NTSB Factual Report

HISTORY OF FLIGHT

On March 30, 2010, about 1830 eastern daylight time, a Cessna 182P, N52790, registered to Montgomery Aviation Ltd., operated by Montgomery County Department of Transportation, lost engine power and sustained substantial damage during a forced landing at Monocacy National Battlefield, Frederick, Maryland. Visual meteorological conditions prevailed at the time and a Washington, D.C. SFRA flight plan was filed for the public use flight from Montgomery County Airpark (GAI), Gaithersburg, Maryland. The certificated commercial pilot and the sole passenger sustained minor injuries. The flight originated from GAI about 1620.

The purpose of the flight was for the passenger, a Montgomery County employee, to observe traffic congestion in the county and to relay that information to county traffic management employees. The pilot stated that before departure she completed her normal pre-flight and noted the winds appeared to be challenging but not outside her safety margins. She filed a SFRA flight plan and intended on returning at 1800 hours. At some portion of the flight while flying a route, she noticed that the surface winds were increasing at the departure airport and the flight was encountering increased turbulent conditions than normally encountered when the surface winds gust to 25 knots. As a result she elected to return earlier than planned.

The flight proceeded to the departure airport and the pilot further stated she aborted her first approach because she was unable to maintain a stabilized approach due to turbulence and/or windshear. She initiated a climb to altitude and because she had been in contact with and monitoring communications from the Washington Reagan National Airport (DCA) air traffic control tower, she was aware that the wind velocity was lower at DCA than at her intended destination (GAI). She remained airborne hoping that the wind velocity at her destination airport would decrease, and after 1800, she elected to execute a second approach to her intended destination airport. During the approach, the flight encountered windshear strong enough to cause the headsets they were wearing to fall off. She aborted the approach and after being given the surface wind for Frederick Municipal Airport (FDK), elected to proceed there. When the flight was approximately 5 nautical miles south of the destination airport the flight encountered severe turbulence causing the airplane to quickly climb then immediately and violently descend. At that time the engine abruptly lost power and was not responsive to throttle movement. Attempts to restart the engine were unsuccessful. She looked for a suitable landing site in the area and maneuvered the airplane for a forced landing at the Monocacy National Battlefield while encountering 30 plus knots gusty wind conditions. She aimed for the nearest end of the field and while maintaining a suitable airspeed given the gusty wind state, the airplane touched down on wet grass then bounced. The airplane touched down again and during the landing roll out she reported the braking as nill. The airplane traveled into a culvert and nosed over. The passenger exited the airplane first and assisted the pilot in exiting the airplane.

The passenger stated that during the forced landing, the airplane touched down on wet grass 1/3 to 1/2 way down the Monocacy National Battlefield and bounced 2 or 3 times. While rolling on the main landing gear with the brakes applied the airplane collided with a culvert located at the intersection of Urbana Pike and New Technology Way.

PERSONNEL INFORMATION

The pilot, age 40, holds commercial and flight instructor certificates with airplane single and multi-engine land, instrument airplane ratings at the commercial level. She was issued a second class medical certificate on March 10, 2010, with a restriction to wear corrective lenses for near and distant vision.

She listed on the NTSB Pilot/Operator Aircraft Accident/Incident Report having a total time of 2,332 hours, of which 1,426 were in the accident make and model airplane. Additionally, she listed having 2,185 hours as pilot-in-command (PIC), of which 1,270 hours were as PIC in the accident make and model airplane.

AIRCRAFT INFORMATION

The airplane was manufactured in 1974 by Cessna Aircraft Company, as model 182P, and was designated serial number 18262846. It was powered by a 230 horsepower Teledyne Continental Motors (TCM) O-470-U37(B) engine and equipped with a McCauley fixed pitch propeller.

Review of the maintenance records revealed the engine was last "rebuilt" by TCM on June 16, 2005, and installed in the accident airplane on July 14, 2005. The engine remained installed in the airplane up to the accident date and had accumulated 1,258 hours since then. Further review of the maintenance records revealed the last magneto timing check was performed on January 12, 2010. The airplane had accumulated 129 hours since then at the time of the accident. There was no record of a direct entry indicating inspection of either magneto primary contact points since the rebuilt engine was installed.

METEOROLOGICAL INFORMATION

A surface observation weather report taken at the departure airport at 1615, or approximately 5 minutes before departure indicates in part that the wind was from 320 degrees at 13 knots with gusts to 24 knots.

A surface observation weather report taken at Frederick Municipal Airport at 1823, or approximately 7 minutes before the accident, indicates the wind was from 340 degrees at 11 knots with gusts to 21 knots. The visibility was 10 statute miles, scattered clouds existed at 3,900 feet, broken clouds existed at 6,000 feet, and overcast clouds existed at 6,500 feet. The temperature and dew point were 13 and minus 6 degrees Celsius respectively, and the altimeter setting was 29.68 inches of mercury. The accident site was located approximately 197 degrees and 2.7 nautical miles from FDK.

WRECKAGE AND IMPACT INFORMATION

Examination of the inverted airplane at the accident site was performed by an FAA airworthiness inspector. Flight control continuity was confirmed for roll, pitch, and yaw. The fuel selector was found in the "both" position. Broken engine mounts were noted. Engine control continuity was confirmed from the cockpit to each respective control at the carburetor; however, the mixture control lever at carburetor was in the idle cutoff position and the mixture control in the cockpit was in the full rich position. The mixture vernier cable at the carburetor was pulled out of the clamp which holds the outer metal casing of the cable stationary while the cable inside is allowed to move to adjust the mixture. Additionally, an adel clamp which secures the cable to the engine mount was oil soaked. The left fuel tank was found to contain approximately 12 gallons, while the right fuel tank was found to contain approximately 8 gallons. No fuel was noted in the fuel strainer, and there was no blockage of the fuel supply lines from the fuel strainer to each wing root. Examination of the P-leads and ignition switch by an airframe and powerplant mechanic with inspection authorization revealed no evidence of preimpact failure or malfunction.

Examination of the engine following recovery of the airplane by an FAA airworthiness inspector revealed crankshaft, camshaft, and valve train continuity. Compression was noted at each cylinder during rotation of the engine. Inspection of the carburetor revealed approximately 3/8 inch of fuel in the carburetor bowl. Inspection of the floats showed no indication of binding, sticking or chafing. There was no evidence of external leakage on the carburetor. Inspection of the spark plugs revealed normal color; however, the spark plugs on the left side of the engine were oil soaked due to the position of the engine (being inverted). The ignition harness tested satisfactory. The magneto to engine timing was checked and they were found to be timed approximately 22 degrees before top dead center (BTDC) (specification is 24 degrees BTDC). During rotation of the engine with the ignition leads connected to the spark plugs, no spark was noted at any of the spark plugs. The magnetos were removed for further examination; no defects were noted to either magneto driven gear.

Examination of the left magneto revealed that during hand rotation, very weak spark was noted. The primary contact point gap was found to be approximately 0.002 inch (specification is 0.008 to 0.012 inch). The point gap was set to 0.010 inch and during hand rotation of the magneto, no spark was noted. A new set of contact points was installed and set to 0.010 inch. The magneto was rotated by hand and spark was noted. The accident set of contact points were cleaned and dressed then reinstalled and set to 0.010 inch. The magneto was rotated by hand and produced spark.

Examination of the right magneto revealed that during hand rotation, very weak spark was noted. The primary contact point gap was found to be approximately 0.002 inch (specification is 0.008 to 0.012 inch). The point gap was set to 0.010 inch and during hand rotation of the magneto, spark was noted.

TESTS AND RESEARCH

The magneto maintenance and overhaul manual (L-1363C) indicates that the primary contact points are to be inspected every 500 hours.

NTSB Probable Cause

A loss of engine power for undetermined reasons following a reported severe turbulence encounter.