ATL07CA122

NTSB accident investigation · Bell 206B · West Palm Beach, FL · August 28, 2007

Accident · No injuriesData collectionFinal report
Date
August 28, 2007, 16:45 local (20:45 UTC)
Place
West Palm Beach, FL
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N100RWBell 206B
Weather
Visual (VMC) · Day
Status
Completed · report October 31, 2007
Report
Approved by Office Director
Parties
Ft Lauderdale FSDO
Case key
66528

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 flight Instructor's delayed activation of the throttle during recovery from a demonstartion of an autorotation resulting in touchdown on soft terrain and a nosedown.

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.

Nose downLanding - flare/touchdown
Autorotation - intentionalPilot in command(cfi)
Throttle/power control - delayedPilot in command(cfi)Cause
Terrain condition - soft
Touchdown - inadvertentPilot in command(cfi)

Analysis

According to the Flight Instructor, "the flight was concluding a training flight. The final exercise was a demonstration of an autorotation to a powered recovery. The entry and glide were normal. During the flare the throttle was opened to reinstate the engine power. At this point I was aware that I did not have sufficient power to bring the aircraft to a hover. I leveled the aircraft and prepared for a touch down autorotation. Contact with the ground was level but with some forward movement. The grass runway was soft due to recent rainfall and as a result the front of the skids dug into the runway bringing the aircraft to a sudden stop. The helicopter tipped forward with some force resulting in the mast tipping forward and the blade flexing down. As the blade rotated to the rear of the aircraft it came into contact with the tail boom and severed the tail rotor drive shaft. The aircraft did remain upright and level and I was able to perform a normal shut down. We then exited the aircraft to inspect the damage." The Flight Instructor further stated that "I should have opened the throttle prior to the [flare] in order to give the engine more time to recover before pulling pitch. I was simply late bringing the power back in." The Flight Instructor reported no engine or mechanical malfunction or failures.

Factual narrative

According to the Flight Instructor, "the flight was concluding a training flight. The final exercise was a demonstration of an autorotation to a powered recovery. The entry and glide were normal. During the flair the throttle was opened to reinstate the engine power. At this point I was aware that I did not have sufficient power to bring the aircraft to a hover. I leveled the aircraft and prepared for a touch down autorotation. Contact with the ground was level but with some forward movement. The grass runway was soft due to recent rainfall and as a result the front of the skids dug into the runway bringing the aircraft to a sudden stop. The helicopter tipped forward with some force resulting in the mast tipping forward and the blade flexing down. As the blade rotated to the rear of the aircraft it came into contact with the tail boom and severed the tail rotor drive shaft. The aircraft did remain upright and level and I was able to perform a normal shut down. We then exited the aircraft to inspect the damage." The Flight Instructor further stated that "I should have opened the throttle prior to the flair in order to give the engine more time to recover before pulling pitch. I was simply late bringing the power back in." The Flight Instructor reported no engine or mechanical malfunction or failures.

Aircraft

Registration
N100RW
Reported as
Bell 206B
Category
Helicopter
Serial number
1360
Airframe hours
531
Engine
Allison C20B, 400 horsepower, turbo shaft
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Ocean Helicopters Inc.
Registered owner
Klokkenga Helicopter Leasing, Inc
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · September 1, 2006 · 91 hours before
Departed
F45 · West Palm Beach, FL
Airport
F45 · North Palm Beach County Airpor, runway 8L, 3,700 × 75 ft, grass/turf

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
44
Injuries
None
Certificates
Flight instructor, Commercial
Medical
Class 2, With waivers/limitations
Last flight review
March 1, 2007
Seat
Left
Flight hours
3,180 total · 171 in this make and model · 3,099 as pilot in command · 37 in the last 90 days · 35 in the last 30 days · 1 in the last 24 hours
Role
Student pilot
Age
46
Injuries
None
Certificate
Student
Last flight review
March 1, 2007
Seat
Rear
Flight hours
49 total

Weather

Conditions
Visual (VMC) · Day
Wind
80° at 10 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
88 °F, dew point 73 °F
Altimeter
30.02 inHg
Observed at
PBI