N1K2J - The miracle chopper

[MANDOBLE]

Straffo, Tac explanation is very good. But I will do my best to clarify the point.

N1K2J had a very powerfull engine (more than 1900 Hp) for a very light airframe. In the vertical, once you are well below stall speed, there are little or no resistance from the airframe against the engine rotation, so the plane would start rotating acording with the engine with little or no control (propwash alone). If you want to overcompensate that effect, you will need to apply a lot or ruder and aileron, and even cutting the throttle. All these are unnecesary with the N1K2. And to make the effect more evident, I added firing guns, supposedly shaking the airframe and adding a braking factor.

If you try this move with most of the planes (even planes with much less Hp/weight ratio), you will find yourself needed too much overcompensation to keep in the vertical to have any aiming chance, much worse if u fire the guns at the same time.

For example, in the DMF film, a D9 kept there for 3 or 4 secs (and not firing) while the N1K2 kept for 9 secs. Not only that, but N1K2 needed no pilot effort at all to keep nose up in the vertical well below stall speed.

In planes like P38 one engine compensates the other one, so, keeping controled in the vertical at very low speeds should be much easier.

[-ammo-]

Will do mandoble, I have made two films of just that, however they were too big even zipped to attach using the BBS function. I will  get it done soon. (at work)

[straffo]

I got it now

Btw did someone check how the Zeke handle in such a case ?

[straffo]

Originally posted by Tac
A plane that would kill its pilots at low speeds because of its torque.

I thought that it was killing when near stall speed (at landing and so at low alt ) and when passing rapiditly (sp?) from idle to full power ?
I was believing that it was the rapid change in torque (or p-stream effect) who was hard to handle ?

[Sikboy]

Originally posted by straffo


I thought that it was killing when near stall speed (at landing and so at low alt ) and when passing rapiditly (sp?) from idle to full power ?
I was believing that it was the rapid change in torque (or p-stream effect) who was hard to handle ?

My faulty memory recalls this being a takeoff problem, when the Ensigns would punch the throttle as if it were an AT-6. But we all know how reliable my memory is

-Sikboy

[straffo]

at least we agree on the throttle variation

[Samm]

This is mostly addressed to Tac, since we're all pretty much in agreement that Mandoble won't concede to reason.

Well the p51 does not go into a spin when you hang it on it's prop . I allready said the the p51 is just as easy if not easier than the n1k2 to do this with, try it, it doesn't tumble on itself and enter a spin.  The 190 is even more docile, it basically recovers itself .

 Why do you think the weight to hp ratio should dictate a planes  departure characteristics ? Light planes with powerfull engines (190, 109, yak, spit) are difficult to spin, in fact in AH they never spin . The only planes that I've ever gotten to spin in AH are heavy planes, the p51 and f4u and f6f, although I've heard the p38 will but I've never gotten it to spin for me .

Why do you think the n1k2 should behave like the p51 when none of the other planes do ? Why do you think a light plane with a powerful engine should have worse departure characteristics than a relatively heavy plane ? Please explain.

 Nobody so far has been able to get the n1k2 to do anything unusual . All we have is mandoble saying that he saw one "hover" like a helicopter while standing in a tower, I think that speaks for itself .

And of course any plane moving slower than 100mph in AH will have stability and controll problems . That's why they have flaps .

[Vermillion]

Ummmm Mandoble.  You might wanna check your preconceptions with some actual data.  You keep quote the horspower of the N1K2-J, and calling it a "very light airframe".

From the AH Help Pages:

N1K2-J
Normal loaded weight:  9040 lbs

Fw 190D-9
Normal loaded weight:  9414 lbs

So using your numbers of 1990 hp for N1K2, and the 2200 hp for the D9, if give you powerloading numbers of 4.54 lbs/hp for the N1K2 and 4.28 lbs/hp for the D9.

This would indicate from your arguement that the D9 should have more torque than the N1K2, which is does in AH.

Now, in my opinon (and I stress opinon), I agree with you that the N1K2 doesn't exhibit as much "torque effect" as it probably should.  But the arguement that your basing your conclusion upon is flawed.

I think you have the right answer, but for the wrong reason.

[Samm]

The 190's are more apt to wing over in stalls than n1k2, I've noticed all the high wingload planes have that tendancy, but that has nothing to with torque . The n1k2 does have substantial torque . When you attempt to hang one on it's prop you notice this . As dynamic pressure decreases on the controll surfaces as your speed decreases the plane requires more and more aileron to compensate for the torque, try it .

Ask yourself this, which is more influencial of how prop torque affects the aircraft, hp/weight ratio, or propweight/acweight ratio ?

Also when doing these manuevers the prop is no longer accelerating, it's stabalized at max rpm so inertia is on it's side so you're not going to see any drastic torque effects . You may see some oscillation when in a nose high attitude at low speeds but thats not due to torque I think that is related to gyroscopic behavior of the prop .

[Tac]

umm..samm, any 190 will spin or have one hell of a time at slow speeds because of its torque. I have a miserable time sciscoring in them because of it (and 'cause im used to the 38). But try it in a n1k.. bleh, ye can keep pulling all you want way below 100mph without entering into a spin.

As far as the P-51, when you nose it up till stall, if you leave it on its own it enters into a real nasty flat spin. Happens to me almost all the time (some times it does wing over and nose down, but you will have one heck of a problem trying to keep it under control until it speeds up beyond 100mph. In short, if you wanted to do an evasive or pull nose up just after the nose flipped earthward, you'd spin the plane).

"Light planes with powerfull engines (190, 109, yak, spit) are difficult to spin, in fact in AH they never spin "

Eh? All those , with the exception of the spit do spin quite easily at speeds below 100mph. The yak9U will give you one hell of a time keeping it under control, but its a great little accelerator from 0 to 200mph (almost like the 38) so it regain speeds quickly.

Here's something that happened to me just last night, I really wish I wouldve filmed it. On the field thats just above the port of the SE corner country (bish last night) Kappa, Fester and I were on vulch pattern as the goon arrived to town. 2 fighters came from high so I went to HO em before they got the goon.. thankfully, those 2 cons entertained themselves with the 12k buffs we had overhead as the goon dropped. I return to field and see a n1k just taking off.. im about 6k above the field flying at 200mph do a shallow dive to it.. n1k is level, barely a few hundred ft off the dirt.. get within d800 from it, im 300mph, n1k does a hard turn to evade me when I get to d500, i pull straight up. Look behind me and LO and behold the lil' n1k has its nose straight up pointed at me.. and it had closed in to d400'ish before I started my zoom up.. I look back d450...d480...d500.. n1k is firing like mad.. d550 ... d600.. n1k is STILL pointing nose up.. my speed is 150'ish... d650.... d700.. I start to pull nose over with 2 notches of flaps as my speed drops below 100mph, n1k is STILL pointing nose up AND firing.. D650 (im starting to go down).. d600 n1k STILL has nose up!!! And this is when he scores a toejamload of hits on me and whacks me down. This is what confuses the hell outta me. I saw him TAKE OFF. He may have leveled and WEP'd for the 3 to 5 seconds it took me to close in on him.. and yet he has enough speed to turn hard, turn nose up and hang on prop for the whole time a P-38 zooms up, loses all its superior E on the zoom up and flips over? Thats like 10 to 12 seconds hanging on that prop man, FIRING all the way. I went to DA right after that and tried it. Hell yes, the n1k does that, all the way down to 20mph with no control problems, you can even WIGGLE the damn tail to aim at your leisure. *bangs head on wall* DANGER WILL ROBINSON DANGER!

[Fatty]

Well Tac, I'm hardly suprised, considering I have stated in this thread using the exact same tactic when vultched (except with 109s instead of n1k2s)

And Mandoble I still don't see the problem that planes with higher stall speeds can't hold the angle at as low a speed as planes with lower stall speeds.

[Samm]

I think you are confusing wing over stalls (accelerated) with spins, especially if happening when doing scissors, which btw has nothing to do with torque, you can pull wingover stalls in a 190 with the engine off .

I did four consecutive  0mph tail stands in p51d yesterday right after take off, not once did I need to apply remedial action.

 I have spun p51's before, but not doing verticle manuevers, that's not to say that one can't .

If you have evidence that the n1k2 is doing things that a toejam hot fighter plane shouldn't be able to do, bring it .

[Sikboy]

anyone ever hear about unintentional acceleration Incidents?

-Sikboy

[MANDOBLE]

Samm, the problem is not being able to go to 0 mph and still nose up, but the time you are able to keep in this attitude once you are below 100mph in the vertical. That is what I saw from the tower and that is what Tac is describing, exactly the same thing. Repeat your tests with your P51 and count the seconds from 100mph to control loose, if you are able to get to 9 seconds while firing and without cutting the throttle then your P51 handles like a n1k2.


Fatty, in the vertical, if you have enough air flow you will be able to handle your plane. Basically, if you are above stall you would expect to have a good control, but below that air speed you are more and more dependent of the prop wash to have some air flow to make your surface controls effective. If not enough prop wash, then your will need to open even more the throttle, increasing the torque effect and the effect of the egine in your airframe. The more heavier the airframe, the more tendency to keep in its current pos (inertia) and the more difficult to make it to spin with your prop.  


Verm, do you know what is the weight of a 25% fuel loaded N1K2 compared to a 25% loaded 190D9? What is what you consider "normal loaded"?

[Samm]

Originally posted by Tac
umm..samm, any 190 will spin or have one hell of a time at slow speeds because of its torque.

No it won't spin, yes you will have on hell of a time controlling it at slow speeds . And no torque is not the culprit .

The only time prop torque should affect the aircraft substantialy is durring acceleration, that is prop acceleration, not airspeed acceleration .