When Cylinders Fail

Believe it or not, the cylinders in aircraft engines have been known to fail. While this doesn’t happen every day (thank goodness!) it certainly can’t hurt to know what you need to do, or to understand the telltale signs that will tell you your cylinder may not be a “cylinder” anymore.

When an aircraft cylinder fails, it can fail in several ways. A valve can jam, and get beat to a pulp by the piston. The top of the cylinder can separate from the barrel, and cause a loss of compression and a loss of oil from the engine. On rare occasions, a connecting rod can break, causing a loss of power.

The signs that a cylinder may have failed are fairly easy to spot…

  • The event usually starts with a loud BANG.
  • This is followed by a sudden loss of power, along with a rough running engine;
  • Oil starting to stream from under the cowling and usually becomes plentiful on your windscreen or windows;
  • Oil pressure begins to drop off;
  • Aircraft with engine monitors, will reflect the problem with CHT and EGT readings that can get pretty wacky, but generally don’t look anywhere near normal;
  • At night, you may see a shower of glowing sparks from the cylinder.

You are not going to be flying much longer — look for a place to land. With the cylinder failed, the engine is breached and you don’t know how long the oil will remain in the engine. Because of that, you don’t know how long the engine will continue to run. With that said, one thing is certain: the engine won’t be running long, so start heading toward the nearest airport, or if your altitude is low, the nearest acceptable flat spot — acceptable is of course relative to need. As dictated by your emergency procedures, get to your best glide speed to optimize the distance as you can glide. (There are sometimes other airspeeds that will come in handy.

This is one. Declaring an emergency will get you assistance from ATC, and will frequently help you to find the airport nearest to your position. Once you have that airport, head toward it both LAND and shut down the engine AS SOON AS POSSIBLE.

IT CAN’T HAPPEN TO ME… Cylinders DO fail, and they don’t care what you think … or how well you take care of your engine. When problems like this strike, the only way to survive is to keep a cool head, follow your emergency procedures, get help and land. If you know in advance what actions to take, you will be better able to cope with the problems that an aircraft can throw at you. At 7,000 feet and 180 miles per hour, when this type of problem often happens to strike, understanding is half the battle. The rest is getting down safely.