Learjet 45
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 45; Flight Crew Total 11250; Flight Crew Type 450
Time Pressure; Workload
Aircraft Equipment Problem Critical; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Overcame Equipment Problem; Flight Crew Landed As Precaution; Flight Crew Regained Aircraft Control; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft
[We] experienced primary pitch trim failure upon gear up call. As the aircraft accelerated; it became more and more difficult to maintain control and; of course; the autopilot would not work. Combine this situation with the fact that [while] on an RNAV SID we are expected to follow it precisely. Not knowing the best way to communicate with ATC concerning this; we declared an emergency. In my opinion; since we had recovered the aircraft with secondary trim; it was not really an emergency per se; but we did not want to be confined with trying to perform the RNAV SID. We may have been able to talk with ATC and try to explain all of this; however the 'e word' came quick and easy and with one word it was done. Of course we climbed to a safe altitude and did all the QRH procedures and returned to base successfully. There is much guidance on how to fly an RNAV SID normally; but not much in the way of when it is abnormal and time is at a premium. An engine failure here would have been easier but a flight control/jammed stab is entirely different and more demanding. It would be great if ATC had a word for a navigation emergency or such; just to be clear as to the nature of things.
Learjet 45 flight crew experienced a primary pitch trim failure on an RNAV departure; declared an emergency; regained control with secondary trim; and returned to base.