General aviation flight crew reported engine problems and power loss immediately after takeoff. They were able to return to their departure airport.
Synopsis
General aviation flight crew reported engine problems and power loss immediately after takeoff. They were able to return to their departure airport.
Narrative
My copilot and I performed the preflight with no notable issues. We started the engine and performed the run up and experienced a standard drop of 100 rpms for each magneto. The only instrument that showed any irregularity was the oil temperature; which was reading just below green range; which we noted as acceptable with the cooler temperatures of the morning; and how close it was to being in the green range. The plane had just had maintenance performed on it for slight oscillations in power on a different flight the week before; in which the mechanic had replaced the carburetor. Our intentions were to perform a quick flight within 25nm to the northeast of the airport at cruise airspeeds and power settings to determine if the problem was still persisting. Upon finishing our run up we continued to the runway and waited in sequence before eventually be instructed to line up and wait. We decided to perform a short field takeoff; so we held the brakes and introduced full power till peak RPMs and held for about 5-10 seconds before releasing the brakes after verifying no red flags in the cockpit. We lifted off and approximately 200 feet AGL the plane began to shake and I noted a loss of 500 rpms; and my copilot who I had delegated communications to instructed ATC that we needed to land immediately. During this time I performed a quick engine failure emergency checklist from memory to see if the problem could be quickly fixed and determined that everything was configured correctly; the issue did not appear to be a pilot error. I determined that we were to high up and too far down the runway to land on the remaining runway and so began looking for places to land and looking back at the parallel runway to see if there was notable traffic taking off in our vicinity that would limit our potential landing sites. They asked us if we wanted to make a right downwind to circle back to XXR or if we needed to land opposite parallel; to which we told them opposite parallel. They cleared us to maneuver as needed. I kept full power in and aimed the plane northbound to give myself the option to land on a road. I noted that we still had partial power; so I decided to attempt a 180 to land on XYR. We flew too far northbound and cut our turn back too soon to XYR and our turn back left us halfway down the runway of XYR at 200 AGL. I introduced full flaps but even so; I concurred with my copilot that we were too far down and wouldn't make the runway; and I informed the tower that we still had partial power; and I believed we could loop back to XXR for a safe landing on our runway of departure. They cleared us to maneuver as necessary. We overflew XYR headed westbound and performed a 180 west of the field and when landing was assured on XXR; I informed the tower that we would make a landing on XXR and didn't anticipate any further issues. We rolled the plane to parking and had no further irregularities. The issue; from my previous experience felt similar to a single failed magneto considering the loss of only partial power; and how suddenly the loss occurred. The RPMs dropped instantly and the engine quieted notably; and the whole engine began to shake causing the plane in turn to shake as well for the duration of the event until we landed. Despite all these factors; neither magneto indicated any irregularities before the flight; and I am inclined to believe that the issue was most likely linked to the carburetor recently installed by the mechanic.
Second reporter narrative
On Day 0; Aircraft X reported a slight oscillation in power during cruise flight. The flight school sent the plane to our mechanic to resolve the issue. We received a call that the plane was 'fixed'; installed with a new carburetor; and was ready to fly. Myself and another instructor were asked to do a test flight to ensure the plane was in fact safe and ready to fly with students. We planned to remain within 25NM of the airport and fly to the Northeast practice area at cruise airspeeds and power settings to ensure that the problem was fixed.Visually inspected during our preflight there were no concerns and the plane looked ready to fly. during our run-up; everything looked normal; our magnetos had a normal drop of 100RPM on either magneto. the only irregularity was the engine oil temperature reading just below the green range. The pilot flying and I both determined that this was acceptable due to the plane just being started and the cooler temperatures of the day. The oil pressure was in the normal range. There were no other irregularities; messages; or red flags. During our runup procedures; I did note that the oil temperature did rise to the normal green range. Following our run-up; we continued to the runway and waited to be sequenced before eventually being instructed to line up and wait on the runway. We were cleared to take off on runway XXR and we decided to perform a short-field takeoff. holding the brakes with full throttle until reaching peak RPMS verifying instruments were in the normal green range. We took off and at approximately 200' AGL I; the monitoring pilot; could hear some engine roughness and feel the airframe shake. Pilot flying also confirmed engine roughness and felt the shaking of the airframe. I noticed we had a full mixture and then immediately looked outside for the best place to land if we experienced a full loss of power. We called the tower and requested to land immediately. The pilot flying expressed that we were losing power from the engine. From my view; the pilot flying was running a quick emergency engine failure checklist; which we briefed before takeoff and everything was configured correctly. There was no error from the pilot in my view. We were cleared to turn 180 degrees because we had some power available and intended to land on runway XYR. However; we determined that we were too high above the ground and too close and would not be able to land on the remaining runway and requested to turn 180 degrees again to land on runway XXR because we still had some power available. We were cleared to land on runway XXR and did so; safely. We were able to taxi the plane back to parking. There were no visual damages to the airframe of the plane; both the fire department and city personnel confirmed that they did not see any smoke coming from the engine; and there were no fluids leaking.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.