Night, heavyweight aerial refueling
By Col. Dick Hefner, USAF (retired) Former pilot (C-141, B-52 D/G, C-5 A/B)
Busy Bubble (see last article) was over and we returned to normal war wind-down times at U-tapao Air Base Thailand. Typically, we would spend one week on “alert” then fly one or two training missions the next week. This cycle continued for the duration of our stay.
Every training mission in the B-52 consisted of (1) a navigation leg where the navigator demonstrated his ability to get the plane from point A to point B, (2) an aerial refueling segment where the pilot demonstrated his ability to maintain a very tight formation with a tanker while gas was transferred via a boom from the tanker to the bomber, and (3) a high or low altitude bomb run where the bombardier demonstrated his ability to identify that perfect spot in the sky from which bombs could be dropped and hit the designated target. Since we were bombing in Vietnam from high altitudes, then we practiced only high altitude bomb runs.
One of my first training missions in Vietnam involved a night, heavyweight air refueling mission. Aerial refueling is always a little dicey because of the close proximity of the two large airplanes moving so close to each other at high airspeeds. One quick or wrong move can result in a collision or the boom breaking …neither of which are good. Aerial refueling at night complicates the task since many of the visual references used by the receiver pilot to maintain a close formation cannot be seen. Aerial refueling a fully loaded B-52 adds to the difficulty because corrections to fore and aft positions require the pilot to anticipate speed changes (throttle inputs) more quickly.
As I advanced the throttles to the take-off setting, the “tall-tailed buff” slowly accelerated down the runway. The small, under-powered engines of the D model (even with all 8 running) strained to get the heavily laden beast to take-off speed. As the end of the runway approached, I gently pulled the nose into the air and started our climb. Loaded with fuel and bombs, we inched our way up to our assigned altitude and the refueling track.
To get a tanker and its receiver together for this “passing of gas”, we used a point parallel rendezvous. Basically, a tanker (normally a KC-135) flies down the track in one direction while the receiver flies up the track in the opposite direction, from the opposite end of the track and at 1,000 ft. below the altitude of the tanker. The navigators of the two aircraft talk to each other about speeds, winds, and offset distances to determine when the tanker should begin a 180-degree turn so that the two planes end up flying on the same heading. As the two planes approach, the tanker starts a 30 degree banked turn at that calculated point and theoretically rolls out 3 miles in front of the bomber and on the same heading. Sounds easy … but it is not.
On this particular night, the navigators on both planes did a great job, so when the tanker rolled his wings back to level, there he was … or at least there his lights were … about 3 miles in front and 1,000 feet above. As you might imagine, determining distances at night is almost impossible, so pilots are very dependent on radar returns for most of the rendezvous and closure. Carrying 10 knots of closure, I drove in to the 2 and 1 mile points behind the tanker. At the 1-mile point and with the tanker insight, I started my climb to ½ mile behind and 500 feet below. From there I slightly reduced my closure airspeed and carefully continued up and forward, bringing the 2 planes ever closer. At a point approximately 50 feet behind and 10 feet below the tanker, I further reduced the airspeed to match the speed of the tanker. I could now hear his engines and his sight filled the view from our windows.
Once stabilized (side to side as well as fore to aft), the boomer cleared me to move into the refueling position (20 feet behind, 10 feet below) for the hookup. I eased the throttles forward and the buff moved forward. I needed only 2 or 3 knots of additional airspeed to successfully close on the tanker. At about 30 feet and with the noise and vibrations increasing, the bow wave (air moving over the front of the B-52) halted our forward progress. I added more power (almost max power in the D model) and the buff started fighting through the bow wave. Once through, an immediate but slight reduction of power was needed. Any delay and the B-52 would slide too far forward and under the tanker, which would result in an emergency separation, called a “break away”. My slight reduction with the throttles was good so we stabilized in the air refueling position. Weather was not a factor (good visibility and no turbulence) … everything was going perfectly!
When I reached the air refueling position, I stabilized my buff and the boomer started slowly flying the boom towards the opened air refueling doors and the awaiting receptacle. Trying to ignore the boom and its light as it slid within a few feet of my windshield, I kept my focus on the tanker. Finally, the boom was behind me and I could hear it hovering just above the cockpit. Then, with a loud and jarring “thunk” the boom made contact with the receptacle and the receptacle latched onto the boom. The boomer confirmed a good contact between the boom and the receptacle, then started the pressurized flow of JP5 into the open fuel tanks of the buff … everything was going perfectly!
I was about to ask the co-pilot if we were taking fuel into our fuel tanks when I got a loud, high-pitched call from the Electronic Warfare Officer (EWO), “pilot, E-dub, we have fuel coming in the cockpit!” Everything was no longer going perfectly.
BREAK AWAY! BREAK AWAY! BREAK AWAY!
I immediately hit the air refueling disconnect button, pulled the throttles to idle and nosed the plane downward. The tanker pilot hit his disconnect button, pushed his throttles full forward, and pulled his yoke aft to climb away.
“E-dub, tell me more! How much fuel and where is it coming from,” I queried.
“Sir, I cannot tell how much, but it looks like it’s coming from a fuel line aft of the receptacle. It’s causing a spray and the whole area back here is wet with JP5!”
I took off my oxygen mask and could immediately smell the JP5 fumes. I could even feel the wetness on the floor at the pilot’s seat, which was well forward of the refueling lines. Fortunately, the fuel leak stopped when we disconnected, but there was no way to tell how much fuel had pressured its way into the cockpit or the area below. I knew … one spark and we would literally turn into a giant fireball. Even talking on the radios seemed potentially dangerous, but we had to tell someone our situation.
I radioed our plight to the tanker. He wasted no time in “getting out of Dodge”. Then I called our Command Post and repeated our problem. Silence, dead silence. After a few long moments, the Command Post broke the silence and asked, “how much fuel is in the cockpit?’
It was dark! How could I possibly know that! Unfortunately, before I could give his question much thought, my mouth uncontrollably blurted out, “Wait a minute, let me light a match and see!” Instant regret and now, really big-time silence. Then a different voice comes over the radio, “Captain, if you think this situation is funny and a good time to make jokes, you seriously need to re-evaluate and conduct yourself in a more professional manner.”
So there we were, full of gas and bombs and too heavy to land and stop on the runway. Most planes could just jettison some fuel, get down to a weight where it could land and stop, but the B-52 has no way to jettisoning fuel. Finally Command Post came up with the answer. We were instructed to depressurize the plane, climb to the highest altitude possible, and fly in circles while the JP5 evaporated.
Sounded simple, but flying unpressurized above 30,000 feet is very cold and requires pressure breathing … but, we could not think of a better solution. To combat the cold, we used whatever clothing and blankets we had, which was not much since we were in south east Asia. Pressure breathing was something we had all experienced, but never had to do for any length of time. Air is forced into the body under pressure, thereby allowing the needed oxygen to get into the blood cells. Getting the air out of the body requires forcibly exhaling … like blowing up a balloon. Try blowing up balloons for about 2 hours!
Finally we had burned off enough fuel so our landing weight was no longer a limiting factor. Now the question was whether or not we had any residual fuel in the airplane. The cockpit seemed dry, but there was no way to know if the fuel had drained and pooled into other parts of the plane. Our main concern was lowering the landing gear. If residual fuel was in the wheel wells, then one spark is all it would take. As we descended and I lined up with the runway, I could see the fire trucks and emergency vehicles standing by.
Two miles out … time to lower the gear. I announced to the crew, “Here goes guys. Co (co-pilot), lower the gear.” Clunk, grind, whir, and ker-plunk … I heard more sounds coming from a gear lowering then I had ever heard…but no “ka-boom”. Hefner 2; Death 0 (see article on T-38s for first victory over death)
Touchdown and rollout were normal, and we were all glad to be safely on the ground. Yeah, I had to debrief Command Post, but thankfully no one reminded me of my initial “unprofessional” radio response. I think the officers in the Command Post were just as happy as I was that everything had ended well.
We did learn the next day that there was a penalty to pay for pressure breathing for close to two hours. Forcing air out of your body requires the use of seldom-used stomach muscles. For the next several days, we all suffered abdominal pains like we had been sucker punched in the gut about 10 times. I guess we had thoroughly exhausted those exhaling muscles and it was now payback time.
KC-135 (tanker) at night B-52 as seen from tanker at night
B-52 approaching tanker B-52 Cockpit
By Col. Dick Hefner, USAF (retired)