An EMB-145 returned to land after takeoff because the elevator control response on takeoff required a very large input to attain a takeoff attitude. An emergency was declared.
Synopsis
An EMB-145 returned to land after takeoff because the elevator control response on takeoff required a very large input to attain a takeoff attitude. An emergency was declared.
Narrative
I executed a normal rotation for takeoff. As I continued to apply back-pressure to rotate into the command bars the elevator did not respond. I increased back-pressure; the control column moved back; but the elevator did not respond in kind. Approximately 100 FT AGL. Finally; the airplane 'jerked' nose-high. I released back-pressure to lower the angle of attack; it did not respond until it 'jerked' again. Controls became 'slushy' for the climb. By 500 FT AGL I was concerned about the elevator and made the decision to declare an emergency and return to the field. As we set up for the emergency landing; we briefed the Flight Attendant; completed the after landing checklist; in range checklist; and overweight landing checklist. We returned to the field. During the cruise and descent; the elevator functioned normally so we opted to do a precautionary landing rather than have the passengers brace. I opted to use as much nose up trim as I could to avoid reliance on the elevator for pitch control. We touched down uneventfully at less than 200 FPM descent.
NASA callback
The reporter stated that this event was the third time this particular aircraft had been written up for this type of elevator anomaly and one other non documented event had also occurred. Previously all elevator control cables were replaced. The elevator response in this event felt to the reporter as if the flight controls were being operated by a bungee cord. As aircraft speed increased in-flight the controls began returning to a normal response feel. However; the reporter did not deem the aircraft safe to continue and so returned to land. The control column had approximately one foot of movement required in order to get a response. For landing; elevator trim was relied on more than elevator tab for pitch control. The reporter recently discovered that following this flight the right elevator torsion bar was replaced and the aircraft returned to service. The reporter has been on this aircraft for three years and has not seen this type of event before. As far as is known this is an isolated reoccurring anomaly.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.