Eugene F. May tests the Skyrocket

Eugene F. May was test pilot for Douglas Aircraft from 1941 to 1952 and contributed much to the advancement of aviation. He is best known for his work with the Skystreak (the first supersonic jet aircraft) and the Skyrocket (the first Mach 2 aircraft). He was only the sixth person to fly supersonic but was: the first to fly faster than the speed of sound in a jet aircraft; the first to fly faster than the speed of sound in an aircraft taking off under its own power; the first to fly faster than the speed of sound at ground level; the first to fly faster than the speed of sound in two different aircraft models; and the first grandfather to fly supersonic!

When Gene May decided he didn’t want to continue with the Skyrocket program, Bill Bridgeman was a production test pilot for Douglas flying Skyraiders and was asked to become May’s replacement. Before making his decision, Bill went to Muroc to see the plane, talk with Gene and witness a flight. Bill Bridgeman described what it was like to be involved with a rocket plane flight:

The first Skyrocket flight I was to see was called for sunup on Friday morning. It was called for sunup so that the tricky takeoff would be blessed by the cold, stable air found over the desert only in the early‑morning hours, a slight advantage for the exacting flight.

On Thursday afternoon the final preparation began. Gene May, whom I managed to keep step with, staying beside him whenever possible, read the flight plan and hit the top of the hangar over a couple of items that had slipped by Carder which May thought were – to put it quietly – ill‑advised. The engineer‑pilot conflict again. Gene wasn’t about to risk his neck unnecessarily just for the convenience and expedition of the program. “If you think I’m going to pull a buffet check at 4,000 feet, you’re all out of your minds,” he roared. “To hell with that stuff…” Carder deftly handled the situation, even to the extend of removing some of the offending items. It would probably delay the program, but obviously Gene wasn’t going to buy all the items and no matter how you cut it, the pilot has the last word: he flew the plane. I was in no position to take sides, not having a clear idea of what the thorn in Gene’s side was, although intuitively I leaned toward Gene’s camp – the pilot’s inbred distrust of engineers.

After winning his point, Gene hurried out of the hangar door and disappeared onto the base. I had turned briefly to watch the stiletto‑nosed ship being primed for flight and he was gone. It wasn’t easy to stay with the pilot; he moved fast, never sat in a chair for more than a minute at a time. Often he would leave me in the middle of a conversation about some peculiar Skyrocket characteristic as if he suddenly remembered something more important. It was as if he never quite told me all there was to know about one of the ship’s nasty habits. I had the feeling a lot was left unsaid.

There was little point in trying to find him now. I watched the mechanics prime the Skyrocket for flight. Tomorrow he would take her up once more and the mechanics were swarming about in last‑minute attendance. Outside the sun burned low over the empty miles of desert, glinting off the silver skins of the weird, still flock of experimental planes that sat along the field. Shallow waves of heat hung above the white runway, and beyond that lay the baked mud of the dry lake where the Skyrocket would scream into flight tomorrow morning.

Then she was rolled from the hangar, restrained; the enormous power required to send her 15,000 pound, sleek hull into the transonic region lay dormant… a gigantic animal in a somnambulant state, drowsy and docile.

Slowly, gently, the 12 trained attendants rolled the Skyrocket up a ramp onto a 13‑foot‑long “mother” trailer. When the ship’s propellants were once aboard, hoses from pressurized tanks on the trailer continously would feed nitrogen through the rocket engine until the exact moment of flight, to prevent an accidental accumulation of propellants in the combustion chamber, which could result in a highly explosive start. The ship was aboard the trailer; a canopy overhead would protect the Skyrocket and her entourage from the searing morning sun; another form of protection was in one corner, a shower in the event the volatile liquids accidentally sprayed on to the crew members. To safeguard the plane with its explosive load of propellant (a drop of raw hydrogen peroxide is enough to burn a hole in a concrete floor) an intricate system of fire hoses using fog and straight stream was supplied from a 700‑gallon water tank, just part of the crowd of equipment utilizing every inch of the huge conveyance. She was ready for the important and dangerous job of fueling that would begin early in the following morning.

“What time are we due back here?” one of the mechanics asked.

Carder appeared beside the trailer. The project coordinator answered, “I think we can make it at two o’clock this time, boys. Sunup is getting later with the fall coming on. That’ll give us enough time. Dawn is scheduled for five‑forty‑five tomorrow.”

Some of the crew members moaned, “That’s a break, another hour’s sleep.”

“Well, as they warned us in Santa Monica, join in a research program for adventure. Live a little.” The mechanic slapped his complaining companion on the back. “You’re making history, boy.”

The lead man announced, “We’ll come in at two and top off the tanks.” The group dispersed into the coming darkness. The Skyrocket was left deserted in its awkward position, clamped to the bed of the trailer.

Surely I couldn’t have been sleeping more than an hour when the thin, steady, high whistling began. It was as if a strong stream of wind were trapped somewhere, trying to escape. I sat up in the darkness, my mind groping to respond to whatever alarm it might be, and as I came in focus, I could hear no other sound. Obviously no emergency. I fell asleep once more but with the steady, shrill whistle still wailing over the field.

The alarm jarred me awake, signaling that the flight procedure would begin. It was dark and once more I heard the chilling whistle floating over the base, unbroken and piercing.

I made my way toward the Douglas hangar through the empty streets of the sleeping base. The whistle became louder as I drew near the Skyrocket. The eerie scream came out of the weird plane! Tightened, tensed – the explosive fuels oozing slowly into her sides, it was the Skyrocket that emitted the frightened, tortured whine. The men who had been feeding the Skyrocket her fuel at precision rates for the last three hours wore hoods with glass face‑plates, specially made plastic overalls, and heavy gloves to protect their bodies from the volatile fuels as they tended the white, frosted lines and hose connecting the mother trailer to the embryo ship.

Into the underbelly of the airplane the minus‑297‑degree‑below‑zero liquid oxygen was introduced into one of the large twin tanks that sit two inches apart from each other. If the liquid oxygen should be contaminated, it would blow the plane, trailer, crew and spectators off the desert floor. It had to be fed carefully. Once in the tank, the liquid oxygen boiled off continuously at one pound a minute, forming gases that escaped through small orifices in the top of the fuselage. As the stuff steamed off it caused the sustained, early hour whistling, the weird shriek I heard early this morning. Once the oxygen was at the precise level in the tanks it had to be kept there – as it boiled off the top the exact amount of oxygen was replenished through the hose connected to the supply tank on the trailer. Thus, the necessity of the mother vehicle, in order that the lines trending the rocket propellant could remain functioning and undisturbed while the plane was being transported across the eight‑mile dry lake to the position where it was to be released for flight. All the while the gauges reading pressures in the various operations were watched as cautiously as those in a surgery. Less painstakingly, the other hooded members of the crew moved quickly and quietly around the still bird, filling the other big tank with alcohol. The liquid oxygen and alcohol are stored side by side in the twin tanks separated from each other by a thin aluminum vapor seal. A rubber‑like compound is used as caulking to prevent any leakage between the compartment.

When the Skyrocket was ready to go, a small pump similar to the one used in the V‑2 rocket, obtaining its power from decomposed hydrogen peroxide, pumped the subzero liquid oxygen and alcohol aft to the tiny rocket engine. When the two fluids burned in the engine, the resultant expanding gases provided the gigantic thrust that blasted the heavy load off the ground into flight.

Once the very nervous hydrogen peroxide was in the Skyrocket a speck of dirt in the hydrogen peroxide tank or in any of the myriad tub and lines, and the little research ship would be blown to dust. Two models of the Air Force’s X‑1, our rival, the only other rocket airplane in the country – using identical fueling – had blown up in launching last year.

Al Carder took no chances with the Skyrocket. The pressurizing gases – helium and nitrogen – were sieved through Kotex to make certain no insidious segment of dust was carried in the explosive fluids, an operation that explained why I had seen cartons of the incongruous supplies stacked in the hangar.

Carder had confidence in his men; they were trained well, yet he watched the serious business alertly, ready to intercede in case of an error. In his mind lay the whole flight plan; each of his assistants had been assigned various functions of the whole. While he watched the immediate operation, he was thinking ahead, anticipating what could go wrong and the consequent steps to be taken toward prevention. He was figuring how to save five minutes’ time in the expensive flight plan – methods of further ensuring its margin of safety.

Headlights flashed onto the field out of the darkness. The cars carrying the engineers, the technicians, and the pilot converged near the front of the hangar, ready to join the caravan that would begin its way slowly across the runway onto the parched, mosaically cracked clay lake.

Preceding the funeral‑paced procession was the huge trailer carrying the Skyrocket, active as an atomic bomb, locked securely to its bed. Carder, a general leading a column of tanks, headed the fleet in a radio car. Through the mist that floated in long veils across the dead lake, the white plane was carried, with its entourage of green Douglas cars, a fire truck and an ambulance, into the early‑morning light.

The red beacon at the end of the runway flashed green and we began to creep toward the point where the plane was to be unloaded, five miles ahead.

I sat beside Gene May in the back seat of the radio car. In the seat in front of us Carder was issuing last minute orders over the hand mike: “Metro One, this is Metro Six. From now until take‑off transmit the wind direction, velocity and temperature every five minutes.” Metro One, a truck with a big, square, searching theodolite on its roof, had been stationed by Carder midway along the path of flight.

The truck answered, “Metro Six, this is Metro One… wind, velocity, and temperature every five minutes, right.” Carder was absorbed in the important details of the flight, preoccupied as though he were straining to remember something.

Straight ahead the faraway mountains were hidden by the mist – the edge of the huge lake on tall sides was lost by the vapor drifts. The ground we moved over was sterile as concrete, no weed, no green – it was difficult to maintain a sense of direction, we seemed to be a ship on a flat sea sliding across an empty clearing bordered by fog. As if by radar, the dreary little parade moved unfalteringly toward the end of the lake.

Another order from Carder: “Metro Two, this is Metro Six… we will be ready for the fire trucks in 30 minutes.” And at the hangar Metro Two called into the moving car, “We’ll have fire trucks alerted in 30 minutes.” If a program requires the use of more than one fire truck, the extra equipment is only sent at the time it is needed. Fire trucks on a test base are kept very busy and their standby time is allotted.

Between radio calls the project coordinator turned around in his seat to Gene May. “would you like a chase plane to take off and check the turbulence at your dive altitude?”

May rapidly shook his head, “No, the ‘school’ will have their planes up this morning, we can check with them.” The matter was no longer Al Carder’s responsibility; May had lifted this concern from Carder’s pile of important details.

Again Al Carder spoke into the radio, “George,” he called Mabry in one of the fleet of cars, “will you check the north‑south runway for any debris?” The Skyrocket would eat up three miles of lake before she lifted off, a scrap of driftwood blown in off the desert onto her path would be enough to throw her off balance with her belly fat with explosives.

The ground wind came up cold now, clearing the mist away as we pulled to a stop. The deep blue of the sky was fading as the light of the morning brightened. The exact moment of sunup the plane was to leave the ground. The cars parked around the trailer a safe distance from the take‑off point – the noise from the rocket engine would be loud enough to pop eardrums. Doors opened, the mechanics jumped to the ground and the Skyrocket was laboriously unloaded. Grotesquely the trailer “knelt” at the rear wheels so that the ship could be rolled off with its umbilical‑cords still intact. Above the desert the only noise was the putt‑putt‑putt of the motors on the trailer and the incessant whistle escaping from the plane. Carder’s orders were spoken quietly, the mechanics spoke softly to one another, as if to keep from startling the restrained energy they worked around.

Every other minute the men who read the pressure gauges, intently as submarine captains, called out the pressures in the nitrogen tanks: “2,000 pounds” was called and verbally relayed to Carder – “2,000”… “2,000”… and down the line… “2,000.”

“Hold it at 2,000,” the order echoed back. By sunrise the white plane sat into the wind, still fed by its cords, not yet free. Now the pilot was called; he emerged from the radio car. A gladiator heading for the pit, he swaggered with confidence; the wind whipped his flight jacket around his tightly laced G suit. The size of his head was accentuated by the melon‑shaped heavy crash helmet. It was a costume weird enough for the role he played, the narrowness of this body, in the form‑fitting, olive drab covering was congruent with the uncluttered, narrow bullet waiting for him, steaming and puffing on the ground.

Gene May gave his orders, climbed the portable ladder into the tiny cockpit and yelled, “Okay, let’s wind this thing up.” The jet engine assisted in take‑off with two of the four rocket tubes, was started whirling by the electric motor plugged into the side of the plane. A gentle, thin wheeeee‑eee from the engine as the compressor started going and then the loud explosion that spit the flames out the tailpipe like red adders’ tongues. The hurricane blowing out the fanny dug a long rut in the lake bed in back of the Skyrocket. She shrieked like a pig in a slaughterhouse. Sign language was used now; the noise from the plane smothered all other sound. Above an F‑80 shot over – the “chase” plane was in the air. He would follow the rocket ship, looking for trouble to report to its pilot. He was an eyewitness in case the ship didn’t come back. May made a sign, the canopy was closed. A loudspeaker was used now to communicate to the ground crew from the sealed cockpit in the Skyrocket. Carder sat with his assistant in the radio car holding the speaker that connected him directly to the pilot in the cockpit. He watched intently the last‑minute activity around the plane – his runner would quickly deliver orders to the hustling men if he saw trouble.

From the cockpit radio Gene announced, “I’m pressurizing.” The news was repeated down the line: “he’s pressurizing”… “he’s pressurizing”… “he’s pressurizing.” Again from the howling plane came the magnified and unnatural‑sounding voice, “Al, I’m ready to prime.” This announcement increased the tension in Al Carder; he leaned forward. Quickly the mechanics removed the lines and holes from the Skyrocket and for the first time this morning she was unleashed with her load. She steamed heavily – ready to go.

“What’s holding things up?” May’s sharp, rapid words fell.

Into the mike one of Carder’s men advised promptly, “Okay, Gene, you’ve got a good prime.”

The plane would climb with its jet engine, assisted by the two rocket tubes in take‑off only, until 40,000 feet. May would then fire all four tubes to make his high‑speed run.

He was ready for take‑off; he gestured, the crew stood back, and the engineers and technicians ran for the cars standing by. They started the motors so they could follow alongside the plane during take‑off, watching the tail for a successful rocket “light.”

A roar and she rolled rapidly, picking up speed, the green cars barreled alongside her at close to 100 miles an hour for over a mile of the lakebed. Into Carder’s car the pilot called, “Okay, I’m lighting one.” A 20‑foot streak of orange fled into the air.

Carder called back, “One is good.”

And immediately: “Here goes two.”

A second orange streak shot out, Carder saw it and said close into the mike, “Two is good.” The blast from the rockets jolted the moving cars and the plane was still eating up the lakebed, far ahead of us now. Another quarter of a mile and the Skyrocket began to shed the ground; hanging heavily over the desert she reluctantly rolled a bit, the gear went up. I tensed with the pilot in the ship; if anything went wrong at this moment – that would be all! The seconds went by and she gathered speed, rocked obediently over and began the steady climb up. The sky held, only for a few more seconds, the two bright spots with the chase pilot diving to catch up… and then the planes were absorbed into the distance.