BAe 125 Series 800
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; General Declared Emergency
Aircraft
I was the pilot monitoring (PM) and shortly after departure; the Pilot Flying told me that he was unable to trim the plane. He was struggling to keep the nose down with the takeoff power setting. I took the flight controls and confirmed that the elevator trim was stuck. I tried multiple times to trim the plane with both the electric and manual trim. The trim would not move. The PM declared an emergency and asked to return to [departure airport] as soon as possible. During the approach; it took extreme force to control the aircraft. Adding and taking away power was the only way to neutralize the controls. The PM ran the appropriate checklists for the conditions. Once I felt comfortable flying the aircraft; the PM went back and briefed the passengers. We broke out of the clouds at 1;100 FT and a normal landing was made.
I was the pilot flying and while climbing through approximately 1;000 FT MSL I realized that the elevator trim system was not responding to control inputs. As the control pressure required to maintain intended pitch attitude continued to increase I attempted to manually trim the elevator using the manual system. The attempt was unsuccessful; and it was apparent the control wheel would not move in the nose down direction.
BAE-125-850XP flight crew reported they were unable to trim the elevator after takeoff. They declared an emergency and returned to departure airport.