# NTSB FTW98FA186: Foster/Hilsman Q2, N996DT, Siloam Springs, AR, April 19, 1998 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: April 18, 1998, 20:30 local (Apr 19, 1998, 01:30 UTC) - Place: Siloam Springs, AR - Coordinates: 36.179988, -94.539283 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.1800&lon=-94.5393&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report October 24, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 20413 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98FA186 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20413/pdf - Page: https://openairdocs.org/ntsb/FTW98FA186 ## Probable cause The pilot's failure to maintain aircraft control during the forced landing. Factors were the failure of the #4 cylinder head which resulted in a partial loss of engine power and the co-owners/builders' failure to perform a condition inspection of the airplane, which would have detected the leaking cylinder heads prior to the failure of the #4 cylinder head. ## 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,cylinder - loose - engine assembly,cylinder - leak - maintenance,inspection - not performed, owner/builder (contributing factor) - engine assembly,cylinder - failure,total (contributing factor) - Forced landing, descent - emergency - Loss of control - in flight, descent - emergency - aircraft control - not maintained, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis The amateur-built experimental Quickie airplane, occupied by a commercial pilot and a pilot-rated passenger, who were the co-owners/builders of the airplane, impacted the ground in a steep left bank during a forced landing following a partial loss of engine power. Disassembly of the engine revealed that six cylinder head hold-down nuts were loose, and combustion gases had been leaking between the cylinder heads and the barrels of the #2, #3, and #4 cylinders. The escaping gases cut a passage about 3/4 inch in diameter through the #4 cylinder head, resulting in the partial loss of engine power. Maintenance records indicated new cylinder heads were installed 33 hours before the accident in May 1997. A condition inspection of the airplane, which would have included a cylinder compression check, was due in November 1997, but had not been performed. According to a family member, the two owners were in the process of performing a condition inspection on the day of the accident; however, neither owner held a repairman certificate for the airplane or was a certificated airframe and powerplant mechanic. ## Factual narrative HISTORY OF FLIGHT On April 18, 1998, approximately 2030 central daylight time, a Foster/Hilsman Q2 amateur-built experimental airplane, N996DT, impacted terrain following a loss of control during a forced landing approximately 1/2 mile north of Smith Field Airport, Siloam Springs, Arkansas. The two occupants, a commercial pilot and a pilot-rated passenger, who were the co-owners and builders of the airplane, received fatal injuries. The airplane was destroyed. No flight plan was filed and visual meteorological conditions prevailed for the Title 14 CFR Part 91 local personal flight that originated from Smith Field about 2000. According to family members, the two occupants were planning to sell the airplane and had gone to the airport on the day of the accident to prepare the airplane for showing to prospective buyers. Receipts dated April 18, 1998, for the purchase of oil, valve cover gaskets, and other items were found by family members in the commercial pilot's vehicle. During post-accident examination of the hangar where the airplane was kept, several empty 1-quart oil containers were found. Additionally, hand tools, cleaning supplies, and the airplane's maintenance logbooks were found on a bench at the back of the hangar. A witness at the airport reported that approximately 1930, the commercial pilot borrowed a tire pressure gage from him and returned the gage "about 15 to 20 minutes later." Several witnesses at the airport observed the airplane takeoff on runway 36 and reported times for the takeoff varying from 1935 to 2030. One of the witnesses reported that the airplane took off "right at sunset," which, according to the U.S. Naval Observatory, occurred at 1954. A witness saw and heard an airplane fly over his residence, located approximately 2 miles north-northwest of the accident site, about 1930 to 2000. The witness positively identified the airplane flying over as N996DT due to having previously seen it at the airport. According to the witness, the airplane was approximately 300 feet above the ground, headed west, and then made a "tight" left turn toward the south. He stated that the airplane's engine did not sound like it was running at full power and estimated that it was operating at 60 to 75 percent power. He further stated that the engine was running smoothly and was not missing. Another witness, who was inside her residence, approximately 7 miles northeast of the accident site, reported hearing an airplane fly over about 2030. She stated that the airplane's engine was "cutting out, spitting and sputtering." The witness went outside, but did not see the airplane. Approximately 2050, a Siloam Springs police officer, noticed "a flashing light in the sky," which he estimated to be located "just south" of the airport. The sighting of the light led the officer to go to the airport and "check the activity." Upon arriving at the airport, he observed that the runway lights, which are pilot activated, were not on. He also observed a pickup truck parked next to the hangar where the airplane was kept and noted that the hangar was open, the lights were on, and no one was around the hangar. There were no reported witnesses to the accident. When concerned family members reported the airplane missing, a search was initiated, and the wreckage was located approximately 0800 on April 19, 1998. PERSONNEL INFORMATION Testing of blood samples from the airplane seat belts, performed by the Arkansas State Crime Laboratory, Little Rock, Arkansas, determined that the commercial pilot was occupying the left seat. He held a commercial pilot certificate issued on March 20, 1983, with helicopter, single engine land airplane, and instrument airplane ratings. On the application for his most recent medical certificate, dated August 15, 1996, he reported a total flight time of 950 hours. Review of his current logbook indicated he began flying N996DT on November 10, 1996, and as of April 12, 1998, had logged a total of 77 hours in the airplane. According to the logbook, in the 30, 60 and 90 days before the accident, he flew the airplane 2, 4 and 7 hours, respectively. His last biennial flight review was completed on September 17, 1996, in a Cessna 172. The passenger, who occupied the right seat, held a private pilot certificate issued on October 29, 1990, with a single engine land airplane rating. On the application for his most recent medical certificate dated August 13, 1996, he reported a total flight time of 70 hours. Review of his logbook indicated he had logged a total flight time of 76 hours of which 4 hours were in N996DT. He had logged flights in N996DT on February 12, August 23, August 25, and October 6, 1997. According to the logbook, he had not flown in the 90 days before the accident. His last biennial flight review was completed on September 1, 1996, in a Cessna 150. According to FAA records, neither occupant held a repairman certificate for N996DT or was an FAA certificated mechanic with airframe and powerplant ratings. AIRCRAFT INFORMATION The canard equipped, two place, composite construction "Quickie" airplane was powered by a 75 horsepower Revmaster model 2100-D engine. Primary cockpit flight controls consisted of a single central control stick operable from either seat and a single set of rudder pedals for the left seat occupant. The airplane was not equipped with gyro instruments, instrument panel lights, or a landing light. Wingtip mounted navigation and strobe lights were installed. An aircraft registration certificate for N996DT, showing the two occupants as the manufacturers and co-owners of the airplane, was issued by the FAA on October 2, 1996. A Designated Airworthiness Representative (DAR) issued an experimental airworthiness certificate and operating limitations for the airplane on November 6, 1996. The operating limitations indicated that the airplane's initial 40 hours of test flights were to be conducted within the flight test area of "Washington and Benton Counties Northwest Arkansas." The limitations further indicated that following completion of the initial 40 hours of flight, an entry was to be placed in the airplane's logbook by the test pilot stating the following: "I certify that the prescribed flight test hours have been completed and the aircraft is controllable throughout its range of speeds and throughout all maneuvers to be executed, has no hazardous operating characteristics or design features, and is safe for operation." After the initial 40 hours of flight were completed, the operating limitations allowed flights outside the flight test area. The list of limitations applicable to flights outside of the flight test area included three items regarding condition inspections: 8. No person shall operate this aircraft unless within the preceding 12 calendar months it has had a condition inspection performed in accordance with FAR Part Part 43, appendix D, and has been found to be in a condition for safe operation. In addition, this inspection shall be recorded in accordance with limitation 10 listed below. 9. The builder of this aircraft, if certificated as a repairman, FAA certified mechanic holding an Airframe and Powerplant rating and/or appropriately rated repair stations may perform condition inspections in accordance with FAR Part 43, appendix D. 10. Condition inspections shall be recorded in the aircraft maintenance records showing the following or a similarly worded statement: "I certify that this aircraft has been inspected on (insert date) in accordance with the scope and detail of appendix D of Part 43 and found to be in a condition for safe operation." The entry will include the aircraft total time-in-service, the name, signature, and certificate type and number of the person performing the inspection. Review of the commercial pilot's logbook revealed that as of February 2, 1997, he had fl ## Aircraft - Registration: [N996DT](https://openairdocs.org/deregistered/N996DT-1998-11-24), registration cancelled 1998-11-24, S/N 2365 (OpenAirDocs) - Reported make and model: Foster/Hilsman Q2 - Registry model: [Foster D T/Hilsman D Q2](https://openairdocs.org/model/foster-d-t-hilsman-d-q2) (registry code 05603ZO) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 2365 - Airframe hours: 86 - Engines: Revmaster 2100-D 75 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: D.T. Foster & D.L. Hilsman - Airworthiness certificate: Special, Experimental (Special) - Departed: SLG - Airport: SLG, Smith Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 1,028 total, 77 in this make and model, 7 in the last 90 days, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Dusk - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 39 °F - Altimeter: 30.00 inHg - Observed at: FYV, 19 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 19980418007149A](https://openairdocs.org/incident/19980418007149A), Apr 18, 1998: Amtr Q2, Siloam Springs, AR, Destroyed, 2 fatal. (Tty) experi acft was on a maintenance flight when it crashed under unknown cir, 2 POB suffered fatal inj. Siloam Springs, AR. (.4)the amateur-built… 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.