B757 Undifferentiated or Other Model
Flight Crew Last 90 Days 200; Flight Crew Total 18000; Flight Crew Type 2000
Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance
Flight Crew Landed in Emergency Condition; General Maintenance Action; General Declared Emergency
Aircraft; Human Factors
Nothing unusual was noted during the pre-flight walk-around. During taxi-out; all was normal. No nose shaking or shimmy was present. Takeoff roll was normal to about 60 KTS. Nosewheel shaking was noted and was initially thought to be that the airplane was tracking on the center line light assemblies. As speed increased; the PIC moved the plane off the centerline lights; but the shaking continued. After rotation; the shaking continued as the nosewheel retracted. As the nosewheel [brake] snubbers slowed the wheels to a stop; the shaking reduced proportionally to nothing. Enroute; considerable discussion was had as to the situation and the possible cause. Two hours from [our destination]; an emergency was declared; and appropriate information was passed to ATC. At [our destination] the winds were variable to calm. The longest runway was chosen [and] 30-degrees flaps was chosen. The Approach was normal and on-speed. Touchdown was gentle and the nosewheel was lowered extremely slowly. The nosewheel shaking started at nosewheel touchdown; with the same rhythm as related to speed and intensity as during takeoff. The plane was brought to a complete stop on the runway. The nosewheel was examined by a Mechanic; and tow to the gate was initiated. At the gate; the flight crew inspected the nosewheel assembly and discovered on the right wheel; inside rim; about 60 to 90-degrees of the [wheel] rim had broken away; and gone. The tire was still inflated; but seriously out of round.
After landing at [our destination] as an emergency aircraft; we came to a complete stop. [We] had Fire and Rescue Equipment standing-by. We had declared [an] emergency because of loud nosewheel shimmy on takeoff. On landing; we experienced nosewheel vibration until bringing it to a complete stop. [We] requested our merged Air Carrier Y's Maintenance [personnel] to inspect. Maintenance person came and plugged in; identified himself as Mechanic X; although he was outsourced from Air Carrier Y. He told me (Captain) that he had inspected the nose gear and everything looks fine down here; but added that we're going to jack you up and tow you in as a precaution. I agreed; based on the information he gave us. Later; at the gate; the FAA met us with photos of a badly damaged nosewheel - there had been complete metal failure and about one third (1/3) of wheel was off. FAA and others were incredulous that tire had not blown. Tire had been rubbing against a bolt and there was a spray of rubber everywhere. Mechanic X flat out told me that he deliberately lied to me on the runway because; 'was so bad I didn't want to scare you.'  I explained to him the importance of always telling a captain the truth about the maintenance status of the airplane. I mentioned this in earlier report; but I am now filing this additional report because I believe this is a separate and important safety hazard. Risks include: 1) He had no right to unilaterally decide to move the damaged airplane. That right nosewheel tire could have blown at any time; damaging ground personnel; and also possibly airplane. 2) When the wheel fragment exited the nosewheel; the gears were down. It is possible and likely that the fragment struck a main wheel tire or gear on the way back; particularly as it must have spun off the airplane at an angle. Towing the damaged airplane puts additional stress and wear on the main gear and wheels. At the very least; the Captain; Dispatch and Maintenance Control should have assessed the damage and threat together; to determine whether the safest course of action included towing the airplane WITH PEOPLE ON BOARD; in a condition in which there could be further damage; such as tire blowing or potential fire. 3) Nosewheel tire was already damaged and under pressure. FAA stated he could not understand why it did not blow. We had shut engines down; but had APU running. Debris could have been ingested in intakes. 4) If something did deteriorate further; Captain and First Officer are making EVAC/NO EVAC decision. That decision can only be made upon accurate information about the safety of the aircraft. That decision; to risk passenger lives; should be made after consultation with Maintenance Control and Dispatch; referring to limits on tires; gear; aircraft and possible further inspection; then make an informed risk analysis based on Boeing and industry standards.5) It was completely inappropriate for Contractor Mechanic Y to violate FARS; Air Carrier Y's procedure; and take decision into his own hands because he heard a female voice as Captain and decided he didn't want to scare her with how bad it was. Would he have done the same thing if it was a male voice? Would he have worried that he didn't want to get a male pilot angry; so he would lie to him as well? We need to supervise our outside Contractors and make sure that they follow FARs; Air Carrier procedures; and tell the truth to the Captain of the airplane; recognizing Captain's authority for the safety of the airplane and passengers. Aircraft on runway.
A First Officer and Captain report that one third of a nosewheel rim had broken away on the inboard side of the right nose tire on a B757-200 aircraft during takeoff; causing wheel shaking and vibrations. Aircraft landed in emergency conditions at destination. Tire was still inflated; but severely out of round. Captain noted that Mechanic had lied about condition of tire and moved aircraft without discussing with Captain; Dispatch or Maintenance Control.