EMB ERJ 145 ER/LR
Flight Crew Commercial
Distraction; Workload; Troubleshooting
Aircraft Equipment Problem Critical; Conflict Airborne Conflict
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft
The crew began the second day of a four day. The initial plan for us was to do a turn. We arrived on time; conducted all safety checks and boarded the aircraft. We pushed off the gate and taxied out to the runway without incident. Upon initial communication with Ground; we were notified that we had a wheels up time an hour later with a probability of an early departure. We were then given instruction to taxi-out and hold short. We complied and were given clearance to shut the aircraft down; the Captain made a PA announcement. Once our time came up; we started both engines; completed all checklists; informed passengers of our departure status and proceeded to the runway (no incident). We were given departure clearance and climbed without incident up to approximately 4;000 FT MSL. I was the pilot flying and had the autopilot disengaged. Once the aircraft started accelerating to our FLCH Speed (240 KTS); I began noticing a vibration/flutter that I have never noticed before. I adjusted the pitch thinking it could possibly be rough air or other weather phenomena I could have overlooked. I did not notice any change in the vibration. I alerted the Captain about the issue and asked for his input. He concurred that he felt a significant flutter/vibration. During this time; we continued to climb as we started thinking about our options. As we passed through 10;000 FT and accelerated above 250 and approaching 270-280 KTS; the vibration became even more pronounced. As a crew we decided that it was a good decision to do an air return back to the departure airport due its proximity; the Captain notified the Flight Attendant and made a PA announcement. We notified ATC that we were experiencing control issues. ATC asked if we were declaring an emergency; at the time we didn't see the need so we declined. I attempted to engage the auto pilot when our workload started to rise. During this time; ATC wanted us to maintain 11;000 FT and issued a right turn. Although the HDG bug was spun the correct direction (right approximately 30 degrees) the Flight Director would only initiate a left turn. Noticing the discrepancy I disconnected the autopilot before the aircraft would turn the wrong direction. Again; holding altitude; and re-engaging the turn on HDG bug; I attempted to once again to engage the autopilot. Once more; the flight director would only turn left. I disengaged the autopilot and kept hand flying the aircraft. During the turn; ATC informed the Captain that we had traffic; Captain saw it visually and confirmed we were still clear of him. However; we had a TA/RA (descend command). Since the autopilot was off I manually pushed the nose over and went below the 11;000 FT clearance altitude; simultaneously ATC gave us a clearance to a lower altitude. During the RA we were clear of traffic at 10;600. Center coordinated with Approach and handed us off. During this time; the Captain was coordinating with ATC; Operations; and more importantly with Dispatch. Although the digital system is helpful; the system would not pull up landing information for us. It added an additional task on the Captain to use the [flight computer] to find the performance numbers. Once we had exhausted all of our checklists; discussed possible problems that could arise; and our preference to keep the aircraft slow to avoid further damages (if any) we told Approach we were ready to come in. We wanted to minimize our time in the air since we didn't know the extent of the fault. Approach vectored us in; and told us that the equipment will be on standby. We began the approach (no incident) and touched down overweight (44;500 LBS at -100 FPM). As professional pilots; we should look at this from the threat management stand point. I believe we had several threats during this flight; the obvious one being the control issue. In addition; the limitations of the autopilot to shed workload for us contributed to the CA and I doing several items at the same time. Since we were concerned about the time we could possibly have with a good airplane; I deviated from Standard Operating procedure and selected the autopilot. Recognizing that it was not working properly I announced it and confirmed with the Captain that hand flying should be utilized (we were not sure if the two failures were related). In addition to the aircraft issue; the ATC instructions added workload on our end which led to an RA. Even though ATC was not concerned with the descent (they told us to continue descending as we got the RA); we still had to comply with it; adding extra stress on us. Finally; landing performance data acquisition malfunctioning added additional work on us as we were pressed for time to complete everything we needed to do to land the aircraft safely. In all; I believe we mitigated the threats by working with each other and complementing our actions and double checking each decision via checklist and experience/intuition. Although we could have spent more time trouble shooting the problem; I think it was more prudent for us to get on the ground as quickly as possible. The Captain allowed me to keep flying the airplane and trusted my ability to perform my duties. In addition; his insight that the two failures could have been associated might be accurate. Finally; our Flight Attendant kept all of the passengers calm during the problem. I truly believe we probably utilized the threat management model correctly by involving all parties including ATC; Dispatch (who declared an emergency for us); and Operations.
An EMB-145 developed a flight control flutter after takeoff and would only make left turns with the autopilot engaged; so an emergency was declared and the flight returned to the departure airport.