WPR13FA244

The pilot's inability to maintain a climb after departure in high-density altitude conditions, which resulted in a collision with trees and terrain. Contributing to the accident were the pilot's decision not to track the four-lane highway just beyond the departure runway, which he could have used as an alternate landing site; his premature rotation of the airplane; and degraded engine performance that affected the airplane's climb ability.

The pilot had purchased the Beechcraft airplane about 18 months before the accident and based it at his home airport, which was located at an elevation of about 80 ft mean sea level (msl). The pilot flew the Beechcraft to an airport that was at an elevation of about 7,100 ft msl. A few days after his arrival, he returned to the airport for his planned departure and spent about 15 minutes asking the fixed base operator owner, who was also a pilot, multiple questions about the route to his next planned destination. According to the owner, he was surprised by the nature of the pilot's questions, his lack of basic aeronautical information knowledge for area restrictions, and his lack of formal planning for his flight. No witnesses reported anything unusual about the engine start or taxi. At the time the pilot was cleared by the air traffic control tower controller for takeoff, the airport density altitude was about 9,000 ft. No ground witnesses reported observing anything unusual with the takeoff, but a Cessna 172 pilot who was behind the Beechcraft reported that the Beechcraft's climbout was slow. Shortly after his own takeoff, about 75 seconds after the Beechcraft, the Cessna pilot asked the tower controller about the Beechcraft's situation and intentions because the Cessna was already well above the Beechcraft. This prompted the controller to ask the Beechcraft pilot if he needed assistance, and the pilot responded that he was climbing "very slowly" and would remain near the airport. Shortly after that, the Cessna pilot saw the Beechcraft impact trees. The accident site was about 3 miles southeast of the airport at an elevation about 300 ft below that of the departure airport. A postimpact fire obscured or destroyed a significant amount of evidence. Review of the Beechcraft's published performance data revealed that, for the given conditions, the airplane should have been able to successfully depart the airport and climb at a rate of about 500 feet per minute. Most of the engine components and all of the propeller components that survived the accident, displayed no evidence of preimpact mechanical deficiencies. The engine cylinder conditions were indicative of a history of generally lean operation. In addition, the No. 5 cylinder exhaust valve's appearance was consistent with excessively lean operation for an undetermined period of time, and the fuel injector nozzle for that cylinder was found to be partially occluded. Excessively lean operation will reduce engine power output, and will manifest itself as abnormally high exhaust and cylinder head temperatures and possible engine roughness. Further, if the No. 5 cylinder's injector was occluded for the flight, it would have resulted in overly lean operation of and reduced power output from that cylinder, yielded higher exhaust and cylinder head temperatures, and likely manifested itself as engine roughness. (Some witnesses close to the impact site reported that the engine was making "popping" noises.) Although the airplane was equipped to monitor, display, and record temperatures for each cylinder, it could not be determined whether the pilot monitored that display, and fire damage prevented the recovery of that data from the engine monitor. Further, there was insufficient evidence to determine the source of the injector's occlusion, quantify its effects on engine power output, determine its relation to the condition of the exhaust valve, or determine if it was present for the takeoff or an artifact of the postimpact fire. Although the engine was developing power at impact, there was insufficient evidence to quantify the actual power output for the climb or at the time of impact. There was also insufficient evidence to determine whether the pilot ensured that the throttle and propeller controls were set to and remained in their appropriate positions for the departure or whether the pilot adjusted the mixture properly (not overly lean). It is likely that the pilot lifted off prematurely at a speed lower than the prescribed value and was unable to accelerate or climb the airplane once it exited the ground effect regime. Because the surrounding terrain and the impact point were lower than the elevation of the airport, the pilot was able to continue to fly the airplane before crashing. This scenario is at least partially corroborated by the pilot's reported lack of preparation for the flight, which could have included a lack of performance planning. This scenario is also partially corroborated by the observed repetitive minor banking of the airplane, which often occurs when an airplane is flying very slowly. A premature liftoff or a climb attempt at a speed significantly below the prescribed value would place the airplane in a situation where the power required for level flight was very near to or exceeded the available power. A recovery would require the pilot to lower the nose in order to accelerate the airplane to obtain a positive rate of climb. Such an action is counterintuitive when low to the ground and requires accurate problem recognition, knowledge of the correct solution, and sufficient terrain clearance to accomplish. During the departure, the pilot reduced his options by deciding to turn to the east instead of continuing straight ahead to the south. Review of topographic data revealed that a four-lane highway was located just beyond the south end of the runway, and was situated in a north-south valley that descended to the south. However, instead of tracking over that highway, which could have been used as an off-airport emergency landing site, and its descending valley, which provided increasing terrain clearance, the pilot opted to turn east, toward higher, wooded terrain. Although that turn was consistent with both a left traffic pattern (in order to remain close to the airport as the pilot reported to the air traffic controller), and toward the pilot's on-course heading, by making that turn, the pilot reduced the likelihood of a partially or fully successful outcome to the flight.

Partial transcripts of the FLG ATCT ground and local communications surrounding the flight and accident were developed and provided by Serco, the company contracted by the FAA to staff and operate the ATCT. At 1125:45, the pilot first radioed the ground controller, and advised that he was "ready to taxi," but did not specify any additional intentions. The controller cleared the airplane to runway 21 via the alpha and alpha one taxiways, which the pilot acknowledged. About 5 minutes later the pilot advised the ground controller that he did not realize that there was no run-up area near the runway 21 threshold, and asked for instructions to prevent a conflict with a twin-Cessna behind him. The controller and other pilot rectified the situation by routing the twin-Cessna via another taxiway. At 1136:21, the pilot of the Cessna 172 N3923Q who later witnessed the accident, contacted the controller for taxi clearance to runway 21. At 1137:20, the Beechcraft pilot first radioed the local controller, and advised that he was "ready for takeoff headed to Tuba City." A few seconds later, the controller cleared the airplane for takeoff, to which the pilot responded "ready for takeoff taking runway two one can you tell me which way for a uh uh downwind departure?" The controller instructed the pilot to make a left downwind, and the pilot acknowledged that communication. At 1139:24, Cessna 172 N3923Q radioed the local controller that he was ready for takeoff from runway 21, requested a left turnout, and was cleared for same a few seconds later. At 1141:44, the Cessna pilot stated that he was making his left turn, and asked the controller whether the Beechcraft was "okay, he is awful low." At 1141:51, the controller asked if the Beechcraft pilot needed any assistance, and the pilot responded "yah...I'm climbing very slowly and uh I'm climbing very slowly and staying close to the airport." At 1142:15, the Cessna pilot radioed that he did not "understand why he didn't stay over the interstate." At 1142:47, the Cessna pilot radioed that the Beechcraft had crashed and was on fire; the pilot circled the impact location for several minutes in an attempt to guide first responders to the site. After the accident, the ground controller and the local controller each provided a written statement regarding the flight and accident. Neither statement explicitly cited whether its author actually witnessed the takeoff or climbout. The local controller's statement reported that he was advised of the Beechcraft climb problem by the subsequently-departing Cessna. FAA information indicated that the pilot's home airport, MCC, was situated at an elevation of 77 feet above mean sea level. FAA information indicated that FLG runway 3/21 measured 8,800 by 150 feet, and the airport elevation was listed as 7,140 feet above mean sea level. The runway was served by a single parallel taxiway ("alpha") with 9 access taxiways between the two. There was no dedicated runup area at either runway threshold. A dedicated runup area was situated on taxiway alpha about midway between the ramp and the runway 21 threshold, and the end of the taxiway could also be utilized for that purpose. The airport was situated in a 2- to 3-mile wide valley that was oriented approximately north-south, with a gentle continuous descent to the south. Calculations using the meteorological conditions at the time of the accident resulted in an airport pressure altitude of 6,983 feet, and a density altitude of 8,983 feet for FLG. Airframe Examination Details About 8 feet of the left wing, and the entire right wing, were fracture-separated from the airplane. The left tip tank did not contain any fuel, and did not display any signatures of hydraulic deformation. The right tip tank was breached, did not contain any fuel, and did not reveal any hydraulic deformation. Significant portions of each wing, including both fuel tank bladders were significantly or completely consumed by fire. Both ailerons remained attached to their respective wings at all mounting hinges, and sustained thermal damage. Aileron cable continuity was established from the right and left control column sprockets to the right and left aileron bellcranks. The aileron trim actuator remained intact and attached to the left wing. The aileron trim actuator extension equated to 2 degrees left tab trailing edge up. The flaps and flap actuators were all found to be in the flaps-retracted position. Although significantly fire-damaged, the speedbrakes appeared to be in the retracted position at impact. The horizontal stabilizers remained attached to the aft fuselage and displayed post-impact fire exposure. The left and right elevators, including their balance weights, remained attached to the horizontal stabilizers at the hinges. Elevator control cable continuity was established from the control column to the elevator bellcrank. The left and right elevator trim surfaces remained attached to their respective elevators at their hinges. The elevator trim actuator extensions equated to approximately 6 degrees tab trailing edge down. Elevator trim cable continuity was confirmed from its cockpit control wheel to the actuators in the empennage. The vertical stabilizer was fracture-separated from the aft fuselage at its spar roots. A portion of the rudder torque tube, the rudder bellcrank, and fragments of the rudder remained attached to the aft fuselage. The remainder of the fracture-separated rudder, including the rudder balance weight, was found near the aft fuselage. Continuity determination of the rudder control system was limited due to fire damage. No pre-impact anomalies such as corrosion, wear, or misrouting, were observed on the primary or secondary flight control cables, but thermal and impact damage precluded a complete determination of the cables' pre-accident condition. All cable damage was attributed to impact overload and/or thermal exposure. Both main landing gear assemblies were found in their retracted positions. The nose landing gear appeared to be in a near-retracted position. Engine and Fuel System Examination Details The engine came to rest upright, leaning towards its left side. The throttle, propeller, and mixture control cables remained attached to the throttle quadrant and their respective engine components. The two magnetos were found properly secured to their mounting pads on the engine. Magneto-to-engine timing testing determined that both magnetos were timed to within 1 degree of the manufacturer's setting, and within 1 degree of each other. Due to the thermal damage the magnetos were shipped to Continental Motors. Examination of the magnetos did not reveal any pre-impact anomalies. After the thermally-damaged capacitor in each magneto was replaced, the right magneto functioned normally, but the left magneto only operated intermittently. That failure was attributed to additional internal thermal damage to the magneto. The ignition leads remained attached to the magnetos and spark plugs, but sustained significant thermal damage. All spark plugs were removed, and displayed a "normal worn" condition. However, the top and bottom spark plugs from the number 5 cylinder bore very light soot, and the number 5 top plug also held a globule of solidified lead down in its barrel, at the base of the insulator. There was no evidence of lead fouling on any of the other spark plugs. Oil on the number 2 bottom, number 4 bottom, and number 6 top and bottom spark plug electrodes was attributed to the engine orientation after it came to rest. With the exception of the top spark plug from the number 6 cylinder, which had a cracked insulator, all spark plugs produced sparks during bench testing. Once the spark plugs were removed, the crankshaft was rotated manually. Thumb compressions were obtained on all six cylinders, which confirmed crankshaft, camshaft, connecting rod, and rocker arm continuity. With th