The Dawn of Discipline
A B-47 pilot remembers when an airplane—and Curtis LeMay—stiffened the spine of the Strategic Air Command
- By Walter J. Boyne
- Air & Space magazine, July 2009
(Page 3 of 5)
In May 1954, I arrived at McConnell Air Force Base and was crewed up with two fine officers, Major Harold McCarty, the aircraft commander, and Captain John Rosene, the radar observer. They were probably not too thrilled to have a low-time copilot on board, but they were polite.
The instructors were very experienced, and during training, they pointed out what made the B-47 capable and what made it dangerous. One of the most talked-about of the latter qualities was the fabled “coffin corner,” a point in the flight when the aircraft’s weight and altitude rendered the difference between a high-speed stall and a low-speed stall negligible. Recovering from a high-speed stall required a swift reduction in power to allow the speed to bleed down to a point where you re-established control. Recovering from a low-speed stall was more conventional. You lowered the nose and applied power, if necessary. The trick was to recover from one without transitioning into the other. In my view, the danger of the coffin corner was overblown, for if you executed correctly a well-planned mission, you would not find yourself in a situation where it might occur.
Flight control issues were far more important, especially the need to react with the correct control inputs if you lost an outboard engine as you neared the takeoff point. The loss of power on the far right (number six) engine, for example, would cause a loss of lift on the right wing, initiating a roll to the right. In a piston-powered aircraft, the traditional reaction was to turn the control wheel to the left, which raises the left aileron and lowers the right one, thus raising the right wing. In the B-47, however, the correct procedure was to boot in rudder pressure to lift the right wing, and you had to do it within 1.7 seconds of the loss to be effective.
Many a squadron briefing was spoiled by film clips of heavily laden B-47s caught at the wrong moment: as an engine failed on takeoff. The films would show the wing going down, the wrong control inputs applied, and then a veering, bounding cartwheel ending in a huge explosion, a sea of flames, and deaths.
But despite the dangers and the new techniques required, flying the B-47 was a joy. Far more maneuverable than the bombers it replaced, it had superb visibility. In the B-50, you labored through a takeoff and wheezed to altitude, the piston engines gasping for air. In the B-47, you blazed down the runway and climbed out at an exhilarating 310 knots (355 mph)—faster than the B-50 cruised. You slowed gradually until you leveled off minutes later at the optimum altitude, perhaps 30,000 feet, well above most of the traffic of the time. The cruise speed was typically Mach .74, about 420 knots true airspeed.
While takeoffs required good technique, they were not (unless you lost an engine) as demanding as landing. Setting the B-47 down safely required careful attention to weight, balance, and airspeed. The bicycle gear required that you touch down on the aft gear first. Touching down hard on the nose gear sometimes resulted in a series of porpoising bounces that could grow in size and end in disaster.
The landing problems stemmed primarily from the very clean design of the aircraft, which made deceleration difficult, and the still-primitive nature of the early jet engines, which accelerated slowly. These two factors made it necessary for the pilot to employ a long, low final approach.
The General Electric J47 engine was a workhorse, the later models generating 7,200 pounds of static thrust with water-alcohol injection, but accelerating from the low rpm of the engines at idle to full power still took up to 20 seconds. In the event a B-47 pilot decided to abort a landing and go around, his application of the throttle did not get an immediate response. Boeing overcame the problem by installing an approach chute: Derived from German practice, the 16-foot-diameter ribbon parachute was deployed to increase the drag of the aircraft, allowing engine power to be increased to maintain the desired airspeeds. If a go-around was necessary, thrusting the throttles forward would provide almost instant power because the engines were being made to work at the higher rpm necessary to overcome the drag of the parachute.