This is a picture of Marty Knutson taken at the Las Vegas 2007 Roadrunners Reunion. He was one of the first U-2 pilots based in Turkey.
He flew long missions years before INS or GPS were available - using Magellan equipment - sextant, drift sight with 2 x zoom facility, grid navigation, ADF (crank the handle, use BFO, if you knew the frequency) and pencil and paper.
The autopilot had two knobs for (pitch) Mach hold, an A & a B system. Rotating the knobs tweaked the gain in flight to achieve speed holds of 1 or 2 knots accuracy - and when one 'pot' got tired the other 'pot' was used. If both pots were bad, you were in major trouble with a 4 knots stall/mach buffet margin at high altitude.
Marty went on to be the Boss of NASA Ames and flew the SR-71.
