The flight instructor reported that, shortly after the student pilot conducted the takeoff for the instructional flight, they felt the engine vibrate and the Cessna 172 shudder.
They then noticed that the rpm had decreased and that the engine’s performance had degraded.
The instructor took the controls and lowered the nose to prevent a stall.
He attempted to land on the intersecting runway at the airport in Lynchburg, Virginia. The plane touched down with about 100 feet of runway remaining.
Realizing that the plane could not be stopped within the remaining runway, the instructor steered the airplane right to avoid a steep drop-off past the runway end. The airplane subsequently hit a ditch and then came to rest in grass in a nose-down position.
The left wing sustained substantial damage.
Post-accident examination of the engine revealed that the No. 2 cylinder exhaust valve was stuck open. Given this evidence, it is likely that the stuck exhaust valve resulted in the partial loss of engine power.
Probable cause: The stuck No. 2 cylinder exhaust valve, which resulted in a partial loss of engine power and a subsequent forced landing and impact with a ditch.
NTSB Identification: ERA19LA019
This October 2018 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Are you saying to disassemble the cylinders every 100 hours to clean valve stems and guides? Gonna be an expensive annual!
I have a couple of thoughts on this;
– the 172S engine has 2,100 hrs on it…close to their required tbo. [ run out ]
– aggressive leaning will just about eliminate lead deposits on the exhaust valve stems.
[ see Mike Busch’s article on lead fouling/ deposits ].
– it seems to me that a 7,100 ft runway has enough room to land after a rejected take off ….if the pilot uses 30 degees flaps. [ the crash pics show ‘0’ flaps. ]
-Then there is the forward slip to lose altitude fast.
– lastly landing straight ahead , there is a long grass run off area on rwy 34.
So, a young, low time cfi and a 4 hr student….sad results.
Serious engine problems over the takeoff runway frequently end in stall/spin accidents, and this one did not. I think the CFI did a fantastic job of saving his student at a critical moment under high stress. I would hire him any day!
During my flight training with a USAF aeroclub, we practiced power loss on take off at 200-300 ft and had no problem landing on the remaining runway which is 6,000 ft.
We learned to do the ‘big push’ to get the nose down and select full flaps.
Of course, the take off has to be at Vx, then Vy, otherwise a casual cruise climb will leave little runway remaining at 300 ft.
I agree with D Brock. It is easy to make judgements without all of the facts while sitting safe and sound at a computer. That’s called armchair quarterbacking. As we all know an armchair quarterback never won a game.
Every body walked away. Those are good stats.
We all have opinions. Some of us are experienced pilots who have done these maneuvers….in an aircraft…no armchair.!
Nothing in the NTSB narrative confirms they used the entire length of runway 4 for the takeoff, so assuming they didn’t, rejected takeoff is off the table. Looking at the layout, from 200 ft it was probably evident that 35 would give them a little more pavement to work with.
As mentioned in the report, the long grass run-off area at the end of 35 is a steep embankment, which the CFI avoided by steering right.
A forward slip from 200 ft isn’t going to save you that much, and it eats valuable seconds having to transition back to coordinated flight. Off the table.
This CFI did everything right. The two walked away from the accident, and the plane was able to be repaired (it’s actually flying as I type this reply). https://flightaware.com/live/flight/N924MM
I own and fly a Cessna 150M. I can assure you I lean more aggressively than anyone you fly with. I had a stuck valve on my O-200 10 miles from my destination last July. There are a million different opinions about what causes valves to stick (use MoGas, don’t use MoGas, use TCP, use MMO, etc), and Mike Busch had a lot of good points. But it sounds like you missed the biggest point of his presentations and articles on the matter. Clean the valve stems and guides every 100 hours or so and you won’t have a stuck valve. This is what every mechanic I’ve ever talked to says on the matter. Additives are snake oil, and so is MoGas, when it comes to stuck valves. I know pilots that tried them all and still got stuck valves 150 hours in. Check and clean the valves every 100 hours. TCM and Lycoming should just put out an AD and be done with it.