# NTSB NYC00LA044: Bell 47G, N940B, Coudersport, PA, November 27, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 27, 1999, 16:15 local (21:15 UTC) - Place: Coudersport, PA - Coordinates: 41.770744, -78.00933 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.7707&lon=-78.0093&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 2, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47842 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC00LA044 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47842/pdf - Page: https://openairdocs.org/ntsb/NYC00LA044 ## Probable cause The pilot's improper preflight planning and decision to attempt a takeoff with the passenger from the confined area. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, takeoff - object - tree(s) (contributing factor) - planning/decision - improper, pilot in command (cause) - Loss of control - in flight, takeoff - In flight collision with terrain/water, descent - uncontrolled ## Analysis The pilot with a passenger, landed the helicopter in a clearing that was about 40 feet wide, by 150 feet long, and surrounded by 'very tall trees.' The pilot said he made a normal run-up and lifted the helicopter to a hover. He used full throttle and maintained 3,100 RPM. When the helicopter started to accelerate forward, at about 12-15 knots, the RPM dropped to 3,000 and the pilot lowered collective to keep the RPM from dropping further. The helicopter's main rotor blades contacted a pine tree about 30 feet above the ground. The helicopter then rolled to the left and impacted the ground. The elevation at the accident site was about 1,800 feet Ms. The pilot did not report any mechanical malfunctions with the helicopter's airframe or engine. After the accident, the pilot stated that the helicopter was with-in it's maximum gross weight; however, the helicopter did not have enough power available to climb and he should have never landed in the clearing. ## Factual narrative On November 27, 1999, about 1615 Eastern Standard Time, a Bell 47G, N940B, was substantially damaged when it struck a tree while departing from a clearing near Coudersport, Pennsylvania. The certificated private pilot and a passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the personal flight conducted under 14 CFR Part 91. Earlier in the day, the pilot and passenger departed a private heliport in Glen Rock, Pennsylvania, and flew to the Grand Canyon State Airport (N38), Wellsboro, Pennsylvania, where the helicopter was refueled. They then departed N38, and landed in a clearing, located about 1/2 mile northwest of Coudersport. According to the pilot, the clearing was about 40 feet wide, by 150 feet long, and was surrounded by "very tall trees." The pilot said he made a normal run-up and lifted the helicopter to a hover. He used full throttle and maintained 3,100 RPM. When the helicopter started to accelerate forward, at about 12-15 knots, the RPM dropped to 3,000 and the pilot lowered collective to keep the RPM from dropping further. The helicopter's main rotor blades contacted a pine tree about 30 feet above the ground. The helicopter then rolled to the left and impacted the ground. According to a Federal Aviation Administration Inspector, the elevation at the accident site was about 1,800 feet msl. The pilot did not report any mechanical malfunctions with the helicopter's airframe or engine. After the accident, the pilot stated that the helicopter was with-in it's maximum gross weight; however, the helicopter did not have enough power available to climb and he should have never landed in the clearing. ## Aircraft - Registration: [N940B](https://openairdocs.org/deregistered/N940B-2013-09-11), registration cancelled 2013-09-11, S/N 672, built 1952 (OpenAirDocs) - Reported make and model: Bell 47G - Registry model: [Bell 47G](https://openairdocs.org/model/bell-47g) (registry code 1181002) (OpenAirDocs) - Registry engine: [Franklin 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 672 - Airframe hours: 7510 - Engines: Franklin 6V-355-A 210 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Lawrence W. Vance - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 7, 1999, 32 hours before - Departed: NONE - Destination: NONE, GLEN ROCK, PA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 28; private; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 156 total, 76 in this make and model, 18 as pilot in command, 14 in the last 90 days, 11 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: 7,500 ft - Temperature: 50 °F, dew point 34 °F - Altimeter: 29.00 inHg - Observed at: ELM, 56 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 19991127047829A](https://openairdocs.org/incident/19991127047829A), Nov 27, 1999: Bell 47G, Coudersport, PA, Substantial damage. (-23) Pilot attempted take-off from confined area surrounded by trees with full throttle and began to lose engine RPM. He lowered the collective to maintain… ## Other investigations on N940B (2) 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 NYC68A0072](https://openairdocs.org/ntsb/NYC68A0072), Nov 16, 1967: Bell 47G (N940B), Newark Apt Fac, NJ, substantial damage - [NTSB UNK65X1503](https://openairdocs.org/ntsb/UNK65X1503), Jun 16, 1965: Bell 47G (N940B), Nassau, Burkina Faso, 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.