ATL94FA179

NTSB accident investigation · Robinson R-22B · Knightdale, NC · September 28, 1994

Accident · FatalField investigationFinal report
Date
September 28, 1994, 09:47 local (13:47 UTC)
Place
Knightdale, NC
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Enroute
Aircraft
N83112Robinson R-22B
Weather
Visual (VMC) · Day
Status
Completed · report April 25, 1995
Report
Approved by Office Director
FAA report
19940928032129A
Case key
3304

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

Divergence of the main rotor from its normal plane of rotation for an undetermined reason(s) resulting in rotor blade contact with the tailcone.

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.

Airframe/component/system failure/malfunctionClimb
Rotor system,main rotor - undeterminedCause
Mast bumping - encounteredPilot in commandCause
Misc rotorcraft,main rotor/tail boom contact - blade strike
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The flight was delayed because of a fog layer at the airport. According to witnesses at the airport, the helicopter departed without incident. A minute into the flight they heard the pilot, also a helicopter CFI, say, 'hey! I've got a...'. No other radio transmissions were heard. A witness located near the accident site recalled watching the helicopter fishtail, and heard a sputtering sound coming from the helicopter. Radar data depicted the helicopter at 700 ft MSL, flying in an easterly direction, and then reverse course to a westerly heading, within 23 secs of coverage. The main fuselage impacted the ground in a wooded area; other debris from the helicopter was scattered over an area 800 feet long and 100 feet wide. A post impact fire further damaged the airframe. Examination of the separated tailcone and fuselage components showed evidence of inflight main rotor blade contact; the wreckage examination also showed signs of mast bumping.

Factual narrative

History of flight

On September 28, 1994, at 0947 eastern daylight time, a Robinson R-22B helicopter, N83112, collided with the ground after the main rotor system struck the tail boom of the helicopter near Knightdale, North Carolina. The business flight operated in accordance with 14 CFR Part 91, with no flight plan filed. Visual weather conditionsprevailed at the time and location of the accident. The helicopter was destroyed during the inflight breakup sequence and a post impact fire; the pilot was fatally injured. The flight departed Raleigh East Airport in Knightdale, North Carolina, at 0945 hours.

According to the President of Raleigh Helicopters, the pilot arrived at Raleigh East Airport at 0800. There are no records of the pilot receiving a weather briefing. According to witnesses at the airport, the airport fogged in when the pilot arrived. The flight was delayed until visual weather conditions prevailed. According to witnesses at the airport, the takeoff and initial climbout were normal, but a minute into the departure, they heard the pilot of N83112 transmit in an excited voice, "Hey! I've got a..". No other radio transmissions were heard.

Eyewitnesses, located 1/2 mile east of the accident site, recalled seeing the helicopter as it flew west at an altitude between 200 and 300 feet above the ground. They stated that the helicopter appeared to "fishtail", and a sputtering sound was also heard coming from the helicopter. The witnesses continued to observe the helicopter until it disappeared into the 80 foot tall trees; seconds later, a fireball was seen rising from the area where the helicopter was last seen.

Personnel information

Information on the pilot is included in this report at the data field labeled "First Pilot Information." The 35 year old, commercial rated pilot was certificated to fly single and multiengine airplanes, and helicopters; he was also a certified flight instructor (CFI) in helicopters. According to the President of Raleigh Helicopters, the pilot was hired as a part-time flight instructor/pilot on April 16, 1994. Under this agreement, the pilot flew as an independent contractor and received compensation for flight instruction given to students from Raleigh Helicopters; the pilot was seeking additional employment when the accident occurred.

A review of the pilot's flight logs revealed that, on July 23, 1990, he received initial helicopter flight training from South Carolina Helicopters, Saluda, South Carolina, in the Hughes 269A helicopter. On July 31, 1990, the pilot received a private helicopter rating. The flight log review also showed that the pilot completed as many as four flights in one day and he flew a total of 31.4 hours within seven days, to complete helicopter rating requirements.

Subsequent to his initial helicopter qualification, the pilot flew several hours in different aircraft, and received an initial checkout in the Robinson R-22 helicopter from Raleigh Helicopters, Knightdale, North Carolina on December 14, 1991. Records indicated the pilot completed the Robinson Helicopter Company (RHC) Pilot Safety Checkout in accordance with RHC R-22 Flight Training Guide (see attached maneuvers listed in the RHC Pilot Safety Checkout Worksheet).

Raleigh Helicopters flight training program is outlined in the flight training manual. The flight training manual includes the following areas:

1. Flight Training Syllabus 2. Ground Training Syllabus 3. R-22 Maneuver Guide 4. School Safety Procedures 5. RHC Safety Notices (RSN-1 through 29)

The operator also reported that implementation of the flight training guide varied due to the part-time status of many students. Often part-time students would have extended breaks in their training program and require additional review periods to restore student proficiency before continuing the flight training program.

Aircraft information

Information on the helicopter is contained in this report at the data field labeled "Aircraft Information." N83112 arrived in Knightdale as a sales aircraft. On July 27, 1994, Triangle Helicopter Leasing, LLC, purchased N83112 from the Robinson Helicopter Company and subsequently leased the helicopter to Raleigh Helicopters (see attached N83112 purchase history). A review of the aircraft maintenance records failed to disclose any carryover or delayed maintenance actions for the powertrain or flight control systems.

Meteorological information

Visual weather conditions prevailed at the accident site at the time of the accident. Weather information is contained in this report at the data field labeled "Weather Information." Witnesses at the airport and within 1/2 mile of the accident site confirmed that the fog layer had dissipated when the accident occurred. Approximately 18 miles west of the accident site, instrument weather conditions were reported at the Raleigh-Durham International Airport, at the time of the accident.

Wreckage and impact information

The main wreckage and accident site were located 1 1/2 miles west of Raleigh East Airport and north of a single set of Norfolk and Southern Railroad tracks. Examination of the accident site revealed that wreckage debris from the helicopter was scattered over an area 800 feet long and 100 feet wide. The wreckage distribution path was orientated on a westerly heading (see attached wreckage diagram in Airworthiness Group Chairman's Factual Report).

A general examination of the accident site revealed that the main rotor assembly and the aft five foot section of the tail cone, with tail rotor assembly attached, were located within 125 feet of the main wreckage. The tail rotor drive shaft was 600 feet west of the main wreckage. All helicopter flight control components and accessories were recovered for examination. The cockpit and fuselage were fire damaged. Despite the fire damage, flight and powertrain control components were located in the wreckage debris. Plexiglass debris from the windshield and skylight was recovered from the wreckage path 200 feet east of the main wreckage.

During the reconstructive phase, flight control rod ends were located and traced to their respective positions (see attached Airframe and Systems Damage Charts). The tail rotor drive shaft and a section of the tail cone were not recovered initially, but a month after the accident, a local family found the drive shaft in their backyard; the tail rotor drive shaft was 600 feet west of the accident site. The recovered section of the tail cone was located 200 feet east of the main wreckage.

The fire damaged fuselage section of the airframe rested on the left side orientated on a northerly magnetic heading. The post impact fire destroyed the cockpit section of the airframe and the engine compartment sustained extensive thermal damage. Fire also melted part of the right skid assembly and portions of the flight control tubes. Although the transmission and mast assemblies were within the fire pattern, they sustained little heat distress.

Further examination of the accident site disclosed that the main rotor assembly separated from the transmission mast just above the swashplate assembly. The main rotor assembly, with both blades attached, was located 31 feet north of the main wreckage. Examination of main rotor blade S/N 8262C showed that the blade was bent gradually upward over the entire length except for a small area on the inboard side of a fracture on the leading edge spar. This fracture was 7 feet 3 inches from the tip of main rotor blade S/N 8262C. All fractures in the blade skin and spar materials were typical of overstress separation. Main rotor blade S/N 8246C also exhibited upward bending over the entire length of the blade surface. Further examination of the main rotor blade, S/N 8246C, revealed red and gray paint smears on the upper skin and along the leading edge (see attached Airworthiness Grou

Aircraft

Registration
N83112
Reported as
Robinson R-22B
Category
Helicopter
Serial number
2446
Airframe hours
124
Engine
Lycoming O-320-B2C, 160 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Business · Part 91
Operator
Raleigh Helicopters
Registered owner
Triangle Helicopter LLC
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · August 30, 1994 · 48 hours before
Departed
W17
Destination
W17 · NC
Airport
W17 · Raleigh East, runway 19, 3,000 × 60 ft, asphalt

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
35
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Right
Toxicology
Performed
Flight hours
790 total · 305 in this make and model · 704 as pilot in command · 132 in the last 90 days · 40 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Visibility
0.75 statute miles
Lowest ceiling
300 ft broken
Temperature
63 °F, dew point 63 °F
Altimeter
29.00 inHg
Observed at
RDU, 18 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.