Primary finding
Probable cause
The pilot's decision to depart into known adverse weather conditions over mountainous terrain, which required operation near the limits of the airplane's performance capability and which resulted in a loss of airplane control and subsequent ground impact. Contributing to the accident was an improper clearance issued by the air traffic controller and the pilot's acceptance of that clearance. Also contributing to the accident was the extended loss of radar data from the Rock Springs Air Route Surveillance Radar, which caused loss of radar contact and consequent loss of minimum safe altitude warning protection for the flight.
Investigator assessment
Analysis narrative
The owner/pilot and his three sons flew in the single engine, normally aspirated airplane from the Minneapolis, Minnesota, area to Jackson, Wyoming, to attend a family function. The return trip was planned for Sunday, but the pilot canceled that flight due to winter weather conditions. Also due to weather concerns, he booked a Monday return to Minnesota via commercial airline. However, that commercial flight was canceled for non-weather reasons, and the pilot chose to return in his airplane. He contacted flight services twice by telephone to obtain weather briefings and filed a flight plan. Both weather briefings included AIRMETs for mountain obscuration, turbulence, and icing along the planned flight route and altitude. About 2 hours after the second call, the pilot filed a second instrument flight rules (IFR) flight plan by computer, with a proposed departure time 10 minutes after the filing time. About 20 minutes after filing, the pilot was issued a clearance that differed from the one he had requested. The differences included a departure to the south instead of the north, an off-airway segment, and a clearance altitude 5,000 feet higher than originally requested. The assigned altitude was lower than and counter to Federal Aviation Administration (FAA) published requirements for the area in which the pilot was flying, but neither the pilot nor the controller questioned the altitude assignment. The airplane departed 8 minutes after the clearance was issued. About 30 minutes after takeoff, when the airplane was on the off-airway segment, radar coverage from the Rock Springs Air Route Surveillance Radar was lost because the system at the FAA facility that was handling the airplane was intentionally made unavailable to controllers due to data reliability concerns. However, controllers at another FAA facility that was not handling the airplane continued to successfully use that same data. Four minutes later, the pilot filed a report with flight services that he was encountering light turbulence and a trace of rime icing. About 6 minutes later, the airplane was reacquired by ground radar. The controller then asked the pilot to climb to 16,000 feet, the minimum IFR altitude in that sector. Two minutes later, the pilot reported that he might not be able to reach 16,000 feet. About 2 minutes after that, the pilot reported that he was in a "severe mountain wave," and that he was "descending rapidly." There were no further communications from or radar targets associated with the airplane. The wreckage was located 7 days later, at an elevation of about 11,000 feet. Damage patterns were consistent with impact while the airplane was in a left spin. Examination of the engine and airframe did not reveal any preexisting mechanical deficiencies or failures that would have precluded normal operation. The pilot appeared intent on returning home that day and had made alternate travel plans, which were foiled for reasons beyond his control. His repeated checks of the weather and multiple flight plans indicated that he was attempting to take advantage of the continuously changing conditions and depart in his airplane as soon as a short-term window of opportunity arose. This self-imposed time pressure, coupled with his lack of recent IFR experience, likely resulted in his acceptance of the non-conforming clearance. While the pilot was responsible for accepting a clearance that did not comply with minimum instrument altitude requirements, air traffic control (ATC) services were deficient in not ensuring that the clearance complied with FAA requirements. The controller should have been aware of the minimum instrument altitudes in his area of responsibility and ensured compliance with them. The decision of the FAA facility handling the airplane to not utilize certain radar data diminished the performance of the minimum safe altitude warning system by preventing the system from detecting a hazardous situation and depriving the controller of a timely altitude alert, which might have enabled him to better assist the pilot. The airplane took off at or near its maximum certificated gross weight. Although the information was available to him, the pilot was either unaware of or discounted the fact that the clearance route that he was issued and accepted required a minimum altitude near the performance limits of the airplane, and that altitude was significantly higher than the altitude he had requested. The altitudes filed for by the pilot and assigned by ATC were also above the freezing level and in forecast icing conditions. The assigned altitude also required supplemental oxygen for all four persons on board, but the onboard system was only configured for two persons. Meteorological information indicated that IFR conditions, turbulence, and icing were likely present in the vicinity of the descent, and possibly more significant than previously reported by the pilot. It could not be determined whether the airplane was actually in a mountain wave, but the pilot was unable to arrest the airplane’s descent. Those factors, combined with the small difference between the airplane's stall speed and best climb speed, likely resulted in the stall and subsequent spin of the airplane. Although it would not have aided the airplane occupants in this case, if the airplane had been equipped with a 406-MHz emergency locator transmitter, it is likely that the time and resources expended to locate the wreckage would have been significantly reduced. Based on the findings of this accident, the NTSB issued three safety recommendations to the FAA. Safety recommendation A-11-32 asked the FAA to “establish Standard Instrument Departure procedures that provide transition routes and minimum instrument flight rules altitude information for aircraft cleared over commonly used navigational fixes from Jackson Hole Airport and similarly situated airports.” The FAA has established standard instrument departure procedures with minimum altitude information for Jackson Hole Airport and continues to survey other mountainous airports; thus, safety recommendation A-11-32 is classified “Open—Acceptable Response.” Safety recommendation A-11-33 asked the FAA to “modify en route automation modernization software such that en route minimum safe altitude warning alerts are provided for aircraft in coast track status that are receiving automatic position updates.” Safety recommendation A-11-34 asked the FAA to “modify en route automation modernization software such that cautionary warnings are provided to controllers when an aircraft is predicted to enter a minimum instrument flight rules altitude (MIA) polygon below the MIA.” The FAA is researching whether the en route automation modernization software can be modified to address safety recommendations A-11-33 and -34, which are classified “Open—Acceptable Response.”
Source record
Factual narrative
HISTORY OF FLIGHT On the afternoon of November 1, 2010, the wreckage of a Mooney M20J, N201HF, was located by ground searchers in the Wind River mountain range near Lander, Wyoming. The airplane became the subject of a week-long search after it was lost from ground-based radio communications and radar tracking facilities about 45 minutes after it departed from Jackson Hole Airport (JAC), Jackson, Wyoming, on October 25, 2010. The instrument rated owner/pilot and his three sons were fatally injured. The four had flown from the Minneapolis, Minnesota, area to JAC on October 21, 2010, and the accident flight was the first leg of the return trip to Minnesota. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91, on an instrument flight rules (IFR) flight plan. According to information from Lockheed Martin Flight Services (LMFS) and the Federal Aviation Administration (FAA), on the morning of the accident, the pilot obtained his initial telephone weather briefing about 0918 mountain daylight time. About 1037, he telephoned again, obtained an abbreviated weather briefing, and filed an IFR flight plan. Both weather briefings included AIRMETs (Airmen's Meteorological Information) for mountain obscuration, turbulence, and icing along the planned flight routes and altitudes. The 1037 flight plan specified a planned departure time of 1130, and a destination of Rapid City Regional Airport, (RAP) Rapid City, South Dakota. The filed route of flight was Dunoir (DNW) very high frequency omni-range (VOR) navigation facility, Boysen Reservoir (BOY) VOR, Muddy Mountain (DDY) VOR, and then direct to RAP. DNW, the initial navigation fix in that flight plan, was located about 22 miles north of JAC. About 1237, the pilot used the internet to file another IFR flight plan, which again specified JAC as the origination airport. The filed departure time was 1247, and the filed route was DNW, Riverton (RIW) VOR, DDY, Newcastle (ECS) VOR, Rapid City (RAP) VOR, and Philip (PHP) VOR. The destination was Pierre Regional Airport (PIR), Pierre, South Dakota, and the filed altitude was 9,000 feet. About 1258, the JAC air traffic control tower (ATCT) controller issued the pilot his clearance, with some revisions. The altitude was amended to 16,000 feet, and the route of flight was to the KICNE intersection, then direct RIW, and then as filed by the pilot. The controller finished issuing the clearance by asking the pilot if he could accept 16,000 feet, and then informed the pilot that 9,000 feet was an "unavailable IFR altitude." The pilot responded that he would prefer 14,000 feet, and the clearance was then amended to 14,000 feet. KICNE, the initial navigation fix in the ATC-amended flight plan, was located about 26 miles south of JAC. The airplane departed JAC runway 19 about 1306, and was in communication with, and tracked by, FAA air traffic control (ATC) at Salt Lake City Air Route Traffic Control Center (ARTCC). About 1340, the pilot filed a pilot report with LMFS which stated that he was 72 miles west of "Riverton" (the RIW VOR) at 14,000 feet, and that he was encountering "light chop," with a "trace of rime" icing. The first radar target was recorded about 1309, and the airplane was tracked until about 1336, when it was at an altitude of 14,000 feet. The airplane was reacquired by ground radar about 1346, still at 14,000 feet. About 1347, the controller advised that the minimum IFR altitude in that sector was 16,000 feet, and asked if the pilot was climbing to that altitude, to which the pilot responded "..wilco." Two minutes later, the pilot reported that he might not be able to reach 16,000 feet. The controller responded that the minimum instrument altitude in that region was 15,800 feet, and asked the pilot whether he could maintain his own terrain clearance for the next 10 minutes. The pilot responded in the affirmative. About 1351, the pilot reported that he was in a "severe mountain wave" and that he was "descending rapidly out of 13,700" feet. About 1352, the last radar target associated with the airplane was recorded, with an indicated altitude of 13,300 feet. There were no further communications with the airplane. The victims were recovered on November 2, 2010. Due to terrain elevation, topography, and seasonal conditions, the wreckage was recovered on August 24, 2011. PERSONNEL INFORMATION General Information According to FAA records, the pilot held a private pilot certificate with airplane single engine land and instrument airplane ratings. He obtained his private pilot certificate in May 2002, and he obtained his instrument rating in June 2009. Review of his personal flight logs indicated that neither of those flight evaluations, or any of the associated training flights, was conducted in the accident airplane make and model. The pilot became the co-owner of the accident airplane in February 2010, when he had a total flight experience time (TT) of about 760 hours. At the time of the accident, he had a TT of about 940 hours, including about 138 hours in the accident airplane make and model, all of which was in the accident airplane. The remainder of time appeared to be in Cessna 172 and Beech 23 airplanes. Review of his flight logs indicated that the pilot had limited flight experience in mountainous terrain. The three children were all male. Two were 14 years old, and one was 12 years old. Pilot's Instrument Time At the time of the accident, the pilot had logged a total of about 23 hours of actual instrument flight time, and about 22 hours of simulated instrument time. His total logged actual instrument time included about 3 hours in the accident airplane. The pilot's most recent flight review included an instrument proficiency check that was conducted in two flights on 2 days, about 1 week before the accident. The first flight was on October 16, 2010, and the pilot recorded a flight duration of 1.7 hours in his logbook. The second flight, on the following day, had a logged duration of 4.0 hours. Both flights were conducted in the accident airplane. Prior to those flights, the pilot's most recent logged instrument flight was on August 31, 2009, in a Beech 23 airplane. Flight Instructor Comments The certificated flight instructor (CFI) who provided most of the training for the pilot's instrument rating was employed by a company whose primary business was to provide accelerated flight training to pilots located across the United States. The pilot contracted with the company, and the CFI was assigned to provide the flight training to the pilot. Prior to that, neither individual was acquainted with the other. The CFI traveled to the Minneapolis area, provided about 40 total hours of training over a period of 10 continuous days, and provided the pilot with a logbook endorsement to take his instrument rating flight test. The CFI reported that the pilot had obtained some instrument training prior to the CFI's training period with the pilot. The CFI also reported that his training sessions with the pilot were conducted in the pilot's Beech BE-23 Sundowner, a rented Cessna 172, and a ground-based flight training device. Some of the training flights were conducted in actual instrument meteorological conditions (IMC). The CFI noted that the training he provided did include the topic of aeronautical decision-making (ADM). A few weeks prior to the accident, the pilot again contracted with the same flight training company and the same CFI to provide training for his commercial certificate. The CFI again traveled to the Minneapolis area and provided the flight training over the course of 4 days on two consecutive weekends. That training was conducted in the accident airplane, and the CFI provided the pilot with a logbook endorsement to take his commercial flight test. That endorsement was dated October 17, 2010. During the course of that training, the pilot in