Narrative:

During straightforward tow into hangar after 'high speed distance' tow (faster than walking speed and approximately 1/4 mile from gate to hangar). I was doing a line operations safety assessment (losa) observation of this movement when approximately 50 ft from park; the towbar broke it's 'shear' bolt; causing erratic nose gear movement. Brakes were applied; towbar removed and nose gear inspected for damage. After inspection; serviceable towbar was installed and tow continued without incident. Tow tractor that local maintenance director wants used for 'distance' towing is a tug GT50H (B777 tractor). Towbar used is manufactured by XXX industries. Local mechanic called XXX industries yesterday; due to disconnects during towing that have occurred three-times. XXX industries states they have never sold the B737NG towbar with (different head; latching mechanism; and greater tensile shear bolt) to our air carrier. We have a classic B737 towbar for B737-100/200/300/500 aircraft which are half the weight of the B737-900ER (90;600 pounds empty). Also; tow tractor is high profile [shape-design] and only portion viewed [from the cab of the tug] during the tow is [the aircraft's] radome and wingtips. [Tug rider] passenger must stand to view [aircraft's] maximum turn radius indicator (red stripe) and give direction to the driver. I filed a losa observation for this incident and sent towbar out for repair. Although this incident resulted in tooling damage; soon it will be aircraft or personnel if correct ground support equipment (gse) is not afforded. Tractor is not a covered 'hood' type. Three technicians have incurred 'jet blast' from other aircraft while towing on taxiways. Monthly safety meeting was conducted two days prior to this event; all of the 15-members that were present agreed that this gse towing practice is unsafe; but director has not halted its practice. Technicians feel threatened for their career due to previous 'firing' comments if safety isn't followed. Equipment unsafe; unreliable and no instructions.

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Original NASA ASRS Text

Title: An Aircraft Maintenance Technician (AMT) describes some of his observations and safety concerns involving recent tow bar disconnections that have occurred during towing of B737-800 aircraft and the difficulty viewing the same aircraft when using large tow tractors.

Narrative: During straightforward tow into hangar after 'high speed distance' tow (faster than walking speed and approximately 1/4 mile from gate to hangar). I was doing a Line Operations Safety Assessment (LOSA) observation of this movement when approximately 50 FT from park; the towbar broke it's 'shear' bolt; causing erratic nose gear movement. Brakes were applied; towbar removed and nose gear inspected for damage. After inspection; serviceable towbar was installed and tow continued without incident. Tow tractor that local Maintenance Director wants used for 'distance' towing is a TUG GT50H (B777 Tractor). Towbar used is manufactured by XXX Industries. Local Mechanic called XXX Industries yesterday; due to disconnects during towing that have occurred three-times. XXX Industries states they have never sold the B737NG towbar with (different head; latching mechanism; and greater tensile shear bolt) to our Air Carrier. We have a Classic B737 towbar for B737-100/200/300/500 aircraft which are half the weight of the B737-900ER (90;600 LBS empty). Also; tow tractor is high profile [shape-design] and only portion viewed [from the cab of the tug] during the tow is [the aircraft's] radome and wingtips. [Tug Rider] passenger must stand to view [aircraft's] maximum Turn Radius Indicator (red stripe) and give direction to the Driver. I filed a LOSA observation for this incident and sent towbar out for repair. Although this incident resulted in tooling damage; soon it will be aircraft or personnel if correct Ground Support Equipment (GSE) is not afforded. Tractor is not a covered 'hood' type. Three technicians have incurred 'jet blast' from other aircraft while towing on taxiways. Monthly safety meeting was conducted two days prior to this event; all of the 15-members that were present agreed that this GSE towing practice is unsafe; but Director has not halted its practice. Technicians feel threatened for their career due to previous 'firing' comments if safety isn't followed. Equipment unsafe; unreliable and no instructions.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.