Aviation Accident Summaries

Aviation Accident Summary MIA06FA024

Mims, FL, USA

Aircraft #1

N666DE

Piper PA-32-300

Analysis

During cruise flight, the pilot reported to air traffic control that the airplane's engine had ceased operating and declared an emergency. Subsequently, the pilot reported that there was "oil all over the windshield" and that he was attempting a forced landing. The airplane collided with trees in a densely wooded area. No witnesses to the accident were identified. During examination of the wreckage, oil was noted on the bottom of the fuselage, the inboard bottom skins of the left and right wings, and the tail surfaces. The #2 cylinder was found separated from the engine. Examination of the engine revealed that all 8 of the fasteners (6 studs and 2 through bolts) securing the #2 cylinder to the crankcase were separated. Fretting was noted on the mating surfaces of the cylinder base flange and the crankcase deck (flat face around the cylinder bore) and on the mating surfaces of the crankcase halves. Metallurgical examination of the 8 fasteners indicated they all separated due to fatigue cracking probably due to insufficient clamping force. Insufficient clamping force can result from improper torque application at cylinder installation or from the clamped surfaces moving closer over time. Fracture of the studs led to separation of the #2 cylinder from the crankcase and a loss of engine power. Examination of the maintenance records showed that the engine had accumulated about 839 hours since a major overhaul approximately 13 years prior to the accident. There were no entries in the records indicating removal of the #2 cylinder since the major overhaul.

Factual Information

HISTORY OF FLIGHT On November 23, 2005, at 1041 eastern standard time, a Piper PA-32-300, N666DE, registered to Legal Air LLC, and operated by a private individual, as a Title 14 CFR Part 91 personal flight, experienced a loss of engine power and collided with trees during a forced landing near Mims, Florida. The private pilot and the passenger received fatal injuries, and the airplane incurred substantial damage. Visual meteorological conditions prevailed, and a visual flight rules (VFR) flight plan was filed for the personal cross country flight. The flight originated from West Palm Beach, Florida, about 0850, and the intended destination was Greenville, South Carolina. According to information obtained from the FAA's Daytona Beach Air Traffic Control Tower, the flight was receiving VFR flight following services from air traffic control. At 1039:15, the pilot declared an emergency, stating "mayday, mayday, mayday just blew an engine...." Subsequently, the pilot reported that there was "oil all over the windshield" and that he was attempting a forced landing. The controller told the pilot that he was directly over Interstate Highway 95 (I-95) and about 7 miles north of Arthur Dunn Airpark. At 1040:27, the controller informed the pilot he was at an indicated altitude of 2,800 feet, about 1/2 mile east of I-95 and 7 miles north northwest of Arthur Dunn Airpark. The pilot asked if Arthur Dunn had a paved runway. The controller responded that the runway was paved, suggested a heading of 160 and informed the pilot he was at an indicated altitude of 2,000 feet. At 1041:22, the pilot responded "roger," which was the last transmission received from the airplane. Between 1041:25 and 1043:01, the controller made 7 additional transmissions directed to the accident airplane. In 4 of these transmissions, the controller pointed out the airplane's position as "just east" of I-95. About 1044, the Brevard County Sheriff's Office received notification that the airplane was down and immediately began a search with ground and air units. The accident site was located in a densely wooded area about 0.2 nautical miles east of I-95, in the vicinity of mile marker 225. The location was at latitude 28:41.02 North and longitude 080:52.443 West. No witnesses to the accident were identified. PERSONNEL INFORMATION The pilot held a private pilot certificate with single engine land airplane and instrument airplane ratings. His most recent medical certificate was a third class medical certificate issued on November 17, 2003, with no limitations. Review of the pilot's logbook indicated that he had accumulated about 1,390 hours total flight time. The last flight recorded in the logbook was dated July 17, 2005. AIRCRAFT INFORMATION Review of the airplane's maintenance records indicated that the 1975 model Piper Cherokee Six received its most recent annual inspection on July 16, 2005, at a total time of 2,960.0 hours. As of that date, the engine, a Lycoming IO-540-K1A5, S/N L-13304-48A, had accumulated 824.8 hours since major overhaul. When the accident occurred, the airplane had been flown about 15.7 hours since the annual inspection. The engine major overhaul was completed on January 16, 1992. On June 14, 1995, the #4 cylinder was removed due to low compression, repaired, and reinstalled. There were no other logbook entries indicating removal of cylinders since the major overhaul. METEOROLOGICAL INFORMATION At 1050, the reported weather conditions at the Space Coast Regional Airport, Titusville, Florida, located about 11 nautical miles south southeast of the accident site, were wind from 330 degrees at 9 knots, visibility 7 statute miles, sky clear, temperature 11 degrees C, and altimeter 30.06 inches. WRECKAGE AND IMPACT INFORMATION The main wreckage, consisting of the fuselage, empennage and wings, was located at the base of a large tree. Bark was missing and scrape marks were visible at the 30-foot level of the tree. Semicircular indentations on the inboard leading edge of the right wing were consistent with tree impact. A wreckage debris path extended from the main wreckage for approximately 65-feet along a measured magnetic heading of 130 degrees. The instrument panel with the attached engine was separated from the fuselage and found 45-feet forward of the main wreckage. The #2 cylinder was found approximately 20-feet forward of the engine and instrument panel. The fuselage came to rest inverted and sustained heavy impact damage. Oil was noted on the bottom fuselage skins. The left and right wings remained partially attached to the fuselage. Both wings sustained leading edge impact damage. Oil was noted on the bottom inboard skins of both wings. The empennage remained attached to the fuselage. The top of the vertical stabilizer and rudder sustained impact damage, and the outboard section of the right stabilator was bent upwards approximately 90 degrees. Oil was noted on the inboard stabilator skins, the rudder and the vertical stabilizer. All control surfaces remained attached to their respective attach points. All control cables were traced and were either intact or exhibited evidence of tensile overload. The propeller remained attached to the engine crankshaft. All three propeller blades were bent aft and displayed torsional twisting and spanwise abrasion to the cambered surfaces. Examination of the engine revealed that all 8 of the fasteners (6 studs and 2 through bolts) securing the #2 cylinder to the crankcase were separated. A fragment from each of the 6 cylinder barrel-to-crankcase studs remained inserted in the #2 cylinder deck portion of the engine case, and the 2 through bolts remained attached to the opposite side of the case. None of the hold down nuts or separated ends of the broken fasteners were found. The #2 cylinder exhibited damage to the skirt from contact with the #2 connecting rod. Fretting was noted on the mating surfaces of the cylinder base flange and the crankcase deck (flat face around the cylinder bore). The #2 piston and connecting rod assembly was missing from inside the crankcase and was not located at the accident site. The #2 connecting rod crankshaft journal did not display signatures of heat distress, scoring, or lack of lubrication. The crankshaft was rotated by hand and continuity of the undamaged valve train and internal gears was verified. The remaining 5 cylinders produced thumb compression when the engine was rotated. Both magnetos produced spark at all towers during manual rotation. Residual fuel was found within the engine driven fuel pump. The oil filter and suction screen were free from debris. Fastener torque on the remaining cylinders was checked and all were found secure according to the required specifications. The remaining cylinder assemblies were removed and the crankcase was opened. Fretting was noted on the mating surfaces of the crankcase halves. The #2 cylinder, the crankcase halves, and the 8 crankcase through bolts were retained for further examination. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies of the pilot and passenger were performed by the District #18 Medical Examiner, Rockledge, Florida. No findings that could be considered causal were reported. Toxicological testing on specimens from the pilot were conducted by the FAA's Toxicology and Accident Research Laboratory. The tests detected no carbon monoxide, cyanide, ethanol or drugs. TESTS AND RESEARCH The #2 cylinder, crankcase halves, and 8 crankcase through bolts were examined at the NTSB Materials Laboratory in Washington, DC. Visual and bench binocular microscope examination of the fracture faces of the 8 separated fasteners from the #2 cylinder revealed crack arrest features typical of fatigue cracking. The fatigue cracks emanated from multiple origins at the root of the threads. With the exception of one stud, the fatigue crack in each stud propagated through at least 75% of the cross section of the stud. The fracture features located outside the fatigue zones exhibited features typical of overstress separation. For further details of this examination, see the Materials Laboratory Factual Report in the public docket for this investigation. ADDITIONAL INFORMATION The airplane wreckage with the exception of the #2 cylinder, the crankcase halves, and the 8 crankcase through bolts, was released to a representative of the owner on November 25, 2005. The retained parts were returned to the owner's representative on March 15, 2007.

Probable Cause and Findings

The loss of engine power due to improper installation of the #2 cylinder by maintenance personnel, which resulted in the separation of the cylinder as a result of fatigue cracking of the cylinder to crankcase fasteners. A contributing factor was the lack of suitable terrain for the forced landing.

 

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