Aircraft Accident/Incident Report

Idaho City, Idaho 83631
Sunday, November 29, 1998 17:56 MST

NTSB Narrative Summary Released at Completion of Accident

The McDonnell Douglas MD-900 medevac helicopter was dispatched to a car accident at a site characterized by high terrain and high trees. Prior to landing, the pilot requested information about wires and was advised by ground personnel that 'there were none.' Subsequent to landing, the pilot examined the landing site and proposed departure route for wires, and reportedly observed none. The departure from the site was conducted under dusk to dark night conditions. While climbing out vertically due to the narrow canyon conditions at the site, the helicopter struck unmarked transmission lines approximately 150 feet above ground. The pilot then determined that the helicopter was controllable and displayed no unusual flight characteristics, and chose to proceed to his destination. Post-flight examination revealed crazing of the windscreen and damage to four of the five main rotor blades requiring major repair/replacement.

NTSB Probable Cause Narrative

The pilot-in-command's not obtaining/maintaining clearance with the unmarked transmission lines. Contributing factors were environmental (dusk) conditions, the transmission lines, and both the pilot-in-command and the ground personnel not identifying the existence of the hazardous condition (high wires).

Event Information

Type of Event Accident
Event Date 11/29/1998
Event Day of the Week Sunday
Time of Event 1756
Event Time Zone Mountain Standard Time
Event City IDAHO CITY
Event State IDAHO
Event Country --
Zipcode of the event site 83631
Event Date Year 1998
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1856 Mountain Standard Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID BOI
Elevation of weather observation facility 2868
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation MST
Lighting Conditions Dusk
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 6
Dew Point at event time (in degress fahrenheit) 4
Wind Direction (degrees magnetic) 100
Variable Wind Indicator Unknown
Wind Speed (knots) 14
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 4
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1511
NTSB Notification Source --
NTSB Notification Date Nov 30 1998 12:00AM
NTSB Notification Time 901
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jan 23 2001 9:44AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N977LF
NTSB Number SEA99LA016
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name McDonnell Douglas
Aircraft Model MD-900
Aircraft Series Identifier MD-900
Aircraft Serial Number 900-00027
Certified Max Gross Weight 6250
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 2
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Nov 16 1998 12:00AM
Airframe hours since last inspection 22
Airframe Hours 1752
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ALVAC, INC.
Aircraft Owner Street Address PO BOX 1582
Aircraft Owner City BOISE
Aircraft Owner State ID
Aircraft Owner Country
Aircraft Owner Zipcode 83701
Operator is an individual? --
Operator Name IDAHO HELICOPTERS, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 2471 COMMERCE AVENUE
Operator City BOISE
Operator State ID
Operator Country
Operator Zip code 83705
Operator Code GAKA
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1756
Departure Time Zone MST
Destination Same as Local Flt --
Destination Airport Code U56
Destination City BOISE
Destination State ID
Destination Country
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 23 2001 11:29AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight Yes
Medical Flight Medical Emergency