Jean, NV, USA
N2421D
Piper PA-38-112
The airplane impacted flat desert terrain following an in-flight loss of control. There were no witnesses to the accident. The local solo instructional flight departed about 45 minutes prior to the accident. Recorded radar data indicated that the airplane flew on a southerly course and conducted numerous aerial maneuvers consistent with the type normally practiced during primary flight training. Following the maneuvers, the airplane landed at a nearby uncontrolled airport, then departed again in a northeast direction for 3.8 nm until radar contact was lost. The last radar contact was about 800 feet laterally west of initial impact point, at an above ground altitude of 2,400 feet. The airplane impacted the ground in a steep left bank with a nose low attitude around 30 degrees. The debris field was approximately 100 feet in length, with an energy path opposite in direction to the flight track shown by the recorded radar data. All flight control surfaces were located within the immediate area of the accident site. The right wing separated from the fuselage and was located 30 feet from the fuselage. The right wing aileron balance cable exhibited a tension overload failure inside the right wing. The right wing primary aileron cable was found disconnected at the turnbuckle where it attaches to its corresponding rod end clevis fitting located in the fuselage. The turnbuckle barrel remained attached to the primary cable assembly and the clevis fitting remained attached to the link assembly. The turnbuckle barrel was safety wired on the outboard half that attaches to the primary cable and the safety wire looped back onto itself locking the turnbuckle barrel to the cable. No safety wire or locking device was found on the inboard half of the turnbuckle barrel or clevis fitting. Visual inspection of the threads of both the turnbuckle barrel and the clevis end disclosed that they were undamaged. According to the Piper PA-38-112 parts catalog, the primary cable turnbuckle barrel is to be secured with NAS651-16S locking clips on both sides; however, no clips were found at the accident site or during the subsequent detailed inspection of the wreckage. With the particular configuration of the turnbuckle assembly, it could not be properly secured by the use of safety wire alone. Measurement of the primary right wing aileron cable found that it was not stretched and there was no evidence to indicate that it was connected during the impact sequence. Aircraft records indicated the aileron flight control cable system, including the primary right wing aileron turnbuckle area, were visually inspected at the last 100-hour inspection. The aircraft maintenance records did not have any entries involving the adjustment, removal, or replacement of the aileron flight control cables or components, and the investigation was unable to establish when the safety wire was substituted for the NAS651-16S clips. The three pilots who had flown the airplane on the day before the accident (including one instructional flight and a private pilot practical flight test) reported that there were no discrepancies with the airplane during the flights. The physical evidence is wholly consistent with the primary aileron cable turnbuckle not being connected at ground impact. It is unlikely that the departure from controlled flight that resulted in the ground collision was due to the disconnected aileron cable; however, such a disconnect clearly could hinder any upset recovery effort. Visual meteorological conditions prevailed with no evidence of unusual, hazardous, or violent weather in the area. Evidence clearly shows the engine was producing significant power at ground impact.
HISTORY OF FLIGHT On March 18, 2004, at 1717 Pacific standard time, a Piper PA-38-112, N2421D, impacted terrain 3.7 nautical miles (nm) east of Jean, Nevada. Desert Southwest Airlines was operating the airplane under the provisions of 14 CFR Part 91. The student pilot, the sole occupant, sustained fatal injuries; and the airplane was destroyed. The solo instructional local flight departed Henderson Executive Airport (HND), Henderson, Nevada, at 1636. Visual meteorological conditions prevailed, and no flight plan had been filed. The primary wreckage was at 35 degrees 45.302 minutes north latitude by 115 degrees 15.295 minutes west longitude. The operator reported that the student pilot had checked out the airplane at 1600 for a solo training flight. The control tower at HND recorded his departure time as 1636. The National Transportation Safety Board investigator-in-charge (IIC) reviewed recorded radar data. The review found that at 1642 a secondary 1200 (VFR) beacon code was noted at a mode C reported altitude of 4,200 feet mean sea level (msl). Recorded radar data indicated that the target continued on a southerly course until north of Jean Lake, where a series of turns were conducted. The radar return indicated numerous aerial maneuvers with mode C altitude changes from 5,000 feet msl to the lowest reported altitude of 3,500 feet msl and finally leveling off at 4,500 feet msl. The duration of the maneuvering was over a 13-minute period. The radar track then departed the area of Jean Lake at a mode C reported altitude of 4,500 feet msl and continued in a southwest direction. At 1657, radar contact was lost 3 nm north of Jean Airport (OL7) with a recorded mode C altitude of 3,700 feet msl. At 1715, a radar target was recorded about 3 nm southeast of OL7 with the mode C reported altitude of 4,200 feet msl. The target continued northeast until radar contact was lost about 3.8 nm east of OL7. The last radar contact was about 800 feet laterally west of the first identified point of contact (FIPC), at an altitude of 4,400 feet msl, which was about 1,500 feet agl. The radar data showed the target traveling northeast in a direct line course towards HND. The accident site was discovered about 0600 on March 19, 2004, by a miner on his way to his work site. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed that the pilot held a student pilot certificate. The certificate was endorsed for solo privileges in a PA-38. The pilot held a first-class medical certificate that was issued on November 19, 2002. It had the limitations that the pilot must wear corrective lenses. An examination of the pilot's logbook indicated a total flight time of 42 hours. He logged 8 hours in the last 90 days, and 1 hour in the last 30 days. He had logged 42 hours in the accident make and model. AIRCRAFT INFORMATION The airplane was a Piper PA-38-112, serial number 38-79A0305. A review of the airplane's logbooks revealed a total airframe time of 5,091.2 hours at the last 100-hour inspection, which was completed on January 20, 2004. The logbooks had an entry for an annual inspection dated March 17, 2003. The tachometer read 483.9 at the last inspection. The tachometer read 556.0, and the Hobbs hour meter read 5,389.9 at the accident scene. The engine was a Textron Lycoming O-235-L2C engine, serial number L-17979-15. Total time since overhaul on the engine at the last 100-hour annual inspection was 508.2 hours. The engine was a four cylinder, air cooled, direct drive, horizontally opposed, normally aspirated (carburetor), internal combustion engine factory rated at 115HP at 2,800 revolutions per minute (rpm). The subject engine had been modified to produce 125 hp at 2,800 rpm by way of a Supplemental Type Certificate (STC) SE792NW. A supplemental data plate had been affixed to the engine. Examination of the maintenance and flight department records revealed no unresolved maintenance discrepancies against the airplane prior to departure. Fueling records at HND established that the airplane last fueled on March 17, 2004, with the addition of 3.2 gallons of 100LL octane aviation fuel. Aircraft records indicated the aileron flight control cable systems were visually inspected at the last 100-hour inspection. The aircraft records did not indicate any entries involving the adjustment, removal, or replacement of the aileron flight control cables or system components. The FAA IIC interviewed three pilots who had flown the accident airplane on March 17, 2004, which was the day before the accident. They reported that during an instructional flight, and during a private pilot check ride, there were no noted discrepancies with the airplane. METEOROLOGICAL INFORMATION The closest official weather observation station was the departure airport HND, located 14 nm north of the accident site. The elevation of the weather observation station was 2,492 feet msl. An aviation routine weather report (METAR) for HND was issued at 1745. It stated: winds from 180 degrees at 8 knots; visibility 20 miles; skies clear; temperature 81 degrees Fahrenheit; dew point 25 degrees Fahrenheit; altimeter 29.90 inHg. WRECKAGE AND IMPACT INFORMATION Investigators from the Safety Board, the FAA, New Piper Aircraft, and Textron Lycoming examined the wreckage at the accident scene. The accident site was located 20 nm south of Las Vegas, Nevada, and 3.7 nm east of Jean. The terrain was flat desert with low desert shrubs. The ground elevation at the accident site was 2,878 feet msl. The first identified point of contact (FIPC) was a long thin ground scar leading 50 feet to where the propeller was found with one blade imbedded in the sand. The debris path was along a magnetic bearing of 160 degrees. The debris field was approximately 100 feet in length. All flight control surfaces were located within the immediate area of the accident site. The FIPC contained red glass fragments, semicircular in shape, similar in color, shape, and size of a navigation light lens, which would be normally installed on the left wing tip. The propeller, left cabin door and a portion of the left wing fuel tank separated from the aircraft and were located about 50 feet from the FIPC. The main wreckage consisted of the fuselage; the left wing and tail section located about 70 feet beyond the FIPC. The right wing separated from the aircraft and came to rest about 30 feet beyond the main wreckage. The orientation of the fuselage from the tail to the nose was on a magnetic bearing of 140 degrees. ENGINE COMPONENTS The propeller was found separated from the engine assembly and was imbedded with one blade buried into the ground. The two-bladed fixed pitch propeller was separated from the crankshaft flange attachment point. The bolts were bent to the left at a 45-degree angle opposite of the direction of normal rotation. The propeller blades displayed leading edge gouging, torsional twisting, chordwise striations across the cambered surface and trailing edge "S" Bending. The engine remained attached to the airframe by the engine mounts. The engine sustained impact damage to the forward bottom section encompassing the oil sump and attached components. The accessories section sustained crush damage between the engine and the firewall. The propeller was separated from the crankshaft flange. The crankshaft flange was bent and impinged against the engine case precluding rotation of the crankshaft. The cylinders were borescoped and were unremarkable. The onsite engine examination revealed no evidence of preimpact catastrophic mechanical malfunction or fire. The carburetor remained securely attached at the mounting flange of the oil sump. The throttle/mixture controls were found securely attached at their respective control arms of the carburetor. All engine compartment fuel lines were found to be in place and secure. The fuel pump was attached to the engine at the mounting pad. The fuel lines remained secure at their respective fittings. The left and right magnetos sustained impact damage, and were displaced from their respective mounting pad. The pieces of magneto flange that remained at the mounting pad were securely clamped. Magneto to engine timing could not be ascertained. The spark plugs were secure at each position with their respective spark plug leads attached. The top spark plugs were removed, examined and photographed. The spark plug electrodes remained mechanically undamaged, and according to the Champion Spark Plugs Check-A-Plug chart AV-27, the spark plug electrodes displayed coloration consistent with normal operation. AIRFRAME COMPONENTS Left Wing The left wing separated from the fuselage at the wing root area from ground impact and was extensively damaged. The wing assembly was bowed in an upward direction. Both the aileron and flap surfaces were damaged but remained attached to the wing. The left wing primary aileron control cable was continuous and securely fastened at both ends. The left wing primary control cable turnbuckle barrel was found attached and secured to the cable assembly and clevis rod end by two NAS651-16S locking clips. The balance cable that connects at the left and right wing aileron bellcranks were broken and separated in the right wing. The cable strands were broomstrawed. The outboard section of the right side balance cable remained attached to the aileron bellcrank. Right Wing The right wing separated outboard of the wing root area at nose rib station 37.5. The wing came to rest about 30 feet forward of the fuselage. The fuel tank assembly separated from the wing and came to rest a few feet forward of the main spar. Both the aileron and flap surfaces remained attached to the wing. The right wing primary aileron control cable was found disconnected at its turnbuckle where it attaches to the corresponding rod end clevis fitting located in the fuselage. The clevis fitting attaches to the torque tube assembly that extends aft through a tunnel in the fuselage by means of a link assembly. The turnbuckle barrel remained attached to the primary aileron cable assembly and the clevis fitting remained attached to the link assembly. No NAS651-16S locking clips were found at the accident site. The turnbuckle barrel was safety wired on the outboard end that attaches to the primary cable. The safety wire looped back onto itself locking the turnbuckle barrel to the cable. No safety wire or locking device was found on the inboard end of the turnbuckle barrel or clevis fitting. Visual examination of the threads of both the turnbuckle barrel and the clevis end disclosed they were undamaged. The outboard end of the right primary control cable remained attached to the aileron bellcrank assembly. The end of the cable that attaches to the aileron bellcrank has a swedge ball that fits into a socket of a clevis fitting. The ball where it contacts the socket area of the clevis fitting exhibited a shinny and polished surface. The balance cable that connects between both the left and right wing aileron bellcranks was broken and separated in the right wing. The cable strands were broomstrawed. The outboard section of the right side balance cable remained attached to the aileron bellcrank. EMPENNAGE The rear tail cone section remained attached to the fuselage. The rear empennage T-tail section had twisted around and downward coming to rest upside down on the left side of the tail cone section. Both sides of the elevator surface and the rudder surface remained attached at their respective attach fittings. The rudder and elevator control cables remained attached and were continuous to the cockpit. Fuselage The forward fuselage and cabin area sustained extensive ground impact damage and were destroyed. Examination of the cockpit flight controls revealed that the rudder cables remained attached to the rudder control arms and the elevator control cables remained attached at the tee bar assembly. The aileron chain was broken and off the left side upper control column sprocket assembly. The chain remained engaged to the right side upper control column sprocket assembly. The chain remained engaged in the lower control column sprocket. The fuel selector valve was selected to the RIGHT main position. The Emergency Locator Transmitter (ELT) separated from its mounting rack and was destroyed by impact forces. The ELT switch was found in the "ARM" position. MEDICAL AND PATHOLOGICAL INFORMATION The Clark County Coroner completed an autopsy on March 20, 2004. The FAA Toxicology and Accident Research Laboratory performed toxicological testing of specimens of the pilot. The results of analysis of the specimens were negative for carbon monoxide, cyanide, volatiles, and tested drugs. TESTS AND RESEARCH Investigators examined the wreckage at Air Transport, Phoenix, Arizona, on April 14, 2004. The PA-38-112 aircraft utilizes a right wing primary aileron cable that is 112.375" plus or minus 0.125" measured from the center of the clevis bolt hole to the tip of the threads of the turnbuckle fitting. The free length of the primary cable in the accident aircraft was measured and found to be within the above stated tolerance. According to the Piper PA-38-112 parts catalog, the primary cable turnbuckle barrel is to be secured with NAS651-16S locking clips on both sides. The configuration of the turnbuckle assembly would not and could not be properly secured by use of safety wire. According to Piper PA-38-112 maintenance manual, Chapter 27-10-05 titled RIGGING AND ADJUSTMENT OF AILERON CONTROLS, following any rigging or adjustment, "check complete system for operation and safety of turnbuckles, bolts, etc." In addition, the Inspection Report found in Chapter 5 of the maintenance manual under WING GROUP states every 100, 500, and 1,000 hours to "Inspect all control cables, electrical leads, lines and attaching parts for security, routing, chafing, deterioration, wear, and correct installation." ADDITIONAL INFORMATION The IIC released the wreckage to the owner's representative on May 17, 2004.
The student pilot's failure to regain control of the aircraft following an upset due to the disconnected primary right aileron control cable. The failure of the company maintenance personnel to detect and correct the improperly secured turnbuckle fitting at the last 100-hour inspection is also causal.
Source: NTSB Aviation Accident Database
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