Pilot: Rushworth
Test 1: Dampers off controllability - Dutch roll mode
Flight conditions: 5.2 > M > 4.8 S.B. = O
8° > a > 4° Power Off
q » 500 PSF
1. Are these flight conditions essentially correct?
Yes, these flight conditions are correct.
2. With dampers at (8-6-0-0), estimate the following airplane attitude excursions resulting from the rudder pulse.
T 1/2 = 16 sec, f/b = small ·f, bmax = ±1.5-2°, fmax = ±5°, amax = 4°
Dampers at 8-6-0, 4° a, when pulsed, it seemed almost steady state. When I went to 8-4-0, it did not show much of a change. It shut it off after about two cycles and watched it at 8-0-0 and got the realization that the yaw cycling was always indicating to the right, or nose-left. Pulled on up and because of the fight with steady-state sideslip, I did not have as good control as I expected. In general, the conditions did not seem to be as bad at 4° angle of attack, and seemed slightly worse going up to 8° angle of attack, from what I had seen on the simulator. All of this has to do with the steady sideslip that was prevalent. (Could you give an estimate of what the Phi-beta ratio might have been with the roll damper on?) Phi-beta with damper on--I could not tell if there was anything there, at 4° angle of attack. From there on I pulled up with the dampers off.
3. Did the yawing excursions appear to reinforce or reduce the rolling motion?
There did not seem to be any large excursions. There may have been small ones but not that I could determine. Certainly less than ±5°.
4. With dampers at (8-0-0-0), rate the piloting task with the following real and hypothetical restraints.
b. Up to ten minutes, ratings were about the same and from there on it gets to be tiresome trying to control the airplane. I am sure that after a while, you could get it down to reasonably steady conditions and the rating would probably level out to somewhere around 5 for a roll and yaw, but based on the effort expended to keep it there, probably effects the rating. If it were a short period of time after reaching the steady state you could probably say it was 3, but if it is a long period of time I am sure it would be 5.
c. I would not change any of the ratings from taking a quick check on the subsystems. I continually check around four different instruments and it did not cause me any problem.
d. I would say the rating in maneuvering the airplane, 2 1/2 in theta, 4 1/2 in roll, and probably 3 in sideslip. I have a feeling that sideslip was not going to cause any problem as long as I stayed at 4° angle of attack. Probably would just be a steady out of trim. If I had made the turn to the right it would have been easier to control the airplane. If I had to go left I would have been fighting it all the way just because having to hold force against the out-of-trim condition.
e. Pilot rating - Trying to make a tracking task out of it, pitch - 4, roll - 6, and sideslip - 6.
f. Pilot rating in severe clear air turbulence would be the same - 4-6-6.
g. If pitch damper were disengaged, I think it would be six to seven all the way across the board for those two previous conditions. For the actual flight, if I had also had a pitch damper out, I would expect to rate theta as 4 or 5, roll - 4 to 5, and sideslip - 4. (You do not think you were that close enough to the controllability boundary that the oscillation at alpha would hurt you?) No, I don't think so. The biggest problem would be trying to control the two axes problem, of having to hold against the sideslip and be controlling pitch at the same time.
I do not know of any other task that we have encountered in flying the airplane that would have effected the rating other than the pitch damper coming off intermittently. If I continue to lose pitch damper along the way, the ratings would have been at least that bad.
6. From this flight test, what do you estimate the controllability limit to be?
I do not think I can answer 6a. I can't answer 6b other than the answer I have already given. The big problem is even with the damper on or the damper off, how much two-axes controlling is necessary at the time? The airplane is just that wormy -- if you are holding against one, it is going to make the other axis controllability much more difficult, because then you are fighting two problems at once. If you could let go with one, and control one, and then the other you do not have too much of a problem. If it were necessary to go up to 8° angle of attack, I could have done it anywhere along the way but I did not think that it was quite as good as what I saw on the simulator at 8° angle of attack. I have to say that it is probably because of this steady sideslip. If I had had enough time to get that out, or hold the correct amount of force, to trim the airplane up and then pull it up, I think I could have done it without any problem at all, other than what I have indicated.
(6a - amax with pitch damper on)
(6b - amax
with pitch damper off)
Test 2:
Dampers off controllability - Dutch roll mode
Flight conditions: 4.5 > M > 3.9 S.B. = 0
8° > a > 4° Power off
q » 640 psf
Yes, the flight conditions are essentially correct and I did not get to the 8°, I only got to the 6° angle of attack.
2. With dampers at (8-6-0-0), estimate the following airplane attitude excursions resulting from the rudder pulse.
T 1/2 = 15 sec, bmax = ±1.5°, fmax = small, amax = 6°
All of the conditions were what I expected to see from the simulator at 4° angle of attack.
3. Did the yawing excursions appear to reinforce or reduce the rolling motion?
I could not see that the yawing excursions were reinforcing the roll motion--it just seemed to be reasonably steady state. I could not tell if there was very much damping. It was not a good cycle for me to watch because everything was going one way. The majority of the oscillation was one way.
4. With dampers at (8-0-0-0), rate the piloting task with the following real and hypothetical restraints.
With dampers at 8-0-0, pilot rating on up to 4° angle of attack to 6° angle of attack, 2 l/2 in theta, 5 in roll, and 3 l/2 in sideslip. Pilot ratings for 4b through 4g would be about the same as Test l.
5. Note any additional piloting task which would yield less favorable pilot ratings than those already given.
If we had the additional pilot task from no damper in pitch it would be different. I do not think the nose gear out would have made any difference. Matter of fact, we were at essentially that same place on the previous flight. Main landing gear out would have been bad.
6. From this flight test, what do you estimate the controllability limit to be?
Controllability limit with pitch damper on, I would have to guess from the simulator. Pitch damper off at 6° angle of attack is not unreasonable even with the pitch damper off and if you had a trimmed airplane, you could spend all of the time watching the pitch oscillation and controlling it. Pitch damper off at 6° angle of attack is not any worse than a pilot rating of 4.5 to 5. That would be all dampers off at 6° angle of attack.
8° > a > 4° Power off
q » 640 psf
1. Are these flight conditions essentially correct?
The conditions were essentially correct. I did not go up to 8° angle of attack because I did not need to get level again.
2. With dampers at (8-6-0-0), estimate the following airplane attitude excursions resulting from the rudder pulse.
T 1/2 = 8 sec, bmax = ±1.5°, fmax = very small, amax = 4°
Just about what was found on the simulator. I thought that was the first honest one that I saw.
3. Did the yawing excursions appear to reinforce or reduce the rolling motion?
There was absolutely no roll because of sideslip on this one that I can recall. The airplane was real steady--there was no roll movement at all. Nice sideslip.
4. With dampers at (8-0-0-0), rate the piloting task with the following real and hypothetical restraints.
a. Pilot rating - pitch - 2, roll - 2, sideslip - 2.
b through e are all the same as #a.
f. pitch - 2, roll - 3, sideslip - 4.
g. Pitch damper engaged 3 1/3 and 4.
5. Note any additional piloting task which would yield less favorable pilot ratings than those already given.
The 4g condition would apply here.
6. From this flight test, what do you estimate the controllability limit to be?
I could not see any problems. Pitch damper on - pitch damper off. The airplane was pretty well honest for those conditions.