MORRIS, MN, USA
N2114Z
MUMM LANCAIR
A witness who observed the airplane before the accident, saw the airplane 'performing a steep climb and then slowly turning left and coming back down. The airplane then straightened out and repeated the maneuver.' The airplane wreckage was discovered approximately 25 minutes later. The pilot/owner-builder told a friend the day before the accident that he intended to test the airplane to see how it would handle in stalls and stall recoveries. Examination of the wreckage revealed that the elevator bob weight was mounted on the idler arm upside down. A mock up of the assembly revealed the upside-down elevator bob weight was contacting the aft elevator push rod, resulting in a partial blockage of the elevator whenever forward stick controls were applied. This limited the elevator control surface to approximately 7 degrees of down elevator travel range. The assembly plans, provided by the kit manufacturer, were designed to provide a down elevator travel range of 13 degrees. The aircraft logbook indicated that as of 12/21/95, the airplane had logged 13.1 hours.
HISTORY OF FLIGHT On December 23, 1995, at 1234 central standard time (cst), a Lancair, N2114Z, operated by a private pilot, was destroyed when it impacted the terrain near Morris, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The flight was being conducted under 14 CFR Part 91. A flight plan was not on file. Both the instructor pilot and the dual student pilot/owner-builder on board sustained fatal injuries. The local flight departed Morris, Minnesota, at 1210 cst. A friend of the pilot/owner-builder, reported that the pilot told him the day prior to the accident, that he was going to test the airplane to see how it would handle in stalls and stall recoveries. The pilot never told him when he was going to do this, but that it was going to be in the near future. Approximately 1200 cst, a certified flight instructor at Morris Municipal Airport, also a friend of the pilot/owner-builder, observed the airplane, with the pilot/owner-builder in the right seat and instructor pilot in the left seat, beginning to taxi for takeoff. Several other witnesses at the airport observed the airplane taxi and takeoff uneventfully. Approximately 1220 cst, a witness observed the airplane "performing a steep climb and then slowly turning left and coming back down. The airplane then straightened out and repeated the maneuver." The witness was at a convenience store on the north side of Morris, Minnesota, when he saw the airplane. The airplane wreckage was discovered six miles north of Morris, Minnesota, by a local resident who reported it to the Stevens County Sheriff's department at 1244 cst. PERSONNEL INFORMATION The instructor pilot's logbook record indicated he had a total flight time of 13,074 hours as of October 14, 1995. This record showed that 13,024 hours were in single-engine land airplanes. Of that single-engine land airplane time, 1.0 hour was in a Lancair. The pilot/owner-builder's logbook record indicated he had a total flight time of 981.1 hours as of December 21, 1995. This record showed that 954.8 hours were in single-engine land airplanes. Of that single-engine land airplane time, 14.1 hours was in a Lancair. According to both pilot logbook records, the instructor pilot and the pilot/owner-builder had accomplished a 1.0 hour Lancair checkout flight at Neico Aviation, Incorporated, Redmond, Oregon, on July 13, 1994. The instructor pilot did not log any flying time in the airplane involved in the accident. AIRCRAFT INFORMATION The airplane was a homebuilt kit constructed by the pilot/owner- builder. The airplane was issued a special airworthiness certificate, experimental, amateur-built airplane, on November 16, 1995. According to the aircraft logbook, the airplane made its first flight on November 17, 1995. The aircraft logbook indicated that as of December 21, 1995, the airplane had logged 13.1 hours. WRECKAGE AND IMPACT INFORMATION The NTSB on scene investigation began on December 27, 1995 at 1100 cst. The wreckage had been moved into a work bay at an automobile wrecking yard in Morris, Minnesota. Examination of the accident site revealed two ground scars, approximately ten feet apart, in a frozen, level corn field, 138 feet south of Stevens County Road 74, an east-west gravel road. The first ground scar was six feet long and four feet wide. At its deepest point where the propeller was recovered, the depth of the first ground scar was approximately 14 inches. The second ground scar was five feet long and three feet wide. A spray of earth and debris, approximately 15 feet in length, fanned out 30 degrees from the second ground scar on a 090 degree heading. The second ground scar was eight inches deep at its deepest point. Pieces of the left wing position light cover were recovered from this scar. Frozen oil, accompanied by small pieces of the canopy, oil pan, forward fuselage and instrument panel, extended from the first ground scar, along a 140 degree heading, 42 feet to a third scar where the airplane's engine was recovered. Small unrecovered pieces of wreckage continued along the 140 degree heading for approximately 100 feet. Examination of the wreckage revealed the fuselage was intact aft of the crew compartment to just forward of the empennage. The fuselage, forward of the wings, and crew compartment were fragmented. Both wings had separated from fuselage at the roots. The center section of main wing spar remained with the aft fuselage. The right wing forward of the control surfaces was shredded. The left wing was fragmented into several pieces. The left aileron separated from the wing at the hinge mounts. The ailerons and parts from the wing sections were attached to the remaining cockpit by the aileron control cables and hydraulic lines to the main landing gear. Both built-in wing tanks were ruptured. The main landing gear actuators were in the up position. The aileron controls showed continuity. The tail cone had fractured forward of the horizontal stabilizers. The empennage remained mostly intact. The tip and leading edge of the left horizontal stabilizer and tip of the elevator were fractured. The right horizontal stabilizer and elevator was undamaged. The vertical stabilizer showed damage to the top leading edge. The rudder counterweight separated from the top of the rudder. The push-pull rods to the elevator were fractured in several places. The elevator idler arm assembly mount had sheared midway up from the floor of the fuselage. Rudder control cables showed continuity. The propeller exhibited torsional bending and chordwise scratching. The engine was completely separated from the engine mount. The crankshaft was sheared near the flange. The forward crankcase and front bearings were cracked. Subsequent engine and propeller examination revealed no evidence of a preimpact malfunction. The elevator idler arm assembly and sections of the elevator push-pull rods were retained for further testing. MEDICAL AND PATHOLOGICAL INFORMATION The autopsies of the pilot/owner-builder and the instructor pilot were conducted on December 24, 1995, by the Stevens County Medical Examiner, in Morris, Minnesota. The autopsies revealed no evidence of physical incapacitation or impairment. The results of FAA toxicological testing of specimens from the instructor pilot were negative for all tests conducted. Testing of specimens from the pilot/owner-builder revealed the following volatile concentrations: 14.000 (mg/dl) Ethanol detected in brain fluid 14.000 (mg/dl) Ethanol detected in liver fluid 14.000 (mg/dl) Ethanol detected in lung fluid 1.000 (mg/dl) Acetaldehyde detected in liver fluid 1.000 (mg/dl) Acetaldehyde detected in brain fluid 106.000 (mg/dl) Methanol detected in brain fluid 47.000 (mg/dl) Isobutanol detected in brain fluid 2.000 (mg/dl) 1-Butanol detected in brain fluid A national resource specialist in the National Transportation Safety Board Office of Research and Engineering determined that these volatile concentrations were the result of post mortem putrefaction. TESTS AND RESEARCH Assembly plans for the flight controls were obtained from the pilot/owner's estate. Comparison of the recovered elevator idler arm assembly with the plans from which it was constructed revealed that the elevator bob weight had been mounted on the idler arm upside-down. A two-inch long, 1/4-inch wide witness mark was observed on the aft push-pull rod corresponding to a position beneath where the elevator bob weight was located. Plans and diagrams for the elevator idler arm assembly mount bracket were obtained from Neico Aviation, Incorporated, the airplane kit manufacturer. Comparison of the company-provided diagram of the attach bracket, with the diagram of the attach bracket obtained from the pilot/owner-builder's estate, revealed that the company's diagram called for a larger base dimension of 5 inches, versus the 2 and 1/2-inch base dimension called for in the diagram used by the pilot/owner-builder. The pilot/owner- builder's diagram was obtained from Neico Aviation, Incorporated, in March, 1993. The elevator idler arm assembly mount bracket was examined and tested at the United States Forest Service, Forest Products Laboratory, Madison, Wisconsin. Examination of the mount bracket revealed that "the direction of tears in the fiberglass on the floor of the fuselage and left sides of the plywood brackets indicates that the direction of force applied to the bob weight end of the idler arm came from the right side. Fiberglass at the base of the right-side bracket was torn away, whereas fiberglass at the base of the left-side bracket is mostly intact and acted more as a hinge. The overall thickness of the 3-ply plywood is 3/16-inch." Plywood of 1/4-inch thickness was called for in the mount bracket construction plans. "The core veneer was 1/8-inch thick, and two face veneers were 1/32-inch thick." Testing of the fibers revealed that the wood came "from the Shorea-Lauan- Mertanti species group." A piece of "12-ply birch aircraft plywood" for firewall and mount bracket construction, is provided in the kit. The elevator idler arm assembly was examined and tested at Neico Aviation, Incorporated, Redmond, Oregon, on May 22, 1996. Using a mock up of the flight controls on a manufactured Lancair 320, testing revealed that the elevator bob weight, installed upside- down, would contact the aft elevator push rod whenever forward stick controls were applied. The partial blockage caused by the upside-down bob weight limited the elevator control surface to approximately 7 degrees of down elevator travel range. The construction plans, provided by the kit manufacturer, specify a down elevator travel range of 13 degrees. ADDITIONAL INFORMATION Parties to the investigation were the Federal Aviation Administration Flight Standards District Office, Minneapolis, Minnesota, Neico Aviation Incorporated, Redmond, Oregon, and Textron Lycoming, Williamsport, Pennsylvania. All wreckage, including the retained components, were released and returned to Ed Fisk and Associates, Inc.
the partially blocked elevator and improper installation of the elevator bob weight by the owner/builder which prevented full travel of the elevator control system. Factors relating to this accident were the intentional stall and inability to adequately recover from the stall.
Source: NTSB Aviation Accident Database
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