# NTSB FTW93LA228: Bell 206B, N16814, Pearland, TX, August 4, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 4, 1993, 14:00 local (19:00 UTC) - Place: Pearland, TX - Coordinates: 29.549779, -95.26947 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.5498&lon=-95.2695&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 26, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 18807 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW93LA228 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18807/pdf - Page: https://openairdocs.org/ntsb/FTW93LA228 ## Probable cause PILOT'S FAILURE TO MAINTAIN PROPER ROTOR RPM, THE DELAYED FLARE, AND IMPROPER TOUCHDOWN. FACTORS WERE TOTAL FAILURE OF THE POWER TURBINE DUE TO OIL STARVATION TO THE #8 BEARING ASSEMBLY. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, climb - to cruise - fluid,oil - starvation (contributing factor) - reason for occurrence undetermined - engine assembly,bearing - failure,total (contributing factor) - Forced landing, descent - emergency - Hard landing, landing - flare/touchdown - autorotation - initiated, pilot in command - rotor rpm - not maintained, pilot in command (cause) - flare - delayed, pilot in command (cause) - touchdown - improper, pilot in command (cause) - misc rotorcraft,tail boom - separation ## Analysis DURING A MAINTENANCE FLIGHT CHECK FOLLOWING A TURBINE REPLACEMENT, A TOTAL LOSS OF ENGINE POWER OCCURRED. AS THE PILOT BEGAN TO CUSHION WITH COLLECTIVE DURING THE AUTOROTATION THE HELICOPTER TOUCHED DOWN, ROCKED FORWARD AND THEN BACK. THE MAIN ROTORS SEVERED THE TAILBOOM. EXAMINATION OF THE ENGINE REVEALED A LACK OF OIL TO THE NUMBER EIGHT BEARING ASSEMBLY. ## Factual narrative On August 4, 1993, at 1400 central daylight time, a Bell 206B, N16814, sustained substantial damage during a forced landing near Pearland, Texas. The airline transport rated pilot and a mechanic aboard the helicopter were not injured. Visual meteorological conditions prevailed for the local maintenance check flight. The Pilot/Operator report and statement submitted by the pilot reported that he performed the preflight, and after a 10 minute ground run was cleared for takeoff. During initial climbout, at approximately 200 to 280 feet above the ground (AGL), the engine made a noise and decelerated. An autorotation was initiated to an open field. The pilot stated that "at about 30 to 40 feet I began a gentle deceleration and reduced my ground speed to about 0 at about 4 feet and waited for the aircraft to settle, then I began to cushion with collective." He further stated "the aircraft touched down and rocked forward and then back." During the backward movement, the pilot heard a loud bang. Damage to the helicopter included a severed outboard portion of the tailboom. The mechanic reported in the enclosed statement that he was aboard the helicopter for a maintenance operational flight check following a turbine replacement. He further reported that the engine "seized at about 300 feet" above the ground. Examination of the engine by the operator and FAA inspectors (enclosed statement) indicated a lack of lubrication to the number eight bearing. The representative of the engine manufacturer (enclosed report) examined the engine and found that the #8 bearing was "not fully engaged with the groove in the G. P. Support and the bearing had partially failed." ## Aircraft - Registration: [N16814](https://openairdocs.org/deregistered/N16814-2010-06-14), registration cancelled 2010-06-14, S/N 2229, built 1977 (OpenAirDocs) - Reported make and model: BELL 206B - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250 SER 250HP](https://openairdocs.org/engine/allison-250-ser-250hp) (registry code 03002, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2229 - Airframe hours: 7509 - Engines: ALLISON 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 91 - Registered owner: Houston Helicopter, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 14, 1993, 3 hours before - Departed: TX10 - Destination: TX10 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; airline transport, flight instructor; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 10,000 total, 2,500 in this make and model, 9,750 as pilot in command, 74 in the last 90 days, 35 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F ## 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 19930804027659A](https://openairdocs.org/incident/19930804027659A), Aug 4, 1993: Bell 206B, Pearland, TX, Substantial damage. Maintenance check flight after turbine replaced. Lost power. Autorotated. Rocked landing. Chopped tail. Dry bearing ## Other investigations on N16814 (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 FTW98LA260](https://openairdocs.org/ntsb/FTW98LA260), Jun 7, 1998: Bell 206B (N16814), Corpus Christi, TX, substantial damage. Probable cause: The failure of the tail rotor drive shaft due to the separation of a bolt at one of the drive shaft disc couplings for an undetermined reason, which resulted in the pilot's inability to maintain… 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.