Towing: Gliders and unpowered ultralight vehicles

Aero-towing a glider has its own safety rulebook. Under § 91.309 no aircraft may tow a glider or unpowered ultralight unless:

• the tow-plane PIC is qualified under § 61.69 (the tow-pilot training and currency rule);
• the towing aircraft has an approved tow-hitch appropriate to its airworthiness certificate;
• the towline breaking strength is between 80% and 200% of the glider/ultralight's maximum certificated operating weight — and if a stronger line is used, safety links of the correct strength must be installed at each end (the tow-plane end up to 25% stronger than the glider end);
• before towing within the surface areas of Class B/C/D/E airspace, the PIC notifies the control tower (or the flight service station if there's no operating tower); and
• both pilots have agreed in advance on the plan — takeoff and release signals, airspeeds, and emergency procedures.

Finally, a pilot may not intentionally release the towline after the glider releases in a way that endangers people or property on the ground.

Summary: Glider/ultralight aero-tow rules: the tow pilot must be § 61.69-qualified, the aircraft must have an approved tow-hitch, the towline must be 80–200% of the towed craft's max weight (with safety links if stronger), the tower/FSS must be notified in controlled airspace, and both pilots must pre-brief signals and emergencies.