CEN14FA300

The pilot's improper decision to enter an area of known adverse weather, which resulted in the loss of airplane control. Contributing to the accident was the air traffic controller's failure to provide critical weather information to the pilot to help him avoid the storm, as required by Federal Aviation Administration directives.

The private pilot was conducting a personal flight during day, instrument flight rules (IFR) conditions. The pilot checked in with an air route traffic control center, and, after radar data showed multiple changes in altitude that were not in accordance with the assigned altitudes, an air traffic controller queried the pilot about the altitude changes. The pilot reported an autopilot problem and then later requested clearance to deviate around weather at a higher altitude. The airplane passed through several sectors and controllers, and it was understood that the pilot was aware of the adverse weather due to the deviation information in the flight strip. The air traffic controller did not provide additional adverse weather information and updates to the pilot, as required by a Federal Aviation Administration order; however, general broadcasts of this weather information were recorded on the frequency the pilot was using before the accident. Multiple weather resources showed rapidly developing multicellular to supercell-type convective activity with cloud tops near 48,000 ft. Forecasts and advisories warned of potential strong to severe thunderstorms with the potential for moderate-to-severe turbulence, hail, lightning, heavy rains, and high wind. Radar data indicated that the pilot turned into the intense weather cells instead of away from them as he had requested. The pilot declared a "mayday" and reported that he had lost visual reference and was in a spin. Damage to the airplane and witness marks on the ground were consistent with the airplane impacting in a level attitude and a flat spin. No mechanical anomalies were noted that would have precluded normal operation before the loss of control and impact with the ground. The investigation could not determine if there was an anomaly with the autopilot or if the rapidly developing thunderstorms and associated weather created a perception of an autopilot problem. The autopsy identified coronary artery disease. Although the coronary artery disease could have led to an acute coronary syndrome with symptoms such as chest pain, shortness of breath, palpitations, or fainting, it was unlikely to have impaired the pilot's judgment following a preflight weather briefing or while decision-making en route. Thus, there is no evidence that a medical condition contributed to the accident. The toxicology testing of the pilot identified zolpidem in the pilot's blood and tetrahydrocannabinol and its metabolite in the pilot's cavity blood, which indicated that he was using two potentially impairing substances in the days to hours before the accident. It is unlikely that the pilot's use of zolpidem contributed to the accident; however, the investigation could not determine whether the pilot's use of marijuana contributed to the cause of the accident.

N2428Q received ATC handling by ASE ATCT, ASE approach, two radar controllers at ZDV, three radar controllers at ZAB; R16, R15, and R87, and two radar controllers at ZFW sector R93. N2428Q reported an equipment issue, and also exhibited numerous altitude deviations and a course deviation. No information regarding the equipment issues or the multiple altitude and course deviations was passed between controllers during the transfer of radar identification. Federal Aviation Administration Order (FAAO) 7110.65, Air Traffic Control, paragraph 5-4-3b4, Transfer of Radar Identification, Methods, states in part: Advise the receiving controller of pertinent information not contained in the data block or available flight data unless covered in an LOA or facility directive. Pertinent information may include: (a) Assigned heading. (b) Speed/altitude restrictions. (c) Observed track or deviation from the last route clearance. (d) Any other pertinent information. During the period leading up to the accident, moderate, severe, and extreme levels of precipitation were present and indicated on the controller's radar presentation. As a result of the weather conditions, numerous aircraft, including the accident aircraft, were requesting deviations from their filed flight plan routes to avoid the weather. The tops of the weather cells were being reported at 41,000 to 43,000 feet. FAAO 7110.65, Air Traffic Control, paragraph 2-6-4a, Weather and Chaff Services, requires that air traffic controllers issue pertinent information on weather and chaff areas by defining the area of coverage in terms of azimuth (by referring to the 12-hour clock) and distance from the aircraft or by indicating the general width of the area and the area of coverage in terms of fixes or direction from fixes. Paragraph 2-6-4g states in part that when requested by the pilot, provide radar navigational guidance and/or approve deviations around weather or chaff areas. Paragraph 2-6-4g states: When requested by the pilot, provide radar navigational guidance and/or approve deviations around weather or chaff areas. In areas of significant weather, plan ahead and be prepared to suggest, upon pilot request, the use of alternative routes/altitudes. 1. An approval for lateral deviation authorizes the pilot to maneuver left or right within the limits of the lateral deviation area. In the radar data block of N2428Q, "DR" indicates that the aircraft is authorized to deviate to the right of the filed route of flight. Automated information transfer (AIT) procedures utilizing en route fourth line data block free text are to be used within and between en route ATC facilities as defined in a facility AIT directive and letter of agreement. At 1615, the ZAB R87 controller initiated a transfer of control to the ZFW R93 controller. At 1617 N2428Q checked in with the ZFW R93 controller at FL260 climbing to FL270 and advised the controller that he was in a turn for weather avoidance. The controller did not provide information on weather in the area because block 4 of the radar data block indicated "DR" for deviating right for weather. The controller stated that since N2428Q was already deviating, he did not issue weather to the aircraft because he thought the pilot was "obviously" aware of it. At 1625, a position relief briefing began at the ZFW R93 position. The position relief briefing took four minutes to accomplish. During the position relief briefing, the controller being relieved was busy with multiple intra-facility coordination requirements, responding to numerous requests for deviation and numerous aircraft transfer of control actions/handoff to adjacent sectors. ZFW sector 93 did not have a radar associate coordinator position staffed. There were no radio transmissions or coordination recorded at the ZFW R93 position for the next 50 seconds. No weather information was provided to N2428Q or any other airplane during this time. At 1630 the oncoming ZFW R93 controller asked N2428Q if the pilot "was going to go north of that weather there." The pilot responded that he was trying to "go through a window." Fifty seconds later, noting that N2428Q was climbing above his assigned altitude of FL270, the R93 controller asked the pilot 3 times if he needed a higher altitude. The pilot did not respond. The controller who had previously been on at the ZFW R93 position remained in the area after being relieved and, noting the flight deviation of N2428Q, opened the D93 position to assist the R93 controller. At this time the controller-in charge (CIC) was also monitoring the developing situation from an adjacent control position At 1632, the R93 controller advised N2428Q that he was in the middle of moderate to extreme precipitation and once again asked the pilot if he needed a different altitude. The pilot did not respond. After observing N2428Q climb and then begin to descend, the R93 controller coordinated with the Lubbock low sector controller, sitting next to her, as N2428Q was about to depart her airspace and enter the airspace of the Lubbock low sector. While she was coordinating with the Lubbock sector controller, a single "MAYDAY" transmission was made. Although the MAYDAY transmission was recorded on the frequency, the controller stated that she did not hear the MAYDAY transmission. Immediately after the pilot transmitted MAYDAY, the controller asked N2428Q to say altitude. A pilot responded "nineteen." According to the FAA Official Guide to Basic Flight Information and ATC Procedures; the Aeronautical Information Manual (AIM), chapter 6, Emergency Procedures, Section 3; Emergency and Distress Procedures, paragraph 6-3-1; Distress and Urgency Communications, states: a. A pilot who encounters a distress or urgency condition can obtain assistance simply by contacting the air traffic facility or other agency in whose area of responsibility the aircraft is operating, stating the nature of the difficulty, pilot's intentions and assistance desired. Distress and urgency communications procedures are prescribed by the International Civil Aviation Organization (ICAO), however, and have decided advantages over the informal procedure described above. b. Distress and urgency communications procedures discussed in the following paragraphs relate to the use of air ground voice communications. c. The initial communication, and if considered necessary, any subsequent transmissions by an aircraft in distress should begin with the signal MAYDAY, preferably repeated three times. The signal PAN-PAN should be used in the same manner for an urgency condition. d. Distress communications have absolute priority over all other communications, and the word MAYDAY commands radio silence on the frequency in use. Urgency communications have priority over all other communications except distress, and the word PAN-PAN warns other stations not to interfere with urgency transmissions. The AIM, chapter 6, Emergency Procedures, Section 3; Emergency and Distress Procedures, paragraph 6-3-2; Obtaining Emergency Assistance, paragraph a3a states in part: Transmit a distress or urgency message consisting of as many as necessary of the following elements, preferably in the order listed: If distress, MAYDAY, MAYDAY, MAYDAY; if urgency, PAN-PAN, PAN-PAN, PAN-PAN. FAAO 7110.65, Air Traffic Control and the AIM pilot controller glossary define MAYDAY as the international radiotelephony distress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is requested. Twenty three seconds after N2428Q responded to the altitude query, a pilot on the frequency asked if the controller had heard the MAYDAY call followed by a transmission by AAL1536 stating that he believed he heard a MAYDAY call as well. After several unsuccessful attempts by the R93 controller to contact N2428Q and a request to Alaska Airlines flight 670 to attempt to contact N2428Q, the pilot o