Teledyne Continental announced yesterday that it has made significant strides in getting the lead out of its assets-piston aircraft engines. The Mobile, Alabama engine-maker announced completion of a series of flight and test-cell trials with an unleaded fuel-labeled 94UL-replacing 100 Low Lead aviation gasoline powering engines ranging from the O-200 (100-hp range) to the IO-550 series. The 94UL product is essentially 100LL without the tetraethyl lead content. Tests under the most demanding conditions-steep climbs on a hot summer day-have yet to be conducted. But standard climb tests so far have indicated 94UL could be a viable fuel. The main concern is whether the octane level is sufficient without the lead additive. Among the reasons for moving to lead-free aviation fuel is the requirement that all leaded fuel be segregated from any contact with unleaded automotive fuel-in pipelines, tanks and tanker trucks. Continental expects 94UL to eventually be considered as an FAA-approved replacement for 100LL. The company will file an application within a few weeks with ASTM, and approval from that authority could come as early as this fall. FAA certification could take much longer.