# NTSB SEA06LA135: Hughes 369D, N369PB, Moab, UT, June 30, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 30, 2006, 17:35 local (23:35 UTC) - Place: Moab, UT - Coordinates: 38.633335, -109.25 - Nearby events: https://openairdocs.org/map.md?lat=38.6333&lon=-109.2500&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 26, 2007 - Report: Approved by Office Director - Parties: Boeing, FAA FSDO - NTSB case key (mKey): 64055 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06LA135 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64055/pdf - Page: https://openairdocs.org/ntsb/SEA06LA135 ## Probable cause The failure of the collective bungee support bracket due to non-compliance with a service information notice, which resulted in the pilot executing a precautionary autorotative landing. A contributing factor was the lack of suitable terrain for the landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - maintenance,service bulletin/letter - not complied with, other maintenance personnel (cause) - rotorcraft flight control system,collective trim - failure (cause) - precautionary landing - initiated, pilot in command - On ground/water encounter with terrain/water, landing - flare/touchdown - terrain condition - rough/uneven (contributing factor) - terrain condition - none suitable (contributing factor) - misc rotorcraft,main rotor/tail boom contact ## Analysis The pilot reported that he was maneuvering the helicopter at an altitude of about 200 feet agl conducting filming operations when he heard a loud bang after which the collective control felt "mushy" and "as if there was no positive control." He initiated a precautionary power on autorotative landing. The helicopter touched down on top of a ridgeline and then slid approximately 50 to 75 feet into a gully area, coming to rest in a 40 to 45 degree nose down attitude. During the landing, the main rotor contacted and severed the tail boom. Examination of the helicopter revealed that the collective bungee support bracket was fractured. A service information notice issued by the helicopter's manufacturer on March 7, 1980, called for a one time inspection of the collective bungee support bracket to ensure that thickness of the machine web surface in the aft lug area of the bracket was 0.065 inch or more. Excerpts from the helicopter's maintenance records provided by the pilot indicated that the service information notice was complied with prior to June 25, 1997. Examination of the fractured bracket revealed that the web thickness varied from 0.036 to 0.052 inch, which was below the minimum thickness requirement. Additionally, a hole that would have been drilled in the bracket during compliance with the service information notice was not present, indicating the procedure was not performed. ## Factual narrative On June 30, 2006, about 1730 mountain daylight time, a Hughes 369D helicopter, N369PB, sustained substantial damage during a precautionary autorotative landing on rough terrain in Castle Valley near Moab, Utah. The commercial pilot and the two crewmembers aboard the helicopter were not injured. The helicopter was registered to Helicopter Aviation Services and Leasing Inc. of Miami, Florida, and operated by Camera Copters Inc. of Miami. Visual meteorological conditions prevailed and a company flight plan was filed for the 14 CFR Part 91 business flight. The purpose of the flight was to film a ground event. The pilot reported that he was maneuvering the helicopter at an altitude of about 200 feet agl conducting filming operations when he heard a loud bang after which the collective control felt "mushy" and "as if there was no positive control." He initiated a precautionary power on autorotative landing. The helicopter touched down on top of a ridgeline and then slid approximately 50 to 75 feet into a gully area, coming to rest in a 40 to 45 degree nose down attitude. During the landing, the main rotor contacted and severed the tail boom. Examination of the helicopter revealed that the collective bungee support bracket was fractured. According to a representative of the manufacturer of the helicopter, the collective bungee helps maintain the pilot's selected collective pitch stick position in flight by counteracting forces that are fed back into the collective pitch stick. The collective bungee counteracts these forces so that collective stick loads are relatively constant throughout the full range of collective stick travel. Failure of the collective bungee bracket would not result in loss of use of the collective control. It would result in the pilot experiencing varying degrees of feedback forces to the collective stick depending on collective position. The helicopter manufacturer's representative provided a copy of Service Information Notice No. DN-54.1 issued on March 7, 1980. The notice called for a one time inspection of the collective bungee support bracket to ensure that thickness of the machine web surface in the aft lug area of the bracket was 0.065 inch or more. The pilot provided excerpts from the helicopter's maintenance records. According to the pilot, these excerpts detailed major repairs made to the helicopter in Canada. Examination of the excerpts revealed that an entry dated June 25, 1997, stated in part, "COLLECTIVE BUNGEE ASSY P/N 369D27371 INSTALLED (PREV CERT C-FOZW)." Additionally, the entry included "DN 54.1 COLLECTIVE TORQUE TUBE BRACKET" in a list of DNs that "were found to be previously complied with." The fractured collective bungee support bracket was examined under the supervision of an FAA inspector at the helicopter manufacturer's facility in Mesa, Arizona. The examination revealed the following: 1. The collective bungee support bracket fractured due to fatigue emanating from one of the corners bracketing the recessed area on the machined web. No material anomalies were observed at the fatigue origin. 2. Hardness of the material was measured to be 79 HBS, which coincides with the hardness range typical for the material used to manufacture the part. 3. Service Information Notice DN-54.1 directed that a hole be drilled in the web to perform a measurement of the web thickness. No hole was present at the prescribed location in the bracket, indicating that the procedure was not performed. 4. The machined web, including coating thickness, varied from 0.036 to 0.052 inch thick at the fracture surface, below the minimum thickness requirement of 0.065 inch specified in Service Information Notice DN-54.1. ## Aircraft - Registration: [N369PB](https://openairdocs.org/aircraft/N369PB), registered now, S/N 480305D, built 1978 (OpenAirDocs) - Reported make and model: Hughes 369D - Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 480305D - Airframe hours: 3595 - Engines: Allison 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Other work use, Part 91 - Operator: Camera Copters, Inc. - Registered owner: Helicopter Aviation Services & Leasing Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 1, 2006, 4 hours before - Departed: CNY, Moab, UT - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; flight instructor, commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, without waivers/limitations; last flight review May 1, 2005; seat: left; flight hours: 10,000 total, 6,000 in this make and model, 10,000 as pilot in command, 185 in the last 90 days, 80 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day ## 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 20060630013469A](https://openairdocs.org/incident/20060630013469A), Jun 30, 2006: Hughes 369D, Moab, UT, Substantial damage. (-23) While engaged in aerial filming at approximately 200 feet AGL the pilot heard a loud bang followed by what he perceived as loss of positive collective… 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.