LAX02LA016

NTSB accident investigation · McDonnell Douglas 600N · Laughlin, NV · October 24, 2001

Accident · No injuriesLimited investigationFinal report
Date
October 24, 2001, 14:00 local (21:00 UTC)
Place
Laughlin, NV
Injuries
6 uninjured
Damage
Substantial damage
Phase of flight
Standing
Aircraft
N451DLMcDonnell Douglas 600N
Weather
Visual (VMC) · Day
Status
Completed · report December 30, 2003
Report
Approved by Office Director
Parties
Federal Aviation Administration
Case key
53681

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

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

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Miscellaneous/otherStanding - starting engine(s)
Procedures/directives - not issuedManufacturerCause
Weather condition - unfavorable wind
Acft/equip,inadequate aircraft manualsManufacturerCause

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
Reported as
McDonnell Douglas 600N
Category
Helicopter
Serial number
RN-042
Airframe hours
451
Engine
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.

Role
Pilot
Age
70
Injuries
None
Certificate
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