Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Time Pressure; Situational Awareness; Communication Breakdown; Distraction
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft; Equipment / Tooling; Environment - Non Weather Related
Flight was a functional flight check to investigate vibrations reported by multiple crews on [the aircraft]. Maintenance had accomplished multiple maintenance repairs. They showed me all their documentation as well as a balanced AML and the spotting message. The IOC Duty Chief Pilot walked me through FM; and Dispatch and [Maintenance Control] briefed me on the spotting message. [The] Maintainer gave us a thorough walk around and briefing on what we would be looking and listening for. We then could not sign in on CCI due to our location at CLT. My sharp copilot FO (First Officer); called IOC and had them talk us through signing in through our smart phones.We finally taxied about 38 minutes late. Climbout was normal but busy as my FO was Pilot Flying; and I was coordinating with ATC for an altitude and route that would allow us to run the tests. The filed route by Dispatch would not work. We were both coordinating with the Technician on the jump seat as we investigated the vibrations. Just about top of climb; FL300; I noticed a printer message. Much to my surprise; it was a reassignment from tracking; or additional flying as it is now called. [The FO] and I ignored it and almost on cue the vibrations and noises started as we were leveling off. We flew the rest of the [Flight Check]; compiling with ATC and [the Maintainer's] requests; and landed uneventfully. I realize that IOC Scheduling is in crisis mode most of the time. However; tracking MUST NOT ever reschedule or add flying to pilots on a functional check flight. These flights are NOT the norm for line and reserve pilots and can be very busy and even stressful. I was behind due to multiple delays as mentioned above. Before we even started engines; I told [the FO] and [the Maintainer] we would NOT rush. DO NOT RESCHEDULE OR ADD FLYING TO [FLIGHT CHECK] CREWS.
A319 Captain reported aircraft vibration and noise due to unknown cause during a flight check following a difficulty in signing in for duty and an attempt by Scheduling for additional flying.