Flight Testing Jet Bombers. A Boeing Wichita Story
|Chapter 4: Test Pilot School & B 47 Flight Testing
In the fall of 1954 I left the B47 testing for 6 months to attend the Air Force Test Pilot’s School at Edwards Air Base at Muroc, California. This gave me exposure to Air Force fighter jockeys, an interesting group. Many had been in the Korean War. They had many tales of fear and heroism to tell. They were a great group of pilots. Some were killed later in test work.
I remember one Air Force pilot, Stu Childs, who I inadvertently gave a problem, which he solved very well. Just before I went to Edwards I was flying a fuel vent test on a B47. This amounted to filling the B47 with hot fuel and climbing to high altitude to see if the generated fuel vapors escaped properly. Stu was the chase pilot flying an F86. When we got to 40,000 ft we were headed away from Wichita at high speed. Stu mentioned his fuel quantity, which didn’t register with me, because at the time I wasn’t familiar with the F86. Some time later he asked if we were headed for Wichita, because he was low on fuel. I turned but it was too late. He ran out of fuel about 70 miles north of Wichita. We were close to Salina, Kansas that had an Air Force base with a long runway, but it was cloud covered. He dead sticked the F86 all the way back to McConnell Air Base at Wichita and landed safely. An amazing feat I thought.
The tour at Edwards was somewhat tedious with lots of studying and data reduction. I was ready to leave when the time came. It was too much study and not enough flying.
When I got back to Wichita I got checked out it the F86, which by that time was an old airplane, but a goodie. The new fighters such as the F100 and F102 were out by then. A fire warning marked my first flight in the F86 right after take off. This was stimulating as the pilot sat right over the engine, and of course there was only one engine. At low altitude that eliminated the possibility of shutting the engine down, which left the choice of ejecting or ignoring the warning. I chose the latter because I didn’t see any smoke in the rear view mirror. I did decide to land immediately to have things checked. The external wing tanks were full, so I was heavier than normal for landing. I declared an emergency and got priority to land, but over shot the runway line turning final. I finally got lined up properly, but my sashaying alarmed the tower. They called to see if I had things under control. It wasn’t neat, but I got back OK. It turned out that the fire warning was caused by some bleed air pipes, which hadn’t been connected properly after a minor over haul.
I had a couple more adventures in the F86 while teaching myself aerobatics and while trying to go supersonic. The first loop I tried I pulled too tight and did a couple of vertical snap rolls. At first I thought I was in an inverted spin. When the airplane stopped rolling I thought I was in heaven. All I could see was blue sky, and it was real quiet. I was pointed up about 40 degrees and just sitting there with flying speed, so I rolled around to find the ground and recovered. This taught me that you did all of the pulling on the first part of the loop, not near the top when the speed was down.
The ambition of most any one who was checked out in the F86 was to go supersonic. The problem was that to do it you just about had to go straight down starting from 30 or 40 thousand feet. After trying unsuccessfully a couple of times with mild push overs and getting nothing but wing roll off, I decided to force myself to approach it more aggressively by trying from a split S; that is roll up side down and pull on through. I talked to an Air Force pilot who recommended it. I asked him how much altitude was lost during such a maneuver and he said only about 5 thousand feet. This didn’t sound too bad so the next flight I gave it a try. I climbed to 40 thousand feet, near the ceiling of the airplane, rolled over and headed down. I saw the Mach Meter jump and go past 1.0, then I heard funny noises in the air conditioning system, then I began to gray out. I looked at the G Meter and it read 4.0 Gs. No wonder things looked gray. I also looked at the altimeter, which read 20 thousand ft. My maneuver had used up 20 thousand ft. So much for expert advise. I later found it was easier to go supersonic by pushing over, only more aggressively than I had on my previous attempts. I am sure I went supersonic twice, but my disappointment was that it was not recorded in the local newspaper.
My acrobatic experiments in the F86 came in handy later when doing immelmanns with the B47. By this time (mid-fifties ) it had been decided that to penetrate Russia and escape detection and subsequent elimination, it was necessary to go in at low altitude under the radar screen. Then the problem was how to drop an atomic bomb and not get blown out of the sky. The method devised was to pull up, release the bomb, which would lob in to the target on an arc, while the B47 Bomber would escape by continuing on over the top. The bomber would then roll over and dive back down to low level and go back in the direction from whence it came.
Dick Taylor was my instructor on these so called Combat Maneuvers. He was the project pilot for the flight test development of this method of bomb delivery for the B47. The maneuver was started at 425 kts airspeed. A 3g pull up was initiated and held until light buffet was felt. The pull up was held in light buffet until a half loop was completed. Then the airplane was rolled over and dived back down to low level. During the pull up it felt like the airplane was going up forever. When the gyro horizon flipped you knew you were pointed straight up. Shortly after that you tilted your head back and looked for the earth to appear so you could roll out and complete the maneuver. There was instrumentation so the maneuver could be done on instruments. It was a G meter with a roll out light. The rest of the necessary flying information came from the airplane’s normal instruments. I never did the maneuver completely on instruments, but I guess Mr. Taylor and some Air Force pilots did. During the pull up the airspeed generally bled down to 125 kts or so, but could go lower depending how efficiently you had performed the pull up. On a loose maneuver the airspeed could go below l00kts. The airplane did not stall because it was upside down and falling back toward earth at less than 1 g.
After Mr. Taylor had perfected the maneuver, the Air Force pilots started practicing it to become proficient. Shortly thereafter there was an accident at the Salina, Kansas Bomb Range. A B47 had crashed while doing a combat maneuver. It happened that I went to the accident investigation, including the interrogation of the pilot. He was the only surviving crew member. His survival was a miracle. It seems that during the last part of the pull up the airplane entered a cloud layer at 10 thousand feet. As the pilot pulled on over apparently the roll out light did not come on so that he exited the clouds pointed straight down. From this position there was no possible recovery for the airplane. There was no way to slow the airplane as there were no drag devices, and the airplane could not be pulled up in time to avoid the earth. The pilot ejected, but fell out of part of his chute because the chest buckle was undone. He had unbuckled it prior to the maneuver to reach in his shirt pocket for a cigarette to smoke while waiting outside the bomb range for his turn to make a run. He forgot to re-buckle after the smoke. After his chute opened he fell out and was hanging by one leg. This was OK, but then the airplane hit the ground and blew up. This made a big fireball, which he almost floated into. He was all right except for bruises, a black and blue face, and two black eyes caused by the high speed bail out. The navigator had ejected, but his chute did not have time to open. The co-pilot did not eject. I think that pilot was one of the world’s most lucky guys.
Eventually combat maneuvers for the B47 were dropped because the wings started breaking off the airplanes. One airplane had a wing failure in just a 45 degree banked turn. Some wing fittings called “Milk Bottle Fittings” suffered early failure and had to be replaced for the whole fleet. After this replacement the combat maneuvers for the B47 just faded away.