WPR12GA243

The flight crew's misjudgment of terrain clearance while maneuvering for an aerial application run, which resulted in controlled flight into terrain. Contributing to the accident was the flight crew's failure to follow the lead airplane's track and to effectively compensate for the tailwind condition while maneuvering.

Tanker 11 departed the tanker base to conduct its second fire retardant drop of the day in the same location. Upon arriving in the fire traffic area, Tanker 11 followed the lead airplane into the drop zone, which was located in a shallow valley 0.4 mile wide and 350 feet deep. The lead airplane flew a shallow right turn onto final and then dropped to an altitude of 150 feet above the valley floor while approaching the intended drop zone. While making the right turn onto final behind the lead airplane, Tanker 11's right wing tip collided with terrain, which resulted in a rapid right yaw and subsequent impact with terrain. The wreckage created a 1,088-foot-long debris field, and a postimpact fire ensued. Two witnesses took photographs of the accident sequence photos, and an examination of these photographs showed that the lead airplane was positioned ahead of the tanker throughout the flight; however, the orientation of the lead airplane compared to the orientation of Tanker 11 indicated that Tanker 11 did not directly follow the lead airplane's path to the final drop course. Rather, it was about 700 feet left of the lead airplane's path and made a wider right turn as it attempted to align with the final drop course. The accident flight crewmembers had previously flown nearly the same exact drop and the lead pilot cautioned them about tailwind conditions during the flight; however, the wider turn suggests that they did not properly compensate for the wind conditions while maneuvering. In addition, the previous flight was conducted at an altitude above the ridgeline. GPS evidence indicates that the accident flight was conducted below the ridgeline, which would have made it more difficult to detect the rising terrain during the wider turn. A review of the airplane's cockpit voice recorder audio information revealed that the flight crew did not recognize or attempt to correct the reduced clearance between Tanker 11 and the rising terrain until about 2 seconds before impact.

Appareo GAU2000 The Appareo GAU2000 recorder is a lightweight, self-contained attitude, air-data and GPS recording system. The small recorder has an internal GPS unit that provides latitude and longitude position, and GPS altitude and GPS track. The unit also has air data inputs, that when attached to the aircraft's pitot static system, provides indicated airspeed and pressure altitude of the aircraft. The unit also has a mini attitude reference (AHARS) unit that senses 3-axis accelerations and records sufficient information to derive aircraft pitch, roll, and yaw. The memory module that was recovered at the accident scene was sent to the NTSB Vehicle Recorder Laboratory, Washington, DC. The memory chip from the accident unit was removed from what was left of the circuit card. The chip was cleaned and placed in the lab's memory chip programmer/reader using the appropriate device socket. An image copy of the accident memory chip was obtained. The recording contained approximately 60 flights, which dated back several years. It should be noted that the recorded data stops about ¼ of a mile from the point of 1st impact as provided by the investigator-in-charge (IIC). The Appareo units buffer a small segment of data prior to writing it to memory. Where the unit is at in its buffer/write cycle determines how much data is lost during a catastrophic shutdown of the unit. The data for the day of the accident included the flight tracks for both the first retardant drop of the day and the accident flight. Both the first retardant drop flight and the subsequent accident flight departed from the Cedar City airport, with the intended retardant drop zone in the same location. The track data of the first flight depicts the tanker flying northwest from Cedar City 58 miles. Upon arrival into the FTA, the track shows a single 180° holding orbit, followed by a teardrop type course reversal that progresses into a right-hand turn onto the final drop course. During the 90 seconds prior to the release of the retardant load the mean sea level (msl) altitude data depicts a fairly steady 6° glide slope into the target area, starting at 8,500 feet msl, down to 7,750 feet msl at a rate of descent of 562 feet per minute (fpm); during the same period the ground was rising at a rate of about 1,350 fpm. During the last 10 seconds of the run the airplane descended 500 feet, then leveled off at 7,250 feet msl, about 100 feet above ground level (agl), and remained at that altitude for 5 seconds before gaining altitude. The track data shows that the airplane departed from the drop zone by making a climbing right-hand turn towards a southwest course back to Cedar City. The data for the accident flight is continuous from Cedar City to ¼ mile before the location of terrain impact. The track data depicts the tanker flying northwest from Cedar City 58 miles. Upon arriving in the FTA, the track data shows Tanker 11 executing a right-hand 360° holding orbit, followed by a tighter 270° orbit, then a left turn for a teardrop type of course reversal to start the approach into target zone. The last 74 seconds of data depicts the tanker at a steady altitude of 7,750 feet msl (zero glide slope) while the terrain was rising at a rate of about 712 fpm. The ground track of Tanker 11 as it aligned its final course with the drop zone was similar to the first drop earlier that morning. Comparing the two flights, certain aspects tend to stand out. The same drop zone was identified for both the first and second retardant drops. Tanker 11 approached the drop zone from the south, in a right-hand turn, and the direction of the final drop course was exactly the same for both flights. Tanker 11's rate of turn on to the final course for both drops was performed at the same rate. The most significant difference between the first drop approach and the accident drop approach was that Tanker 11's first approach into the drop zone was initiated from a higher altitude, about 1,000 feet above the ridge line surrounding the west side of the fire, and had a relatively steady rate of descent on to the final drop course. In comparison, the accident flight approached the final drop course from a lower altitude that approximated the elevation of the ridge lines surrounding the west side of the drop zone in level flight while it turned onto the final drop course. The track and altitude data that depict the first drop shows that Tanker 11 flew over the west ridge line and then rapidly descended to get to the proper drop altitude while on the final drop course. The track and altitude data that depict the accident flight shows that Tanker 11 was turning inside and below the shallow valley formed by the western ridge line, which would have reduced the amount of altitude needed to descend in order to establish the proper drop altitude as the airplane rolled out onto its final drop course. Cockpit Voice Recorder (CVR) Tanker 11 was equipped with a CVR that records the last 30 minutes of aircraft operation. The digital audio recording is stored on solid state memory modules. Four channels of audio information are retained: one channel for each flight crew and one channel for the cockpit area microphone (CAM). Upon examination of the CVR by the NTSB Vehicle Recorder Laboratory, it was evident that the CVR had sustained extensive fire and heat damage. The memory case was removed and the interior crash-protected case was opened. The memory board within the crash-protected case was checked for heat or structural damage, and none was found. The accident memory was successfully downloaded from the memory board using the laboratory's surrogate Universal CVR chassis. The recording and transcript began at 1308:28, just prior to engine start. The recording continued uninterrupted during the taxi, takeoff, and transit to the fire. The crew made contact with the lead airplane (Lead 8) at 1328:54. At 1335:55, the captain calls to start the jet engines and position flaps to 10 degrees. At 1336:25, the first officer states that the number 2 jet engine didn't start, and at the same time Lead 8 informs the crew that there is a bit of a tailwind and to start on to final early. During the same transmission Lead 8 states that 7,100 feet will clear the terrain, and that there will be higher terrain off of the right wing. At 1337:26, the crew gets the number 2 jet engine started. At 1339:09, the captain calls to Lead 8 and states that the spacing (between their aircraft) is good. Lead 8 replies that he'll start the base turn and keep it in all the way to final. At 1340:08, Lead 8 says he has the retardant line in sight. At 1340:13 the captain calls for "jets to idle." Eight seconds later the captain calls for "jets," the first officer calls for "airspeed," the captain calls out "jets" again, which was followed by the sounds of first impact. The recording ended at 1340:24 when electrical power to the recorder was discontinued. An autopsy was performed on the captain on June 4, 2012, by the Utah Department of Health, Office of the Medical Examiner, Salt Lake City, Utah. The listed cause of death was blunt force trauma. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI) performed forensic toxicology on specimens from the captain with negative results for ethanol and listed drugs. Carbon monoxide and cyanide tests were not performed. An autopsy was performed on the first officer on June 4, 2012, by the Utah Department of Health, Office of the Medical Examiner, Salt Lake City, Utah. The listed cause of death was blunt force trauma. The FAA Forensic Toxicology Research Team, Civil Aerospace Medical Institute (CAMI) performed forensic toxicology on specimens from the first officer with negative results for cyanide, ethanol, and listed drugs. Carbon Monoxide tests were not performed due to the suitability of the specimens. The Hamblin Valley terrain consisted of two ridges that run