Sacramento Mather Airport
Aircraft Accident/Incident Report

Sacramento, California 95825
Wednesday, October 15, 2003 13:27 PDT

NTSB Narrative Summary Released at Completion of Accident

The helicopter landed hard following a loss of engine power in the traffic pattern. The pilot reported that he picked up the helicopter after maintenance was performed on the audio and visual low rpm warning systems and was positioning the helicopter to back to the airport. As he entered the pattern, he heard a bang and what he described as "a horribly loud grinding sound coming from the rear of the aircraft," and lost engine power. The pilot entered an autorotation to a clear area on the airport. As the helicopter neared the touchdown point, the pilot realized the selected landing area was sloped and so he increased collective to extend the glide to reach a flat area. The helicopter landed hard. A teardown and examination of the engine disclosed that the type and degree of damage to the engine was indicative of the separation of a portion of a planetary reduction gear, which resulted in a piece of inlet housing entering the compressor. This resulted in damage to the compressor airfoils and a loss of power. The separation of the portion of planetary reduction gear was determined to be the result of a fatigue fracture emanating from the aft root corner of one gear tooth. The root cause of the fatigue fracture could not be determined due to smearing of the initiation site. The planetary gears installed in the engine were military direct purchase breakout parts. The engine manufacturer does not approve of the use of military direct purchase hardware in FAA certified or military surplus engines used in public-use operations.

NTSB Probable Cause Narrative

The loss of engine power due to the fatigue failure of a planetary reduction gear.

Event Information

Type of Event Accident
Event Date 10/15/2003
Event Day of the Week Wednesday
Time of Event 1327
Event Time Zone Pacific Daylight Time
Event City SACRAMENTO
Event State CALIFORNIA
Event Country --
Zipcode of the event site 95825
Event Date Year 2003
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 383323N
Event Location Longitude 1211700W
Event Location Airport Sacramento Mather
Event Location Nearest Airport ID MHR
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 99
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1253 Pacific Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID SMF
Elevation of weather observation facility 27
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 26
Dew Point at event time (in degress fahrenheit) 6
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) 6
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.97
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 21799
NTSB Notification Source FAA
NTSB Notification Date Oct 15 2003 12:00AM
NTSB Notification Time 1400
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jul 25 2007 12:22PM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office WP-SAC-FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N114FD
NTSB Number LAX04TA018
Missing Aircraft Indicator --
Federal Aviation Reg. Part Public Use
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bell
Aircraft Model UH-1H
Aircraft Series Identifier --
Aircraft Serial Number 72-21558
Certified Max Gross Weight 9500
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 12
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Sep 1 2003 12:00AM
Airframe hours since last inspection 17
Airframe Hours 3956
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name SACRAMENTO METRO FIRE DISTRICT
Aircraft Owner Street Address 2101 HURLEY WAY
Aircraft Owner City SACRAMENTO
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 95825
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Public Use
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code --
Departure City Rancho Murietta
Departure State CA
Departure Country USA
Departure Time 1320
Departure Time Zone PDT
Destination Same as Local Flt --
Destination Airport Code MCC
Destination City Sacramento
Destination State CA
Destination Country USA
Specific Phase of Flight Landing
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Jun 8 2007 6:20PM
User who most recently changed record COOS
Since inspection or accident Last Inspection
Event Location Runway Number and Location 22L
Runway Length 11301
Runway Width 150
Sight Seeing flight No
Air Medical Flight No
Medical Flight --