LAX99TA115

NTSB accident investigation · McDonnell Douglas 600N · Rialto, CA · March 10, 1999

Accident · Minor injuriesFinal report
Date
March 9, 1999, 17:55 local (Mar 10, 1999, 01:55 UTC)
Place
Rialto, CA
Injuries
3 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N626SBMcDonnell Douglas 600N
Weather
Instrument (IMC) · Day
Status
Completed · report January 18, 2001
Report
Approved by Office Director
FAA report
19990309002109A
Case key
45899

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

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Probable cause

The pilot's improper in-flight decision to maneuver in the area while observed inclement weather approached, which led to a loss of control. Contributing factors were the low ceilings, mountainous terrain and spatial disorientation.

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.

Loss of control - in flightManeuvering
Weather condition - low ceilingFactor
Terrain condition - mountainous/hilly
In-flight planning/decision - improperPilot in commandCause
Flight into known adverse weather - inadvertentPilot in commandCause
Aircraft control - not maintainedPilot in commandCause
Spatial disorientationPilot in commandFactor
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - mountainous/hillyFactor

Analysis

During a routine law enforcement patrol flight, the pilot responded to the 4,700-foot mean sea level mountainside to investigate circumstances related to an apparent abandoned vehicle. Upon arriving at the site, the pilot performed a toe-in landing to discharge his crewmember. The crewmember proceeded to evaluate the vehicle while the pilot orbited the area. While orbiting, the pilot observed that low elevation clouds were approaching. However, the visibility initially was about 10 miles, and the cloud height appeared between 500 and 600 feet above the ground. After a few minutes, the crewmember returned to the helicopter, and they departed. Seconds after taking off the pilot lost visual reference with the ground. The pilot further indicated that he continued flying by reference to his flight instruments and the helicopter began spinning. Between 1 and 1.5 minutes later the spinning stopped, and the helicopter lost altitude until impacting the mountainside.

Factual narrative

On March 9, 1999, about 1755 hours Pacific standard time, a McDonnell Douglas 600N, N626SB, entered instrument meteorological conditions (IMC) and collided with 4,700-foot mean sea level mountainous terrain about 7 miles north of Rialto, California. A company visual flight rules (VFR) flight plan was filed. The helicopter was substantially damaged. The commercial pilot, the flight officer (crewmember), and the passenger sustained minor injuries. The aircraft was operated by the San Bernardino County Sheriff's Department, San Bernardino, California, as a public-use aircraft under the provisions of 14 CFR Part 91. The local area flight originated from San Bernardino about 1708.

In the pilot's completed report, and during an interview, he indicated that the accident occurred while on a routine law enforcement patrol flight. In summary, the pilot reported that he was on a mission to investigate circumstances related to an apparent abandoned vehicle. Upon arriving at the mountainside, he performed a toe-in landing to discharge the crewmember. While the crewmember evaluated the vehicle, the pilot orbited the area, and noted that low elevation clouds were approaching. However, the visibility was about 10 miles, and the clouds appeared to have been between 500 and 600 feet above the ground. After a few minutes, the crewmember returned to the helicopter, and they departed. Seconds after taking off the pilot lost visual reference with the ground. The pilot further indicated that he continued flying by reference to his flight instruments and the helicopter began spinning. Between 1 and 1.5 minutes later the spinning stopped, and the helicopter lost altitude until impacting the mountainside.

Aircraft

Registration
N626SB
Reported as
McDonnell Douglas 600N
Category
Helicopter
Serial number
RN024
Airframe hours
266
Engine
Allison 250-C47M, 808 horsepower, turbo shaft
Damage
Substantial damage
Flight
Public aircraft · Part 91
Registered owner
San Bernardino Cty Sheriff Dpt
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · February 18, 1999 · 66 hours before
Departed
L67 · Rialto, CA
Flight plan
Company VFR

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
34
Certificates
Commercial, Military
Airplane ratings
Single-engine land
Instrument ratings
Helicopter
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
1,654 total · 35 in this make and model · 1,612 as pilot in command · 104 in the last 90 days · 72 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Day
Wind
240° at 11 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
52 °F, dew point 43 °F
Altimeter
30.00 inHg
Observed at
ONT, 17 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.