Saturday, March 16, 2019

Flight Control System Malfunction / Failure: Robinson R22 Mariner, N923SM, accident occurred May 02, 2018 in Panama City, Florida

Aviation Accident Final Report - National Transportation Safety Board

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Vestavia Hills, Alabama

Investigation Docket - National Transportation Safety Board:

Location: Panama City, FL
Accident Number: ERA18LA140
Date & Time: 05/02/2018, 1000 CDT
Registration: N923SM
Aircraft: ROBINSON R22
Aircraft Damage: Substantial
Defining Event: Flight control sys malf/fail
Injuries: 1 Minor
Flight Conducted Under: Part 91: General Aviation - Positioning 


The float-equipped helicopter was in cruise flight at an airspeed of 80 knots and an altitude of 800 ft mean sea level when it slowly started losing airspeed. The commercial pilot responded by pushing the cyclic control forward, but the airspeed continued to decrease, and the helicopter began to lose altitude. The pilot continued to push the cyclic forward until it contacted the control stop; he then realized that he had no cyclic control authority. The helicopter descended with no forward airspeed until it impacted the water. The helicopter floated briefly until waves struck its side and it rolled inverted. Postaccident examination of the helicopter revealed that the main rotor blades were deformed, the fuselage was substantially damaged, and the tail boom was partially separated. Further, the ropes used to tie down the helicopter’s main rotor blades were  found wrapped around the rotor head swashplate and pitch control rods.

Before the flight, the pilot conducted a preflight inspection of the helicopter, which would have included removing the rotor blade tie-down ropes and associated socks that cover the rotor blade tips and storing them under the cockpit seat. However, because the ropes were found wrapped around the swashplate and pitch control rods, it is likely that the tie-down ropes were not properly removed and secured and, at some point during the flight, became entangled with the swashplate and pitch control rods, which prevented the pilot from being able to effectively control the pitch of the helicopter.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's failure to properly remove and secure the tie-down ropes during the preflight inspection, which resulted in the ropes becoming entangled in the rotor head swashplate and pitch control rods during flight and the subsequent loss of pitch control. 


Personnel issues Incomplete action - Pilot 
Aircraft Pitch control - Attain/maintain not possible 
Personnel issues Preflight inspection - Pilot 
Environmental issues  Water - Contributed to outcome

Factual Information

On May 2, 2018, about 1000 central daylight time, a Robinson R-22 Mariner helicopter, N923SM, operated by N923SM LLC., was substantially damaged during a forced landing near Panama City Beach, Florida. The commercial pilot received minor injuries. The flight was operated in accordance with Title 14 Code of Federal Regulations Part 91 as a positioning flight. Visual meteorological conditions (VMC) prevailed and no flight plan was filed for the flight that departed Perry-Foley Airport (40J) Perry, Florida at 0830, that was destined for Destin Executive Airport (DTS), Destin, Florida.

The pilot reported that about 90 minutes after departing 40J, while in cruise flight at 80 kts and 800 ft mean sea level (msl), the helicopter slowly started losing airspeed; he pushed the cyclic forward, but the airspeed kept decreasing and the helicopter was beginning to lose altitude. He continued to push the cyclic forward until it hit the stop and then realized he had no cyclic authority. The pilot stated there was no forward airspeed and the helicopter continued to descend until it impacted the water with nearly zero forward airspeed and little flare. The helicopter floated briefly until waves struck the side of it and it turned inverted.

Prior to the flight, the pilot was conducting a preflight inspection, which included removal and storage of the blade tie down ropes and associated "socks" that cover the rotor blade tips. During this procedure, the pilot removed the tie down ropes and thought he placed them under the left cockpit seat storage container. In addition, the flight was conducted with the doors off; they were not installed on the helicopter.

A coworker and fellow pilot was flying in formation with the accident helicopter about 700 ft msl. He was at the 5 o'clock position of the accident helicopter at the same altitude when he noticed that the helicopter slowed from about 80 knots to 30 knots in about 15 seconds. He reported that "I felt something wrong and flew to his 10 o'clock position to see what was happening to him." The pilot further reported that the helicopter was descending in a reverse gliding attitude and struck the water with the tail boom first, before rolling upside down.

Witnesses on the ground from the United States Coast Guard and salvage company stated that the tie down ropes used for the rotor blades were found wrapped around the rotor head assembly, swash plate and pitch control rods. The ropes remained in place when the Coast Guard and recovery team arrived prior to the recovery operation taking place.

According to the pilot and Federal Aviation Administration (FAA) records, the pilot held a commercial pilot certificate with a rating for rotorcraft-helicopter as well as a flight instructor certificate with a rating for rotorcraft-helicopter. The pilot reported 467.7 total hours of flight experience and 467.7 of those hours where in the accident helicopter make and model. In the previous 90 and 30 days, the pilot reported about 50 hours and 20 hours respectively.

According to the FAA airworthiness and the helicopter's maintenance records, the two-seat, semi-rigid single-main-rotor, single-engine helicopter, serial number 1923M, was manufactured in 1991 and was issued a standard airworthiness certificate. The helicopter was equipped with floats and powered by a 160-horsepower Lycoming O-320-B2C series engine, which had 4,988.6 hours total time. As of the most recent annual inspection completed on December 28, 2017, the airframe had 6,988.7 hours total time. The current airframe and engine logbooks were on the helicopter at the time of the accident and were lost.

Examination of the helicopter by an FAA inspector revealed that the main rotor blades were deformed, the fuselage was substantially damaged, and the tail boom was partially separated. In addition, a tiedown rope and blade sock used to secure the helicopter rotor blades on the ground was found tightly wrapped around the swash plate and pitch change links of the main rotor.

At 0953, the weather recorded at Northwest Florida Beaches International Airport Panama City (ECP), Florida, about 12 miles north of the accident site included no clouds or restriction to visibility, wind from 140° true at 9 knots, and visibility 10 statute miles. The temperature was 20°C, and the dew point was 18°C. The altimeter setting was 30.27 inches of mercury. 

History of Flight

Prior to flight Preflight or dispatch event
Enroute-cruise Flight control sys malf/fail (Defining event)
Enroute-cruise Loss of control in flight
Emergency descent Collision with terr/obj (non-CFIT)

Pilot Information

Certificate: Commercial
Age: 22, Male
Airplane Rating(s): None
Seat Occupied: Right
Other Aircraft Rating(s): Helicopter
Restraint Used: 3-point
Instrument Rating(s): Helicopter
Second Pilot Present: No
Instructor Rating(s): Helicopter
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 05/08/2018
Occupational Pilot: Yes
Last Flight Review or Equivalent: 04/08/2018
Flight Time:  (Estimated) 467.7 hours (Total, all aircraft), 467.7 hours (Total, this make and model), 369.2 hours (Pilot In Command, all aircraft), 50 hours (Last 90 days, all aircraft), 20 hours (Last 30 days, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Make: ROBINSON
Registration: N923SM
Model/Series: R22 MARINER
Aircraft Category: Helicopter
Year of Manufacture: 1991
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 1923M
Landing Gear Type: Float; Skid;
Seats: 2
Date/Type of Last Inspection: 12/28/2017, Annual
Certified Max Gross Wt.: 1369 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 6988.7 Hours as of last inspection
Engine Manufacturer: LYCOMING
ELT: Not installed
Engine Model/Series: O-320-B2C
Registered Owner: N923SM LLC
Rated Power: 160 hp
Operator: N923SM LLC
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: ECP, 68 ft msl
Distance from Accident Site: 12 Nautical Miles
Observation Time: 0953 CDT
Direction from Accident Site: 320°
Lowest Cloud Condition: Clear
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 9 knots /
Turbulence Type Forecast/Actual: /
Wind Direction: 140°
Turbulence Severity Forecast/Actual: /
Altimeter Setting: 30.27 inches Hg
Temperature/Dew Point: 20°C / 18°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: PERRY, FL (40J)
Type of Flight Plan Filed: None
Destination: DESTIN, FL (DTS)
Type of Clearance: None
Departure Time: 0830 EST
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Minor
Latitude, Longitude: 30.173889, -85.807500 (est)

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