ROUGH DRAFT
PILOTS COMMENTS
We had a few little
problems in the physiological trailer that held us up a little bit before
takeoff. We had an EKG recording that wasn't coming out right and finally
got that fixed up pretty well and when we pressurized the suit we found
we had a little leak some place which we managed to fix but it took a little
time, then repressurized it turned out to be all right and resulted in
us reporting in out at the airplane a little bit behind schedule. I think
we pretty well caught up though in this, during the cockpit check portion.
The EKG went sour, the physiological recordings went sour and Joe wasn't
getting very much of anything up at NASA 1 and, furthermore, I was getting
a burn due to one of the temperature thermistor pickups on my leg so we
disconnected that system and decided to go without it. I think everything
was in pretty good shape in the climb-out. During the check list this new
cooling procedure seems to work pretty satisfactorily as long as all the
poor guys who get involved in it understand what each other is saying.
It seems to work pretty well. The radio checks were all okay with the exception,
if I remember correctly that I wasn't reading 279.9 from the Beatty station
on the X-15 radio, of course, I'm shielded by the B-52 from that direction,
however, we were reading the other frequency loud and clear so I can't
explain that particular thing. We had a pretty good inertial situation
with the exception of the doppler, and Butch will get around to that later,
but it looked good in my cockpit and we got transferred over to internal
power today without any problems. We were not able to duplicate the situation
we had last week. The analyzer check was apparently outstanding, I don't
know whether there were actually any wires between the X-15 and the B-52
or not. Apparently we went through without any failures of any kind. This
is certainly what we're looking for as long as it isn't at the expense
of really understanding the condition of the system. In the minute, in
the last 10 seconds we had good pump idle and at about 360 psi and good
igniter idle at about 155 or something like that but real solid when they
dropped away and I did, indeed, launch before lighting the engine, or attempting
to light the engine, and attempted to light at 75% and I'm sure that probably
some malfunction lights light up but I did not see any light, light. All
I saw was the igniter pressure go to zero and silence. I checked around
the engine instruments and switches and one thing and another, I couldn't
find anything the matter and restarted successfully, although that sure
seems like it takes a long time the second time for that engine to light
up. Well, we were pretty far down the line at this point, I'd guess I was
approaching 35,000 feet by the time I got rounded at the bottom and of
course this means that our standard flight plan is not very good for getting
high q se we left the throttle at 75% as advertised, I believe, on our
flight plan. I think we mentioned this on the flight plan for under the
alternate situations and I caught a check point on the air data airspeed
at 530 knots at 17 seconds that Joe called out and we were right on and
our experience before had told us if we left the power right there till
we got through 25 seconds we'd probably be all right. At 24 second checkpoint,
we should have been at 610 knots, of course, I'm not sure what the altitude
was but if we would have been higher we should have been at 610 knots anyway.
Since we were lower we turned out to be at 600 knots indicated and I thought
that looked about as close as we could hope for under an alternate plan
and at that time went up to a 100%. I had engage the roll hold at about
17 seconds, I guess, and it engaged satisfactorily without transient but
a little later between there and 25 we got some little roll wiggles. It
wandered back and forth and then settled out, although I didn't feel any
limit cycle. A couple of times in the climb, I did feel the shakes come
up through the fuselage like we had run into at low q on flight two, just
a ripple, a structural ripple came up the fuselage and disappear. I did
feel that but I didn't feel any extended limit cycles throughout this part
and I .......... the q will come out but I would suspect that we came fairly
close to what we were shooting for. We got pitch attitude hold at 35°
and it was holding 35° quite well and, unfortunately, again I was unable
to look to see the switches under 100% thrust. At least when we got down
to the weights where you're interested in seeing those switches. I'm not
altogether sure that I always had the hold switches in the position that
I thought I did, I can't be sure. We'll have to look at the data to determine
that. Joe, I guess, called out 65 and 70 seconds but I was busy holding
the mike down and didn't hear him, but I did watch, was watching the speed
and I knew that we would have to change the flight plan on powered time
and I was going by inertial speed since it had been checking pretty well
up to this point, and I shut down, I meant to shut down at 4050 ft per
sec and I saw it at 4100 and realized that I was a little late and it was
indicating about 42 when the power was finally off. I knew, then, since
we were on glide path angle that we were going to go about 10,000 feet
high probably. That was a 9 second addition to powered time, I believe,
I think it was about 79 seconds of burning according to my watch. (I didn't
think it was that high.) Maybe not quite that much, I didn't look at the
clock. I did punch CSS and in this time period and got no limit cycles
due to normal acceleration feedback. After burnout got the angle of attack
down to zero and steamed on and, of course, Joe's checkpoints were 140
and 160,000 indicated but we indeed were going to end up with a high of
about 10,000 feet high. On top the inertial system was still working good,
I indicated 150,000 feet when Joe called 140 but on top I indicated 180
and he called 180. At this time, I took a time out to look around and see
out the window and I was going to make some wise comment. I was really
enough impressed but I was too busy to talk about it. Engaged pitch attitude
hold here and it did hold. My impression at this time was that the reaction
controls were working much better than I thought they were. They were actually
working about as good as we had seen on the simulator, in other words,
it was actually damping the airplane or holding an attitude as well as
we'd had and when we kicked the rudder off or the roll it would actually
return at about the manner we had seen on the simulator but about that
time we started getting roll overshoots, and I suppose they might have
been on the order of 30°, plus or minus bank angle of 30° and they
just gave the impression that the thing was, that the reaction controls
were staying on too long and it was catching itself too late. This was
at about 10° angle of attack, or so, I would guess about this time.
About this time the peroxide low light came on and I had not been observing
the decay of peroxide sources, I might well have been doing. I looked at
it and it read, when Joe called it, it read about 1600 pounds, I think.
I believe I read about 1600 pounds and I did hit the peroxide transfer
immediately and it wasn't too far, thereafter, that the light went out
and apparently we were getting transfer and I discontinued worrying about
it. Joe called out, he recommended a 30° bank angle which would call
for about 3° more angle of attack or 4 and he called out 15° as
the recommended value. About this time I could see Rosamond Lake right
out the window and it looked to me like, out my left window, like I wasn't
going to have a problem. About this time I was having difficulty with the
angle of attack and I was on q
hold and was attempting to change it with the vernier and I was unable
to get a
above about 11° from the low side which with the .......... would have
been about 12 and the rolling was still taking place at this time so I
decided the thing to do was not worry about a 30° bank angle since
I could apparently make the field and make the reentry continue at about
the 11 or 12° that I had indicated and proceeded to do so. The G's
started coming up and just then a couple of, a funny thing happened, a
couple of lights came on the panel and the engine box and I observed it
to be a valve malfunction light and second stage igniter light and I'm
told that it was very likely also engine overspeed, and I couldn't imagine
what was causing this, the only thing I thought of was that I might not
have got the throttle all the way in the détente and when the G's
came that it jiggled around or something so I just banged the throttle
sort of on and off and made sure it got in the détente and apparently
it was all right there was no engine light up or anything like that primed
away all fuel. I didn't notice the airspeed on the recovery so I don't
know whether we hit the desired q on the way in or not but we were about
the right attitude and we came level and Joe recommended the hard left
turn, I had in mind that if I had any room to spare I'd get on fixed gains
there while I was still straight and level and get CSS while I was at a
one G reference but I bowed to his judgment and started turning left and
then in the middle of the turn dropped for the gains to fix to minimum
gains and got pulses on all 3 axes and this was still supersonic. Then
I dumped the G off to one, engaged CSS and then dove some, I was down to
250 knots and I dove some to pick up some speed to try a windup turn but
I didn't get into high G, a little over maybe 2 1/2 G's or something in
that turn and there was light buffet associated at the angle of attack
I was .......... and I wasn't sure whether it was buffet or normal acceleration
limit cycle and I turned the CSS back off and then approaching the field
did trim runs and then I was quite pleased with the trim runs, the null
value on the side stick set at 1° leading edge down or nose up and
then I did both directions on the center stick and gave them plenty of
time so to try and stabilize out and they looked like it was a reasonable
value for that and then I did it on the side stick .......... with the
center stick in zero, went from .......... against the stop and a side
stick trim then back up to an indicated value of 5 and it seemed to be
working. On downwind I could see that I didn't have any problems as far
as having enough energy to get home. I actually used some brakes over the
field, pressurized and then I turned CSS back on, determined that we weren't
getting a limit cycle and decided to go ahead and make the approach and
land with CSS on. Approach was a standard approach and after I got in the
flare I decided I really didn't like the CSS very well, the best explanation
of the reason I don't like it is that I felt I had to put in large pitch
commands to make the airplane respond and larger than I like to make and
so, consequently I couldn't plant it on the 2-mile marker like I'd like
to and I sort of let it set and put in small commands which made the airplane
respond slowly and drifted on down and landed long. That's all. I'd say
when I got up to about 2 G's. I had the impression also that the reaction
controls came on considerably earlier than they needed to on the exit.
I thought it burned out at an inertial indication of, I believe, 90,000
feet or thereabouts and it wasn't long thereafter that I caught a few wisps
out of the nose, which I assumed were reaction control exhausts and I felt
that we really didn't need it at that point. Of course that could have
been contributing to our excessive .......... peroxide usage. I did call
steady state side slip values a couple of times and as I remember on top
before this oscillation started it was running about 1-2° steady state
sideslip .......... left sideslip, as I remember.
PILOT FLIGHT NOTES
Aircraft: X-15-3
#672 Date: 4-5-62
Flight: 3-3-7 Takeoff:
0923
Configuration: MH-96
Flt cont. system Launch: 1005
Pilot: Neil A. Armstrong
Land: 1017
Launch Aircraft:
B-52 #003 Total: :12
Crew: Allavie &
Fulton
Launch Panel: S.
P. Butchart
Some delay prior
to cockpit entry may be attributed to difficulty in obtaining satisfactory
electrocardiogram recordings in the physiological trailer. Physiological
telemetry data was unsatisfactory, and when a skin temperature sensor started
burning the skin, the physiological instrumentation was deenergized.
The MH-96 airborne
analyzer check was completed with no malfunctions indicated. This was the
most successful airborne sequence to date. The inertial velocity was predicted
to be questionable inasmuch as doppler operation was erratic.
The launch was performed
on the side stick with all axes engaged in the adaptive mode and the stabilizer
trim position indicating 1° nose up (leading edge down) and 4°
differential (left roll). Pump idle manifold pressures at 360 psi and 2nd
stage igniter pressure at 155 psi were solid. At this time the throttle
was moved from the cutoff position, igniter and manifold pressures dropped
to zero. No engine malfunction lights were noted.
While descending
without power the angle of attack reached 15° and light buffet was
observed. Approximately 9000 feet had been lost at the time of a successful
engine light at 75% throttle (Pc = 470 psi).
No prescribed method
of obtaining the desired value of dynamic pressure (1200 psf) during the
climb had been devised for a delayed engine light. Inertial velocity and
altitude could not be used since the initial conditions would be unknown.
Indicated airspeed is not presented in the simulator. In an attempt to
achieve an acceptable value of dynamic pressure, the 75% throttle setting
and a 10° angle of attack were maintained until a precomputed schedule
of indicated airspeed versus burning time was intercepted. At 17 seconds
(burning time) and 530 KIAS, the angle of attack was reduced to 7°.
When the 24 second checkpoint indicated 600 KIAS (10 KIAS slow) the throttle
was advanced to 100% thrust. Although subsequent data reduction indicated
dynamic pressure to have reached a value of 1400 psf at M = 2.7, no limit
cycles were observed with either the standard flight control mode or with
the control stick steering energized to include normal acceleration feedback
in the pitch loop.
Although roll hold
was engaged without transient (wings level) at 17 seconds, some mild roll
oscillations were in evidence at approximately 25 seconds. Pitch attitude
hold was engaged at 35° q.
As longitudinal acceleration increased, a sensation of increasing pitch
attitude was noted. A cross check on the standby artificial horizon indicated
the instrument to be unusable in this range after which a flight path angle
confirmation was requested from NASA 1. This sensation is believed to be
due to the rotation of the total acceleration vector due to an increase
in Ax while maintaining a constant value of Az.
Speed brakes were
extended at 50 seconds. Due to the previously described trajectory changes,
the shutdown time of 68 seconds was abandoned in favor of the desired inertial
velocity (4050 fps). An inadvertent delay resulted in an indicated inertial
speed of 4200 fps at engine shutdown.
CSS was used to
reduce the angle of attack to zero and angle of attack hold was engaged.
Reaction control and damping was quite good although the reaction controls
were automatically energized considerably earlier than had been anticipated.
Altitude-vertical velocity cross checks indicated the peak altitude would
be 180,000 ft. Roll and yaw overpowers indicated exceptionally good control
and damping.
Pitch attitude hold
was engaged at near the peak altitude. The APU/BCS H2O2 low light illuminated
at this time and the H2O2 transfer system energized. NASA 1 recommended
a 15° a,
30° q
entry due to a slight westward deviation of the ground track.
A rudder step at
approximately 10° a
initiated a rolling oscillation of ±30° bank angle, apparently
being maintained by roll reaction rockets. After being unable to trim angle
of attack above 11°, it was decided to proceed with the entry at 11°
a
and wings level.
As the normal acceleration
began to rise, several engine malfunction lights were observed. The throttle
was cycled out of and into the détente to insure the cutoff position,
and the lights were extinguished.
During the early
part of the entry, a wings level yaw oscillation of ±3 degrees sideslip
was noted. This oscillation was similar to that of a fixed gain, 23°
a
simulator entry. No structural feedback manifestations of limit cycle were
noted. Occasional 2-3 cycle tremors were noted, as on previous flights.
Speed brakes were retracted as the airplane neared level flight.
All axes were reduced
to fixed gain during the space positioning turn and pulses and steps recorded
in each. A wind up turn with control stick steering engaged was limited
to 2-1/2 g due to low airspeed. Light buffet was observed, but limit cycles
were not noted. Stabilized, full trim deflection (center stick) pitch maneuvers
were recorded in each direction and appeared to be near the desired value
of 2 °/sec. Similar maneuvers were performed on the side stick with
full nose down trim and 5 units of nose up trim. The trim value for zero
pitch rate was approximately 1 unit nose up.
The approach and
landing were performed on the side stick with normal acceleration feedback.
No difficulties were noted during the approach. Subsequent to the flare
it became obvious that the gains applied to the Nz feedback were excessive
for the final landing. Excessive stick motion was required for the small
corrections required near the ground.
(Signed)
Neil A. Armstrong
Aeronautical Research
Pilot
NAA:bjc