# NTSB ERA10LA238: Mcdonnell Douglas Helicopter 369E, N400MB, Newfane, VT, April 21, 2010 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: April 21, 2010, 11:01 local (15:01 UTC) - Place: Newfane, VT - Coordinates: 42.997501, -72.620834 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.9975&lon=-72.6208&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report July 18, 2011 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 75812 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA10LA238 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75812/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75812 - Page: https://openairdocs.org/ntsb/ERA10LA238 ## Probable cause The pilot's inadvertent encounter with a rope while maneuvering during powerline operations for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Not specified; cases with it: [Mcdonnell Douglas Helicopter 369E, 3 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=3027369), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=3027369), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480) (defining event); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-events/480/sequence.md?model=3027369), [All aircraft, 51 cases](https://openairdocs.org/ntsb-events/480/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Mcdonnell Douglas Helicopter 369E, 9 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3027369), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The accident occurred during a procedure to install a hold-down block onto a pulling rope located between powerline structures. An all stop order to quit pulling the rope was reportedly given 3 to 5 minutes before the accident and confirmed by the pilot via radio before maneuvering to begin the hold-down block installation. No movement of the pulling rope was reported by personnel associated with the installation. The pilot confirmed there was adequate clearance to work and positioned the helicopter near one of the structures as the additional lineman in the helicopter installed the hold-down block. After completion, the lineman in the helicopter saw two waves in the pulling rope. The first wave missed the helicopter but the second wave contacted the main rotor blade, wrapping around the main rotor mast. The lineman jumped into the helicopter, which descended to the ground and came to rest on its left side nearly inverted. The operator reported that there was no preimpact mechanical failure or malfunction with the helicopter. No determination could be made as to the reason for the reported wave in the pulling rope. ## Factual narrative HISTORY OF FLIGHT On April 21, 2010, about 1101 eastern daylight time, a McDonnell Douglas 369E, N400MB, registered to and operated by Air 2 LLC, impacted with a "pulling" rope and crashed near Newfane, Vermont. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 133 rotorcraft external load flight. The helicopter sustained substantial damage. The commercial certificated pilot and one additional crewmember sustained serious injuries. The flight originated about 16 minutes earlier from a landing zone near the accident site. According to the aircraft operator, installation of 54 miles of 345 kV transmission lines was being performed parallel to existing 345 kV transmission lines between Vernon and Cavendish, Vermont. The installation was being supported in part by personnel and equipment from Air 2 LLC, and Cianbro Corporation. The purpose of the accident flight was for the additional crewmember of Air 2 LLC to install a hold down block (X100 Block) onto a white colored "pulling" rope that was connected between transmission structures Nos. 141 and 163. The X100 Block was to be installed on the south side of structure 144, and is used to facilitate installation of transmission lines. The pulling rope connects to a solid diameter wire which is attached to the conductor wire intended to be installed. The pilot stated that on the day of the accident earlier that morning, he checked the weather and visual flight rules (VFR) conditions were forecast to exist in the area. He performed a pre-flight on the helicopter, and did not find any discrepancies. He started the engine and departed from Springfield, Vermont, and flew to landing zone (LZ)-11, where he landed about 0715. While there he, “…Had daily tailboard meeting. Setup to hang fiber blocks, glass conductors, and blocks….” Later that morning he flew Air 2 LLC employees to structure No. 166 for installation of equipment. He was then requested to install additional equipment (hold-down) block at structure No. 144. He brought back two employees of Air 2 LLC to LZ-11 and dropped them off, then flew to structure No. 166, where he picked up the remaining Air 2 LLC employee and flew to structure No. 144. Cianbro Corporation personnel advised they needed the hold down on the North side of the pole. When he arrived at the structure, they contacted Cianbro Corporation personnel to confirm what side for placement of the equipment (South side), and then called personnel from Air 2 LLC located at LZ-7 asking if the pull had been stopped. Personnel from Air 2 LLC contacted personnel from Cianbro Corporation and was informed that the pull had been stopped and the helicopter was clear to proceed. The project manager for Cianbro Corporation later reported that the all stop command was given on a citizens band (CB) radio transceiver approximately 3 to 5 minutes before the time of the accident, and several company employees confirmedthat there was no pulling occurring at the time of the accident. One employee reported that at the time of the accident, there was no movement of the running board. The pilot further reported that personnel from Air 2 LLC relayed the response from Cianbro Corporation to him that the pull was stopped and he could precede. After confirming that the pull was stopped, he began to setup for his approach. He made notice of the trees on the right of way border and the weather, which consisted of clear skies and light and variable wind from 0 to 5 miles-per-hour with no gusts. He hovered high above the proposed work site to check aircraft power and determined there was adequate power, and confirmed the lineman in the helicopter was ready. He began his approach towards the structure and slowly hovered down and determined he had plenty of room to do the work. He positioned the helicopter approximately 50 ft. from the pole and started to slowly approach the rope to a position where it would be level with the floor of the helicopter. When the helicopter was close enough, the lineman installed the X100 Block (hold-down block). The additional crewmember stated that he had installed the hold down block on the pulling rope, and was in the process of getting ready to drop the rope (attached to the hold down block) to the ground, when he saw a wave on the pulling rope coming from structure 144; this wave in the rope did not contact the helicopter. A short time later he saw a second wave approaching that was obviously going to contact the main rotors. He jumped into the aft cargo area and was completely inside the aft cargo compartment. After completion of installation of the hold-down block, the pilot reported he slowly started backing away, making sure to keep the block and the floor of the helicopter level and even. When he was almost adequate distance away from the X100 Block to start climbing out of the work area, he felt something hit the helicopter. After the initial impact he felt 3 to 4 tugs and the helicopter began descending. He attempted to make an emergency landing. The next thing he remembers was being out of the helicopter walking around trying to figure out what had just happened. Following ground contact, the additional crewmember was ejected from the helicopter and landed on his entire left side of his body. According to a nearby witness, he observed the helicopter hovering near structure No. 144, and then heard a pop followed by seeing the helicopter descending to the ground. PERSONNEL INFORMATION The pilot, age 56, holds private and commercial pilot certificates with rotorcraft helicopter and instrument helicopter ratings at the commercial level, and was last issued a second class medical certificate issued April 12, 2010, with a limitation to wear corrective lenses. The Pilot/Operator Aircraft Accident/Incident Report submitted by the operator indicated the pilot’s total time was 16,420 hours, of which 15,180 hours were in rotorcraft typeaircraft and 8,000 were in the accident make and model helicopter. The pilot was admitted to a hospital on the day of the accident, and was released from the same hospital on April 26, 2010. AIRCRAFT INFORMATION The helicopter was manufactured in 1990 by McDonnell Douglas Helicopter Company as model 369E, and was designated serial number 0420E. It was powered by a Rolls-Royce Corporation (formerly Allison Engine Company) 250-C20R/2 turboshaft engine. Review of the maintenance records revealed the helicopter was last inspected in accordance with a 100-Hour inspection on April 14, 2010; the helicopter total time at that time was 2,673.8 hours. The helicopter total time at the time of the accident was 2,688.2 hours. METEOROLOGICAL INFORMATION A surface observation weather report taken at Dillant-Hopkins Airport (EEN), Keene, New Hampshire, at 1055, or approximately 6 minutes before the accident indicates the wind was from 220 degrees at 5 knots, the visibility was 10 statute miles, and clear skies existed. The temperature and dew point were 17 and 3 degrees Celsius, respectively, and the altimeter setting was 29.82 inches of Mercury. The accident site was located approximately 17 nautical miles and 290 degrees from EEN. COMMUNICATIONS The communication for the all stop which was broadcast using a CB radio transceiver was not recorded. WRECKAGE AND IMPACT INFORMATION The project manager of the company that was installing the transmission lines (Cianbro Corporation) reported that when he arrived at the accident site, he noted that the "pulling" rope was broken between structure Nos. 143 and 144. The "pulling" rope found wrapped around the main rotor mast remained connected to structure No. 143, which was continuous to structure No. 141. The other end of the broken "pulling" rope was secured to structure No. 144, and was continuous to structure No. 163. He also stated that following the accident but before his arrival, ground personnel secured the broken "pulling" rope to structure No. 144. Examination of the accident site by an FAA inspector revealed the helicopter came to rest on its left side nearly inverted. Two of the five main rotor blades were fractured but found in close proximity to the resting point of the helicopter. A white colored rope was wrapped around the main rotor static mast below the swash plate. The operator reported that there was no helicopter preimpact mechanical failure or malfunction. The operator also reported that their postaccident examination of the accident site and surrounding area revealed “…evidence of structure movement North of the crash site at structure…” 157, as evidenced by numerous fresh tracks in the ground near the structure, fresh backfill on the left and right poles of structure No. 157, and fresh seeping creosote at ground level of one of the poles. TESTS AND RESEARCH According to personnel associated with the installation of the power-lines, re-plumbing of structure No. 157 was initiated and completed onApril 19, 2010. The job involved the use of an excavation bucket, and other equipment. Personnel of the operator reported that a rope inside the cabin area planned to be utilized by the additional crewmember was physically different than the "pulling" rope that was found wrapped around the main rotor mast. Postaccident, the operator of the helicopter evaluated their procedures and implemented changes including: 1) AIR2 edited it's safe work procedures on helicopter use during wire stringing operations. 2) While the conductor or pulling line is being pulled or in motion by a power driven device, employees are not permitted directly beneath overhead operations or on the structure except as necessary to guide the stringing sock or board over or through the stringing sheave. 3) During all active wire stringing operations, the helicopter shall maintain a distance that will allow for obstruction clearance between the helicopter and the structures including all stringing equipment, ropes, hard lines and conductors. 4) In the event that it becomes necessary to use the helicopter to perform work or adjust equipment to facilitate the stringing operations, all wire movement, rope movement, and work within the segment must stop. The work with the helicopter can proceed only after the following has occurred: a) Three-way communications must be established between the person in charge of the wire pulling operation and the pilot confirming that all work has stopped. b) b) The pilot must perform an aerial reconnaissance of the entire segment to visually confirm the verbal statement of the person in charge that the pull is in an "ALL STOP", and that there are no other work activities or problems in that segment. c) Once these tasks are completed, the pilot can proceed with the work activity. Upon completion of the work activity, the pilot will communicate to the person in charge when the helicopter is in the clear and it is safe to resume pulling. ## Aircraft - Registration: [N400MB](https://openairdocs.org/aircraft/N400MB), registered now, S/N 0420E, built 1990 (OpenAirDocs) - Reported make and model: MCDONNELL DOUGLAS HELICOPTER 369E - Registry model: [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e) (registry code 3027369) (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: 0420E - Airframe hours: 2674 - Engines: ALLISON 250-C20R/2 375 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Air 2 LLC - Registered owner: Air 2 LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 14, 2010, 14 hours before - Departed: Newfane, VT - Destination: Newfane, VT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: serious; commercial, private; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review March 20, 2009; seat: left; flight hours: 16,420 total, 8,000 in this make and model, 16,420 as pilot in command, 200 in the last 90 days, 50 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 37 °F - Altimeter: 29.81 inHg - Observed at: EEN, 17 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 20100421032529A](https://openairdocs.org/incident/20100421032529A), Apr 21, 2010: Mcdonnell D 369E, Brookline, VT, Destroyed. Helicopter operatd by company named AIR-2, LLC. Crew of two; pilot in left front seat, line worker on door sill & left skid behind pilot, were assisting with… ## Docket (12 files) The files NTSB released with the investigation on May 25, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75812. 4.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 880 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335866&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Passenger Statement (item 2, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341557&FileExtension=.PDF&FileName=Passenger%20Statement-Master.PDF - Weather Reports and Records (item 3, .PDF, 13 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335867&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Statements from Air2 LLC Personnel (item 4, .PDF, 326 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341832&FileExtension=.PDF&FileName=Statements%20from%20Air2%20LLC%20Personnel-Redacted.PDF - Record of NTSB Conversations (item 5, .PDF, 575 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342051&FileExtension=.PDF&FileName=Record%20of%20NTSB%20Conversations-Redacted.PDF - Record of FAA Conversation (item 6, .PDF, 8 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341573&FileExtension=.PDF&FileName=Record%20of%20FAA%20Conversation-Redacted.PDF - Daily Maintenance Report (item 7, .PDF, 248 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341605&FileExtension=.PDF&FileName=Daily%20Maintenance%20Report-Redacted.PDF - Timeline and Operator Notes from Vermont Electric Power Company, Inc. (VELCO) (item 8, .PDF, 229 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341833&FileExtension=.PDF&FileName=Timeline%20and%20Operator%20Notes%20from%20Vermont%20Electric%20Power%20Company,%20Inc.%20(VELCO)-Redacted.PDF - Photo 1: Digital Photograph Provided by Vermont State Police. View of the Helicopter at the Accident Site. (item 9, .PDF, 392 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341913&FileExtension=.PDF&FileName=Photo%201%3A%20Digital%20Photograph%20Provided%20by%20Vermont%20State%20Police.%20View%20of%20the%20Helicopter%20at%20the%20Accident%20Site.-Master.PDF - Photo 2: Digital Photograph Provided by Vermont State Police. Another View of the Helicopter at the Accident Site. (item 10, .PDF, 396 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341915&FileExtension=.PDF&FileName=Photo%202%3A%20Digital%20Photograph%20Provided%20by%20Vermont%20State%20Police.%20Another%20View%20of%20the%20Helicopter%20at%20the%20Accident%20Site.-Master.PDF - Photo 3: Digital Photograph Provided by Federal Aviation Administration. View of a Portion of the Main Rotor Static Mast Assembly. Note the White Colored Rope. (item 11, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341917&FileExtension=.PDF&FileName=Photo%203%3A%20Digital%20Photograph%20Provided%20by%20Federal%20Aviation%20Administration.%20View%20of%20a%20Portion%20of%20the%20Main%20Rotor%20Static%20Mast%20Assembly.%20Note%20the%20White%20Colored%20Rope.-Master.PDF - Photo 4: Digital Photograph Provided by Federal Aviation Administration. Close-Up View Showing White Colored Rope Wrapped Around Main Rotor Static Mast Assembly near Swash Plate. (item 12, .PDF, 668 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341918&FileExtension=.PDF&FileName=Photo%204%3A%20Digital%20Photograph%20Provided%20by%20Federal%20Aviation%20Administration.%20Close-Up%20View%20Showing%20White%20Colored%20Rope%20Wrapped%20Around%20Main%20Rotor%20Static%20Mast%20Assembly%20near%20Swash%20Plate.-Master.PDF 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.