Regional Jet 700 ER/LR (CRJ700)
Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
General Maintenance Action
Human Factors; Equipment / Tooling; Aircraft
We were dispatched to move a CRJ-700 aircraft. As we were going the taxiway; [over] the first hump; I looked back and saw that the plane's front main shifted to the right while in the cradle. This is not the first time this happened. I reported a few months back [that the] same thing happened with other CRJ-700 aircraft; where the tires were cut. Our ground support equipment department tell us there's nothing they can do. My fear that one day as we are towing other CRJ-700s that it will disconnect from the Super Tugs; [causing] injury or killing someone.
Reporter stated he has many years of experience towing EMB-145s; 170s and CRJ-700 regional aircraft using their Super Tugs for over two years. The tug has a cradle system that is shaped like a horseshoe that is part of the Super Tug Frame Assembly. The tug is backed up to the nose gear tires; a lever is moved and the on-board computerized electric hydraulic cradle system automatically captures and clamps the nose gear using sensors as guides without anyone touching the equipment. The hydraulic unit is located approximately centerline and at the forward end of the cradle system.Reporter stated he has informed company management about the problem of only CRJ-700 nose gears suddenly shifting inside the nose gear cradle while towing. Somehow a gap seems to open inside the cradle; allowing the nose gear to shift. That gap contributed to a recent incident where the driver was turning left and the nose gear shifted right; striking the center hydraulic unit and cutting the nose tires. He had an incident where the nose gear slammed into the hydraulic unit. If the hydraulic unit had not been located at centerline; the nose gear would most likely have jumped out of the cradle and slammed into the cab where he was driving. His company management agrees a problem exists and removes the tug from service and requests maintenance to look at the problem. Maintenance says there is nothing wrong with the equipment; that the problem is operator error and releases the Super Tug back into service where the same problem reoccurs.
A ramp employee describes his efforts to address an unsafe condition that occurs while towing CRJ-700 aircraft using Super Tugs that have an automated electric-hydraulic nose gear cradle system. CRJ-700 nose gears have shifted sideways inside the cradle during turning motions causing nose tires to be cut after striking the cradle hydraulic unit. Other times the nose gear will slam forward into the hydraulic unit.