# NTSB NYC07LA125: Cessna 172E, N3982S, Leesburg, VA, May 23, 2007 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 23, 2007, 16:55 local (20:55 UTC) - Place: Leesburg, VA - Coordinates: 39.06361, -77.636665 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.0636&lon=-77.6367&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 65862 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC07LA125 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/65862/pdf - Page: https://openairdocs.org/ntsb/NYC07LA125 ## Probable cause The loss of engine power that resulted from the failure of an exhaust valve rocker arm during cruise. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - engine assembly,rocker arm/tappet - cracked - engine assembly,rocker arm/tappet - failure (cause) - Forced landing, descent - emergency - On ground/water encounter with terrain/water, emergency descent/landing - terrain condition - ditch ## Analysis The pilot was relocating a Cessna 172E for the airplane's annual maintenance inspection. During the flight, the engine suffered a partial loss of power and began to "shake and misfire violently." The pilot then attempted to control the engine by adjusting the throttle and mixture controls, without result. As the airplane descended, the pilot looked for a place to land and spotted an open field. After turning final, he extended his wing flaps to the 40-degree position and touched down. During the emergency landing the airplane approached a ditch. The pilot attempted to get over the ditch by raising the flaps, but the airplane struck the far side of the ditch. During a postaccident examination of the engine, it was discovered that the No.2 cylinder's exhaust valve rocker arm was fractured and had separated into two parts. The initial fracture on the exhaust valve rocker arm was on the push rod side of the arm. This fracture had features indicative of overstress. The fracture on the valve side of the arm was secondary to the overstress fracture on the push rod side. The fatigue cracking at this location appeared to be the result of bending loads generated after the fracture on the push rod side was created. The fracture on the push rod side of the arm was generated from some type of high load event, possibly during an overhaul 34.8 hours prior to the accident. The pilot/owner had purchased one of the cylinders on "eBay," and there were discrepancies in the engine maintenance records. ## Factual narrative On May 23, 2007, about 1655 eastern daylight time, a Cessna 172E, N3982S, was substantially damaged during a forced landing, shortly after takeoff from Leesburg Municipal Airport (JYO), Leesburg, Virginia. The certificated private pilot received minor injuries. Visual meteorological conditions prevailed and a visual flight rules (VFR) air defense identification zone (ADIZ) flight plan was filed for the flight destined for Culpeper Regional Airport (CJR), Culpeper, Virginia. The personal flight was conducted under 14 Code of Federal Regulations Part 91. According to the pilot, the purpose of the flight was to relocate the airplane to CJR for the airplane’s annual maintenance inspection. After departure from runway 17, the pilot started a turn to the west and made his initial call to air traffic control (ATC). After the airplane crossed state route 15, the pilot made a power reduction to 2,400 rpm. The engine "without warning lost most of its power" and began to "shake and misfire violently." The pilot attempted to control the engine by adjusting the throttle and mixture controls, without result. He then declared an emergency with ATC and began to receive vectors from the controller. He looked for a place to land and spotted an open field. He obtained best glide speed, turned on to a base leg for the field he had selected, and after turning on to a final leg, extended his wing flaps to the 40-degree position and touched down. The airplane passed through a row of trees located halfway down the field; however, a ditch existed on the opposite side. The pilot attempted to get over the ditch by raising the flaps, but the airplane struck the far side of the ditch, the nose gear collapsed and the airplane was substantially damaged. The pilot held a private pilot certificate with a rating for airplane single-engine land. He had accumulated 235.7 total hours of flight experience; 53.1 hours of which were in the accident airplane make and model. According to Federal Aviation Administration and maintenance records, the airplane was manufactured in 1964. The airplane’s most recent annual inspection was completed on May 18, 2006, and at the time of the accident, it had accumulated 4017.3 total hours of operation. According to the pilot, the engine had accumulated 2,996.5 total hours of operation at the time of the accident. An overhaul of the engine had been completed on March 25, 2005. The time since overhaul was 34.8 hours and the engine had been operated 6.9 hours since the most recent annual inspection. Examination of the airplane and engine by National Transportation Safety Board investigators revealed no preimpact malfunctions of the airplane or its systems; however, during examination of the engine, it was discovered that the No.2 cylinder’s exhaust valve rocker arm was fractured and had separated into two parts. The fractured exhaust valve rocker arm, rocker shaft, push rod, and intact intake valve rocker arm were examined by the Safety Board’s Materials Laboratory. The examination revealed that the exhaust valve rocker arm had fractured at two locations through the rocker shaft hole, with about one-third of the pivot hole circumference on one piece of the arm and two-thirds on the other. Both fractures intersected oil holes on the inside diameter of the rocker shaft hole. The features on the push rod side fracture emanated from a single location at the forging flash line on the inboard side of the arm. This fracture propagated into the arm, turning into the inside diameter of the arm’s central pivot hole. The fractographic features were rough, and when viewed optically, were indicative of overstress. No crack arrest positions were noted. Examination of this fracture with a scanning electron microscope did not revealed any features conclusively indicative of other cracking modes. Optical examination of the fracture on the valve side of the rocker arm revealed that more than half of the fracture contained features that were typical of fatigue cracking. Fatigue initiation was from the pivot hole inner surface adjacent to the oil hole. Fatigue propagation extended approximately 5 millimeters from the pivot hole inner surface into the arm. Fracture features beyond that depth were typical of overstress. Compression damage on the portion of the fracture furthest from the origin area, and scuffing damage on the bushing adjacent to this fracture, were consistent with the exhaust valve side fracture being secondary to the fracture on the push rod side of the arm. The wear pattern on the exhaust valve contact surface on the exhaust valve rocker arm was off-center and blurred. Two overlapping wear patterns were noted on the intake valve contact surface on the intact intake valve rocker arm. No unusual wear patterns were noted on the push rod contact area on either of the rocker shafts. No damage or unusual wear patterns were noted on the rocker shaft. The push rod however, exhibited a bend measuring approximately 0.005 inch. According to the owner, one of the cylinders was purchased on "eBay." During examination of the accident airplane’s engine maintenance records, no serviceable tags for the engine cylinders were discovered. Further examination of the engine maintenance records revealed that the engine removed previously was listed as serial No. 33130-D-5-D. The engine listed as having been installed after overhaul was serial No. 33150-D-5-D. Examination of the engine revealed that the data plate on the engine was flat, did not conform to the shape of the case, was held on with two rivets, and displayed the serial number as 33130-D-5-D. ## Aircraft - Registration: [N3982S](https://openairdocs.org/deregistered/N3982S-2025-06-24), registration cancelled 2025-06-24, S/N 17251182, built 1964 (OpenAirDocs) - Reported make and model: CESSNA 172E - Registry model: [Cessna 172E](https://openairdocs.org/model/cessna-172e) (registry code 2072412) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17251182 - Airframe hours: 4017.3 - Engines: Continental O-300-D 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 18, 2006, 6.9 hours before - Departed: JYO, Leesburg, VA - Destination: CJR, Culpeper, VA - Flight plan: VFR - Airport: JYO, Leesburg Municipal Airport, runway 17, 5,500 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; flight hours: 236 total, 53 in this make and model, 236 as pilot in command, 4 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 10 knots, gusting 15 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 54 °F - Altimeter: 30.37 inHg - Observed at: JYO, 4 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20070523016289A](https://openairdocs.org/incident/20070523016289A), May 23, 2007: Cessna 172E, Leesburg, VA, Substantial damage. (-23) Approximately five minutes into flight engine started sputtering and quit. Pilot just fueled at Leesburg on his way to winchester for an annual… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.