# NTSB WPR19FA118: Northrop N9M, N9MB, Norco, CA, April 22, 2019 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 2 · Field · Final report - Date: April 22, 2019, 12:09 local (19:09 UTC) - Place: Norco, CA - Coordinates: 33.929443, -117.575279 - Nearby events: https://openairdocs.org/map.md?lat=33.9294&lon=-117.5753&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 2 - NTSB office: Western Pacific Region - Parties: Planes of Fame Air Museum, Federal Aviation Administration - NTSB case key (mKey): 99294 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR19FA118 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99294/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99294 - Page: https://openairdocs.org/ntsb/WPR19FA118 ## Probable cause The pilot's loss of control for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Northrop/Air Museum N9M, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=6458006), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Northrop/Air Museum N9M, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=6458006), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Northrop/Air Museum N9M, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=6458006), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Northrop/Air Museum N9M, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=6458006), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot was conducting a local post-maintenance test flight following the completion of the airplane's annual inspection. Radar information showed the airplane flying on a roughly easterly heading before the accident; however, no altitude information was captured. Multiple witnesses located adjacent to the accident site reported observing the airplane flying at low altitude when it pitched upward and banked left before abruptly banking right and nosediving toward the ground. One witness stated that, as the right roll continued, the rpm of the engines increased quickly, and the airplane entered a "diving right corkscrew turn" until it descended out of sight. A video provided by a witness near the accident site did not capture the airplane but did capture the sound of modulating engine noise before the impact, likely a result of an in-flight loss of control. Wreckage and impact signatures were consistent with a near-vertical, high speed impact with terrain. All major structural components of the airplane were accounted for during the examination of the accident site and recovered wreckage, and no evidence of any preexisting mechanical malfunction was observed with the airframe, engines, or propellers; however, the extent of damage sustained in the accident sequence precluded functional testing of the flight control system, its associated hydraulics, and the engine systems. The location of the canopy located within the debris path and the unlatched seat restraint suggest that the pilot, who was wearing a parachute, may have initiated egress following a loss of control, but it is likely that he did not have sufficient altitude to do so before impact occurred. Although toxicology revealed the presence of ethanol in the pilot's muscle tissue, it is likely that some or all the detected ethanol may have been from sources other than ingestion. Additional testing from a secondary laboratory found unspecified amounts of ethanol and pseudoephedrine/ephedrine. It is unlikely that ethanol or medication use contributed to the accident. It is likely that the pilot experienced an inflight loss of control; however, given the significant fragmentation of the wreckage, the reason for the loss of control could not be determined from the available information. ## Factual narrative The single-seat, tricycle retractable gear flying wing airplane, serial number 04, was powered by two 300-horsepower Franklin XO-540-7 engines, serial numbers 88 and 89, driving two Hamilton Standard 2B20-225 constant speed propellers. The airplane's flight control system primarily comprised control cables that extended to all primary flight controls, with hydraulic-boosted actuators. On April 22, 2019, about 1209 Pacific daylight time, a Northrop N9M airplane, N9MB, was destroyed when it was involved in an accident near Norco, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. Representatives from the Planes of Fame Air Museum, Chino, California, reported that the accident flight was a post-maintenance check flight in preparation for their annual air show. Multiple witnesses adjacent to the accident site saw the airplane flying on an east-northeasterly heading at a low altitude. One witness, who was a pilot, was located about 0.5 mile southeast of the accident site and reported seeing the accident airplane in level flight with what sounded like a cruise power setting; both engines appeared to be functioning. The witness said that the airplane then pitched upward no more than 15°, and during the climb, the airplane banked left about 10 to 20°, before it abruptly banked to the right until the airplane was inverted. The witness added that once the airplane was inverted, the engines began to sputter; however, as the roll continued, the engines' rpm increased quickly, and the airplane entered a "diving right corkscrew turn." The airplane continued to descend below a tree line out of the witness's view; however, he could hear "a very loud noise from the engines" followed by the sound of impact; he subsequently saw a rising plume of black smoke. Another witness stated that the airplane appeared to initiate a "barrel roll" at a low altitude and begin to wobble back and forth before the canopy separated from the airplane. The witness added that the airplane wobbled a second time before it rolled to the right and descended into the ground. Review of radar data obtained from the Federal Aviation Administration (FAA) showed a primary radar target on an easterly heading about 3 miles south of Chino Airport, Chino, California, as seen in figure 1; no altitude information was available. The last return was about 0.3 mile west of the accident site. Two videos were submitted by witnesses who were located along the flight path and near the accident site. In the first video, the airplane was seen flying in a level attitude with both engines operating. The airplane was not visible in the second video; however, the sound of both engines could be heard from the start of the recording until a plume of smoke could be seen in the upper left corner of the video frame. Variances in the tone of the engine noise could be heard during the last 14 seconds of the recording. Figure 1. View ofradar track information, with witness video locations depicted. The Riverside County Coroner's Office, Perris, California, performed an autopsy of the pilot. The pilot's cause of death was multiple traumatic injuries. The FAA's Forensic Sciences Laboratory performed toxicology testing on the pilot's tissue samples, which revealed 22 (mg/dL, mh/hg) of ethanol in the muscle. A secondary laboratory performed toxicological testing of muscle samples. Unspecified amounts of ethanol and pseudoephedrine/ephedrine were detected. The testing did not measure its quantity and did not distinguish pseudoephedrine from ephedrine. The pilot held type ratings in A-320, ATR-42, ATR-72, Cl-65, CV-LB30, DC-9, B-25, and SF-340 aircraft. Personnel from Planes of Flame Air Museum estimated that the pilot had accumulated about 25 hours of flight time in the accident airplane over the span of about 4 years. The pilot was wearing a parachute during the accident flight. The airplane impacted the outpatient housing yard of the California Rehabilitation Center. The debris path was oriented on a heading of about 124° magnetic and measured about 474 ft long and 200 ft wide. The first identified point of contact (FIPC) was green lens fragments, consistent with the right wing navigational light lens, as shown in figure 2. From the FIPC, a blue-and-yellow colored mark extended about 32 ft to a large ground impression/crater that measured about 2 ft deep and 3 ft wide. Within the ground scar were remains of the right engine. The ground scar extended about 16 ft and contained portions of the cockpit, nose landing gear, and airframe structure. Wood debris, various fragments of both engines, and airframe structure were located throughout the debris path. The left and right propeller assemblies were located about 100 ft from the FIPC. The farthest portion of debris was a propeller blade tip, located about 474 ft from the FIPC. Figure 2. Initial impact marks and start of debris path. Canopy structure and window debris was located about 60 ft northwest of the FIPC and about 330 ft west of the FIPC. Both areas where window and canopy structure were located were in the opposite direction of the debris path, as shown in figure 3. Figure 3: Accident site overview. The heavily fragmented wreckage was recovered for further examination. Remains of all major structural components were located throughout the wreckage, including both engines, flight controls, wing structure, engine mounts, propellers, cockpit structure, canopy, and landing gear. The seatbelt clasp ends were located within the recovered wreckage and found in the unlatched position. Remains of flight control cables were located throughout the recovered debris, in addition to portions of flight control structure. All the separations in the located cables exhibited splayed signatures, consistent with overload separation. Additionally, all of the recovered control cable turnbuckles were intact and had either safety clips or safetywire in place. The flight control trim drums were located within the wreckage with the trim cables still attached. All trim drums exhibited varying degrees of impact damage. The left and right elevon box actuator housings were located within the recovered wreckage. Both boxes exhibited varying degrees of impact damage. The hydraulic actuators within the boxes were impact damaged. The hydraulic selector valve and follower linkages were impact damaged. The left and right engines were both displaced from the engine mounts and were fragmented into multiple pieces. Both crankcases were severely fragmented. Remains of all sixteen cylinders, pistons, and connecting rods were observed within the recovered wreckage. Both crankshafts were severely deformed. The torque convertors and driveshafts were impact damaged. The outboard portion of one propeller was separated about 15 inches from the tip, with a large portion of the leading edge missing, consistent with impact with a circular object. The opposing blade exhibited some aft bending with varying degrees of leading-edge damage. The other propeller exhibited "S" bending on both blades with varying degrees of leading-edge impact marks. ## Aircraft - Registration: [N9MB](https://openairdocs.org/aircraft/N9MB), registered now, S/N 04, built 1945 (OpenAirDocs) - Reported make and model: NORTHROP N9M - Registry model: [Northrop/Air Museum N9M](https://openairdocs.org/model/northrop-air-museum-n9m) (registry code 6458006) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 04 - Year built: 1945 - Airframe hours: 732.8 - Engines: Franklin XO-540-7 300 horsepower reciprocating; Franklin XO-540-7 300 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: Planes of Fame Air Musuem - Registered owner: Planes of Fame Air Musuem - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, May 3, 2018 - Departed: CNO, Chino, CA - Destination: CNO, Chino, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: fatal; airline transport; airplane ratings: single-engine land, multi-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: center; toxicology performed; flight hours: 20,029 total, 25 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 11 knots - Lowest ceiling: none - Temperature: 70 °F, dew point 52 °F - Altimeter: 30.00 inHg - Observed at: KCNO, 4 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 20190422008259A](https://openairdocs.org/incident/20190422008259A), Apr 22, 2019: Northrop/Air Museum N9M, Norco, CA, Destroyed, 1 fatal. Multiple witnesses located near the accident site reported observing the airplane flying on a north eastern heading at a low altitude when it performed a… ## Docket (11 files) The files NTSB released with the investigation on January 25, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99294. 31.9 MB in all. - NTSB video review (item 1, PDF, 3 pages, 2 photos, 221 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11336778&FileExtension=pdf&FileName=5%20NTSB%20Video%20Review-Rel.pdf - Witness statements (item 2, PDF, 15 pages, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11335495&FileExtension=pdf&FileName=1%20witness%20statements_Redacted-Rel.pdf - FAA radar plot (item 3, PDF, 1 page, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11336943&FileExtension=pdf&FileName=3%20radar%20data%20plot-Rel.pdf - Record of conversation - planes of fame (item 4, PDF, 1 page, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11336568&FileExtension=pdf&FileName=4%20Record%20of%20Conversation%20POF%20on%20Maintenance-Rel.pdf - NTSB accident site, airframe, and engine examination summary (item 5, PDF, 11 pages, 13 photos, 5.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11336078&FileExtension=pdf&FileName=2%20NTSB%20Accident%20site%20Airframe%20and%20Engine%20Examination%20Summary-Rel.pdf - Statement of party representatives to NTSB investigation (item 6, PDF, 2 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11338219&FileExtension=pdf&FileName=12%20NTSB%20party%20forms_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 7, PDF, 1 page, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11337606&FileExtension=pdf&FileName=13%20Wreckage%20Release%20form_Redacted-Rel.pdf - Toxicological report - pilot (item 8, PDF, 1 page, 287 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11336993&FileExtension=pdf&FileName=9%20pilot%20tox%20flat_Redacted-Rel.pdf - NTSB photo array (item 9, PDF, 20 pages, 20 photos, 4.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11337923&FileExtension=pdf&FileName=photo%20array-Rel.pdf - Witness video 1 (item 10, MOV, 868 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11337425&FileExtension=MOV&FileName=6%20Video%201-Rel.MOV - Witness video 2 (item 11, MP4, 10.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11337813&FileExtension=mp4&FileName=7%20Video%202-Rel.mp4 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.