X-15 Adventures:
Flight 1(1-1-5) -- June 8, 1959

X-15's first flight 

A glide to a challenging landing

First launch, X-15 flight 1 (1-1-5)

Flight statistics 
  Maximum altitude   37,550 feet
  Maximum speed Mach 0.79
522 mph
  Flight duration 4 min. 56.6 sec.
  Rocket burn 0 sec

Scott Crossfield already had years of experience with the X-15 before piloting its first flight. He left NACA to join North American Aviation specifically to contribute a rare combination of skills to shaping the X-15.  He offered the perspective of an aeronautical engineer who already was one of the most experienced test pilots of rocket powered aircraft, as well as early jets.

One of the control effectiveness issues that he raised during design would unexpectedly show itself on the first flight, challenging his piloting skills and threatening to end the flight with a crash instead of a landing.  By June, 1959 the X-15 had completed several captive-carry flights under the wing of a B-52. Some were deliberate, testing system X-15 systems, B-52 systems, and aerodynamic characteristics of both aircraft. Others were aborts, intended to be the first free flight but terminated due to a variety of problems. They ranged from APUs (auxiliary power units) that incinerated themselves to a torn glove on Crossfield's pressure suit. The program was well behind its expected schedule,  everyone felt the need for a successful free flight.

On the morning of June 8, 1959 the B-52 and X-15 went aloft again.  The objective was to do a simple glide to a landing, checking the X-15's flying characteristics for the first time.  All systems looked good except that the pitch mode of the SAS (stability augmentation system) didn't work. On a hypersonic flight this would have been grounds for yet another abort, but this was to be an easy subsonic flight. The decision was to go ahead as planned.

Flight path for X-15 flight #1  (1-1-5)

After takeoff the B-52 flew a spiral pattern around Edwards Air Force Base, staying within X-15 glide range of a landing area in case of an early drop.  Rogers Dry Lake was the primary landing site, Rosamond Dry Lake was available as a backup for the western part of the climb pattern.

The first objective was to confirm that the X-15 would drop away from the B-52 cleanly at launch. On the B-52's pylon the X-15 rode in air flow disturbed by the carrier aircraft's wing and engine nacelles, as well as by the X-15 itself. Because the B-52 has swept wings, the X-15's left and right wings experienced different airflow before launch. There was very limited room to avoid damage to both aircraft if the X-15 would pitch up or down, yaw left or right, or roll left or right at the moment of release.

Aerodynamic analysis and wind tunnel tests predicted that the X-15 would roll to the right after release but would drop away cleanly if its pitch trim was set correctly.  Crossfield set the trim to 1 degree nose-up in preparation for launch. The B-52 completed its turn onto heading 040 magnetic and quickly closed on the launch point over Rosamond Dry Lake at an altitude of 37,550 feet. With a short countdown, B-52 pilot Charlie Bock pulled the release -- A hydraulic ram in the pylon disengaged three shackles, dropping the X-15 for the first time at 8:38 a.m. and 40 seconds.

NASA film clip of first X-15 launch
    NASA movie clips of first launch:
160x120 15-fps QuickTime 1,352 KB
320x240 30-fps QuickTime 1,055 KB
320x240 30-fps MPEG-1    2,592 KB

The X-15 pitched down and rolled to the right, more than Scott Crossfield expected but little enough to produce clean separation. Following the flight plan, he quickly checked out the new aircraft's handling qualities before retrimming and slowing. Two more "getting the feel" phases followed -- first slowing to near-stall airspeed, then diving a bit more to accelerate to 190 knots. Here he dropped the flaps for a quick check of flying qualities as they would be on approach, shortly before touchdown. Raising the flaps, he accelerated again to perform the last planned handling tests and to enter the landing pattern. The pilot had to be a quick learner on this flight -- With a glide ratio of about 4:1, the X-15 had only about 5 minutes of flying time available.

Crossfield found that the X-15 handled nicely, though a bit sensitive in pitch due to the inoperational SAS mode. Rounding the turn to final approach, he jettisoned the ventral fin, which parachuted down for recovery.

X-15 flight 1  landing with F-104 chase plane    X-15 flight 1, on approach to landing

Preparing for touchdown, he dropped the flaps. Unexpectedly, the nose rose. Trying to recover, Crossfield found sluggish and late response to his pitch inputs.  The X-15 entered a PIO (pilot-induced oscillation), porpoising through large pitch excursions. Crossfield's challenge was to learn in a matter of seconds how to arrest the instability or to time the motion well enough to set down without crashing. The solution had to be found before the X-15's airspeed bled off so far that it would stall, dropping abruptly into the lakebed. Crossfield tamed his bucking aircraft just in time, touching down on the lakebed at about 145 knots (160 m.p.h.). North American's design had anticipated a normal touchdown speed of about 200 knots.

.X-15 flight 1 landing photo sequence  x-15 flight 1 landing sequence  X-15 flight 1 landing sequence  X-15 flight 1 landing sequence  X-15 flight 1 landing sequence  X-15 flight 1 landing sequence  X-15 flight 1 landing sequence  X-15 flight 1 landing sequence

Postflight analysis showed that the horizontal stabilizers couldn't move quickly enough to track the pilot's control inputs -- once the PIO started the pilot and the aircraft were out of synch with each other. The stabilizers were driven by hydraulic actuators with only enough power to move the control surfaces up to 25 degrees per second. Changing valving in the hydraulic systems raised this limit to 35 degrees per second, and the problem never recurred in the 198 X-15 flights that followed.

Related materials:

Flight summary form
as a web page (html)    

Scans of flight summary form
 from NASA flight log files:

X-15 flight 1, flight summary form draft copy
X-15 flight 1  flight summary form

Radio communications transcript

Flight plan for X-15 pilot as a web page (html)

Scans of flight plan form
for X-15 pilot
 from NASA flight log files:

X-15 flight 1, flight summary form draft copy
X-15 flight 1  flight summary form

X-15 flight 1 drawing of planned flight path Planned flight path

Note by Milt Thompson on X-15 flight 1  Note by Milt Thompson on flight 1 (1-1-5)

Scott Crossfield, Bob White, and Neil Armstrong flew the X-15 for North American Aviation, USAF, and NASA.  On flight 1 (1-1-5) Crossfield flew the X-15, White flew the F-104 chase plane.

Crossfield, White, and Armstrong  Scott Crossfield, pre-flight

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