14 CFR Part 91: General Aviation
Accident occurred Friday, July 29, 2011 in Sarasota, FL
Probable Cause Approval Date: 12/11/2013
Aircraft: TL ULTRALIGHT SRO STING S3, registration: N2442
Injuries: 1 Fatal, 1 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
After departure for the demonstration flight for the pilot-rated student, who was seated in the left seat, the airplane climbed to between 2,300 and 2,400 feet, and the pilot-in-command (PIC) then performed a stall. Subsequently, the flight entered a spin from which the PIC was unable to recover. The airplane descended uncontrollably into a large tree and then impacted the ground. The PIC reported that he could not recall how or why the airplane entered a spin. Although the airplane had been spin tested by the manufacturer, it was not approved for intentional spins. Examination of the wreckage, including the flight controls, and engine revealed no malfunctions or failures that would have precluded recovery from the spin.
Although the airplane was equipped with a ballistic recovery system parachute, it was found unarmed and, thus, did not deploy. The PIC reported that he chose to depart with the parachute system activation handle safety pin installed instead of removed, which was not in accordance with the procedures in the Pilot Operating Handbook. Further, the location of the activation handle behind the left seat on this airplane make and model would have rendered it difficult for the PIC, who was in the right seat, to access during the uncontrolled descent. The manufacturer moved the activation handle to the lower portion of the pilot’s instrument panel to allow for easier access.
The PIC reported that he performed weight and balance calculations before departure and based his calculations on the provided passenger weight (275 pounds); the airplane was at the top of the envelope but within weight and balance limitations. However, postmortem external examination indicated that the passenger actually weighed 340 pounds, which resulted in the airplane being 64 pounds above the maximum allowable ramp weight at engine start. Further, his actual weight was 90 pounds over the left seat’s design limitations (1.3 times the ultimate design load factor limit of each lapbelt attachment point), which caused the left seat outboard attachment structure to separate during the impact sequence.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The inability of the pilot-in-command (PIC) to recover from an inadvertent spin following a stall demonstration for reasons that could not be determined because aircraft and engine examinations did not reveal any anomalies that would have precluded recovery from the spin. Contributing to the severity of the accident were the PIC’s failure to remove the airframe parachute system safety pin before takeoff, the exceedance of the left-seat weight limitation, and the location of the parachute system activation handle behind the PIC’s seat, which prevented easy access during the uncontrolled descent.
HISTORY OF FLIGHT
On July 29, 2011, about 1247 eastern daylight time, a special light sport airplane (SLSA) TL Ultralight sro TL 2000 Sting S3, N2442, registered to N2442 Aviation, LLC, operated by Universal Flight Training, LLC, descended uncontrolled and crashed into trees then the ground about 13 nautical miles southeast of the Sarasota/Bradenton International Airport (SRQ), Sarasota, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 demonstration local flight from the SRQ airport. The airplane sustained substantial damage, and the certified flight instructor (CFI) sustained serious injuries while the pilot-rated student sustained fatal injuries. The flight originated from SRQ about 1230.
The purpose of the flight was demonstration of the airplane to the pilot-rated student. The pilot-in-command (PIC) seated in the right seat advised the Federal Aviation Administration (FAA) inspector-in-charge (IIC) when interviewed while hospitalized the day after the accident that they were practicing stalls and he did not recall how or why the airplane entered a spin. The FAA-IIC reported that the PIC was unable to recover from a spin and the airplane continued in a spin until contacting a tree then the ground.
The CFI was able to exit the airplane; however, due to his injuries, waited on the ground next to the airplane for rescue personnel. While trapped in the wreckage the pilot-rated student called 911 and advised the dispatcher of their last known position, and that they had crashed through a tree canopy. During the conversation he advised the dispatcher that they were flying between 2,300 and 2,400 feet, and, “we were practicing stalls and it went into a spin and we were talking about how the plane was spin proof its not the instructor couldn’t pull it out of the spin….” The dispatcher remained on the call while rescue crews were en route to the crash site and continued to talk with the left seat occupant.
Rescue teams arrived and the left seat occupant was extricated from the airplane. Both occupants were airlifted by helicopter to a hospital in St. Petersburg, Florida.
The airplane was equipped with an airframe parachute recovery system; however, it was not deployed. The FAA-IIC asked the PIC why the aircraft’s ballistic parachute system was not armed or activated, and he responded that he does not arm the system on flights that are below 3,000 feet mean sea level (msl). He later stated that he was not trained in the use of the airplane parachute system and that is why he did not remove the safety pin.
PERSONNEL INFORMATION
The PIC seated in the right seat, age 56, holds a commercial pilot certificate with airplane multi-engine land, airplane single engine land, and instrument airplane ratings. He also holds a flight instructor certificate with airplane single engine issued August 13, 2010. He was issued a third class medical certificate with a limitation to wear corrective lenses on October 26, 2010. On the application for his last medical certificate he listed a total time of 1,100 hours. He estimated that at the time of the accident he had 1,200 hours total time, and 10 hours make and model, all as PIC.
The left seat occupant, age 71, held a private pilot certificate with airplane single engine land rating. He was last issued a third class medical certificate with a limitation to wear lenses for near and distant vision on December 15, 1989. On the application for his last medical certificate he reported having 415 hours total time, and 12 hours in the last 6 months. He also reported weighing 275 pounds.
The left seat occupant also completed an application with the operator on July 23, 2011, indicated his total time as pilot-in-command was 1,600 hours, and he weighed 275 pounds.
While on the phone with the 911 dispatcher awaiting rescue, the left seat occupant stated that he had not flown in 16 years and the flight was a refresher flight for him.
AIRCRAFT INFORMATION
The airplane was manufactured as a Light Sport Aircraft in 2008 by TL Ultralight, sro as TL 2000 model Sting S3, and designated serial number TLUSA174. It met the standard specification Design and Performance established by ASTM document F2245, but was not required to comply with FAA Part 23 certification processes. It was powered by a 100 horsepower Rotax 912ULS engine and equipped with a 3-bladed ground adjustable Woodcomp propeller. It was also equipped with a TruTrak Flight Systems electronic flight information system (EFIS), and a I-K Technologies AIM-Sport Engine Monitor; neither of which record and retain flight or engine data. The instrument panel was also equipped with a panel dock for a portable GPS receiver.
Review of ASTM F2245-04, revealed section 4.5.9.1 pertaining to spins which indicates that for airplanes placarded “no intentional spins”, the airplane must be able to recover from a one-turn spin or a 3 second spin, whichever takes longer, in not more than one additional turn, with the controls used in the manner normally used for recovery. That condition is with flaps retracted and flaps extended, the applicable airspeed limit and limit maneuvering load factor may not be exceeded. The section also indicates that it must be impossible to obtain uncontrollable spins with any use of the controls.
The airplane was equipped with a Galaxy GRS ballistic parachute rescue system which is activated by a red “T” handle installed behind the co-pilot’s seat. According to data provided by the manufacturer, the parachute system design is purposefully constructed for the fastest possible opening.
Review of the maintenance records revealed the airplane was last inspected in accordance with an annual inspection on December 10, 2010. The airplane total time at that time was recorded to be 178.8 hours, while the hour meter reading at the time of the accident was 247.1, or an elapsed time of 68.3 hours since the annual inspection had been signed off as being completed.
METEOROLOGICAL INFORMATION
A surface observation weather report taken at SRQ at 1253, or approximately 6 minutes after the accident indicates the wind was from 080 degrees at 7 knots, the visibility was 10 statute miles, and scattered clouds existed at 4,000 feet. The temperature and dew point were 33 and 23 degrees Celsius, respectively, and the altimeter setting was 30.08 inches of Mercury. The accident site was located approximately 13 nautical miles and 119 degrees from SRQ.
FLIGHT RECORDERS
The airplane was equipped with a GPS; however, it was not located in the wreckage when it was examined by NTSB and a representative of the U.S. Field Technical Director following recovery.
WRECKAGE AND IMPACT INFORMATION
Examination of the accident site by an FAA airworthiness inspector revealed the airplane came to rest at the base of a large oak tree and was obscured from view by low branches. The accident site was located at 27 degrees 17.43 minutes North latitude and 082 degrees 20.55 minutes West longitude. The FAA-IIC reported that the first responders removed the left wing during the extrication process of the left seat occupant, while the right wing remained attached. All components necessary to sustain flight remained attached or were found in close proximity to the main wreckage. No fire was observed on any component. The right wing was cut to facilitate recovery of the airplane.
Examination of the airplane and engine following recovery was performed with Safety Board oversight by a representative of the U.S. Field Technical Director of the airplane manufacturer and a representative of the engine manufacturer. The examination of the airframe revealed the fuselage was fractured circumferentially approximately 12 to 18 inches aft of the firewall. The rudder remained attached to the vertical stabilizer which also remained attached; however, evidence of overtravel of the rudder to the right was noted. Further inspection of the lower portion of the rudder revealed the rudder shaft was fractured. Rudder control cable continuity was noted between the rudder torque tube and the rear bellcrank near the control surface. The fractured rudder shaft was retained for further examination. The horizontal stabilizer remained attached; however, both sides were fractured about 30 inches from the fuselage centerline. The elevator remained connected by the anti-servo tab push/pull rod, and the anti-servo tab remained attached to the elevator at all hinge locations. The left side of the elevator was fractured in 2 pieces, while the right side of the elevator was full span. Inspection of the aileron and elevator flight control systems revealed no evidence of preimpact failure or malfunction.
Examination of the cockpit revealed the pilot’s control stick was bent forward, and was approximately 6.25 inches forward of the position of the right stick; however, both control sticks remained interconnected. The flap selector was in the full down position. The fuel shutoff valve was open, and the throttle was full forward with control cable continuity confirmed. The auxiliary fuel pump switch was separated from the instrument panel; however, electrical power was applied directly to the switch and it was found to operate satisfactory. Examination of the pilot’s (left seat) restraint system revealed the outboard lapbelt remained attached to structure which was structurally separated, while the inboard lapbelt and shoulder harness remained attached to the structure. Testing of the pilot’s shoulder harness inertia reel by hand revealed it tested satisfactory. Examination of the pilot’s seat revealed the seat back was pulled out, and the bottom side of the lower seat pan exhibited impact mark approximately 5.6 inches aft of the seat base screws associated with contact by the flight control tube. The instrument panel contained a panel dock for a GPS receiver; however, the receiver was not located.
Inspection of the co-pilot’s seat revealed no obvious seat frame pull-out. The inboard and outboard portion of the lapbelts in addition to the shoulder harness remained attached to structure. The co-pilot’s shoulder harness tested satisfactory when tested by hand. Examination of the bottom side of the lower seat pan exhibited impact mark approximately 5.6 inches aft of the seat base screws associated with contact by the flight control tube.
Examination of the left wing revealed it was fragmented and in multiple pieces, though the flap and aileron remained attached. The aileron push/pull rod was fractured in bending overload about 2/3 span, but remained connected to the bellcrank near the control surface. The flap torque tube indicated the flap was fully extended, which agreed with the position of the flap selector in the cockpit. No obstruction of the fuel supply from the wing root to the fuel strainer was noted.
Examination of the right wing revealed the aileron and flap remained attached, although the aileron was delaminated full span at the trailing edge. The flap torque tube indicated the flap was fully extended, which agreed with the position of the flap selector in the cockpit. A tree limb had penetrated the lower wing skin near the pitot static port, and evidence of a tree contact was noted at the inboard portion of the aileron. The fuel vent and fuel supply system were free of obstructions.
Examination of the rudder shaft was performed by the NTSB Materials Laboratory located in Washington, D.C. The results of the examination revealed the tube on the shaft consisted of two pieces, one long and one short, which could be rotated. The tip of the longer portion of the tube, adjacent to the circular flange, had been locally deformed and was bent. Examination of the fractures on the shaft revealed grainy surfaces on slant planes, consistent with bending overload, no evidence of preexisting cracks was noted.
Examination of the engine revealed the propeller remained attached to the engine and the engine remained attached to the airframe. One propeller blade remained connected to the propeller hub while the other 2 blades were fractured. Impact damage was noted to the carburetor sockets, air filters, oil tank, and coolant lines. The engine was removed from the airframe for further inspection which revealed continuity and compression on all cylinders. Inspection of the ignition system, carburetors, oil system components, cooling system, exhaust system, and auxiliary fuel pump which was operationally tested revealed no evidence of preimpact failure or malfunction. Inspection of the fuel strainer revealed the remains of fuel and some debris; however, the fuel screen was not blocked. Rotation of the engine using the starter revealed the engine-driven fuel pump would not pick up fluid from the source. The pump was removed from the engine and actuated by hand which produced the same results. The pump was retained for further examination.
Inspection of the propeller revealed the blade that remained connected to the propeller hub exhibited delamination at the blade tip, while the remaining 2 blades were fractured at the propeller hub. Inspection of the separated blades revealed minimal damage to the leading edges of both blades. The blade angles of all 3 blades were at 22 degrees (lowest blade angle is 16 degrees while the maximum blade angle is 26 degrees).
MEDICAL AND PATHOLOGICAL INFORMATION
The certified flight instructor and pilot-rated student seated in the left seat were rescued and airlifted to a hospital in St. Petersburg, Florida, for treatment of their injuries. The left seat occupant expired at 0034 hours on August 1, 2011.
A postmortem examination was not performed of the left seat occupant; however, an external examination was performed. According to the external examination report, he weighed 340 pounds, and was identified to be “overly-nourished.” The cause of death was listed as complications of blunt trauma, while contributory conditions were Arteriosclerotic Cardiovascular Disease and Diabetes Mellitus. The report also indicates that a bandage and cast are present on the lower portion of the left leg and foot.
Blood specimens of the left seat occupant taken upon admittance to the hospital were submitted to the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, and also to the Pinellas County Forensic Laboratory, Largo, Florida. The toxicology report by FAA stated testing for carbon monoxide, cyanide, volatiles, and listed drugs could not be performed due to the insufficient quantity of blood submitted. The results of testing by Pinellas County Forensic Laboratory were negative for volatiles, drugs of abuse, and other tested drugs.
SURVIVAL ASPECTS
The airplane restraint system is designed to comply with ASTM standard 2245, Chapter 5.10, titled “Emergency Landing Conditions” which indicates that the structure must be designed to protect each occupant during emergency landing conditions when occupants (through seat belts or harnesses or both), experience the static inertia loads corresponding to 3 G’s up, 9 G’s forward, and 1.5 G’s lateral ultimate load factors. Section 5.1.2.2 of the same standard also indicates that special ultimate load factor of 2.0 shall be applied to seat belt/harness fittings including the seat if the seat belt or harness is attached to it.
Calculations by the airplane manufacturer were performed in an effort to determine the design load amount for each lapbelt attach point for the forward G loading limit of 9 G’s, and was based on the maximum seat limit of 250 pounds, or 113.4 kilograms (kg’s). The formula specified 60 percent of the forward load limit distributed to the lapbelt while the remaining 40 percent of the forward load limit distributed to the shoulder harness. The formula used for the calculations was:
113.4 kg (9 G’s) (2) (.6) = 612.4 kg
2 (Number of lapbelt attach points)
Using that same formula and the left seat occupant’s actual weight in kg’s (154), at the maximum 9 G forward design limit, the G loading of each lapbelt attach point of his seat was calculated to be approximately 832 kg, which was approximately 1.3 times the ultimate design load factor limit of each lapbelt attach point. No calculations were performed to determine the actual G loading at the moment of impact.
TEST AND RESEARCH
As previously mentioned, both the pilot and co-pilot bottom surface of the lower seat pans exhibited impact marks approximately 5.6 inches aft of the seat pan screws, which correlated with contact by each flight control tube. The airplane manufacturer was asked to correlate the position of the impact marks on the lower seat pan with the position of the elevator flight control position at impact and it was determined that the elevator control was approximately full nose-up to have caused the marks at the documented locations, although deformation of the seat pan was required to have the contact marks occur.
The PIC stated that he performed weight and balance calculations based on the provided weight of the passenger, and determined that the airplane’s weight was at the top of the envelope but within weight and balance.
Postaccident weight and balance calculations were performed using the empty weight of the airplane (822 pounds), the weight of the left seat occupant per the external examination report (340 pounds), the weight of the right seat occupant per his interview (185 pounds), and the total reported usable amount of fuel on-board at takeoff (9.5 gallons or 57 pounds). The calculations indicate that at the moment of engine start, the gross weight was 1,404 pounds and the center of gravity (CG) was calculated to be 83.25 inches aft of datum.
Postaccident weight and balance calculations were also performed using the empty weight of the airplane (822 pounds), the weight of the left seat occupant per his completed application form (275 pounds), the weight of the right seat occupant per his interview (185 pounds), and the total reported usable amount of fuel on-board at takeoff (9.5 gallons or 57 pounds). The calculations indicate that at the moment of engine start, the gross weight was 1,339 pounds and the center of gravity was calculated to be 82.91 inches aft of datum.
The Pilot Operating Handbook (POH) indicates that the maximum pilot or co-pilot seat load is 250 pounds, the maximum ramp weight is 1,340 pounds, the maximum takeoff weight is 1,320 pounds, and the forward and aft center of gravity limits are 80.2 inches and 86.7 inches aft of datum, respectively. The POH also indicates that it, “…is certified as a Light Sport Aircraft and is not approved for aerobatic flight including spins.” Section 3 of the POH contains information on the aircraft parachute system, and also a checklist of items to accomplish to deploy the aircraft parachute system. The same section also discusses the steps to accomplish to recover from an inadvertent spin, which indicates to bring the throttle to neutral, neutralize the ailerons, apply full rudder opposite the direction of rotation, and apply forward elevator to break the stall. Following ceased rotation, neutralize the rudder, apply aft elevator to recover from the nose-low attitude, and in the event the aircraft does not recover, deploy the parachute. The pre-taxi and before takeoff checklists found in Section 4 or the normal procedures section both indicate to either remove or verify removal of the airframe parachute GRS safety pin.
The airplane manufacturer performed spin testing at maximum gross weight in the most forward and aft CG positions. Spins with and without power were performed and with the flaps retracted and fully extended. The flight test report considered proprietary indicates that in the various configurations, airframe buffet proceeds a stall, the position of the flaps did not aggravate the spin process but care must be taken to avoid a flap overspeed during the descent, the airplane had a tendency to return to normal flight after about ½ turn, the ailerons must be kept neutral, and upon spin entry immediately push the control stick forward and apply opposite rudder input.
The engine-driven fuel pump was sent to Rotech Flight Safety, Inc., in Vernon, British Columbia for further testing with Safety Board oversight. The pump was installed on a new Rotax 912ULS engine which was installed on a test stand. The engine-driven fuel pump would not supply an adequate amount of fuel to sustain engine operation; the fuel pressure reading was 0.32 psi (normal psi range 2.2 to 5.8 psi). The auxiliary fuel pump was turned on and fuel was noted to pass internally through the pump indicating there was no blockage. Although there was no damage to the fuel pump, fuel leakage was noted at the base of the pump. The new engine was started using the auxiliary fuel pump and the engine was found to operate normally. The fuel pump was disassembled which revealed the inlet screen was clean and no debris was inside the filter, though the diaphragm was noted to be cracked on the air side. The pump was then sent to Austria Civil Aviation Safety Investigation Authority for examination at Rotax’s facility.
Examination of the engine-driven fuel pump at Rotax’s facility in Austria with Austria Civil Aviation Safety Investigation Authority revealed superficial cracks on the dry side of the diaphragm in the area of the diaphragm plate. An adapter was used to perform an airflow test of the diaphragm with connected push rod which revealed a slight pressure reduction. The internal components of the pump were reconstructed in a housing, and placed in a fixture which revealed fluid leakage at the weep holes; however, functionality in terms of fuel flow and fuel pressure was verified. The reconstructed fuel pump was installed on a new Rotax 912UL engine which was started and operated for 30 minutes without the electric fuel pump operating. The engine was noted to start normally and run smoothly with the system fuel pressure within limits over the full range of different rpm settings.
NTSB Identification: ERA11LA427
14 CFR Part 91: General Aviation
Accident occurred Friday, July 29, 2011 in Sarasota, FL
Aircraft: TL ULTRALIGHT SRO STING S3, registration: N2442
Injuries: 1 Fatal,1 Serious.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
On July 29, 2011, about 1247 eastern daylight time, a special light sport airplane (SLSA) TL Ultralight Sro Sting S3, N2442, registered to N2442 Aviation, LLC, operated by Universal Flight Training, LLC, was lost from radar and crashed about 12 nautical miles southeast of the Sarasota/Bradenton International Airport (SRQ), Sarasota, Florida. Visual meteorological conditions prevailed at the time and flight plan information is unknown for the 14 Code of Federal Regulations (CFR) Part 91 instructional local flight from the SRQ airport. The airplane sustained substantial damage, and the certified flight instructor (CFI) sustained serious injuries while the pilot-rated student was fatally injured. The flight originated from SRQ about 1230.
According to the Federal Aviation Administration (FAA) inspector-in-charge, the purpose of the flight was checkout of the pilot-rated student. After departure, the flight proceeded to a practice area southeast of SRQ, and while performing a power off stall, the airplane entered a spin, which the CFI was unable to recover. The airplane impacted the canopy of a large oak tree before coming to rest at the base of the oak tree. The CFI was able to exit the airplane; however, due to his injuries, waited on the ground next to the airplane for rescue personnel. The pilot-rated student had to be extricated from the airplane. Both occupants were airlifted by helicopter to a hospital in St. Petersburg, Florida.
The airplane was equipped with an airframe parachute recovery system; however, it was not activated.
Myakka, Florida -- A small aircraft has crashed at Myakka State Park in Sarasota.
It happened shortly before 1 p.m. Friday near Hi Hat Ranch at Utopia and Diebold roads.
Kathleen Bergen from the FAA tells 10 News that based on preliminary information, the ultralight airplane took off from Sarasota Bradenton Airport and flew about 10 miles east-southeast. The Sarasota Sheriff's Office says that's when the plane's engine stalled, sending the aircraft into a spin.
Two people, 56-year-old Larry Eslinger and his student pilot, were injured in the crash and air lifted to Bayfront Medical Center for treatment. Deputies say the student was able to call 911 and dispatchers used GPS satellites to locate the cell phone and crash site.
Photo Gallery: Small plane crashes in Myakka State Park
Aerial footage shows the plane crashed in a heavily wooded area of the park.
The Federal Aviation Administration and National Transportation Safety Board will investigate the cause of the crash.
Based on the plane's tail number, it appears the aircraft is a TL-Ultralight, fixed wing single-engine airplane.
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