Trodi Checks Fury : Speed of a Navy North American XFJ-2 Fury Jet is checked by Trodi (padestal at left) as it lands on the USS Midway. The new instrument, a touchdown, rate of descent indicator, was developed and built by North American's Electro-Mechanical Department. It makes it possible to determine the proper rate of descent for carrier landing in a fraction of the time previously required. Trodi sends out two beams of light which the approaching plane intersects and the instrument then rec