# NTSB CHI94LA133: Bell 47-62, N6711D, Aurora, MO, March 5, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 5, 1994, 13:15 local (19:15 UTC) - Place: Aurora, MO - Coordinates: 36.960147, -93.719375 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.9601&lon=-93.7194&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 9507 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9507/pdf - Page: https://openairdocs.org/ntsb/CHI94LA133 ## Probable cause THE DUAL STUDENTS INADEQUATE FLARE AND THE PILOT IN COMMAND'S (FLIGHT INSTRUCTOR) DELAYED REMEDIAL ACTION. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - autorotation - simulated, dual student - flare - inadequate, dual student (cause) - remedial action - delayed, pilot in command(cfi) (cause) ## Analysis THE CFI AND DUAL STUDENT WERE PRACTICING AUTOROTATIONAL LANDINGS DURING A LOCAL INSTRUCTIONAL FLIGHT. A 180 DEGREE AUTOROTATION WAS INITIATED BY THE STUDENT. THE CFI STATED THE GROUND CLOSURE RATE WAS TOO FAST AND THE FLARE WAS NOT SUFFICIENT TO SLOW THE RATE OF DESCENT. THE CFI REPORTED THAT JUST AS HE REACHED FOR THE CONTROLS, THE HELICOPTER CONTACTED THE GROUND. THE HELICOPTER STRUCK THE GROUND ON THE REAR ONE THIRD PORTION OF THE SKIDS AND BOUNCED. THE MAIN ROTOR BLADES STRUCK AND SEVERED THE TAIL ROTOR DRIVE SHAFT. ## Factual narrative On March 5, 1994, at 1315 central standard time, a Bell 47-G2, N6711D, operated as an instructional flight, sustained substantial damage when it landed hard while practicing autorotations at the airport in Aurora, Missouri. The Airline Transport Pilot/Certificated Flight Instructor (CFI) and the Commercially certificated dual student reported no injuries. Visual meteorological conditions prevailed for the flight, no flight plan was filed. The flight operated under 14 CFR Part 91, and originated from Aurora, Missouri, approximately 1230. Both pilots reported the purpose of the local flight was to practice autorotational landings. The CFI stated the student satisfactorily completed several normal and 180 degree autorotational landings during the flight. The student initiated another 180 degree autorotation. The CFI stated everything was normal as the autorotation was initiated. He reported the rotor RPM climbed during the turn, but this was corrected by the student. The CFI realized the closure rate was too fast and the flare was not sufficient to slow the rate of descent. As he reached for the controls, the helicopter contacted the ground on the rear one third portion of the skids, then bounced. The CFI reported the main rotor blades struck the tail rotor drive shaft, and the helicopter began to rotate to the right. The helicopter bounced again and came to a stop approximately 220 degrees from the touchdown heading. ## Aircraft - Registration: [N6711D](https://openairdocs.org/aircraft/N6711D), registered now, S/N 2192, built 1958 (OpenAirDocs) - Reported make and model: BELL 47-62 - Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 2192 - Engines: LYCOMING VO-435-A1B 200 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Wallace, Milo V. - Registered owner: Wallace, Milo V. - Airworthiness certificate: Standard, Normal - Airport: 3AU, Aurora Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; commercial, airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 10,564 total, 718 in this make and model, 7,744 as pilot in command, 37 in the last 90 days, 21 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 7 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 57 °F - Altimeter: 29.00 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 19940305008289A](https://openairdocs.org/incident/19940305008289A), Mar 5, 1994: Bell 47G2, Augusta, KS, Substantial damage. Practicing autoratations student allowed high descent rate. CFI took over too late. Hard landing chopped tailboom. ## Other investigations on N6711D (4) 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 MIA76FLG13](https://openairdocs.org/ntsb/MIA76FLG13), Aug 26, 1975: Bell 47G-2 (N6711D), Elliott, SC, substantial damage - [NTSB MIA74D1011](https://openairdocs.org/ntsb/MIA74D1011), Aug 31, 1973: Bell 47G-2 (N6711D), Dalzell, SC, substantial damage - [NTSB MIA73FLG07](https://openairdocs.org/ntsb/MIA73FLG07), Jul 22, 1972: Bell 47G-2 (N6711D), Pinewood, SC, substantial damage - [NTSB ANC69D0040](https://openairdocs.org/ntsb/ANC69D0040), Jul 14, 1968: Bell 47G-2 (N6711D), Minchumina, AK, substantial damage 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.