CEN18LA299

During the pilot's departure for the local flight, witnesses observed the airplane climbing at a shallower attitude than normal. The airplane appeared to level off and then contacted transmission lines about 1/2 mile from the departure end of the runway, which resulted in substantial damage to the airplane. A postaccident examination of the engine found fouled sparkplugs in cylinder No. 2 and a compression check of all the cylinders revealed that they were all below 60 psi. Cylinder No. 2 was at 18 psi, and the other three cylinders were about 50 psi. An engine manufacturer's service letter stated if the pressure reading is below 60 psi, removal and overhaul of the cylinders should be considered. A weight and balance calculation revealed that the airplane was operating near its maximum gross weight. The circumstances of the accident are consistent with the partial loss of engine power due to low compression in all of the cylinders and fouled sparkplugs in the No. 2 cylinder. The loading of the airplane near its maximum gross weight combined with a reduction in available engine power likely did not allow for the airplane to climb normally.

***This report was modified on September 3, 2020. Please see the docket for this accident to view the original report.*** On July 28, 2018, about 1225 central daylight time, a Piper PA-28-140 airplane, N624FL, was substantially damaged when it was involved in an accident near Columbia, Illinois. The pilot and two passengers were seriously injured, and one passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 as a personal flight. According to information obtained by the responding Federal Aviation Administration (FAA) inspector, the airplane departed runway 3 at Sackman Field (H49) and was en route to Alton, Illinois. Witnesses told the FAA they observed the airplane depart the airport and climb at a shallower than normal attitude. The airplane appeared to level off as it continued away from the airport until it contacted transmission lines about 1/2 mile from the departure end of the runway. The FAA inspectors postaccident examination of the airframe did not find any anomalies which would have precluded normal operation. An examination of the engine conducted by the FAA inspector found fouled sparkplugs in cylinder No. 2 and a compression check of all the cylinders found low compression on each. (The No. 1 cylinder compression was 50 psi, the No. 2 cylinder compression was 19 psi, the No. 3 cylinder compression was 52 psi, and the No. 4 cylinder compression was 50 psi.) A borescope and visual inspection of the No. 2 cylinder did not detect the reason for its low compression. Lycoming Service Instruction 1191A states that "if the pressure reading for all cylinders is equal and above 70 psi; the engine is satisfactory; less then 65 psi indicates wear has occurred and subsequent compression checks should be made at 100 hour intervals to determine rate and amount of wear. If the pressure reading is below 60 psi …, removal and overhaul of the cylinders should be considered." The instruction also states that low pressure in a single cylinder is indicative of air passing by the piston or valve. In addition, the FAA inspector performed a weight and balance calculation with the occupants' weights obtained by first responders and verified by the pilot. The calculation revealed that the airplane was near the airplane's maximum gross weight.