# NTSB LAX02LA016: McDonnell Douglas 600N, N451DL, Laughlin, NV, October 24, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 24, 2001, 14:00 local (21:00 UTC) - Place: Laughlin, NV - Coordinates: 35.166147, -114.5742 - Nearby events: https://openairdocs.org/map.md?lat=35.1661&lon=-114.5742&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 6 uninjured - Status: Completed, report December 30, 2003 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 53681 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX02LA016 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53681/pdf - Page: https://openairdocs.org/ntsb/LAX02LA016 ## Probable cause the manufacturer's failure to provide warning information and ground training about the possibilities of boom strikes by the rotor blades in windy conditions and low rotor rpm situations. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, standing - starting engine(s) - procedures/directives - not issued, manufacturer (cause) - weather condition - unfavorable wind - acft/equip,inadequate aircraft manuals, manufacturer (cause) ## Analysis The McDonnell Douglas 600N helicopter sustained substantial damage to the tail boom and rotor blades during startup. The helicopter was parked on a formal helipad atop a 26-story building. After the pilot performed a routine preflight, he and the passengers boarded the helicopter for a local area flight. On engine startup, after about two revolutions of the rotor blades, three of the five blades contacted the tail boom. The pilot stated that the helicopter was pointed south, with the wind out of the north about 20 knots. The wind condition was not unusual for the area and location. The routine for a downwind liftoff was to perform a pedal turn into the wind for departure. The pilot stated that there is nothing in the Rotorcraft Flight Manual nor in the formal factory training for startup in windy conditions. Investigators reviewed the information in the Rotorcraft Flight Manual and found no limitations or restrictions concerning starting engines in strong wind conditions. According to FAA Aircraft Certification information, the helicopter complies with the minimum requirements for main rotor blade separation from the tailboom. According to an engineer in the Aircraft Certification Office responsible for the Type Certificate, the helicopter has a history of and is susceptible to main rotor strikes on the tailboom, if the main rotor rpm drops while the helicopter is either skidding to a halt, or is stationary in a strong wind. ## Factual narrative On October 24, 2001, about 1400 Pacific daylight time, a McDonnell Douglas 600N helicopter, N451DL, operated by the pilot, sustained substantial damage to the tail boom and rotor blades during startup at Laughlin, Nevada. Neither the pilot nor the five passengers were injured. Visual meteorological conditions prevailed for the personal flight operating under 14 CFR Part 91, and no flight plan had been filed. The helicopter was parked on a formal helipad atop a 26-story building. After the pilot performed a routine preflight, he and the passengers boarded the helicopter for a local area flight. On engine startup, after about two revolutions of the rotor blades, three of the five blades contacted the tail boom. The pilot stated that the helicopter was pointed south with the wind out of the north about 20 knots. The wind condition was not unusual for the area and location. The routine for a downwind liftoff was to perform a pedal turn into the wind for departure. The pilot stated that there is nothing in the Rotorcraft Flight Manual nor in the formal factory training for startup in windy conditions. A review of the Rotorcraft Flight Manual for the 600N by Safety Board investigators found no reference to startup restrictions in windy conditions. According to a Federal Aviation Administration Rotorcraft Certification Engineer, "The helicopter complies with the minimum requirements for main rotor blade separation from the tailboom; however, the helicopter is susceptible, and has a history of tailboom damage if the main rotor rpm drops while the helicopter is either skidding to a halt, or is stationary in a strong wind." ## Aircraft - Registration: N451DL (not matched to a registry record) - Reported make and model: McDonnell Douglas 600N - Category: Helicopter - Serial number: RN-042 - Airframe hours: 451 - Engines: Rolls-Royce 250-C47M 808 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: D.J.L. Properties - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 1, 2001, 51 hours before - Departed: NONE, Laughlin, NV ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; commercial; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; last flight review January 20, 2000; seat: left; flight hours: 5,000 total, 250 in this make and model, 4,800 as pilot in command, 75 in the last 90 days, 35 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 340° at 20 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 81 °F - Altimeter: 29.97 inHg - Observed at: KIFP, 1 nm away 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.