NTSB Factual Report

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

NTSB Probable Cause

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.