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after takeoff unless the gear were up. This interdependence would accomplish this: 1) in order to land without the gear down, it would be necessary to forget both the gear and the flaps, an unlikely coincidence. In Howard's estimate, this coincidence would occur only once every 196,000,000 landings- about 150 years of domestic airline operation. 2) It would be impossible to raise the gear on the ground, thinking that it was the flaps that were being raised. 3) It would be impossible to raise the flaps immediately after breaking ground on takeoff instead of the gear, a very dangerous procedure with the present high wing loadings.

In addition to this interconnection, he would interconnect the flaps and throttles, much as is now done with the throttles and flight control lock, to prevent a takeoff with flaps up. That this is an important point is attested by the author's personal experience of having made such a takeoff in a DC-4, in spite of an unhurried reading of the check list with both another Captain and a Flight Engineer in the cockpit and participating. Luckily there was ample runway available, but under conditions of minimum field length with the high wing loadings now used such a takeoff could very easily be catastrophic.

By putting into practice some such ideas, it should be possible to eliminate 7.5% of all accidents and 12.5% of

those attributed to "pilot error", as well as eliminate the exposure to the no-flap takeoff hazard.

The second idea presented here is one in which the pilots have considerable faith, the mandatory use of reverse pitch propellers on all airline aircraft. In the period studied there have been some 62 accidents in which the aircraft has run beyond the field boundary, either as the result of an aborted takeoff or, more frequently, after landing. Since the introduction of reversing propellers, no aircraft equipped with them has been involved in such an accident, with one exception. In that case, the use of reverse pitch prevented a far more serious, and probably fatal, accident. We feel that they should become a required item of equipment, much as the full feathering propellers became a decade ago. Their use, in our estimation, would prevent 10% of all accidents and 21% of "pilot error" accidents.

Since the pilot is the final determinant of flight safety his help should, we feel, be actively sought in the early design stages in order to make his tasks more simple. This is occasionally being practiced, but not nearly to the extent we feel desirable. Raymond(4), in his excellent 39th Wilbur Wright Memorial Lecture, said, in speaking of the time of a new design's first flight:

"Here also enters, too often for the first time,