History of Flight
On December 12, 2009, at about 2355 central standard time, a twin-engine Cessna 310R airplane, N310CR, was substantially damaged when it collided with terrain while executing an instrument approach to the Alva Regional Airport (AVK), Alva, Oklahoma. The commercial rated pilot, sole occupant, was fatally injured. The airplane was registered to and operated by the pilot. An instrument flight rules (IFR) flight plan was filed for the flight that originated from Sundance Airpark (SHD), Oklahoma City, Oklahoma. Night instrument meteorological conditions prevailed for the personal cross-country flight conducted under 14 Code of Federal Regulations Part 91. There were no reported witnesses to the accident; however, family members were reportedly waiting for his arrival and heard the airplane as it approached the airport.
Personnel Information
The pilot, age 44, held a commercial certificate for airplane single and multi-engine land, and instrument rating-airplane. He also held a flight instructor certificate for airplane single and multi-engine airplane, and instrument-airplane. The pilot's most recent application for a second-class Airman Medical Certificate, dated May 1, 2009, indicated "No" in response to "Do You Currently Use Any Medication" and to all items under "Medical History." At the time of his medical application, the pilot reported a total flight time of 4,295 hours with 25 hours in the previous 6 months.
Aircraft Information
The airplane was a 1976 model Cessna 310R, a twin-engine, low-wing, all-metal airplane with retractable tricycle landing gear. The last annual inspection was performed August 23, 2009, at hour meter reading of 1,317 hours. The time accrued on the airplane since the last annual inspection was approximately 33.1 hours. The airframe had accumulated about 2,518 total flight hours. The airplane was powered by two Continental IO-520-M reciprocating engines, each rated at 285 horsepower. Both engines had accumulated about 603 hours since their last major overhaul. The engines were driving McCauley full-feathering, three-bladed propellers, each having accrued about 288 hours since overhaul.
Weather Conditions
Prior to departing SHD, the pilot telephoned the Flight Service Station (FSS) to file his IFR flight plan and obtain a weather briefing. The briefer did not have a weather report for AVK; the pilot told the briefer that he was based at AVK and familiar with the NOTAMs and that the weather station was temporarily down due to runway construction. The automated weather reporting station at Enid, Oklahoma, located approximately 45 nautical miles southeast, was used for the weather brief. The briefer reported that the weather station at Enid was reporting a 600-foot ceiling, seven miles visibility, with winds at 170 degrees at 11 knots, and temperature and dew point both seven. The pilot expressed concern about fog but thought the spread was sufficient. People near the accident site reported that the weather in the area at the time of the accident was foggy. About 30 minutes after the accident notification, first responders had difficulty locating the crash site due to poor visibility.
Communications
The Federal Aviation Administration (FAA) provided a transcript of air traffic control communications with the accident flight. During the flight, the pilot contacted Kansas City Air Route Traffic Control Center (ARTCC). As the pilot approached the airport, he contacted ARTCC and said he was established inbound on the approach. The controller acknowledged and instructed him to report canceling IFR. The pilot responded that he would try to cancel on frequency or on the ground, mentioning a "pretty good layer of ground fog." About four minutes later, the pilot radioed that he was clear on top and was going to circle back to try again. The controller asked if he was going to try the GPS again. The pilot said he would try one more time but noted heavy ground fog. The controller provided weather conditions at Gage and Enid. The pilot acknowledged and said it was clear until within about 10 miles of Alva. Later, the pilot reported inbound on the GPS three-five approach. The controller instructed him to change to advisory frequency and terminate radar services. No further communications or emergency calls were received.
Radar Information
A review of the airplane's radar track showed the airplane approaching the airport's initial approach fix, HINEN, from the southeast at an altitude of 3,300 feet. About two minutes later, the track showed the airplane near the final approach fix, CADAP, at the same altitude. About two and a half minutes after CADAP, radar had the airplane over the airport at 1,700 feet. The radar then tracked the airplane climbing away from the airport in an arc west of the airport. The aircraft continued the arc and approached HINEN the second time from the southwest at about 3,400 feet. The second approach continued inbound, passing CADAP at 2,500 feet. About two minutes later, with the airplane tracking straight to the airport, radar reported the airplane at an altitude of 1,600 feet. The last radar hit about 12 seconds later had the airplane at 1,500 feet.
Airport Information
Alva Regional Airport (AVK) is a public-use airport located about two miles south of Alva, Oklahoma. The airport is non-towered, and pilots were to use the Common Traffic Advisory Frequency (CTAF). The airport features a single asphalt runway: runway 17-35, 4,386 feet long and 75 feet wide. The field elevation is 1,474 feet mean sea level (msl). The instrument approach the pilot was following was the RNAV (GPS) Runway 35. The published minimums for this approach are a 400-foot ceiling, one-mile visibility, and a minimum descent altitude of 1,840 feet. A note on the approach chart states that if the local altimeter setting is not received, use Enid altimeter setting and increase all MDAs by 140 feet.
Wreckage and Impact Information
The airplane wreckage was examined at the site on December 13–14, 2009. All major components were accounted for. The airplane came to rest in an upright position on a heading of approximately 114 degrees, about three-quarters of a mile south of runway 35. The pasture was open, relatively flat, with low cut vegetation. The first impact point was a shallow crater containing several pieces of wreckage, including the left main gear door, the nose gear door, and an antenna. On both sides of the initial impact point, several slash marks consistent with propeller cuts were found in the ground. A second impact point similar to the first was found from the initial impact point to the aircraft wreckage. Along the wreckage path, an engine cowling, wing tip main fuel tank, pitot tube, and various other pieces were located. The wreckage path was consistent with the airplane impacting the ground at a shallow angle and either skipping or sliding along the ground before coming to a stop. The airplane was largely intact, sitting on its belly. The landing gear was in the retracted (up) position; both the gear handle switch and flap switch were found in the up positions. The on-site examination of the airframe failed to identify any pre-impact malfunctions. The aircraft wreckage was retrieved to a salvage yard, where the NTSB and a technical representative from Teledyne Continental Motors examined the engines. The examination did not reveal any pre-impact mechanical anomalies with either engine or their components.
Medical and Pathological Information
The Board of Medicolegal Investigations, Office of the Chief Medical Examiner, Oklahoma City, Oklahoma, conducted an autopsy on the pilot on December 14, 2009. The cause of death was determined to be massive head trauma, blunt force. The FAA Toxicology Accident Research Laboratory conducted toxicological testing. The pilot tested positive for acetaminophen, bupropion, cyclobenzaprine, dihydrocodeine, duloxetine, gabapentin, hydrocodone, hydromorphone, naproxen, and propranolol. Personal medical records obtained on the pilot noted a lifelong history of migraine headaches, indicated in 2006 to be present "on average greater than 4 hours per day" and occurring "on average 6 out of 7 days per week … for 4 months." The records documented treatment of the headaches with various medications, including propranolol, gabapentin, ibuprofen, naproxen, hydrocodone, injected ketorolac, and injected promethazine; treatment of muscle spasm with cyclobenzaprine; treatment of allergy symptoms with injected methylprednisolone; and use of bupropion for smoking cessation. The records included notes from a neurologist and two primary care physicians, including prescriptions for hydrocodone and injections of ketorolac.
Test and Research
A damaged portable GPS unit (Garmin model 696) was located among the wreckage and sent to the NTSB's Vehicle Recorder Division Laboratory. The unit had sustained major damage from impact forces. The lab was able to obtain data from the unit, which contained 42 unique tracklogs dated from September 25, 2009, to December 12, 2010. Downloaded tracklog data included parameters such as index, GPS date/time, GPS altitude, distance from previous update, time since last update, average groundspeed, average course, and latitude/longitude position. Tracklog data recovered for December 12, 2010, was stored in Session 52. Data began at 1056:22 CST with a position fix corresponding to Sundance Airpark (KHSD). The final GPS position location fix was recorded at 1158:00 CDT and placed the aircraft at N36° 45.007', W098° 40.273' with 1,539 feet GPS altitude. The last calculated velocity and direction of travel was 125 mph groundspeed with a course of 355° true. This tracklog ends just south of Alva Regional Airport.