A300 Flight Crew reported excessive vibration on take off. The flight crew performed an air turn back and precautionary landing at departure airport.
Synopsis
A300 Flight Crew reported excessive vibration on take off. The flight crew performed an air turn back and precautionary landing at departure airport.
Narrative
After experiencing unusual aircraft vibration on climb out; we diverted back to our departure airport of ZZZ. During approach we experienced a FLAP/SLAT Fault and suspected flight control malfunction on initial approach. After [requesting priority handling] we performed a successful no flap/no slat landing on Runway XXR. After a normal take-off; the aircraft began vibrating at 14000 ft. MSL and accelerating through 280 IAS. As the Pilot Flying (PF) I dialed the speed back to 250 kts and the vibration ceased. We scanned the ECAM systems pages looking for any discrepancies or probable causes. With vibrations absent we asked for another climb to our cruising altitude of FL340. With an increase in thrust and increase in speed the vibrations returned. Working with Dispatch and Flight Control; we elected a return to ZZZ was the safest course of action and an amended release was received. The First Officer (FO) managed the FMS setup for ILS XXR and briefed the approach. We began configuring and I called for slats extend and the subsequent input resulted in a slat 1/2 fault. We then notified ATC that we needed to break off the approach to work the new issue. Per the ECAM the FO cycled the flap handle and another slat fault was annunciated. At that moment; per ATC instructions I had selected HDG SEL to initiate a left turn away from the localizer path. The aircraft then began to make a right turn. Suspecting a possible flight control malfunction we [requested priority handling]. The FO requested landing data for no flap no slat. Having the required landing distance and performance data we landed on Runway XXR exiting at taxiway F. We requested fire/rescue to visually monitor our brakes for possible high temperature and taxied to the gate. My first thought during the un commanded right turn was a slat asymmetry. At 2200 AGL and having just experienced irregular aircraft vibration; we [requested priority handling] and began working toward an immediate landing. After landing and discussing with local maintenance I do not believe that we had a flight control malfunction. This may have been the aircraft entering LOC Capture mode and attempting to intercept the path. After disconnecting the autopilot the aircraft maneuvered normally.
Second reporter narrative
Upon climb out we got past 10000 ft. and I sent off the ops normal message as we got switched to ZZZ Center then we got clearance to FL340. The aircraft accelerated and through about 14000 ft and 280 KIAS we heard a loud vibration and the entire aircraft shook violently. The Captain leveled off at 14000 ft. and slowed down. I informed Center that we needed to maintain 14000 ft. to work on the issue as the aircraft continued to vibrate. We noticed that the vibration sounds stopped immediately when the airspeed went below 280 KIAS. All engine; hydraulics and pressurization indications during that period were normal during the vibrations. So we decided to attempt a slow climb out back to FL340. Again crossing approximately 280 KIAS the vibration repeated so the Captain slowed to 250 kts. We contacted Dispatch inform him of the issue and our intentions to return to ZZZ. While slowing down and configuring for landing we got a SLAT/FLAP Fault Message on the ECAM. I began working the checklist as the Captain told me to request priority handling and let them know we had flight control issues. We were visual and about 1500 AGL. I got new no slat/flap performance numbers as we made a right 360. The Captain turned off the autopilot and we landed without further incident.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.