# NTSB WPR10LA075: Aerospatiale AS 355F1, N548SA, Temple Bar, AZ, December 6, 2009

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 6, 2009, 10:30 local (18:30 UTC)
- Place: Temple Bar, AZ
- Coordinates: 36.020278, -114.334724 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.0203&lon=-114.3347&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338)
- Highest injury: No injuries
- Injuries: 7 uninjured
- Status: Completed, report March 23, 2010
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 75151
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA075
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75151/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75151
- Page: https://openairdocs.org/ntsb/WPR10LA075

## Probable cause

The pilot’s inadequate preflight inspection. Contributing to the accident was the pilot’s diverted attention during the preflight inspection.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Attention/monitoring: attention](https://openairdocs.org/ntsb-findings/02021510): Personnel issues › Psychological · Pilot (probable cause); cases with it: [All aircraft, 226 cases](https://openairdocs.org/ntsb-findings/02021510/cases.md)
- [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md)
- [Aircraft](https://openairdocs.org/ntsb-findings/01010000): Aircraft › Aircraft handling/service · Inadequate inspection (probable cause); cases with it: [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01010000/cases.md)
- [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Prior to flight: Preflight or dispatch event](https://openairdocs.org/ntsb-events/030); cases with it: [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md)
- [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md)

## Analysis

The pilot reported that after arriving to work late he began his preflight inspection on the helicopter. As the pilot was inspecting the left engine, the refueling truck arrived and the pilot lowered the left engine cowling door and tended to the refueling of the helicopter. The pilot said that following the refueling of the helicopter, he continued his preflight inspection and subsequently boarded the passengers “not realizing I left the engine cowling ‘unlatched’.” While en route to the flight’s intended destination, the pilot heard a “pop” followed by feedback in the cyclic control. The pilot was informed by the pilot of a second helicopter that the left engine cowling appeared to be open and partially separated. The pilot initiated a precautionary landing to the desert surface and landed without further incident. Examination of the helicopter by a Federal Aviation Administration inspector revealed that two of the three main rotor blades were damaged. One main rotor blade exhibited a one-inch-long gouge about one-quarter of an inch in depth near the blade root. A portion of the left engine cowling was separated and not located.

## Factual narrative

On December 6, 2009, about 1030 Pacific standard time, an Aerospatiale AS 355F1 helicopter, N548SA, was substantially damaged during cruise flight when the left engine cowling door opened in flight near Temple Bar, Arizona. The helicopter was registered to and operated by Heli-USA Airways, Inc., Las Vegas, Nevada, under the provisions of Title 14 Code of Federal Regulations Part 135. The commercial pilot and six passengers were not injured. Visual meteorological conditions prevailed and a company flight plan was filed for the cross-country flight. The air tour flight originated from the McCarran International Airport (LAS), Las Vegas, Nevada, about 1000, with an intended destination of Grand Canyon, Arizona. The pilot reported that the morning of the accident, he was late to work due to unforeseen traffic and local events within the area. The pilot stated he was about 40 minutes late to work and upon his arrival, he started his pre-flight inspection. As the pilot was inspecting the area of the left engine, the fuel truck arrived to refuel the helicopter. The pilot “lowered the cowling door [and] walked around to the pilot seat to get the gas cap keys.” After the helicopter was refueled, the pilot “continued the pre-flight, not realizing that I left the engine cowling ‘unlatched’.” The pilot further reported that his passengers were dropped off on the ramp and he proceeded to board them “still not realizing that I left the cowling door unlatched.” The pilot departed the airport and while en route to his destination, he heard a “pop” followed by “shake feed” within the cyclic control. The pilot contacted a second company helicopter to have them visually inspect the helicopter in flight. The pilot of the second helicopter informed the pilot that the left engine cowling appeared to be open and partially separated. The pilot initiated a precautionary landing to the desert surface and landed without further incident. Examination of the helicopter by a Federal Aviation Administration (FAA) inspector revealed that two of the three main rotor blades were damaged. One main rotor blade exhibited a one-inch long gouge about one-quarter of an inch in depth near the blade root. A portion of the left engine cowling was separated and not located.

## Aircraft

- Registration: N548SA (not matched to a registry record)
- Reported make and model: AEROSPATIALE AS 355F1
- Category: Helicopter
- Serial number: 5167
- Airframe hours: 7390
- Engines: ALLISON 250-C20 SER 420 horsepower turbo shaft; ALLISON 250-C20 SER 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 135
- Operator: Heliusa Airways Inc
- Registered owner: Heliusa Airways Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, November 22, 2009, 36 hours before
- Departed: LAS, Las Vegas, NV
- Destination: Grand Canyon, AZ
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review July 15, 2009; seat: right; flight hours: 3,000 total, 2,928 as pilot in command, 200 in the last 90 days, 60 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 39 °F, dew point -0 °F
- Altimeter: 29.81 inHg
- Observed at: LVS, 35 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 (OpenAirDocs).

- [Accident 20091206053779A](https://openairdocs.org/incident/20091206053779A), Dec 6, 2009: Aerospatial AS 355F1, Grand Canyon, AZ, Substantial damage. Airman failed to secure the latches which secure the left hand engine compartment door. Aircraft departed las airport on a 14 CFR part 135 air tour to the…

## Docket (3 files)

The files NTSB released with the investigation on January 19, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75151. 483 KB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Operator (item 1, .PDF, 254 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40324259&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Operator-Redacted.PDF
- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Pilot (item 2, .PDF, 205 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323278&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Pilot-Redacted.PDF
- Helicopter Checklist (item 3, .PDF, 24 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40323475&FileExtension=.PDF&FileName=Helicopter%20Checklist-Master.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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