SEA05LA120

NTSB accident investigation · MBB BO-105 · Billings, MT · June 17, 2005

Accident · No injuriesLimited investigationFinal report
Date
June 17, 2005, 15:30 local (22:30 UTC)
Place
Billings, MT
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N314MSMBB BO-105
Weather
Visual (VMC) · Day
Status
Completed · report October 27, 2005
Report
Approved by Office Director
Parties
Helena FSDO
FAA report
20050617011769A
Case key
61773

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 continue a simulated engine-out autorotation after sensing an excessive descent rate at 100 feet above the ground. Factors include the excessive descent rate, variable winds, and a high density altitude.

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.

Hard landingLanding - flare/touchdown
Emergency procedure - simulatedPilot in command
Autorotation - initiatedPilot in command
In-flight planning/decision - improperPilot in commandCause
Weather condition - variable windFactor
Descent - excessivePilot in commandFactor
Weather condition - high density altitudeFactor
Go-around - not performedPilot in commandCause

Analysis

The instructor pilot had just finished giving the other pilot a proficiency check, and had then taken control of the aircraft so that he could perform some maneuvers for his own proficiency. He performed one simulated engine-out autorotation to a touchdown, and was completing his second, when the accident occurred. He initiated the autorotation from about 1,000 feet above the ground (agl), and began establishing a flare attitude at an altitude of 100 feet agl. At that time he noticed that the descent rate of the helicopter was excessive, but instead of adding power along with the increase in collective, he decided to continue the simulation of the power loss. Just prior to touchdown, the pilot established a landing attitude and used all of the available collective to cushion the landing. When the helicopter touched down, the descent rate was still greater than the pilot desired, and immediately after contacting the ground, the main rotor flexed downward and contacted the top of the tail boom. The pilot reported that there were no problems with the aircraft's flight controls or engine, but the variable wind had changed directions during the descent from 1,000 feet agl, and the aircraft was therefore landing with a tailwind. In addition, the pilot states that the density altitude was approximately 5,700 feet, which left little room for error. In his discussion with the NTSB, the pilot stated that under the conditions, he should have initiated a go-around when he sensed the excessive descent rate at 100 feet agl.

Factual narrative

On June 17, 2005, approximately 1530 Pacific daylight time, an MBB BO-105 helicopter, N314MS, landed hard during a simulated autorotation in an area north of Logan International Airport, Billings, Montana. The certified flight instructor, who was flying at the time, as well as his pilot-rated passenger, were not injured, but the aircraft, which is owned and operated by Metro Aviation, Inc., sustained substantial damage. The 14 CFR part 91 proficiency flight, which departed Logan International about 60 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed.

According to the instructor pilot, he had just finished giving the other pilot a proficiency check, and had then taken control of the aircraft so that he could perform some maneuvers for his own proficiency. He performed one simulated engine-out autorotation to a touchdown, and was completing his second when the accident occurred. He said that he initiated the autorotation from about 1,000 feet above the ground (agl), and began establishing a flare attitude at an altitude of 100 feet agl. At that time he noticed that the descent rate of the helicopter was excessive, but instead of adding power along with the increase in collective, he decided to continue the simulation of the power loss. Just prior to touchdown, the pilot established a landing attitude and used all of the available collective to cushion the landing. When the helicopter touched down, the descent rate was still greater than the pilot desired, and immediately after contacting the ground, the main rotor flexed downward and contacted the top of the tail boom.

According to the pilot, there were no problems with the aircraft's flight controls or engine. He further stated that he felt that the variable wind had changed directions during his descent from 1,000 feet agl, and that he was therefore inadvertently landing downwind. In addition, he felt that the high density altitude (approximately 5,700 feet) left little room for error. In his discussion with the NTSB, the pilot stated that under the conditions, he should have initiated a go-around when he sensed the excessive descent rate at 100 feet agl.

Aircraft

Registration
N314MS
Reported as
MBB BO-105
Category
Helicopter
Serial number
S772
Engine
Allison 250-C-20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Other work use · Part 91
Registered owner
Metro Aviation, Inc.
Airworthiness certificate
Standard, Normal
Departed
KBIL · Billings, MT
Destination
KBIL

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
34
Injuries
None
Certificates
Commercial, Flight instructor
Instrument ratings
Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
April 1, 2005
Seat
Left
Flight hours
2,730 total · 177 in this make and model · 2,361 as pilot in command · 43 in the last 90 days · 24 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Temperature
73 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.