trailing-edge up.
If the aircraft is able to balance out all of these moments and forces by control deflections it is said to be trimmable.
The conditions described above favor an aircraft which has very effective ailerons. This aircraft will be able to most easily reduce lift and induced drag on the left wing.
Our conditions also favor an aircraft which generates small side forces for a given rudder deflection or slip angle, but has significant dihedral and a significant rolling moment due to rudder deflection.
It is the combination of all of these factors which determines whether the aircraft is trimmable or not. These factors all are very sensitive to the size and shape of each part of the airframe (the powerplant plays a role too), so every aircraft will require different balance of these factors to reach equilibrium
Remember that these factors all change with airspeed and altitude. In particular, aileron effectiveness is greatly decreased at very high indicated airspeeds for aircraft of the type in Aces High, and is usually decreased at very low IAS. So the trimmability problem can change greatly depending on your height or speed.
To sum it up, trimmability in this case depends on several factors which are very sensitive to the design of the aircraft and the airspeed/altitude condition for which one wishes to trim. If any one of these factors is not right, then the aircraft can become unflyable. Some aircraft may be trimmable for all conditions, some may be trimmable only for a limited part of the flight envelope, and some may not be trimmable under any conditions.
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Just like I said Funked, your points while nice do not seem to apply in a consistent manner. For example you said that a plane with very effective ailerons would be able to counter this, yet we havbe the Typhoon flying half-wing and it certainly is not known for its very effective ailerons at any speed. Thays all that has me concerned Funked, that it seems atrbitrary just like the old oil-cooler leak run times.
Speaking of the oil-cooler thing, many people protested wildly when some of us brought that innacuracy up, stating all sorts of supposedly fancy/scientific reasons why some planes ran only for 5-10 seconds after hit while others flew on for 5 minutes or more. Ultimately HTC realized the this arbitrary inaccuracy and fixed it making AH more realistic and accurate, maybe if we learn from that experience and keep an open mind to examining these half-wing issues we could come up with more accurate and consistent sim. Well all I really wanted was for HTC to explain how it works, because as you said I really dont see any consistency the way it is now.
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D-9 still sucks when hit there. Actually any FW sucks when hit in the engine.
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Grunzherz don't confuse roll rate with aileron effectiveness. And don't conveniently overlook all the other factors I listed along with the ailerons!
The mechanics are complicated enough that it is possible to get effects that seem "arbitary" even if the missing wing effect is done in the same way on all aircraft.
I think it's extremely unlikely that it is a hack, that they are just arbitarily screwing up the flight model parameters for each plane. I'm 99% sure that HTC are just modeling the plane minus the outer section of the wing, and letting the physics model take care of the changes in flying qualities.
My question is "How much wing area are they removing?". Is it the same amount for each plane, or is it the same percentage of total wing area, or something else? That will have a huge effect on how the plane flies.
[This message has been edited by funked (edited 05-15-2001).]
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Here's what I mean about the ailerons:
Compare Typhoon and Fw 190.
Fw 190 has a much higher roll rate and quicker roll response (angular acceleration).
But Typhoon has more powerful ailerons.
Typhoon ailerons are larger and further from the fuselage, so they can generate a much larger moment than the ailerons on the 190.
The 190 ailerons are quite small actually, and the ailerons are closer to the fuselage than on the Typhoon, so the maximum rolling moment is not nearly as large. The reason the 190 has better roll response is because it has a much smaller wingspan, and as a result there is less damping in roll as well as less inertia to overcome.
But since the Typhoon has larger ailerons that are further out on the wing, it should be able to trim out a constant rolling moment with a smaller aileron deflection than the Fw 190.
[This message has been edited by funked (edited 05-15-2001).]
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All excellent points especially the fact that we dont know how much wing area is removed. Lack of specific info like this is exacltly why I hope HTC takes a few minutes to respond here or in my thread. I really wanna know whats going on.