Aircraft Towing

Flying Safety, August, 2001 by Paul Gallaher

They read like a bad novel.

Towing and taxi mishap reports keep reaching my desk with no end in sight.mishap messages, with stories like AWACS tail strikes Hangar door during towing operation. C-5 towed into stair truck. KC-10 rolls backwards into maintenance stand during towing operations. B-1B taxis into fence. C-130 strikes floodlight during taxi. I could go on and on with a litany of taxi and towing mishaps that have occurred during the last few years. The sad part is that many of these expensive mishaps occurred due to lack of checklist discipline or adherence to written guidance.

So now you're asking me, "What written guidance, other than the T.O.s, pertains"? Well, since you asked, I'll tell you. It's called Air Force Occupational Safety and Health (AFOSH) Standard 91-100. Its title is Aircraft Flight Line - Ground Operations And Activities. Never heard of it, you say? Maybe you have, maybe you haven't. I hope each of you is aware of the basics of Chapter 2, Towing and Taxiing Aircraft. In recent years, the Air Force has seen numerous taxi and towing incidents resulting in expensive repairs. Whether you're an aircraft maintainer or an aircrew member, you need to be aware of the concepts in AFOSH-STD 91-100. In an effort to ensure you all are aware of 91-100's concepts, I'll excerpt some of the key points:

Aircraft Towing:

"Aircraft ground handling personnel will be thoroughly familiar with all published towing procedures pertaining to the type aircraft being towed."

"The tow supervisor will be the only team member authorized to give the all clear to move order and will ensure all team members are qualified per requirements."

"When towing aircraft, team personnel will be stationed to conform to applicable aircraft T.O. procedures for the type aircraft being towed.

"In all cases there will be a towing supervisor."

Other tow team members include: A brake person in the cockpit, a tow vehicle operator, a nose walker (usually the tow supervisor), wing walkers (in most cases) and sometimes a tail walker.

During night operations, luminous wands will be issued to tow team members requiring them. "The use of wands by the towing team supervisor will be required even when the aircraft interphone contact is established."

"Towing speed will not exceed that of walking team members, with a maximum of 5 miles per hour." This may mean you will have to slow down during turns for large aircraft, because the outside wing in a turn will move much faster than the aircraft. If the wing walker becomes a wing runner, you need to slow down.

Control tower clearance is mandatory prior to towing an aircraft on or across an established taxiway or runway.

"...[A]ircraft brake systems will be charged before each towing operation. Aircraft with faulty brakes will not be towed, except to repair facilities."

"Only authorized equipment in good condition will be used in towing operations."

If towing into a dock, "Clear ramps of snow and ice for a distance of 100 feet in front of the dock doors and far enough to each side to accommodate all landing gear wheels." This would be prudent for towing into hangars as well.

Taxiing Operations:

"Wing walkers will be used when the aircraft is taxied within 25 feet of an obstruction. Wing Commanders may waive this provision for locally-based aircraft, if established taxi lines are marked and obstructions are either permanent or other aircraft are on established parking spots or lines."

"Aircraft will not be taxied within 10 feet of an obstruction, unless under one of the following circumstances:

"--During contingency operations when compliance would restrict the mission.

"--From alert, readiness, or protective shelters. A plainly visible centerline must be painted along the exit path and a marshaler will be used.

"--Operating locally-based aircraft from parking spots specifically designed for those aircraft. Parking spots will have a minimum 10-foot wingtip clearance... A marshaler will be used."

"Aircraft will not be taxied without clearance. Radio contact will be maintained with the (tower) throughout taxi operations."

At night, ground crewmembers will use two iluminated wands for signaling taxiing aircraft."

"Pilots and taxi-qualified technicians will use minimum power when moving from row of parked aircraft and will taxi in a way that prevents blast from propellers or jet exhausts from endangering personnel, parked aircraft, or other property." See aircraft T.O.s for recommended safe distance.

"Wing Growth"

This phenomenon is a factor in both towing and taxiing. It is especially prevalent on aircraft with a long wingspan such as the C-5, Boeing 747 and B-52.

"On aircraft with swept-back wings, the wingtip path extends beyond the straight line path when the aircraft is in a turn. The amount depends on the degree of turn and the degree of sweep on the wings."

Towing and taxi mishaps have recently been plaguing the Air Force. I urge everyone to do two critical things: 1) Consult your checklists; and 2) Use common sense. If you aren't sure if you have required clearance to tow or taxi, stop what you're doing and make the effort to do things correctly. This is one area we cannot afford to cut corners (no pun intended) to save a few seconds. AFOSHSTD 91-100 is available on the web at http://afpubs.hq.af.mil.