The story of how the Lear Jet became qualified for flight into known icing conditions is not about Bill Lear but rather a handful of ingenious, dedicated and courageous employees.
The project was led by Frank Schick, a flight test engineer who had held a similar position for Boeing Vertol, before that my roommate in engineering school.
Initially, Frank put a tank of water in another test Lear Jet and used cabin pressure to pump water into the air stream. This system did not pump sufficient volume and there was no control over droplet size. Another approach was needed.
In nearby Hutchinson, Kansas, Rock Island Oil had several B-25's that were intended for conversion to high speed corporate aircraft. Si McDonald headed Rock Island's flight department and did not hesitate to get involved in a test program.
Frank, designed a grid of nozzles that would be lowered on a trapeze about 20 ft below the B-25. A water tank and a jet engine ground start unit was fitted in the B-25 bomb bay. The air turbine would be used to pump water through the nozzles. Si would fly the B-25.
Cecil Powers, an experimental mechanic would run the on board components which had to be one of the most uncomfortable jobs you can imagine. It was hot and noisy with the turbine on, cold and noisy with it off. After every flight, Cecil would stagger off the B-25 and vomit. But he never complained and would be ready to go for the next flight.
Jack Graham flew the test aircraft with Frank in the right seat. I pestered both of them to go on one of the flights. Frank was only too happy to let somebody else fly. Jack and I launched and joined up with the B-25 already airborne and waiting. Jack slid in about 20 yards behind the trapeze, the ride became extremely bumpy and I had to really cinch down on my seat belt.
We moved off to the side to allow Cecil to fire up the turbine and start pumping water. Then Jack eased into the vapor stream behind the nozzles. The purpose of the test was to see how well the windshield de-icing system would shed the ice. Now we were experiencing not only a bumpy ride, but we could not see out the windshield and that boom was just about 20 yards ahead of us.
The tests were extremely dangerous. Apart from the obvious, Si had the throttles of the B-25 jammed "balls to the wall" as they say. The tests needed to be conducted from a high altitude to get freezing temperatures, the trapeze had a lot of drag, and the speeds needed to be fairly high to be meaningful to test a jet aircraft. It was asking a lot for the WWII bomber. Had it lost power on even a single cylinder, it is not likely Jack could have avoided a collision with the boom. Neither the crew in the Lear Jet nor the crew in the B-25, wore parachutes.
The B-25 tests plus some flights into natural icing completed the tests for certification. Luckily, there were no mishaps in the program and everybody would live to fly another day.