On a January night in 1969, I strapped into the right seat of a Pennsylvania Air National Guard Boeing C-97 at Travis Air Force Base in California for the next leg of a two-week odyssey from our home at Willow Grove Naval Air Station to Cam Rahn Bay in South Vietnam. We went through our checklists for a late-night takeoff for the next stopover, at Hickam Air Force Base in Hawaii. I was a new second lieutenant, six months out of pilot training, still mastering where all the circuit breakers were and remembering to check that the floor hatch to the lower deck was closed before I stepped into the cargo area.
The C-97 was a derivative of the B-29 bomber, with the fuselage sliced in half longitudinally and a fatter second deck added on top to make the aircraft more suitable for cargo than for bombs. It had the same engines and wings, and a glass greenhouse for the flight deck, which made for great sightseeing or a 100-degree oven when transiting the tropics at low altitude. Its propellers were driven by four 3,500-horsepower Pratt & Whitney R-4360 Wasp engines that were the culmination of piston-engine technology before jet engines appeared. With engines being driven to their limits, they failed much more frequently than today's jets. As a result, crews unaffectionately called the C-97 the Boeing Tri-motor.
For missions across the ocean to short, hot atoll runways, the norm was 195 mph cruise at 10,000 feet. The range, about 2,760 miles, was typical for four-engine prop jobs of the era, and complemented the Almighty's placement of those infinitely small coral islands across the Pacific. Our leg to Honolulu, 2,415 miles, remains the longest open-water stretch in aviation. In the middle you are more than 1,150 miles from the nearest speck of dirt.
Soon we were well out to sea, sharing our Pacific skies with a billion stars. At 8,000 feet we listened enviously to the position reports of the C-141s and C-135s far above us, doing in four hours what would take us more than 10. As we approached the equal time point—the halfway mark—which in those days actually was marked on the sea by a Coast Guard ship, Ocean Station November, one of the 28 cylinders in the number-four right outboard engine blew a crack in its head. This required immediate feathering of the propeller—turning the blades to an angle that minimized drag—before the oil pressure in the amazingly complex prop dome dropped too low to drive the prop to the feather position. If you failed to do this, the prop would windmill at increasingly higher revolutions per minute until the shaft sheared off, flinging the prop free and too often in the direction of the fuselage, a scenario that had already brought a few C-97s down.
We feathered the prop and finished the checklist. No sooner were our emergency procedures completed than the loadmaster came forward and told us sparks and flames were coming out of the nacelle of the left inboard engine. Later investigation would show that the starter shaft had sheared—not at the designed shear point, near the drive gear, but at the far end of the shaft. Now we had a shaft rod flailing around in the cowling, threatening to gouge the cowling innards clean. We cut that engine to idle so that the remnant would be sheared off or would no longer scour the innards, but the engine was no longer putting out power. We were now a Boeing Bi-motor. We were headed back to San Francisco, and we were at the one place in the world most remote from any land.
Just flying the airplane became an ordeal. With our load we couldn't hold altitude on the remaining two engines, even at full throttle. The asymmetry of thrust made full rudder trim inadequate, so one of us had to hold constant and considerable pressure on the rudder to keep us straight. It was only when we got down to 1,000 feet that we were able to hold altitude with full bore on the throttles, but it was not likely that we could keep those engines and props going at takeoff power for the four-plus hours back to landfall. A night swim in the north Pacific looked like a sure thing.
Ocean Station November, normally a quick fix and a position report, became the communication lifeline for our Mayday call and request for a launch of a Coast Guard rescue HC-130 Hercules out of San Francisco. As we struggled eastward, they would head west to intercept us and prepare for our ditching.
Every moment was consumed by some pre-ditching preparation: raft breakouts, crew duty assignments, navigator position updates (this was pre-GPS—navigators did it the Polynesian way, with the stars). Amazingly, the overworked props kept turning, and after a couple of hours the fuel burnoff allowed us to throttle back a wee bit. As the right-seater, I spent a lot of time setting up for the water egress from the right side of the airplane and copying the elaborate ditching brief from the Coast Guard escort, who was now in UHF radio range. I was fascinated by the catalogue of services the Coast Guard was going to provide: data on swell direction, sea state, winds, and wave heights; laying down a flare trail on the sea for a pseudo-runway; dropping a raft for us.
I read this article in the magazine, and just enjoyed it again online. Although I never flew the C-97 or KC-97, I had KC-135 colleagues who did, and I found it to be VERY entertaining. I was surprised that the author didn't mention the furious rate at which the '97 consumed oil in its engines, and how often the crews had to transfer oil from a storage tank to those engines. My former '97 buddies used to kid about how the KC-97 used as much oil, as it did gasoline. Anyway, thanks for a terrific story!!
Posted by Duke Woodhull on March 30,2008 | 12:13PM