National Transportation Safety Board
Aviation Accident Final Report

 

 

Location:

Ponca City, OK

Accident Number:

CEN19LA068

Date & Time:

01/11/2019, 1145 CST

Registration:

N346AE

Aircraft:

AEROSPATIALE AS350

Aircraft Damage:

Substantial

Defining Event:

Dynamic rollover

Injuries:

2 None

Flight Conducted Under:

Part 91: General Aviation - Positioning

Analysis

 

The pilot and an air ambulance crewmember were repositioning the helicopter due to incoming inclement weather. About halfway into the flight, the front windshields were fogging over, and the pilot increased the demister. Upon reaching the destination, the pilot hovered near the company hangar; by this time, the windshields had completely fogged over. The crewmember warned the pilot that he was getting close to the hangar, which was on the helicopter's left side. The pilot felt that he was high enough off the ground to move the helicopter several feet to the right, but the right skid was too low and contacted the ground, which resulted in a dynamic rollover. The helicopter sustained substantial damage to the rotor blades, fuselage, and tailboom.

Based on the available information, the dynamic rollover was a result of the pilot's failure to maintain altitude during the hover operation with a fogged-over windshield.

 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
 

The pilot's failure to maintain altitude during the hover operation while his view was obstructed due to the fogged-over windshield.

 

Findings

Aircraft

Altitude - Not attained/maintained (Cause)

Flight compartment windows - Not specified (Cause)

Personnel issues

Monitoring environment - Pilot (Cause)

Factual Information

 

On January 11, 2019, about 1145 central standard time, an Airbus Helicopters AS350B2 helicopter, N346AE, sustained substantial damage during a dynamic rollover during landing at the Ponca City Regional Airport (PNC), Ponca City, Oklahoma. The airline transport pilot and helicopter air ambulance crewmember were not injured. The helicopter was registered to and operated by Air Evac EMS, Inc. under the provisions of Title 14 Code of Federal Regulations Part 91 as a positioning flight. Day instrument meteorological conditions prevailed for the flight, which operated on company visual flight rules flight plan. The flight originated from the Ponca City Hospital about 1141.

The pilot was a repositioning the helicopter due to incoming inclement weather. The weather conditions at the time included light rain and a temperature of about 38° F. He contacted the company Operations Control Center (OCC) and he and the OCC staff agreed that the flight could be conducted within the company safety requirements.

The flight was initiated and about halfway into the flight the front windshields were fogging over and the pilot increased the demister. Upon reaching the destination, the pilot hovered near the company hangar by which time the windshields had completely fogged over. The passenger warned the pilot that he was getting close to the hangar which was on the helicopter's left side. The pilot noted that he was looking out of the left chin bubble windshield while attempting to move the helicopter laterally to the right. He felt that he was high enough off the ground to move the helicopter several feet to the right, but the right skid was too low and contacted the ground resulting in a dynamic rollover.

Examination of the helicopter revealed substantial damage to the rotor blades, fuselage, and tail boom.

 

 

History of Flight

Landing-flare/touchdown

Dynamic rollover (Defining event)

 

 

Pilot Information

Certificate:

Airline Transport; Commercial

Age:

75, Male

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Right

Other Aircraft Rating(s):

Helicopter

Restraint Used:

 

Instrument Rating(s):

Airplane; Helicopter

Second Pilot Present:

No

Instructor Rating(s):

None

Toxicology Performed:

No

Medical Certification:

Class 2 With Waivers/Limitations

Last FAA Medical Exam:

11/06/2018

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

 

Flight Time:

6617 hours (Total, all aircraft), 2522 hours (Total, this make and model), 4720 hours (Pilot In Command, all aircraft), 23 hours (Last 90 days, all aircraft), 8 hours (Last 30 days, all aircraft), 0 hours (Last 24 hours, all aircraft)

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

AEROSPATIALE

Registration:

N346AE

Model/Series:

AS350 B2

Aircraft Category:

Helicopter

Year of Manufacture:

1996

Amateur Built:

No

Airworthiness Certificate:

Normal

Serial Number:

2946

Landing Gear Type:

High Skid

Seats:

4

Date/Type of Last Inspection:

01/08/2019, 100 Hour

Certified Max Gross Wt.:

4961 lbs

Time Since Last Inspection:

 

Engines:

1 Turbo Shaft

Airframe Total Time:

11499 Hours as of last inspection

Engine Manufacturer:

Honeywell

ELT:

C126 installed, not activated

Engine Model/Series:

LTS-101-700D

Registered Owner:

Air Evac Ems Inc

Rated Power:

732 hp

Operator:

Air Evac Ems Inc

Operating Certificate(s) Held:

On-demand Air Taxi (135)

Operator Does Business As:

 

Operator Designator Code:

EVCA

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Instrument Conditions

Condition of Light:

Day

Observation Facility, Elevation:

PNC, 1008 ft msl

Distance from Accident Site:

0 Nautical Miles

Observation Time:

1742 UTC

Direction from Accident Site:

Lowest Cloud Condition:

Unknown

Visibility

4 Miles

Lowest Ceiling:

Broken / 900 ft agl

Visibility (RVR):

 

Wind Speed/Gusts:

12 knots /

Turbulence Type Forecast/Actual:

/

Wind Direction:

130°

Turbulence Severity Forecast/Actual:

/

Altimeter Setting:

30.01 inches Hg

Temperature/Dew Point:

4°C / 2°C

Precipitation and Obscuration:

Light - Rain; Moderate - Mist

Departure Point:

Ponca City, OK

Type of Flight Plan Filed:

Company VFR

Destination:

Ponca City, OK (PNC)

Type of Clearance:

None

Departure Time:

1141 CST

Type of Airspace:

Class E

 

Airport Information

Airport:

Ponca City Regional Airport (PNC)

Runway Surface Type:

 

Airport Elevation:

1008 ft

Runway Surface Condition:

Unknown

Runway Used:

N/A

IFR Approach:

None

Runway Length/Width:

 

VFR Approach/Landing:

Unknown

 

Wreckage and Impact Information

Crew Injuries:

2 None

Aircraft Damage:

Substantial

Passenger Injuries:

N/A

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

2 None

Latitude, Longitude:

36.725278, -97.101944

 


 


Administrative Information

Investigator In Charge (IIC):

John M Brannen

Report Date:

06/29/2020

Additional Participating Persons:

Jeff Jennings; FAA - Will Rogers FSDO; Oklahoma City, OK

Publish Date:

06/29/2020

Note:

The NTSB did not travel to the scene of this accident.

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=98887