And hence the problem, if Top speed, and climbs are correct, then Accelerations. Also must be correct.
You can not seperate the items because they are all directly related.
Zoom climbs would also include some loading so you would also have to find out if stustained turn rates are correct.
But if sustained turn, top speed, stall speed,and climb rates are correct. Then accelerations have to be correct, in dive zoom or level.
Stall characteristics are much more subjective then the other pieces of the flight envlope.
HiTech
Dok, Think of Climb rate as a car going up hill. The lift is serving just as the tires of the car do, and has no effect on climb rate.
Drag does effect climb rate, just like it would effect acceleration in a car. But for any given speed the drag does not change if your are flying level or going up hill. As long as the speed remains constant so does the drag.
(Side note drag does drop very slightly in a climb (do to less lift required), but for normal purposes you can ignore the change)
Basicly it is exatly the same as a car, the exess power can either pull you up hill, or increase your speed. Climb rate and acceleration are linear functions of each other.
those statements only underscore the ignorance and incompetence of the HTC flight modeling staff. These statements are absolutely false.
First:
"And hence the problem, if Top speed, and climbs are correct, then Accelerations. Also must be correct."
absolutely false. Consider two aircraft, one with a drag plate area of 4 sq ft such as the P-51, and then another with a plate area of 40 sq ft, both aircraft of the same weight, let's say 10,000 lbs. Let's say we also give one model a wing efficiency of 1, and the other a wing efficiency of .1. A flight model CAN be developed where each aircraft WILL have the same climb rate and the same top speed. However, since the as in the climb, the flight model that has a wing efficiency of .1 will require about 1,000 more hp to produce the same climb rate, likewise, the aircraft with a 40 sq ft drag area will require about 15,000 hp to go 350 mph at sl, whereas the 4 sqft model will only require about 1,500 hp. I guarandamntee you that the difference in wing efficiency in the climb rate will create a change in acceleration, same as with top speed.
Another thing with zoom climbs, you don't know, and cannot calculate, the horsepower at speeds greater than the top level speed. For all you know, the maximum horsepower at top speed could be decreasing on one aircraft, whereas on another it could gain another 10% of horsepower in a dive due to ram effect and prop efficiencies.
"But if sustained turn, top speed, stall speed,and climb rates are correct. Then accelerations have to be correct, in dive zoom or level."
This is absolutely false. The sustained turn performance is greatly tied to wing efficiency. Consider again the equation for induced drag:
induced drag = 2 * weight^2 / (rho pi wingspan^2 wingefficiency velocity^2)
now consider an aircraft in a a 3g turn. The aircraft will weigh 3 times as much, and in relation to drag - that is 3 times SQUARED. Now consider everything being equal in two different aircraft except for horsepower and wing efficiency. So that the equation could be reduced down to a constant * weight^2 / wingefficiency or let C = 2/(rho pi b V^2)
thus you have
induced drag = C W^2/e
now you WILL have a greatly different required HP for the two aircraft if one has a wing efficiency of .95 and one that has an e of .45. EVEN THOUGH the turn rates may be the same, they WILL have different acceleration. So at sea level, for a b=32 ft at 200mph, C = 1/330,000
so for a 10,000 lb aircraft at 3g, the difference in induced drag between a .45 and .95 wing efficiency is 2890 lbs verses 6075 lbs, or a 1535 hp vs 3240 hp. That difference will definitely make a difference in acceleration.
"Dok, Think of Climb rate as a car going up hill. The lift is serving just as the tires of the car do, and has no effect on climb rate."
absolutely false. In a sustained climb, as you know, the lift is constant. However the amount of lift can be changed by the angle of attack of the wings. BUT in changing the angle of attack, you also change the amount of induced drag created. Going back yet once again to wing efficiency. Again, two aircraft with differing wing efficiencies and different climb power rates to create the same climb rate, WILL have different accelerations.
"Climb rate and acceleration are linear functions of each other."
That may be true for a single airspeed for a single aircraft, but as I have already shown, what is the slope of the linearity? You simply can't say that because you have the climb rate correct, that you have acceleration correct.
As far as turn rates go also, it's not just horsepower and wing efficiency, but also the stall. If one aircraft stalls at 75 mph and another stalls at 110mph, the slower one almost certainly will turn inside the faster one. Case in point, and probably my whole reason for this diatribe is simply look at the Spits stall point in the game. You can probably measure the early spits at 75 mph and the later ones around 85mph. BUT these should be IAS speeds. Going back to the Spit 1 where the stalling speed is generally quoted as 76 to 78mph, 78mph in the N1371 report, BUT this is IAS, and if you look at the position error for the Spit, it is nearly 12 mph at this speed, meaning the TAS stall speed is closer to 90 mph than 75. The same goes for the FW 190. Wonder why the 190 has such poor turn performance in AH? It's because of the high stall speed, well over 100mph. The 190 doesn't have any problem turning, the problem is it reaches it's stall WAY to early. The 190 has a wing area of 197 sq ft. Given that Stall speed = (2*W/ (Rho CLMax WingArea))^.5 or that CLMax = 2W / (S * Rho * Vs^2), that gives the 190 a CLMax of of 1.25 at 7000lbs, wherease with the spit, a 75mph stall speed at 6000 lbs give it a CLMax of nearly 1.8, when in fact, there should be very little difference in the CLMax of each aircraft, and both should be closer to 1.5.
The plane and basic facts are that these guys are simply inept when it comes to flight modeling. They can't even realistically calculate a proper stall speed, and use IAS numbers for what should be TAS, and can't even do a CLMax calculation to verify that their assumptions are correct. Their flight modeling technique is just about as good as their spelling.
