N411JTAero Commander 500 S · 1971

On June 24, 2008, at 1020 central daylight time, an Aero Commander 500S, N411JT, registered to Central Airlines and operated by Central Air Southwest, Kansas City, Missouri, was destroyed when the it impacted terrain following a loss of power on both engines while maneuvering near Linwood, Kansas. Visual meteorological conditions prevailed at the time of the accident. The training flight was being conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The two commercial pilots on board the airplane, the company's chief pilot/director of operations and a pilot receiving a flight check, were fatally injured. The local flight originated at 0927 from Charles B. Wheeler Downtown Airport (MKC), Kansas City, Missouri.

The Kansas Highway Patrol and the Leavenworth County Sheriff's Office interviewed all known witnesses and collected their written statements. One witness saw "an eastbound twin engine high-wing [air]plane at low altitude that was extremely loud and flying very slowly" and "appeared to be flying level." The airplane "seemed to be throttled up, but was moving very slowly."

Three surveyors were working at Cantrell Road (County Road 1) at its intersection with 222nd Street. One of the surveyors was sitting in his truck and heard an airplane overhead. He wrote: "Engine was not running smoothly. Heard sputtering loudly, then silence...plane hit ground, what appeared to be nose first, and rest of plane crumbled to the ground until only the tail was visible in the field." He called 9-1-1. Emergency services and his cellular telephone recorded the call at 1022. Later interviewed at the accident site, the witness estimated three to four seconds elapsed from the time he heard the engines sputter to the time the airplane hit the ground.

The second surveyor saw the airplane "coming over the trees from the west. The plane's motor started cutting out and dying. While the plane was heading northeast, [it] was decreasing elevation and speed."

The pilot-in-command, age 47, was employed by Central Airlines on March 20, 1987, was promoted to chief pilot on November 1, 1987, and became the director of operations on March 1, 1988. He held a commercial pilot certificate with airplane single/multiengine and instrument ratings. He also held a flight instructor certificate with airplane single/multiengine and instrument ratings. His first class airman medical certificate, dated May 1, 2008, contained the restriction, "Must wear corrective lenses for distant vision." According to Central Airlines, he had accumulated 10,500 total flight hours, of which 9,400 hours were in multiengine airplanes and 7,550 hours were in the Aero Commander. He had also logged 3,000 hours as a flight instructor, all of which were in multiengine airplanes, and 2,800 hours were in the Aero Commander. His last proficiency check was accomplished on February 13, 2008, in the Aero Commander 500S, and his last 24-month check airman observation was August 15, 2007.

The pilot-in-training, age 24, had been employed by the company for approximately two weeks. He was in the process of receiving his FAA Part 135 standardization ride when the accident occurred. He held a commercial pilot certificate with airplane single/multiengine and instrument ratings. He also held a flight instructor certificate with airplane single and multiengine ratings. His first class airman medical certificate, dated January 16, 2008, contained the restriction, "Must wear corrective lenses." According to Central Airlines, he had accumulated 1,200 total flight hours, of which 224 hours were in multiengine airplanes and 7 hours were in the Aero Commander. He had also logged 711 hours as a flight instructor.

N411JT (s.n. 3097), a model 500S, was manufactured by the Aero Commander Corporation in 1971. It was powered by two Lycoming IO-540-E1A5 engines (s.n. L-3633-48, left; L-801-48, right), each rated at 290 horsepower, driving Hartzell HC-C3YR-2UF three-blade, all-metal, full-feathering, constant speed propellers (s.n. CK5110B, left; CK5109B, right).

According to the Central Airlines, as of June 20, 2008, the airframe had accrued 12,426.6 total hours. The left engine was overhauled on June 14, 2005. It had accrued 12,671.6 total hours and 1,055.2 hours since major overhaul. The right engine was overhauled on November 5, 2007. It had accrued 11,010.1 total hours and 122.4 hours since major overhaul. New propellers were installed on the airplane on May 5, 2006. Both propellers had accrued 480.3 hours since being installed.

The following METARs (Aviation Routine Weather Report) were recorded at Lawrence, Kansas, Municipal Airport (LWC) at 1034, 1049, and 1052, respectively:

LWS 241034: Wind, 080 degrees at 6 knots; visibility, 9 statute miles; ceiling, 2,100 feet broken; temperature, 25 degrees C.; dew point, 20 degrees C.; altimeter setting, 30.08 inches of Mercury.

LWS 241049: Wind, 100 at 7 knots; visibility, 9 statute miles; ceiling, 2,100 feet broken; temperature, 25 degrees C.; dew point, 20 degrees C.; altimeter setting, 30.08 inches or Mercury; remarks: lightning distant north, thunderstorm began 28 minutes past the hour, ended 43 minutes past the hour.

LWC 241052: Wind, 090 at 6 knots; visibility, 9 statute miles; ceiling, 2,100 feet broken, 2,800 feet overcast; temperature, 25 degrees C.; dew point, 20 degrees C.; altimeter setting, 30.08 inches of Mercury; remarks: lightning distant north and northeast, thunderstorm began 28 minutes past the hour, ended 43 minutes past the hour, sea level pressure 1017.9 millibars.

Downloaded GPS (Global Positioning System) data indicates the airplane took off and flew to Topeka, Kansas. It made an approach to runway 31, did a procedure turn, and made another approach to runway 13. The airplane then flew to Lawrence, Kansas, where it made a touch-and-go landing. No one at the airport recalled seeing the airplane make the touch-and-go landing. Up to this point, most of the flight had been conducted between 2,000 and 4,000 feet. The airplane flew eastbound to a practice area in Leavenworth County. It made a 360-degree (short radius) turn to the left, followed by a 360-degree (longer radius) turn to the right.

The airplane continued flying eastbound, but its altitude and airspeed began to decrease steadily (the ceiling at Lawrence was between 2,100 feet broken and 2,600 feet overcast). Between 1133:27 and 1136:58 GPS time, the airplane was flying at less than 1,000 feet. Data recording stopped shortly thereafter when the airplane entered a steep descent from a height of 742 feet.

The on-scene investigation was conducted on June 25 and 26.

There was no lateral ground scar preceding the impact point. Impact with the ground was measured at 53 degrees nose down. There was no evidence of a rebound. The nose was aligned on a magnetic heading of 068 degrees. There was a circumferential break in the fuselage aft of the wings, and the tail was aligned on a magnetic heading of 115 degrees.

The landing gear turnbuckle was extended and the cockpit control handle was in the DOWN position. By jackscrew measurement, the flaps were in the APPROACH setting, or one-quarter DOWN. Both mixture and propeller control handles were full forward. Both throttles were mid-range. The needle on one airspeed indicator was jammed between 85 and 90 mph.

The overhead switch panel was torn away from the cockpit and was located 15 feet in front of the airplane. Examination of the overhead switch panel revealed the left fuel shutoff valve was in the CLOSED position; the right fuel shutoff valve was destroyed. Immediately adjacent to the fuel shutoff valves are the fuel boost pump and the magneto switches. The left boost pump switch was in the ON position; the right boost pump switch was destroyed (see Aero Commander 500S Maintenance Manual, p. 10-2).

Using a crane, the wreckage was lifted up and the fuel valves, located in the fuel sump which is mounted in the baggage compartment, were examined. Both valves were in the OPEN position. The fuel tanks had been breached and there was no fuel in the tanks. Fuel blight was beginning to appear on the ground and surrounding vegetation. Both engines had folded underneath the wings and were inverted. Both engine fuel supply lines were opened. Only residual fuel was noted. Both engine fuel distributor manifolds were opened. Less than a tablespoon of fuel was seen. Both propellers exhibited little rotational signatures.

Autopsies on both pilots were performed at the University of Kansas Medical Center in Kansas City, Kansas. According to these reports, both pilots "died of multiple blunt force injuries." The manner of death was listed as "accident."

Toxicological screens were performed by both the University of Kansas Medical Center and FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. No drugs or ethanol were detected in the pilot-in-training. No drugs were detected in the pilot-in-command. Ethanol (11 mg/dL, mg/hg) was detected in muscle tissue.

The wreckage was removed to the facilities of Dodson International, a salvage recovery firm, in Rantoul, Kansas, where it was further examined on June 26 and 27. Both engines and propeller assemblies were disassembled and examined. No anomalies were noted. Both propellers were in the low pitch-high rpm setting.

The boost pumps tested satisfactorily. Both fuel shutoff valves were in the OPEN position. When battery power was applied, both fuel shutoff valves open and closed in less than one second. No anomalies were noted.

Along with several other FAA inspectors, the principal operations inspector for Central Airlines participated in the on-scene investigation. He said that in recent years, he had given the chief pilot his check rides and was familiar with his mannerisms. He said that when the chief pilot gave a competency/proficiency check to a newly-hired pilot, he always followed certain routine. According to the Aero Commander 500S Flight Manual (p. 1-3 and 2-7), the boost pumps are normally off. During certain "limited aerobatic maneuvers," including steep turns, the boost pumps are turned on by company practice. After performing steep 360-degree turns to the left and right, the boost pumps would be turned off and the chief pilot would ask the trainee to configure the airplane for landing (i.e. gear down, approach flaps). He would then ask the trainee to demonstrate minimum control airspeed maneuvers. Immediately adjacent to the fuel boost pump switches are the fuel shutoff valves (see p. 10-2, Aero Commander 500S Maintenance Manual).

The party representing Central Airlines said that the company's president experienced a similar event, but it only involved one engine. While in cruise flight, he inadvertently turned off the fuel shutoff valve instead of the boost pump. The engine lost power shortly thereafter. Realizing his mistake, he immediately switched it back on and after a short period of time, the engine resumed producing power. The principal operations inspector said that one one occasion, he purposely shut down an engine by closing the fuel shutoff valve. He said it took about 10 seconds for the engine to lose power and about 15 seconds for it to resume operation. He also said that if the airplane was inadvertently stalled, a minimum of 250 feet was required to recover.

Central Airlines is an all-cargo, on-demand air carrier operating on unpublished schedules. Before the accident, its fleet consisted of 36 Aero Commanders, including 34 B models, one U model, and one S models. It also has a Rockwell International 690A Commander.