Narrative:

On departure we were passing through approximately 1;100 ft when we heard a noise and felt a significant vibration from the left side of the aircraft. No EICAS messages were present and the engine gauges were within normal parameters. Shortly afterward the flight attendants called the cockpit about the vibration and to report a slight burning smell; which soon dissipated. At this point we were unsure of what the problem was: all instruments were normal and the smell had gone away; but the vibration remained constant. After consultation with the first officer; we made the decision to return to [departure airport] to have the aircraft inspected. Since our instrumentation was normal; no emergency was declared and we received radar vectors for an approach. When we leveled off; the reduction in power caused the lp vibration on the number 1 engine to advance into the amber range; reaching a maximum noted value of 4.0. Once the engine power was reduced further to maintain speed; the vibration gauge returned to normal parameters. While the first officer flew the aircraft; I ran the QRH procedures for engine abnormal vibration and overweight landing procedure. We turned off the autothrottles per the QRH procedure and the first officer did an excellent job in minimizing thrust lever inputs while doing our best to comply promptly with ATC assigned speeds. The engine vibration varied greatly with thrust level setting; but never again approached the 4.0 value it did on level off. I called the flight attendants; spoke to the passengers; and sent a free text to dispatch notifying them of our situation. We landed safely and the first officer did an outstanding job in achieving a smooth touchdown well within the QRH limitation of 300 feet per minute descent. Brake temperatures remained in the green. We taxied in to the gate and discovered evidence on the post flight walk around of a large bird strike in the number 1 engine. Both the bird strike and the overweight landing were written up appropriately in the aircraft logbook. After deplaning; [operations] informed us that there was an alternate aircraft we could take immediately if the crew was comfortable with continuing on. I consulted with my crew and several appeared shaken up. After such an intense experience I decided it would not be safe to put us immediately back in the air; and made the decision not to continue on the other aircraft. [Operations] accepted this decision and released the crew to the hotel.

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Original NASA ASRS Text

Title: ERJ-170 Captain reported high engine vibration after takeoff; so the decision was made to return to departure airport; where evidence of a bird strike was found in the affected engine.

Narrative: On departure we were passing through approximately 1;100 FT when we heard a noise and felt a significant vibration from the left side of the aircraft. No EICAS messages were present and the engine gauges were within normal parameters. Shortly afterward the flight attendants called the cockpit about the vibration and to report a slight burning smell; which soon dissipated. At this point we were unsure of what the problem was: all instruments were normal and the smell had gone away; but the vibration remained constant. After consultation with the First Officer; we made the decision to return to [departure airport] to have the aircraft inspected. Since our instrumentation was normal; no emergency was declared and we received radar vectors for an approach. When we leveled off; the reduction in power caused the LP vibration on the number 1 engine to advance into the amber range; reaching a maximum noted value of 4.0. Once the engine power was reduced further to maintain speed; the vibration gauge returned to normal parameters. While the First Officer flew the aircraft; I ran the QRH procedures for Engine Abnormal Vibration and Overweight Landing Procedure. We turned off the autothrottles per the QRH procedure and the First Officer did an excellent job in minimizing thrust lever inputs while doing our best to comply promptly with ATC assigned speeds. The engine vibration varied greatly with thrust level setting; but never again approached the 4.0 value it did on level off. I called the flight attendants; spoke to the passengers; and sent a free text to Dispatch notifying them of our situation. We landed safely and the First Officer did an outstanding job in achieving a smooth touchdown well within the QRH limitation of 300 feet per minute descent. Brake temperatures remained in the green. We taxied in to the gate and discovered evidence on the post flight walk around of a large bird strike in the Number 1 engine. Both the bird strike and the overweight landing were written up appropriately in the aircraft logbook. After deplaning; [Operations] informed us that there was an alternate aircraft we could take immediately if the crew was comfortable with continuing on. I consulted with my crew and several appeared shaken up. After such an intense experience I decided it would not be safe to put us immediately back in the air; and made the decision not to continue on the other aircraft. [Operations] accepted this decision and released the crew to the hotel.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.