Over the years, you’ve no doubt heard urgings from various government agencies to always pay careful attention to the weather when you’re in flying mode. This begins with at least a rudimentary understanding of meteorology, coupled with detailed preflight weather briefings and periodic in-flight updates. Weather was a key topic for NTSB experts who made presentations during the FAA’s Safety Forums at this year’s Sun ‘n Fun in Lakeland, Fla. The FAA has been giving prominence to weather issues in some of its current published material. There had been a 10-year government initiative to reduce weather accidents centered around groups most pilots probably never heard of: the Federal Committee for Meteorological Services and Supporting Research, and the National Aviation Weather Program Council. Among other things, they studied the best way to get weather information to pilots, and concluded that the FAA’s NextGen ATC modernization program will do the trick. Participants in the National Aviation Weather Program came from the NTSB, NASA, the Department of Commerce, Navy, Air Force, Department of Transportation and Department of Agriculture.
Without denigrating the government’s efforts to educate, it’s worth noting that NTSB accident reports provide evidence that government itself sometimes needs to pay attention to what it preaches.
The Department of Defense had contracted with a private company to have the twin-engine centerline-thrust airplane flown in support of an Air Force Special Operations Command training exercise on November 17, 2010. At about 8:50 p.m., the Cessna M337B crashed near Avon Park, Fla., after its right wing came off. The commercial pilot and two pilot-rated crewmembers were killed. The weather had deteriorated to instrument conditions with hazardous cells embedded. No FAA flight plan was filed for the local flight, which originated at MacDill Air Force Base Auxiliary Field (AGR), at about 7:32.
The Cessna, using call sign “Jedi 21,” was in contact with AGR tower at the time of the accident. The tower instructed Jedi 21 to report a two-mile final for runway 5. When Jedi 21 didn’t report final, search-and-rescue began. The wreckage was located just after 1 a.m.
The NTSB report didn’t provide details about the nature of the training mission being flown or the specific “aerial support” services being provided by the accident airplane. Air Force Special Operations Command (AFSOC) is involved with the United States Special Operations Command (USSOCOM). USSOCOM is headquartered at MacDill. The idea of a unified special-operations command had its origins in the aftermath of the disastrous attempted rescue of hostages at the American Embassy in Iran in 1980. It has participated in many operations, from the 1989 invasion of Panama to the ongoing War on Terror. It conducts covert and clandestine missions, such as unconventional warfare, foreign internal defense, special reconnaissance, psychological warfare, civil affairs, direct action, counterterrorism and War on Drugs operations.
Several Department of Defense personnel were on the Avon Park Air Force Range at the time of the accident. These persons included range and airspace controllers, a weather forecaster and other flightcrews. An Air Force Staff Sergeant, acting as a primary Restricted Operating Zone (ROZ) controller, reported Jedi 21 checked in on station, and performed its assignment for about an hour, until reporting a “bent sensor.” That indicated a technical problem with sensor equipment. About 30 minutes later, another controller received a call from the Cessna, saying they were returning to base. The controller asked why, but received no response. About five minutes after the airplane crashed, an AGR tower controller asked the ROZ controller about the location of Jedi 21. The controller believed at the time that Jedi 21 had landed. About the same time, the weather conditions became severe at AGR with heavy rain and limited visibility.
An Air Force Staff Sergeant who had been the weather forecaster for the exercise said he began to prepare for the 6:30 p.m. flight group briefing at about 3 p.m. He told investigators that “…conditions looked to be on track with relatively clear skies.” He recalled that, before the briefing, mid-level cloud cover increased at around 7,000 to 8,000 feet with some scattered clouds to the south at about 4,000 feet. He noted some weak returns on the radar to the south, but felt that they would “die out relatively quickly” with the loss of heating as the evening progressed. His overall assessment of the weather on the night of the accident was that “…there was no significant weather event during the operation other than a brief heavy shower.” He also stated that the showers didn’t occur until after communication was lost with the accident airplane.
The weather briefer said that between 7:30 and 8:00, he continued to monitor weather to the south and could see showers continuing to “back build” on radar to the southwest, tracking northeast. He notified exercise command of a possible recall of light and medium fixed-wing aircraft, and requested a pilot report from the south ROZ controller, but there was no response. About 8:10, the briefer received a pilot report of 3,000-foot ceilings and rain to the south. Between 8:15 and 8:30, he contacted the tower to recommend a recall of VFR aircraft due to worsening conditions with rain and lowering ceilings. He reported that, at 8:35, tower recalled light and medium-fixed wing aircraft. From 8:40 to 8:50, he continued to monitor the weather conditions, and from 8:50 to 8:55, a brief, heavy shower moved through, reducing visibility to between one and two miles.
A helicopter pilot reported that between 8:30 and 9:00, the weather was “worse than briefed.” He stated that his aircraft flew through numerous rainshowers with visibilities between one and two miles. Earlier at 8:15, while arriving at AGR, they experienced “zero zero” conditions over the field. After slowing the aircraft, he was able to regain contact with the ground and land.
The pilot of another support aircraft told investigators there was no mention of any precipitation or convective activity during the evening’s weather briefing. During the mission, the weather “…began to change rapidly and deteriorate, with weather moving from south to north.” He aborted his mission and, after maneuvering to avoid weather for about 30 minutes, landed at Avon Park Executive Airport (AVO). He told investigators that he didn’t “…receive any additional weather information throughout the flight” and didn’t “…receive a weather recall.”
A witness who said he lived one to two miles north of the accident site said he heard the accident airplane at “full throttle,” but didn’t see it. He heard a “thud” and called 911. He said that immediately after the accident, it started raining hard. He was drenched because he needed to be outside to get good reception on his phone.
Doppler radar images at 8:52 depicted the accident site under the leading edge of an area of echoes located about 1⁄2 mile east of the accident site. At 8:57, echoes were over the accident site with the edge of a strong core located about 1⁄8 mile east of the accident site. This core corresponded with level 5 “intense” echoes capable of producing severe turbulence and strong outflow winds.
The main wreckage was found adjacent to a retention pond and swamp that were located on a farm pasture. Two sections of the right wing were found northwest of the main wreckage-impact crater, one about 800 feet away and the other about 330 feet away.
Sections of the right-wing front and rear spars and skin were sent to the NTSB Materials Laboratory in Washington, D.C., for examination of the fracture surfaces. The features and deformation patterns were consistent with overstress fractures at all locations. No indications of preexisting cracking from fatigue or corrosion were uncovered.
The NTSB determined that the probable cause of this accident was the pilot’s inadvertent encounter with an unexpected intense rainshower with severe turbulence at night.
On January 17, 2010 at about 4:22 p.m., a Cessna 182R crashed in mountainous terrain nine miles northwest of Corvallis, Ore. The airplane was operated by the U.S. Department of Interior’s Fish and Wildlife Service. The commercial pilot and passenger were killed. The flight originated at Newport Municipal Airport, Newport, Ore., about 4:00.
The airplane had completed a wildlife survey around Olympia, Wash. The airplane landed at Newport Municipal Airport for fuel. The pilot phoned his girlfriend, told her that there was a break in the weather, and that he was having trouble contacting Flight Service. He told her they were going to fly to Corvallis, 38 miles away, and if she had not heard from him by 5:00, to call the FAA.
At 6:33, the airplane was reported overdue, and search efforts began. The wreckage was found in terrain at about 1,500 feet MSL. Radar indicated the airplane had been cruising at about 2,900 feet MSL and was following a highway. It made a gradual descent.
Witnesses in the vicinity of the accident site at the time of the accident reported hearing thunder. A pilot who landed at Corvallis approximately 90 minutes before the accident reported the coastal range and foothills were “totally obscured in mist and low cloud.” The pilot couldn’t identify the base of the overcast layer above the airplane; however, he estimated the scattered layer beneath the airplane to have bases of 650 feet with tops near 800 feet. The pilot also indicated that light mist and drizzle were in the area, and that rain began soon after he landed at Corvallis.
The NTSB determined that the probable cause of this accident was the pilot’s failure to maintain clearance from terrain while operating into a known area of mountain obscuration due to low clouds, precipitation and mist.