The trouble with that idea is that three lights mean three microswitches, plus a fuse or circuit breaker-complication, not simplication. For that matter, you might not notice the light at a critical moment. He later proposed that the microswitch energizing the hydraulic pump be located at the valve, not at the lever, so that you would learn of a disconnect because the pump would keep running even after you centered the handle. This made sense, and I considered some variations on the theme. For example, there could be a single microswitch on the gear valve, but that switch would supply power to the flap and airbrake controls so that they would not operate unless the gear valve were in the off position. Both arrangements would hold the flaps and airbrake hostages to the integrity of a single microswitch circuit-perhaps an acceptable risk, since electrical circuits and environmentally sealed microswitches are quite reliable.
Then I began to consider whether the same cable failure that I was contemplating in connection with the landing gear might not also occur in one of the other systems, so that, for example, raising the gear on a go-around, or lowering it for landing, would also unintentionally retract the flaps or deploy the airbrake. Any of these uncommanded actions could, under some circumstances, be unwelcome and even hazardous.
The more I thought about the question the more baffling it became, like one of those logic problems (the Englishman smokes Old Gold, the man in the yellow house drinks tea, etc, etc) that oblige you to ferret out the hidden implications of a few seemingly unrelated clues. Each solution that I thought of seemed to introduce a new hazard or demand a further backup. The compound interest from simplication was going to my creditor, not to me.
Eventually I saw the obvious-that the root of the entire problem was the cable circuit between the instrument panel and the hydraulic valves. The placement of the valves in the wing was a consequence of an early decision to keep hydraulic lines out of the cabin. If I abandoned that policy and put the valves themselves behind the panel, so that I would be operating them directly, the positions of the gear, flap and airbrake levers would absolutely coincide with the condition of their respective valves and all the difficulties would disappear. What I would lose would be freedom from hydraulic spills, seeps or drips in the cabin-minor irritants, I now realized, compared with retracting the gear on the ground.
No system is so simple as to be immune to malfunction. My father was once approaching the airport at Sedona, Arizona, in a Fournier RF-4, an airplane with a retractable monowheel landing gear operated directly by a lever beside the pilot's right thigh and below the throttle. He was wearing a Bogartian trench coat with loops at the cuffs. It was turbulent, and just as he flared he hit a bump strong enough to make his right hand drop from the throttle and then fly up again. The loop in his cuff caught the handle and lifted it, unlocking the gear, which retracted just as the airplane settled onto the runway.
So much for absolute simplication. But the most direct method of getting something done, with the fewest and most robust components, continues to be the best. Mechanical systems allowing direct visual status checks are desirable not only because they are easily inspected and maintained, but also because their operation can be intuitively imagined by the user. Airplanes are no place for Rube Goldberg contraptions. And one other thing-don't ever fly in a trench coat.