Aviation Accident Summaries

Aviation Accident Summary DEN08FA078

Mount Vernon, MO, USA

Aircraft #1

N2537X

CESSNA P206

Analysis

Surviving skydivers said that as the airplane was climbing to the jump altitude of 10,500 feet agl, the stall warning horn sounded intermittently several times. They paid no particular attention to it because they had heard it on previous flights. When the airplane reached the jump altitude, the pilot signaled for one of the parachutists to open the door. When she did, she told the pilot that the airplane had overshot the drop zone by approximately 1 mile. As the pilot started a right turn back towards the drop zone, the stall warning horn sounded again, then the airplane "rolled off on its right wing" and entered a spin. The skydivers became disoriented and nauseated. Four skydivers managed to bail out safely, but one of them broke her right leg when she struck the right horizontal stabilizer after exiting the airplane. The reserve parachute on the fifth skydiver deployed and became entangled around the tail of the airplane. She sustained fatal injuries. The sixth skydiver was unable to exit the airplane and was found inside, fatally injured. The pilot was seriously injured. Ground witnesses reported hearing the engine RPMs decrease, then saw the airplane spinning. Somewhere between 1,000 and 5,000 feet, the airplane leveled out for a few seconds and witnesses saw a parachute wrapped around the tail. The airplane then spun or dove to the ground. Downloaded data from the onboard GPS and Automated Activation Devices worn by three of the skydivers corroborated these accounts.

Factual Information

HISTORY OF FLIGHT On April 19, 2008, approximately 1615 central daylight time, a Cessna P206, N2537X, registered to and operated by Freefall Express Skydiving, Inc., and piloted by a commercial pilot, was destroyed when it struck trees and impacted terrain following an in-flight loss of control near Mount Vernon, Missouri. Visual meteorological conditions prevailed at the time of the accident. The skydiving flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot and one parachutist were seriously injured, two parachutists were fatally injured, and three parachutists were not injured. The local flight originated from the Mount Vernon Municipal Airport (2MO) approximately 1530. Written statements were received from all four surviving parachutists, and two of them were interviewed in person. The following is a summary of their accounts. As the airplane was climbing to the jump altitude of 10,500 feet agl (above ground level), the stall warning horn sounded intermittently several times. The parachutists said they paid no particular attention to it because they had heard it on previous flights. When the airplane reached the jump altitude, the pilot signaled for one of the parachutists to open the door. When she did, she told the pilot that the airplane had overshot the drop zone by approximately 1 mile. As the pilot started a right turn back towards the drop zone, the stall warning horn sounded again, then the airplane "rolled off on its right wing" and entered a spin. One parachutist wrote, "We were spinning so fast, it was difficult for me to tell what direction we were facing or in what direction we were spinning. I was holding on to the pilot's seat with my left hand, the door frame with my right hand, my head was touching the ceiling, my feet on the floor, and I was being forced to the back of the plane." A second parachutist wrote, "We were holding on to each other. I felt sick from the spinning." A third parachutist said the force of the spin pushed her against the cabin. The pilot told everyone to move aft, "to transfer our weight to the tail of the airplane." Three parachutists exited the airplane and parachuted to safety. A fourth parachutist broke her right leg when she struck the right horizontal stabilizer after exiting the airplane. Because she was disoriented, she said she activated her reserve parachute and landed safely. The reserve parachute on the fifth parachutist deployed and became entangled around the tail of the airplane. She sustained fatal injuries. The sixth parachutist was unable to exit the airplane and was found inside, fatally injured. The pilot was airlifted to Mercy St. John's Hospital in Springfield, Missouri. Seven ground witnesses submitted written statements. One witness said he heard the engine RPMs decrease, "[an] indication that the [air]plane [was] slowing down for the skydivers to jump." Then he saw the airplane "falling nose down and spinning." He said that approximately 5,000 feet, the airplane seemed to slow or stop spinning and he observed four skydivers in the sky. Approximately 3,000 feet, he noticed "a white parachute on the tail of the plane." Approximately 2,000 feet the airplane leveled out on a westerly heading and appeared to climb. Then it started "spinning and heading nose down again." Another ground witness observed the same sequence of events, but estimated the altitude of the airplane to be between 500 and 1,000 feet when she saw the fifth parachute. "It appeared to inflate and then collapse." She said the airplane made a 90 degree turn to the west and she could see the parachute was attached to the tail. "The plane then angled 45 degrees toward the ground and fell nose first." A third ground witness saw the airplane "spiraling downward, nose first, and out of control. The pilot was able to pull the plane out from the downward spiral" between 2,000 to 3,000 feet, and it appeared to climb, then "it began to spiral nose first again." That is when the witness noticed a "white reserve [para]chute caught on the tail of the plane." Another ground witness saw the airplane "in a head-down spin. The plane leveled out and flew normal for a few seconds, and then a white parachute seemed to come out beside the plane and catch on the tail. The plane then began another series of spins." She said the parachute "appeared to come put of the door and inflate beside the plane." PERSONNEL (CREW) INFORMATION The pilot, age 32, held a commercial pilot certificate with airplane single/multiengine land and instrument ratings, dated September 2, 2007. He also held a first class airman's medical certificate, dated October 24, 2007, with the limitation, "Must wear corrective lenses." A photostatic copy of the pilot's logbook was submitted for examination. It contained entries from July 13, 2000, to April 6, 2008. According to this document, the pilot began his flight training at Elmdale Airpark (6F4), Abilene, Texas. He made his first solo flight on October 19, 2001, and received his private pilot license on August 10, 2002. During this time, the pilot had no less than 18 lessons involving 18.2 hours of various stalls and slow flight. On November 12, 2006, the pilot enrolled in Pan Am Flight Training Academy's instrument and commercial curriculums at Deer Valley Airport (DVT), Phoenix, Arizona. The chief flight instructor failed to respond to this investigator's request for an interview. According to the pilot's logbook, he failed the instrument rating practical test on February 26, 2007, then passed it on March 14, 2007. During this time, the pilot was given no less than 6 lessons involving 7.9 hours of various stalls and slow flight. He failed the commercial multiengine practical test on July 24, 2007, then passed it on July 31, 2007. During this time, the pilot was given no less than 12 lessons involving 17.4 hours of various stalls and slow flight. He failed the commercial single-engine practical test on August 31, 2007, then passed it on September 2, 2007. During this time, the pilot was given no less than 2 lessons involving 1.9 hours of various stalls and slow flight. At no time during his training in either Abilene or Phoenix was the pilot given spin instruction. According to the various FAA practical test guides, only flight instructor applicants are required to have spun an airplane (or had a spin demonstrated). On November 15, 2007, he was given a Freefall Express Skydiving checkout in the Cessna 182. Between that date and April 5, 2008, he logged 66 hours in the Cessna 182, all of which was flying skydivers. On April 6, 2008, he flew skydivers in the Cessna P206 and logged 8.5 hours. This was the last recorded entry in his logbook. As of that date, the pilot had logged the following flight time (in hours): Total Time, 320.5 Single engine, 278.5 Multiengine, 42.0 Pilot-in-command, 222.3 Instruction received, 236.3 Night, 55.0 Actual instruments, 4.0 Simulated instruments, 73.5 Flight simulator, 30.0 Cross-country, 73.6 AIRCRAFT INFORMATION N2537X, a model P206 (s.n. P206-0037), was manufactured by the Cessna Aircraft Company, and received its FAA airworthiness certificate on December 11, 1964. It was equipped with a Continental IO-520-F-9 engine (s.n. 553089), driving a McCauley 3-blade, all-metal, constant speed propeller (m.n. D3A34C402). According to the aircraft's maintenance records, the last annual inspection of the airframe and 100-hour inspections of the engine and propeller were accomplished on May 18, 2007, at a tachometer time of 3,227.9 hours. At the time of the accident, the airframe and engine had accumulated 4,302.7 and 4,394.2 hours, respectively. The engine and propeller had accumulated 1,621.7 and 440.95 hours since major overhaul. According to the FAA principal airworthiness inspector who had been recently assigned to Freefall Express Skydiving, neither the engine nor the propeller were certificated for the Cessna P206. Other anomalies that were uncovered by the inspector were: A.D. 76-07-12, Bendix ignition switches, due every 100 hours, last complied with July 6, 2006, 405 hours ago A.D. 78-05-06, fuel system inspection, due every annual inspection, last complied with on July 6, 2006, 21 months ago A.D. 85-10-02, induction air box inspection, due every 100 hours, last complied with on July 6, 2006, 405 hours ago A.D. 87-20-03, seat rails, due every annual inspection, last complied with July 6, 2006, 21 months ago Other recurring inspections that had expired were the transponder, pitot-static system, encoder, and altimeter tests, and the emergency locator transmitter check (see FAA Form 1360-33, attached). METEOROLOGICAL INFORMATION The following Aviation Routine Weather Report (METAR) was recorded at Springfield-Branson Regional Airport (SGF), Springfield, Missouri, at 1552: Wind, 290 degrees at 10 knots; visibility, 10 statute miles (or greater); sky condition, few clouds at 3,500 feet; temperature, 17 degrees C.; dew point, 7 degrees C.; altimeter, 29.94 inches of mercury; remarks, sea level pressure 1038 mb. FLIGHT RECORDERS The airplane was equipped with a Garmin GPSMAP 195, which was sent to NTSB's Vehicle Recorder Division for download and analysis. According to the GPS Factual Report, 33 user defined waypoints, 8 user defined routes, and 2 tracks were recorded on April 19, 2008. The first tracklog began at 1028:06 (a previous flight) and ended at 1218:02. The second tracklog began at 1256:04 and ended at 1606.45. Approximately 1543:23, Track 02 recorded "groundspeeds above 58 mph with motion on a northerly course" over Mt. Vernon Municipal Airport. "Recorded track data indicate that the aircraft maneuvered in the immediate vicinity of the airport for approximately 18 minutes before turning to a northwesterly course. At 1601:15 recorded groundspeed began to drop below 58 mph and fluctuate between 34 mph and 78 mph. At about 1605:01, tracklog data indicates that the aircraft initiated a right hand turn to the southeast with groundspeeds well below 59 mph. At 1605:28, tracklog data indicates that the aircraft made a sharp right hand turn to the north, followed by another sharp right hand turn to the south one (1) second later. Recorded groundspeed during the next 3-4 seconds varied from 246 mph to 187 mph. Tracklog data indicates that the aircraft traveled on a southeasterly heading for the next 5-seconds at groundspeeds between 18 and 162 mph. At 1606:20, tracklog data indicates that the aircraft course changed 90 degrees in one (1) second, to a southwesterly heading. Five (5) seconds later the airplane changed 90 degrees in three (3) seconds to a northwesterly heading, and two (2) seconds later changed back to a southwesterly heading. The remainder of the tracklog data indicate that the aircraft entered a right turn before recording ceased 16-seconds later. The final recorded GPS location was recorded at 1606:45 and placed the airplane at N37 degrees, 04.966'; W093 degrees, 53.886'. Calculated average groundspeed and course during the last 3 seconds of recorded data were 81 mph and 226 degrees true, respectively." Most of the skydivers were wearing Automatic Activation Devices (AADs). The AAD senses freefall speed and, if exceeded, will automatically deploy the reserve parachute at a preselected altitude if the skydiver hasn't already done so or is unable to do so. AADs also record data that can be downloaded. The skydiver whose reserve parachute had deployed and became entangled around the airplane's tail was wearing a Vigil AAD. The Vigil AAD has three modes: PRO, STUDENT, and TANDEM. It was set in the PRO mode. In this mode, the reserve parachute will deploy at 840 feet (256 meters) if the freefall speed is equal to or greater than 78 mph (35 m/sec). According to the company, there is a 260-foot safety margin incorporated to allow for pressure differentials and body positions. The unit should have activated approximately 1,100 feet. Preliminary (filtered) data was graphed by Vigil USA, Deland, Florida, and the raw data was analyzed and graphed by Advanced Aerospace Designs, Vigil, Belgium. According to these graphs, maximum altitude attained was 10,223, feet. Time spent in freefall was 91 seconds, reaching a maximum speed of 101 mph. The AAD deployed the reserve parachute at 1,097 feet. The recording ended at an altitude of 155 feet. The other deceased skydiver was wearing an Cypres-USA AAD, manufactured by Airtec Safety Systems, Bad Wunnenberg, Germany, and distributed by SSK Industries, Inc., Lebanon, Ohio. The Cypres AAD will deploy the reserve parachute at 750 feet (229 meters) if the freefall speed is equal to or greater than 79 mph (35 m/sec). Two flights were recorded on an unknown date (the unit does not have a calendar function). The highest altitude recorded on the second flight, which lasted 23 minutes, was approximately 3,220 meters (10,500 feet) agl. According to Airtec's report, "The parameters for an activation were not met at any time. The unit shut itself off automatically after 14 hours total running time. The unit did not detect a vertical speed higher than 35 m/s (79 mph) below 750 feet on the second flight of the day and therefore did not activate." Since witnesses said the airplane recovered from the spin momentarily approximately 1,000 feet, this cancelled its sensing of the freefall velocity. The surviving skydiver who was seriously injured was wearing an audible altimeter "Pro Track," manufactured by L&B of Germany. It is worn on the skydiver's hemet. It is an audible altimeter and freefall computer. It gives altitude warnings and tracks the skydiver's freefall speed, freefall time, and other parameters, and creates a digital logbook. "Pro Track" data indicates the maximum altitude attained was 10,470.85 feet. Times and distances indicate the skydiver was in the descending aircraft. She exited the airplane and deployed her reserve parachute at 1,576 feet. The airplane was also equipped with an J.P. Instruments EDM 700 Engine Analyzer/Monitor. The unit was removed from the airplane's instrument panel and sent to NTSB's Vehicle Recorder Division for readout. According to graphs attached to this report, the readout included exhaust gas temperature, cylinder head temperatures, fuel flow, fuel used, oil temperature, and battery voltage parameters. The parameters were within normal operating limits throughout the flight. WRECKAGE AND IMPACT INFORMATION The accident site was at a location of 037 degrees, 04.955' North latitude, and 093 degrees, 53.920' West longitude, and at an elevation of 1,232 feet msl. The airplane impacted trees and terrain on a magnetic heading of 285 degrees, and came to rest in a nose down, slightly inverted attitude of approximately 105 degrees. There were chops marks on several tree limbs. Flight control cable continuity was established. The parachute lines were not binding the elevator or rudder. MEDICAL AND PATHOLOGICAL INFORMATION The pilot submitted a written statement to the effect that he had not regained cognitive skills and could not recall the accident. The statement was recorded by his wife. Neither Lawrence County or the State of Missouri requested autopsies on the two deceased skydivers. TESTS AND RESEARCH On June 19, 2008, under the supervision of the National Transportation Safety Board, the engine was successfully test run at the facilities of Teledyne Continental Motors, Mobile, Alabama. Full power was achieved and no anomalies were noted. ADDITIONAL INFORMATION N2537X was equipped with a Sportsman STOL (short takeoff and landing) kit, manufactured by Stene Aviation, Polson, Montana. The kit extends the wing leading edge cuff, adding wing area and thus reducing the stall speed and dampening stall characteristics without an attendant increase in drag. According to a company spokesman, stall speed reduction of 8 per cent (forward c.g.) to 10 per cent (aft c.g.) can be expected. According to the Cessna Aircraft Company, the clean configuration stall speed of the Cessna 206 in a wings-level attitude is 69 mph calibrated airspeed (CAS). In a 60-degree bank, the stall speed is 98 mph CAS. With the installation of the Sportsman STOL kit, the stall speeds should have

Probable Cause and Findings

The pilot's failure to maintain adequate airspeed, resulting in an inadvertent stall/spin. Contributing factors in this accident were the entanglement of the parachute in the elevator control system, reducing the pilot's ability to regain control.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports