This is an excerpt from a report made to the Aviation Safety Reporting System. The narrative is written by the pilot, rather than FAA or NTSB officials. To maintain anonymity, many details, such as aircraft model or airport, are often scrubbed from the reports.
Acting as a flight instructor, conducting an instrument lesson with a student on a VMC day.
The Skyhawk 172 was in the hangar overnight. Everything during preflight and start-up through run-up was normal with the aircraft.
We inspected fuel visually in the fuel tanks using a fuel stick and sumped.
Magneto check, RPM dropped 100 on left and right. Carburetor check, RPM dropped with no rise. All gauges within limits and followed checklist.
On takeoff roll, gauges were within limits and airspeed came alive. We rotated at 55 and began climbing out at Vy. Everything sounded normal, all gauges looked green, we had a positive rate climb.
A little over halfway down the runway around 200 feet AGL — rough estimate, I’m not 100% sure on our altitude before aborting takeoff — the engine began shuddering, and I looked to my student, who looked to me, confirming we both felt and heard the engine roughness.
I took control and looked in front of us and inspected the length of the remaining runway.
I thought to myself, “If I abort now, I may overshoot the end of the runway into the grass, but if I continue and try to troubleshoot and the engine gets worse or fails, then we are headed for trees.”
I also think quickly that the cause could be carburetor icing, but if I pull carb heat and continue with the climb and the engine does not improve, then I have set myself up for a bad scenario.
At this point I think it is better safe than sorry and pull power to idle, begin a forward slip and add full flaps, hoping to get down to the pavement in time.
I announced to ZZZ Tower, “Aircraft X aborting takeoff loss of RPM,” although I unfortunately did not look at the engine gauges as my biggest concern was landing the aircraft safely at that time.
Tower cancelled the takeoff clearance for the aircraft behind us.
As we were descending I realized we would indeed overshoot the end of the runway so I announced to Tower that we would overshoot the runway and roll into the grass, Tower acknowledged this.
We touched down about five to 10 feet before the end of the pavement and rolled into the grass. I kept the yoke pulled back to hold off the nosewheel as much as possible. The grass was pretty tall and helped dampen the roll and bring us to a smooth stop.
Once at a stop I confirmed my student was okay, took a brief look at the gauges, which looked green — although I wasn’t looking very thoroughly here, again we had just stopped — and then announced to Tower that we were at a stop in the grass and us and the plane were okay.
Tower asked to confirm and I reconfirmed and told Tower I would be shutting down the plane now, and Tower responded okay and that service vehicles were on the way. We shut down the plane as normal.
The ground check on the ignition was normal before shutdown. We put the cowl plugs on, the pitot tube cover on, and the yoke control lock in.
I called Dispatch and informed them on what happened. An airport vehicle arrived and they confirmed we were alright.
Primary Problem: Aircraft
ACN: 2008726
great job, always better not to take a bad airplane into the air. You did the right thing because there was no guarantee the roughness would not have gotten worse, making a even more difficult forced landing harder.
Before departing Lake Havasu 8000′ runway the run up was good. While climbing at 100′ the engine began to sputter so I sat her down and taxied back. I did another run up and everything was fine but the same thing happened. It would start to sputter shortly after rotating. I then taxied to the local shop ( I was lucky they were open one on a Saturday) and told them I think I have a problem and they said we know we heard you. He told me to remove the top cowl then he touched all the cylinders and one was not as hot as the others. Then he told me to remove the two spark plugs on that cylinder. We replaced those and I took off and all was good. The moral of the story is carry tools and extra spark plugs with you.
Hmmm. I seem to remember a recent bit about teaching fwd slips being too old fashioned and hardly a current need in the “ modern” training syllabus… ..anyone? LOL. (Old guy that always teaches all manner of slips…). Very nice job on calling it!
Great job! And we know that all happened in a much shorter time span than it took to read it.
But, in cases like this, we all want to know what was determined to be the problem with the engine. .
That’s part of the learning experience of these reports.
VERY curious about that engine roughness.
Nicely done! Initiating a forward slip at 200’ AGL…smart move; glad it worked.