Investigators searching for the cause of the May 2012 plane crash that killed four people with ties to Oral Roberts University have examined a heater that the sole survivor said created a “terrible smell” when the pilot turned it on.
The heater found in the wreckage of the eight-passenger 1991 twin-engine Cessna, which crashed May 11, 2012, near Chanute, Kan., was examined at Cessna Aircraft Co. under the auspices of the National Transportation Safety Board and the Federal Aviation Administration, an NTSB report says.
The plane had departed from Tulsa's Jones Riverside Airport and was en route to a Christian youth rally in Council Bluffs, Iowa.
Pilot Luke Sheets, 23, of Ephraim, Wis., and Garrett Coble, 29, of Tulsa ; Stephen Luth, 22, of Muscatine, Iowa; and Austin Anderson, 27, of Ringwood died as a result of the crash.
Hannah Luce survived, and the NTSB report says she provided a written statement to investigators that told of the smell the heater created and of the “dark, black smoke” that entered the plane when the heater was turned off, which made it difficult to see.
“In an attempt to extinguish the fire” water was poured into the vents, the report says. The pilot attempted to pull up during an attempted emergency landing, but the tip of one of the wings hit the ground first, according to the report.
Craig Sheets, Luke Sheets' father, has previously said his son made a “heroic effort” to land the plane safely. The elder Sheets, a retired commercial pilot who also served as an Air Force pilot during the Vietnam War, has said he believes that the plane's heater malfunctioned.
During the examination of the heater, thermal damage was noted to the ignition unit and spark plug, the NTSB report says.
The report also says the heater's shroud was removed and the duct limit switch was found to be misaligned.
“Discoloration on the switch surface suggested a misalignment prior to heat discoloring the metal,” the report says.
The document also says the combustion chamber's interior had heavy soot and contained several large carbon deposits and debris.
Also, at least four portions of the combustion chamber displayed signs of leaks,” the report says. “At least three leaks existed on welded joints and one leak around the igniter tip.”
The report also says a telephone interview with a certificated flight instructor revealed that, during a flight on April 25, 2012, the heater's overheat light illuminated shortly after the heater was activated. The heater shut down, and no smoke or fumes were detected by the flight crew, so the flight continued to its destination.
The document also mentions a Feb. 9, 2011, work order that described work done on the heater. “Troubleshoot cabin heater. Found that cause of no fuel to fuel pump was due to no electrical power to fuel safety valve. Found stuck airflow switch, cleaned and heater operated normally,” the work order said.
The report says “no preimpact anomalies were detected” with either of the plane's engines.
The document is labeled as the NTSB's “factual report.” The “probable cause” report has yet to be issued.