39 Aircraft towing services; loading and unloading of baggage, cargo and mail; transportation to and from aircraft of baggage, cargo and mail; passenger and baggage check in services; porter services; transportation services, namely, providing wheelchairs at airports to others; in-terminal and inter-terminal transportation of airline passengers; parking-lot shuttle services; transportation of airline crews and employees by bus between terminals and aircraft; operation of mobile passenger lounges, rental of baggage carts; damaged aircraft salvage services; lease of aircraft ground-service equipment, namely, baggage transport carts, push back tractors, aircraft loading equipment in the nature of hydraulic cranes and lifts for use in the loading and unloading of aircraft, air start units, ground power units, aircraft lavatory service trucks, water trucks, conveyor belts, busses, and fueling equipment; aircraft ground-control services, namely, directing the taxiing of departing and arriving aircraft at airports; utility services, namely, transmission of electricity to aircraft for ground air conditioning and heating of aircraft