CEN15FA009

The pilot's loss of airplane control due to spatial disorientation while operating in night, instrument meteorological conditions.

The private pilot and two passengers departed in the multiengine airplane from a controlled airport under night, marginal visual flight rules conditions for a personal flight. Radar data showed the airplane climb to about 2,200 ft mean sea level (msl). At this altitude and when the airplane was about 3 nautical miles (nm) from the airport, it began a descending left turn, followed by a right turn, losing about 700 ft of altitude during this time. The airplane then began a climbing left turn. The left turn continued while its radius decreased until the end of the recorded data. During the final left turn, the airplane initially climbed about 400 ft, descended about 400 ft, and then climbed again about 1,300 ft before reaching its peak altitude of 2,800 ft msl. The final recorded radar point was 0.1 nm from the accident site, and the calculated descent rate between the final two radar points was more than 5,000 ft per minute. Postaccident examinations of the airframe, engines, and propellers, revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The airplane's avionics and instruments could not be functionally tested due to the extent of the impact damage. The recorded weather conditions at the destination airport, located about 6 miles from the accident site, at the time of the accident included a broken ceiling at 1,000 ft above ground level (agl), an overcast ceiling at 1,700 ft agl, and visibility of 6 miles with mist. The radar data indicated that the airplane penetrated the cloud layers during the accident flight. The pilot held the appropriate certificates and ratings for operation of the multiengine airplane in instrument conditions, but no clearance had been issued for operation in instrument meteorological conditions. The weather and light conditions at the time of the accident were conducive to the development of spatial disorientation. Further, the flightpath, which was not consistent with the intended course; the airplane's repeated climbs and descents; and the loss of airplane control and high-speed impact were consistent with the known effects of spatial disorientation. Based on this evidence, it is likely that the pilot experienced spatial disorientation after the airplane entered the clouds at night, which led to his failure to maintain airplane control.

At 2228, the pilot contacted MDW controllers to obtain an instrument flight rules (IFR) clearance. The controller was not able to access the flight plan information and requested that the pilot provide him the information by radio transmission. The pilot queried the controller asking if it would be easier to take off under visual flight rules (VFR). The controller informed the pilot that if departing under VFR, he would only need the aircraft type information and the desired direction of flight. The pilot elected to provide the information and received a VFR clearance to depart MDW. Controllers then issued taxi instructions to the pilot. At 2234:35, the pilot contacted the MDW control tower and stated that he was holding short of runway 22L and requested a VFR departure. At 2234:44, the tower controller issued the current wind condition and cleared the airplane for takeoff. Over the next 4 minutes there were several routine communications between the accident pilot and the MDW tower controller. During these communications, the pilot did not inform the controller of any airplane difficulties. At 2240:21, the tower controller attempted to call the accident airplane due to a loss of radar contact but there was no response. Several more attempts were made but no further communications were received from the accident airplane. During communications between the pilot and controllers, no clearance for flight in instrument conditions was authorized. The Midway International Airport, located in Chicago, Illinois, had five runways and an operating control tower. Three of the runways, 31L/13R, 31C/13C, 31R/13L, were oriented in a northwest/southeast direction. The remaining two runways, 4L/22R, 4R/22L, were oriented in a northeast/southwest direction. The accident airplane used runway 22L which was a 6,445 ft long hard surfaced runway. The airport had multiple radio frequencies in use at the time of the accident. During the final portion of the flight, the MDW tower was in communication with the accident airplane. The airport elevation was 620 ft msl. Fueling records indicated that the accident airplane had been serviced with 20 gallons of 100LL aviation gasoline. A sample of fuel from the truck used to service the airplane was obtained and laboratory testing was performed. The results of the testing confirmed that the water content, particulate content and existent gum content were within acceptable limits for 100LL fuel. The boiling range of the fuel indicated that the sample was moderately weathered but not sufficiently to suggest significant contamination. The airplane was equipped with a Honeywell Enhanced Ground Proximity Warning System (EGPWS) that was capable of recording several flight parameters. The unit was recovered from the wreckage and sent to the NTSB Recorders Laboratory for evaluation. Upon evaluation of the unit it was discovered that the electronic chip that was used to store recorded data had received impact damage and no data could be retrieved. An autopsy of the pilot was performed by the Cook County Coroner's Office, Chicago, Illinois, on October 14, 2014. The pilot's death was attributed to injuries received in the accident. Toxicology testing was performed by the FAA Civil Aerospace Medical Institute. Testing results indicated 17 (mg/dL, mg/hg) Ethanol detected in Kidney. All remaining tests were negative for substances in the screening profile. The airplane impacted trees and terrain in a residential area 6 nm southwest of MDW. Several tree branches exhibited clean cuts consistent with propeller impact and engine power production. Some of the cut branches were about 4 inches in diameter. The initial impact point was about 20 ft north of a house on the neighboring lot. The house and a sport utility vehicle parked in the driveway sustained damage from flying debris. The entire airplane was crushed and fragmented. All of the major airframe pieces were contained within the wreckage distribution path that extended to the southeast, across the street and into the front yards of the houses on the opposite side of the street. Most of the wreckage was located at the initial impact point with smaller pieces of debris scattered along the wreckage path. The proximity of the initial impact point with the surrounding trees was consistent with a near vertical impact. The entire fuselage was crushed and almost unrecognizable. The right engine propeller was about 1 ft below ground level and the engine crankshaft had fractured at the propeller hub. The engine was lying on the ground. The left engine was buried in the ground and the propeller was about 2 to 2-1/2 ft below ground level. The propeller was still attached to the engine. A cage for an air operated gyroscopic instrument was found among the wreckage debris. The circular bore of the cage contained rotational scoring that was consistent with operation at the time of impact. The wreckage was recovered and relocated to a storage facility for further examination. A partial layout of the main airframe pieces was accomplished. All of the major airframe parts and flight controls were confirmed to be present during the layout. The main landing gear was retracted in the wheel wells. The vertical stabilizer remained attached to the aft fuselage. The rudder had separated with the mid and upper hinges and the rudder trim tab remained attached to the rudder. The rudder balance weight had separated. The right horizontal stabilizer remained attached to aft fuselage with the right elevator still attached. The right elevator trim tab remained attached and the right elevator balance weight remained partially attached. The right elevator torque arm remained attached with the control rod still attached. The left horizontal stabilizer remained partially attached to the aft fuselage. The outboard horizontal stabilizer had separated. The left elevator had separated and was torn into two main pieces. The left elevator trim tab remained attached and the left elevator balance weight had separated. The left elevator torque arm remained attached with the aft portion of the control rod still attached. The right wing had fragmented in multiple locations and the right flap had separated into two main pieces which remained attached. The right aileron had fragmented and a portion remained attached to the wing. The right wing tip had separated and was impact damaged with the fuel cap still attached. The left wing was impact damaged with the left outer wing and tip separated at mid aileron. The left inboard aileron remained attached with the aileron trim tab still attached. The cockpit exhibited substantial crushing damage. The airplane's flight control cable system was examined and control cable continuity was verified from all control surfaces to the cabin area of the airplane. Due to the amount of damage to the cockpit, verification of yoke and rudder pedal continuity was not possible. All of the identified breaks in the airplane control system were consistent with impact damage or recovery efforts. The left engine was impact damaged with one magneto separated. The propeller hub remained attached and all three propeller blades had separated near the blade roots. One blade tip had separated. The right engine was impact damaged and the right propeller had separated with the propeller flange. One propeller blade separated and was not observed. The on-scene engine examination consisted of removal of cowling and airframe components to enable shipping for further examination at the manufacturer's facility, and a borescope examination of the cylinders. The borescope examination did not reveal any anomalies. Functional testing of the airplane's flight instruments, avionics, and autopilot system was not possible due to the extent of the damage incurred during the impact. During a subsequent examination, the left propeller was disassembled and no evidence of preimpact malfunction or failure w