Flight Crew Air Transport Pilot (ATP)
Training / Qualification; Troubleshooting
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Aircraft Equipment Problem Dissipated; Flight Crew Inflight Shutdown; General Declared Emergency
Aircraft; Weather
While in cruise at FL360; clear air and SAT -44; I noticed that Number 2 N1 was at 93% while Number 1 and Number 3 were at 95%. When I attempted to advance Number 2 to match Number 1 and Number 3 I noticed that the throttle wouldn't move in either direction. We sent a maintenance report via ACARS advising of the problem. They replied that the cable was likely frozen and to turn on the engine anti-ice in an attempt to thaw it. We did this with no results. As we were approaching our filed destination I requested a descent to the lowest altitude commensurate with terrain. We were initially cleared down to 14;000 FT; eventually down to 9;000 FT. While TAT warmed to +2 and SAT to -15. The throttle was still stuck. We advised Center of the problem and that we would likely have to shut down the engine eventually. When asked if we wanted to declare an emergency I elected to defer this until we were in the destination area. When level at 10;000 FT and still no improvement in the throttle condition we shut down the engine IAW the QRH. Fuel was the other consideration as we were at low altitude and still had 93% on Number 2 with engine anti-ice on. I wanted to be as light as possible. With weather not an issue and being an emergency aircraft by that time I was comfortable landing with an estimated 18;000 LBS; which we did. We declared an emergency with the second Controller we spoke with shortly before being handed off to Approach - I think. I'm not sure of the exact sequence of these events. I believe Approach asked for fuel and SOB. We advised that it would not be necessary to roll the fire trucks. We reviewed 'landing with one engine inoperative' procedures and used flaps 35 with normal configuration points and speeds. We chose to land on the longest runway available. The HUD was a great asset while hand flying a visual approach with RNAV backup and with autothrottles off. Touchdown and rollout were normal. While waiting for clearance across [runway] I noticed that there was some forward movement in the Number 2 throttle; but no backward movement. After taxi in and shutting down the aircraft I noticed that the Number 2 throttle had pretty much full movement. I have been told that a frozen Number 2 throttle cable (if in fact that is what we had) was a known problem with the DC-10 years ago.
We had flown through some moisture early in the flight; but had been in clear air for at least 30 minutes before this happened. We had used the engine anti-ice while in the clouds; so I don't know any way to prevent this and still fly our missions.
A DC-10 Number Two Engine throttle became immobile in-flight because of apparent moisture frozen cable. The engine was shutdown and after a normal landing; throttle movement returned to normal.