Narrative:

I was taking off with full fuel on board and 3 passengers in a piper warrior. After a thorough pre-flight and startup; taxi and before takeoff checklist; I got the permission for takeoff. Rolling into the runway and adding power I confirmed all engine instruments were in the green and airspeed was alive. After liftoff with no runway remaining I experienced intermittent engine power. Immediately reported mayday to the tower and began turning left. Based on the situation; I tried to troubleshoot anything I thought it could cause the engine problem while I had full control of the plane. I turned the carburetor heat on and confirmed my fuel pump was on and mixture set to rich. I got permission to land on any runway and kept pumping the throttle to keep the engine running. When I finished my turn towards runway xx; I realized I was above the middle of the runway and I would not be able to land on the runway xx safely; so I made the decision to turn to runway xy where I landed safely. After I landed I asked to do a quick run up to the engine so I can get an idea what was wrong. During my ground run up everything was working as it was supposed to work. I looked down to the fuel selector and I realized it was halfway between left and right tanks. Based on what I experienced I was almost sure that it was a fuel issue and the position of the fuel selector created the problem and I left the plane in ZZZ for further inspection by a professional mechanic. A few hours later when I relaxed and started putting things together; I recall asking my young student to make certain to remove his feet from the pedals once we obtained clearance for takeoff. After much thought my conclusion is that it is possible that my young student may have actuated the fuel selector accidentally during takeoff resulting in a fuel starvation situation. As a pilot I continually strive to make safe choices during every phase of flight and moving forward I have learned to expect the unexpected including keeping an even closer watch on all items both inside and outside the aircraft cabin.

Related reports:

Google
 

Original NASA ASRS Text

Title: PA-28 flight instructor reported a loss of engine power due to a misaligned fuel selector led to a return to the departure airport.

Narrative: I was taking off with full fuel on board and 3 passengers in a Piper Warrior. After a thorough pre-flight and startup; taxi and before takeoff checklist; I got the permission for takeoff. Rolling into the runway and adding power I confirmed all engine instruments were in the green and airspeed was alive. After liftoff with no runway remaining I experienced intermittent engine power. Immediately reported mayday to the Tower and began turning left. Based on the situation; I tried to troubleshoot anything I thought it could cause the engine problem while I had full control of the plane. I turned the carburetor heat on and confirmed my fuel pump was on and mixture set to rich. I got permission to land on any runway and kept pumping the throttle to keep the engine running. When I finished my turn towards RWY XX; I realized I was above the middle of the RWY and I would not be able to land on the RWY XX safely; so I made the decision to turn to RWY XY where I landed safely. After I landed I asked to do a quick run up to the engine so I can get an idea what was wrong. During my ground run up everything was working as it was supposed to work. I looked down to the fuel selector and I realized it was halfway between L and R tanks. Based on what I experienced I was almost sure that it was a fuel issue and the position of the fuel selector created the problem and I left the plane in ZZZ for further inspection by a professional mechanic. A few hours later when I relaxed and started putting things together; I recall asking my young student to make certain to remove his feet from the pedals once we obtained clearance for takeoff. After much thought my conclusion is that it is possible that my young student may have actuated the fuel selector accidentally during takeoff resulting in a fuel starvation situation. As a pilot I continually strive to make safe choices during every phase of flight and moving forward I have learned to expect the unexpected including keeping an even closer watch on all items both inside and outside the aircraft cabin.

Data retrieved from NASA's ASRS site 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.