twa flight 513 , registration unk , `` star of lisbon '' , was a lockheed unk constellation operated Being_in_operation by transcontinental and western air on a training Education_teaching flight on july 11 , 1946 when it crashed Motion near reading , pennsylvania .

since atc is often unwilling to grant Commitment this discretionary vfr clearance because of traffic volume , many airplanes that need to transit Having_or_lacking_access the new york metro area use the vfr corridor as an alternative to going Self_motion east of the city ( over water ) or west ( toward pennsylvania ) .

over the united states , frederic weakened Cause_change_of_strength for a final time before becoming Becoming extratropical in pennsylvania on september 14 and dissipating Dispersal the next day .