# NTSB CHI94LA274: Nelson Benson B-8M, N26063, Sandwich, IL, August 9, 1994 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: August 9, 1994, 13:45 local (18:45 UTC) - Place: Sandwich, IL - Coordinates: 41.639266, -88.61956 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6393&lon=-88.6196&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report August 21, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9633 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA274 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9633/pdf - Page: https://openairdocs.org/ntsb/CHI94LA274 ## Probable cause IMPROPER PLANNING/DECISION BY THE PILOT (OWNER/PILOT/MECHANIC), AND HIS IMPROPER MODIFICATION OF THE FLIGHT CONTROL SYSTEM, WHICH RESULTED IN HIS FAILURE (OR INABILITY) TO MAINTAIN CONTROL OF THE GYROCOPTER. A FACTOR RELATED TO THE ACCIDENT WAS: THE PILOT'S LACK OF FLIGHT TRAINING. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, climb - planning/decision - improper, pilot in command (cause) - rotorcraft flight control system - inadequate (cause) - maintenance,modification - improper, owner/pilot mechanic (cause) - aircraft control - not maintained, pilot in command (cause) - inadequate training, pilot in command (contributing factor) - lack of certification, pilot in command - In flight collision with terrain/water, descent - uncontrolled ## Analysis SEVERAL WITNESSES TO THE ACCIDENT REPORTED THAT THE GYROPLANE APPEARED UNSTABLE AS IT CLIMBED TO A MAXIMUM ALTITUDE OF APPROXIMATELY 50 FEET. TWO WITNESSES DESCRIBED THE GYROPLANE 'TIPPING' AND 'DIPPING' SHORTLY AFTER TAKEOFF. THEY SAID THE ENGINE SOUNDED AS THOUGH IT WAS RUNNING AT FULL POWER IMMEDIATELY PRIOR TO THE ACCIDENT. THE GYROPLANE PITCHED DOWN IN A MANNER DESCRIBED BY ONE WITNESS AS A 'SOMERSAULT' AND IMPACTED THE TERRAIN IN AN INVERTED, NEAR VERTICAL, NOSE DOWN ATTITUDE. AN UNTESTED/CUSTOM ROTOR HEAD WAS REPORTED TO HAVE BEEN INSTALLED ON THE GYROPLANE. ACCORDING TO THE PILOT'S WIFE, HE HAD MODIFIED THE GYROPLANE AFTER HAVING A PREVIOUS ACCIDENT; SHE DID NOT BELIEVE THE GYROPLANE HAD BEEN SUCCESSFULLY FLOWN SINCE IT WAS MODIFIED. TWO PERSONS, WHO WERE FAMILIAR WITH THE GYROPLANE, INDICATED THAT THE MODIFICATION WOULD HAVE AFFECTED CONTROLLABILITY OF THE AIRCRAFT. NO RECORD WAS FOUND THAT THE PILOT HAD EVER BEEN ISSUED A PILOT CERTIFICATE. TOXICOLOGY TESTS REVEALED TRACES OF METABOLITES OF COCAINE, SUGGESTING USE IN THE PAST THAT HAD BECOME METABOLIZED BEFORE FLIGHT. ## Factual narrative On August 9, 1994, at 1345 central daylight time, a Nelson Benson B-8M gyroplane, N26063, was destroyed when it impacted the terrain near Sandwich, Illinois. The non-certificated pilot sustained fatal injuries. The personal flight originated in a farm field near Sandwich, Illinois. No flight plan was filed, and visual meteorological conditions prevailed. Several witnesses to the accident reported that the gyroplane departed from a farm field, northwest of the intersection of East Sandwich Road and Chicago Road. They reported that it departed toward the east and appeared unstable as it climbed to a maximum altitude of approximately 50 feet. Two witnesses described the gyroplane "tipping" and "dipping" shortly after takeoff. They reported several changes in the sound of the engine and said it sounded as though it was running at full power immediately prior to the accident. The airplane pitched down in a manner described by one witness as a "somersault", and impacted the terrain inverted, in a near vertical, nose down attitude. A Federal Aviation Administration (FAA) Airworthiness inspector examined the wreckage. He reported that all flight controls and engine controls operated normally. The engine rotated freely and had compression. The fuel tank was recovered and was over half full. The inspector reported that the propeller and rotor were replaced in January 1994; however, no records of a condition inspection or aircraft logbooks were recovered. He reported that "dragon wing" rotor blades were installed on the gyroplane. During an interview with a FAA Operations Inspector, the pilot's wife reported that the pilot had purchased the gyroplane in 1982 and had received some flight instruction in it. She said he had "crashed" the gyroplane in May 1994 and sustained minor injuries. She reported that the pilot had subsequently modified the gyroplane and she did not think that he had flown it successfully since the modifications. She said she did not know if he held a pilot license. The inspector provided a record which states that no record or entry has been found which discloses that the pilot was ever issued a recreational pilot certificate or higher level airman certificate. During a telephone interview, Mr. Ernie Boyette of Rotor Flight Dynamics, Lithia, Florida, stated he had inspected the gyroplane several months prior to the accident flight and had recommended to the pilot that he should not attempt to fly it. He said the geometry in the custom control system would potentially inhibit roll control. Additionally, he said that the installation of dragon wing rotor blades on a standard rotor head must include a modification to the balance springs to prevent a nose down trim condition. Mr. Doug O'Conner of the Popular Rotorcraft Association (PRA) reported during a telephone interview that he believed the pilot had some experience flying gyroplanes and believed he was a "pretty good pilot". During a telephone interview, November 28, at 1445, Mr. Thomas Milton, an airframe and powerplant mechanic and member of the PRA, reported that he was familiar with the accident gyroplane. He reported that the pilot had some experience flying gyroplanes but did not believe he had flown very much, if at all, in the past three years. He said that he and several other members of the PRA inspected photographs of the accident gyroplane and reported that the custom control system incorporated several extra linkages. He emphasized the need for tactile feedback from the rotor to the control stick for maintaining aircraft control. He said the extra linkages in the custom control system probably eliminated much of the tactile feedback from the rotor to the pilot. Toxicological testing conducted by the DeKalb County Coroner in Sycamore, Illinois, was negative for all tests performed except for nicotine/cotinine and caffeine. Federal Aviation Administration forensic toxicological testing of the pilot detected cocaine, 1.456 (ug/mL, ug/g) benzoylecgonine, and 0.076 (ug/mL, ug/g) ecgonine methyl ester in the urine specimen. The blood specimen contained 0.035 (ug/mL, ug/g) benzoylecgonine. The autopsy was performed by the DeKalb County Coroner in Sycamore, Illinois on August 10, 1994. ## Aircraft - Registration: [N26063](https://openairdocs.org/deregistered/N26063-2013-02-21), registration cancelled 2013-02-21, S/N B8M9176, built 1977 (OpenAirDocs) - Reported make and model: NELSON BENSON B-8M (BENSON B-8) - Registry model: [Nelson BENSEN B-8M](https://openairdocs.org/model/nelson-bensen-b-8m) (registry code 13021J2) (OpenAirDocs) - Registry engine: [Mcculloch 4318A&E/0-100](https://openairdocs.org/engine/mcculloch-4318a-e-0-100) (registry code 43101, reciprocating) (OpenAirDocs) - Category: Gyroplane, amateur-built - Serial number: B8M9176 - Engines: McCulloch 4318A reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Ronald P. Waid - Airworthiness certificate: Special, Experimental (Special) ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; seat: center; toxicology performed ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 7 knots - Visibility: 12 statute miles - Lowest ceiling: 2,900 ft broken - Temperature: 68 °F - Altimeter: 30.00 inHg ## 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 19940809020939A](https://openairdocs.org/incident/19940809020939A), Aug 9, 1994: Amtrbx BENSENB8M, Sandwich, IL, Destroyed, 1 fatal. Ascended instable wobble to 50FT AGL. Stalled. Somersaulted. Impacted inverted. Had made alteration. Not licensed. ## Other investigations on N26063 (1) 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. - [NTSB CHI83LA010](https://openairdocs.org/ntsb/CHI83LA010), Oct 5, 1982: Benson B8M (N26063), Sandwich, IL, destroyed 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.