# NTSB CHI98LA047: Hall RV-6, N36AH, Blair, NE, November 25, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 25, 1997, 15:00 local (21:00 UTC) - Place: Blair, NE - Coordinates: 41.5405, -96.129142 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5405&lon=-96.1291&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 24, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 10791 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI98LA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10791/pdf - Page: https://openairdocs.org/ntsb/CHI98LA047 ## Probable cause a fatigue failure of the torque tube outside of the weld and the fractured pilot's side left rudder pedal. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, takeoff - initial climb - flt control syst,rudder control attach points - fatigue (cause) - flt control syst,rudder control - fractured (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, emergency descent/landing ## Analysis The pilot said that during the initial takeoff, as the tail wheel came off the ground, the airplane began to 'fishtail.' When the pilot made rudder corrections, the airplane's directional control got worse. The airplane became airborne entering an uncontrolled left turn. The pilot said that he did not have 'positive response' when he turned back parallel to the runway. The pilot reduced power to land. The nose of the airplane tracked right away from the runway heading. The pilot tried to turn back to the left, but the airplane's controls would not respond. The pilot reduced the power to idle and impacted the ground in a left nose down slip approximately 20 feet left of the runway. Examination of the airplane's rudder controls revealed a fracture outside of the weld attaching the base of a T-shaped bar beneath the pilot's left rudder pedal to the torque tube connecting the left rudder pedals to the left and right seats. Further examination of the broken parts revealed a fatigue crack on the torque tube, originating on the rear outside portion of the fracture. ## Factual narrative On November 25, 1997, at 1500 central standard time (cst), a Hall RV-6, N36AH, operated by a commercial pilot, sustained substantial damage when on takeoff the airplane made an uncontrolled left turn. Subsequently, the pilot reduced power and the airplane impacted on the runway. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. No flight plan was on file. The pilot reported no injuries. The flight was originating at Blair, Nebraska, when the accident occurred. In his written statement, the pilot said that during the initial takeoff as the tail wheel came off the ground, the airplane began to "fishtail." When the pilot made rudder corrections, the airplane's directional control got worse. The airplane became airborne entering an uncontrolled left turn. The pilot said that he did not have "positive response" when he turned back parallel to the runway. The pilot reduced power to land. The nose of the airplane tracked right, away from the runway heading. The pilot tried to turn back to the left, but the airplane's controls would not respond. The pilot reduced the power to idle and impacted the ground in a left nose down slip approximately 20 feet left of the runway. The airplane skidded across the ground and came to rest in the center of the runway. A Federal Aviation Administration (FAA) inspector examined the airplane at the accident site. The spinner and lower cowling were crushed inward. The firewall showed buckling at the bottom. The left side of the fuselage from the cowling, through the cockpit and aft to the empennage showed heavy skin wrinkling. The left main landing gear was bent aft and embedded in the bottom fuselage skin. The left wing tip was crushed inward and broken aft. The left forward wing spar was broken aft. The wood propeller was broken aft and split. Examination of the engine and engine controls revealed no anomalies. Examination of the airplane's rudder controls revealed that a fracture had occurred outside of the weld attaching the base of a T-shaped bar, forming the foot rest of the pilot's left rudder pedal, to the torque tube connecting the left and right seat left rudder pedals. Further examination of the broken parts revealed a fatigue crack on the torque tube, originating on the rear outside portion of the fracture. ## Aircraft - Registration: [N36AH](https://openairdocs.org/aircraft/N36AH), registered now, S/N 20814, built 1993 (OpenAirDocs) - Reported make and model: Hall RV-6 - Registry model: [Hall Lee RV-6](https://openairdocs.org/model/hall-lee-rv-6) (registry code 05620VM) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 20814 - Airframe hours: 439 - Engines: Lycoming O-320-D1A 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Aaron Lee Hall - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, May 5, 1997, 61 hours before - Departed: K46 - Airport: K46, Eagle Field, runway 31, 3,450 × 50 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 3,890 total, 429 in this make and model, 3,530 as pilot in command, 15 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 41 °F - Altimeter: 29.00 inHg - Observed at: OMA, 20 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 19971125035789A](https://openairdocs.org/incident/19971125035789A), Nov 25, 1997: Amtr RV6, Omaha, NE, Substantial damage. Acft made unitended left turn after takeoff,pilot lost control and made hard landing on runway, blair, NE. (.4)the pilot said that during the initial takeoff,… 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.