Show W I Device Invented Invent d dT To T O Aid Md Fliers in Blind Landings W WASHINGTON Dec 29 UP UP- UP A. A new instrument which Informs he tho airplane pilot of at his distance from the ground In landing on fields ields obscured by f tog fog g or darkness has has' been perfected by the army ermy air Ir corps a and d tho the General Electric compan com corn pan pany Other altimeters c cease to be ef effective et- et near the earth but tho the n new w Sonic altimeter registers the die die- tane to as little as ns 50 t feet ct It is based on tho the principle of r sound Bound waves wave tho the length of Urno timo from plane piano to o ground and return being registered registered registered regis regis- in terms of distance Charles A A. A Lindbergh and Lieu Lieu- tenant Albert Hegenberger havo have tested the new Instrument until the army array feels it was made mode known to today today today to- to day that one ono of aviation's most Im Important Important important Im- Im problems m has been solved u. u |