SWANTON, OH, USA
N1007A
MOONEY M20K
THE AIRPLANE WAS ON AN IFR FLIGHT PLAN DESCENDING THROUGH 10,400 FEET, WHEN THE PLT REPORTED A VIBRATION AND ROUGH RUNNING ENGINE. ATC PROVIDED RADAR VECTORS TO AN AIRPORT 15 MILES AWAY. THE PLT STATED THAT HE ELIMINATED THE VIB BY FEATHERING THE PROP. WHEN THE ACFT WAS ABOUT 3 1/2 MILES FROM THE AIRPORT, THE PLT REPORTED THE FIELD INSIGHT. THE ACFT STRUCK TREES AND IMPACTED THE GROUND ABOUT 3/4 OF A MILE FROM THE RUNWAY. THE #6 CYL HEAD BARREL WAS FOUND CRACKED APPROX 80% AROUND. THE ACFT WAS EQUIPPED WITH SEVERAL STCS WHICH INCLUDED A HORSEPOWER INCREASE OF 50%, A FULL FEATHERING PROP, AN INCREASED GROSS WT OF 117 LBS, SPEEDBRAKES AND LONG RANGE FUEL TANKS. THE ACFT WAS 500 LBS OVER GROSS AT TAKEOFF, AND WAS 342 LBS OVER THE MAXIMUM FOR LANDING, AT THE ACCIDENT SITE. THE RECOMMENDED ENGINE OUT AIRSPEED WAS 87 KNOTS. THE CALIBRATED AIRSPEED DURING THE DESCENT WAS CALCULATED AT 147 KNOTS. AT MAX GROSS WT AND 87 KNOTS, THE ACFT HAD A GLIDING DISTANCE OF 22 MI FROM 10,000 FEET. SEVERAL LONG FARM FIELDS EXISTED LEFT AND RIGHT OF THE AIRPLANE'S DESCENT PATH.
HISTORY OF FLIGHT On May 17, 1994, at 1937 eastern daylight time, a Mooney M-20K, N1007A, owned and piloted by Raymond J. Homa, was destroyed when it impacted trees during a forced landing near the Toledo Express Airport, Toledo, Ohio. The pilot and passenger were fatally injured. Visual meteorological conditions prevailed and a instrument flight rules (IFR) flight plan had been filed for the flight operating under 14 CFR 91. Mr. Homa was the owner of an electronics firm in Atlanta, Georgia, and the passenger was an employee. According to air traffic control records, Mr. Homa obtained a weather briefing from the Macon, Georgia, Automated Flight Service Station (AFSS), and filed an IFR flight plan from Dekalb-Peachtree Airport (PDK), Atlanta, Georgia, to Detroit City Airport (DET), Michigan. Mr. Homa was issued an IFR clearance to DET by the PDK Clearance Delivery, and at 1651 was cleared for takeoff by the PDK Tower. The pilot contacted Atlanta (ATL) departure control and was issued a climb to 11,000 feet, followed by a communications handoff to ATL Center. At 1701, N1007A requested a climb to Flight Level (FL) 190, and 3 minutes later was issued a climb to that altitude. The flight proceeded uneventful with several frequency changes over the next 130 minutes. Cleveland Center issued N1007A a descent to 11,000 feet, followed by a frequency change to the Toledo Approach (TOL) Control. The Toledo controller issued N1007A a descent to 5,000 feet, and a frequency change to another Toledo controller. At 1930:08, N1007A contacted the new Toledo controller and stated, "Ah, Toledo Approach, Mooney One Zero Zero Seven Alpha with you, ah, we're leaving eleven point seven for ah, five thousand, direct Poofe." The Controller acknowledged the call and provided N1007A the altimeter setting, which N1007A responded with, "Roger, the thirty twenty, Zero Seven A." According to the recorded radar data (RRD) provided by the Cleveland Center, and analyzed by the NTSB Office of Research and Engineering, from 1930:19 to 1932:10, N1007A averaged a rate of descent of 700 feet per minute (FPM). The average ground speed at that time, as indicated by the RRD, was 180 knots. The next communication came at 1932:19, when N1007A stated, "Ah, Toledo approach, Mooney ah, One Zero Zero Seven Alpha we're experiencing ah, quite a bit of vibration I'm de [sic] sure what it is ah, I don't know that we want to go across the ah water 'til we figure this out." The RRD altitude at this time was about 10,400 feet above mean sea level (MSL) with an average rate of descent of 200 FPM. The average ground speed at that time, as indicated by the RRD, was 165 knots. The Toledo controller responded with the offer to vector N1007A to the Toledo Express Airport (TOL) which was 15 miles northeast of his position. N1007A stated, "...affirmative, let's do that." The Controller then provided N1007A a heading for TOL. 1933:24; N1007A advised the controller, "We are running extremely rough, you say I'm one five to the southeast of Toledo Express." The controller responded affirmative and also stated, "...if you'd like a closer airport, you are seven miles southwest of Toledo Metcalf, your choice, wind is zero seven zero at six." N1007A replied, "Ah, negative on that, we'll ah, we'll take Express ah fifteen." After acknowledging a heading assignment, at 1933:58, N1007A stated, "...we have feathered our prop, ah that has gotten rid of the ah vibration." The RRD altitude at this time was 7,500 feet MSL with an average rate of descent of 2,300 FPM. The average ground speed at that time, as indicated by the RRD, was 155 knots. During the next 5 minutes, the Controller provided N1007A heading assignments for a direct flight to TOL. The Controller also provided the airport location and direction several times during the vector. The Controller informed N1007A at 1936:18 that he was 7 miles from TOL. Then at 1936:28, in response to a controller request for his type of aircraft, N1007A replied, "Mooney with an engine out." The last RRD provided was at 1936:33, when N1007A was descending through 3,600 feet MSL at an average rate of descent of 1,200 fpm. The average ground speed at that time, as indicated by the RRD, was 110 knots. The estimated distance from TOL was 6 1/2 miles. 1938:17; The Controller advised N1007A that, "...the airport's 12 O'Clock, three and a half miles, do you have the field in sight." 1938:32; N1007A advised the Controller that he had the field in sight. The Controller responded with, "November Zero Seven Alpha, proceed straight in for runway 34, contact, or correction remain this frequency." N1007A was cleared to land on runway 34 by the approach controller, and at 1939:14, after being given a wind check by the Controller, N1007A replied, "Zero Seven Alpha, thank you ma'am." There were no further communications with the airplane. According to one witness on the ground, when he observed the airplane, "...I noticed a plane coming over when I heard the engine sputter and cut out, then I watched the plane glide over head, it looked like the plane went up, slowed down, and then we heard it crash." An air traffic controller in the TOL Tower at the time of the accident stated, "...I observed the aircraft, it appeared to be in a normal attitude, that is , wings level, and in a descent. However, the aircraft appeared to be losing altitude rapidly. I then lost sight of the aircraft as it descended behind a tree line." The airplane struck trees and impacted the ground approximately 3/4 of a mile from the TOL runway. The accident occurred during the hours of dusk at approximately 41 degrees, 35 minutes north latitude, and 85 degrees, 48 minutes west longitude. PERSONNEL INFORMATION The pilot, Mr. Raymond J. Homa, held a Private Pilot Certificate with ratings for airplane single engine land and instrument airplane. His most recent Federal Aviation Administration (FAA) Third Class Medical Certificate was issued on July 8, 1993. Mr. Homa's pilot log book indicated he had accumulated a total of 2,200 hours of flight time, of which over 1,800 hours was in this make and model. AIRCRAFT INFORMATION The airplane was purchased by Mr. Homa in 1981. It was a standard Mooney M20K with a Continental TSIO-360-GB3, 210 horsepower engine. It was equipped with a King KFC 200 Flight Control System, weather radar, 3M WX-9 weather mapping system, and oxygen bottle. On December 6, 1991, at a total airframe service time of 1,792 hours, a Supplemental Type Certificate (STC) modification for the installation of 100 Series Speed Brakes, produced by Precise Flight, Inc., was completed by Roy Laughton of Medical Lake, Washington. On December 12, 1991, still at total service time of 1,792, a prototype installation of the Rocket Engineering Conversion was completed by Rocket Engineering of Spokane, Washington. This included a Continental TSIO-520NB, 305 horsepower engine, and a three blade constant speed, full feathering, heated propeller. STC certification was received for this installation on April 18, 1992, which returned the airplane to normal category operations. On January 30, 1992, STCs for the installation of Jose Monroy, long range auxiliary fuel tanks and low profile fiberglass doors, was completed by The Mod Squad, Inc., Venice, Florida. METEOROLOGICAL INFORMATION A Toledo Express Airport weather observation taken at 1848, indicated the weather was 5,000 scattered, visibility 10 miles, temperature 63, dew point 45, winds 070 degrees at 10 knots, with an altimeter setting of 30.19. During the preflight briefing with the AFSS, the pilot was given the following winds aloft for 18,000 feet: Atlanta, Georgia - 330 degrees at 19 knots Knoxville, Tennessee - 330 degrees at 34 knots Cincinnati/Columbus, Ohio - 330 degrees at 37 knots Fort Wayne, Indiana - 340 degrees at 32 knots WRECKAGE AND IMPACT INFORMATION The airplane wreckage was examined at the accident site on May 18 and 19, 1994. The examination revealed that all major components of the airplane were accounted for at the scene, and the airplane came to rest upright on an approximate magnetic bearing of 220 degrees, at a ground elevation of about 650 feet above mean sea level (MSL). A tree impact scar was observed at the top of a 70 foot tree, approximately 120 feet from the wreckage. Tree and ground scars, indicated a general magnetic bearing of 360 degrees in the direction of the wreckage. A ground scar about 30 feet from the nose of the wreckage, centered between two 20 foot high trees, contained pieces of red lens glass. Each of the two trees exhibited impact scars, between 4 and 15 feet above the ground. An impact hole about 20 inches deep and 4 feet across was located 10 feet from the nose of the wreckage. The propeller blades and hub were located next to the impact hole, about 8 feet from the nose of the wreckage. The propeller assembly was intact, but separated from the engine at the crank shaft. The propeller blades were in the feathered position. There was no chord wise scratches or twisting of the propeller blades. The last 6 feet of the fuselage, which included the vertical and horizontal stabilizers, rudder and elevator, was separated and twisted from the main fuselage. Control continuity was established from the rudder and elevator through the control tubes to the point of separation of the fuselage. The right wing remained attached to the fuselage while the left wing was detached at the fuselage attaching point. Control continuity could not be confirmed to the ailerons due to compression and buckling of the wings. The baggage and rear seat areas contained 181 pounds of personal baggage and electronic components. The left and right fuel tanks each contained about 2 inches of fuel, and the left and right inboard tanks measured about 1/2 inch of fuel. A fuel sample was taken and was observed to be blue in color. When tested with water finding paste the fuel was found absent of water. The speed brakes were observed to be retracted. The landing gear handle was in the up position and the gear was observed to be retracted. The flap switch was in the center/off position. The flap indicator displayed a takeoff flap setting and the left and right flap panels were measured at a 10 degrees setting. The engine remained attached to the main fuselage. The left magneto, vacuum pump and engine driven fuel pump were broken free of the engine. When the magneto was rotated by hand it sparked on all six connections. The fuel pump could not be rotated due to damage; however, fuel was present in the pump and the attaching lines. The number six cylinder head barrel was observed to be cracked near the bottom of the fin area next to the cylinder head. Exhaust stains were noted on the cooling fins near the cracked area. When the crankshaft was rotated by hand, the number 6 piston became hung-up in the cracked barrel. The engine was removed for further examination at a nearby facility. TESTS AND RESEARCH The engine was removed from the accident scene and examined at the Toledo Express Airport. The number six cylinder head, part number 653142A1, was removed and found to be cracked approximately 80 percent around. The crack was in the vicinity of the 16th and 17th fin. Black exhaust stains were visible on the barrel fin for about 50 percent of the crack. The piston and rings were intact except for the oil scraper ring which had been fractured in several locations. The cylinder head and piston assembly were sent to the National Transportation Safety Board, Office of Research and Engineering for further examination. The metallurgist's factual report stated: "...Examination of the cleaned fracture faces revealed features indicative of fatigue cracking over most of the crack surface. The fatigue features appeared to emanate from a primary origin area located at the tip of the No. 2 cooling fin...deep machining marks [were] observed on the surface of the fractured fins. Deep machining marks were also visible on the surfaces of other fins..." The remainder of the engine was shipped to the Teledyne- Continental Motors Plant in Mobile, Alabama. The engine was examined by the NTSB Investigator-In-Charge on August 16, 1994. The remaining cylinder heads were removed and checked for cracking with a four power magnifying lens. No cracking was detected on the outside or inside of the barrels. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on Mr. Raymond J. Homa, on May 18, 1994, by Dr. Cynthia S. Beisser, of the Lucas County Coroner's Office, Toledo, Ohio. The toxicological testing report, from the FAA Civil Aeromed Institute, Oklahoma City, Oklahoma, revealed negative for carbon monoxide, cyanide, volatiles, and drugs except for 14.1 (ug/ml, ug/g) salicylate (aspirin) detected in the urine. ADDITIONAL INFORMATION Since installation of the Rocket Engineering Conversation with the Continental TSIO-520, the airplane had accumulated a total of 338.4 hours. According to the Mooney Pilot's Operating Handbook (POH) and supplementals, the fuel measured in the wing tanks equaled about 20 gallons of fuel. Weight and Balance The weight and balance figures provided to the pilot on the last weight and balance form, indicated that the airplane had an empty weight of 2,219.5 pounds (lbs), and a useful load capability of 797.5 lbs. These figures included the installation of the various STCs and the new gross weight of 3,017 lbs allowed by the Rocket Engineering Conversation. The original maximum landing weight of 2,900 lbs was retained. According to Epps, the Fixed Base Operator at PDK, N1007A's fuel tanks were filled prior to the airplane's departure. The computed weight and balance for the airplane at takeoff was: Empty weight 2,219 lbs 75.6 gal Fuel 453 29 gallons Aux Fuel 174 Pilot 250 Passenger 240 Baggage and equipment 181 This equaled a total takeoff weight of 3,517 lbs, 500 lbs over the maximum allowed. According to the POH, and Rocket Engineering Data, the 2 1/2 hour flight would have burned approximately 45 gallons, or 275 lbs of fuel. The estimated landing weight of the airplane at the time of the accident was 3,242 lbs, or 342 lbs over the maximum allowed. Engine Out Glide Capability Radar data indicated that N1007A was at an altitude of 7,500 feet MSL, gliding at a ground speed of 155 knots, when the pilot informed the controller that he had feathered his propeller. With an estimated head wind component of 10 knots, N1007A had an approximate true airspeed of 165 knots. Using the Mooney Charts from the POH, N1007A was at a calibrated and indicated airspeed of 147 knots. The maximum glide distance chart contained in the POH for the standard Mooney M20K at 2,900 lbs, lists the best glide speed as 87 knots indicated airspeed, with the propeller windmilling, landing gear retracted and the flaps up. According to the chart, at 87 knots and an altitude of 10,000 feet msl, the Mooney M20K had the ability to glide about 22 nautical miles. In an interview with personnel at Rocket Engineering, with the propeller feathered, N1007A had an estimated glide ratio of 15 to 1. This provided a maximum gliding distance of 30 nautical miles from an altitude of 10,000 feet. Speed Brakes The Precise Flight, Inc., provided a supplemental flight manual for the Mooney M20K with speedbrakes installed. Under the section labeled Emergency Procedures it stated, "Forced Landing After Engine Failure - SBS [Speedbrake Switch) 'Off' (or as required to modulate glide path with use of Speedbrakes)." At the request of the NTSB IIC, Precise Flight, Inc., provided the following rate of descent information, not included in the speedbrake supplement: 1. Level flight without speedbrakes deployed.
FAILURE OF AN ENGINE CYLINDER WHICH RESULTED IN THE LOSS OF ENGINE POWER AND THE PILOT'S FAILURE TO ESTABLISH THE PROPER DESCENT PATH TO AN AIRPORT THAT WAS WITHIN THE GLIDE DISTANCE OF THE AIRPLANE. A FACTOR WAS THE OVERGROSS WEIGHT CONDITION OF THE AIRPLANE.
Source: NTSB Aviation Accident Database
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