# NTSB CEN10LA204: Cessna 680, N606CS, Eagle, CO, February 13, 2010

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 13, 2010, 08:30 local (15:30 UTC)
- Place: Eagle, CO
- Coordinates: 39.638889, -106.909446 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.6389&lon=-106.9094&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Clear air turbulence encounter](https://openairdocs.org/ntsb-events/362)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 27, 2011
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA Windsor Locks FSDO, FAA Denver FSDO
- NTSB case key (mKey): 75759
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA204
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75759/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75759
- Page: https://openairdocs.org/ntsb/CEN10LA204

## Probable cause

The airplane’s encounter with localized severe to extreme mountain wave turbulence which resulted in substantial damage to both wings.

## Findings

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

- [Turbulence: terrain induced turbulence](https://openairdocs.org/ntsb-findings/03032010): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Cessna 680, 1 case](https://openairdocs.org/ntsb-findings/03032010/cases.md?model=2076811), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/03032010/cases.md)
- [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Flight crew; cases with it: [Cessna 680, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=2076811), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md)
- [Turbulence: terrain induced turbulence](https://openairdocs.org/ntsb-findings/03032010): Environmental issues › Conditions/weather/phenomena · Awareness of condition; cases with it: [Cessna 680, 1 case](https://openairdocs.org/ntsb-findings/03032010/cases.md?model=2076811), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/03032010/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: [Cessna 680, 1 case](https://openairdocs.org/ntsb-events/030/sequence.md?model=2076811), [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md)
- [Enroute-cruise: Clear air turbulence encounter](https://openairdocs.org/ntsb-events/362) (defining event); cases with it: [Cessna 680, 1 case](https://openairdocs.org/ntsb-events/362/sequence.md?model=2076811), [All aircraft, 24 cases](https://openairdocs.org/ntsb-events/362/sequence.md)

## Analysis

The airplane encountered extreme turbulence after leveling from a climb at 18,000 feet. The extreme turbulence encounter caused a brief loss of control that lasted less than a minute. The airplane then made an uneventful descent and landing. A postflight inspection of the airplane revealed overstress damage that caused wrinkling and debonding on both wings. The synoptic surface weather chart for the flight identified an area of high pressure to the west and an area of low pressure to the east. These conditions were conducive to mountain wave turbulence. An inflight weather advisory was in effect for moderate turbulence, icing, and mountain obscuration for the accident location and altitude. Low-level significant weather charts advised of moderate or greater turbulence below 20,000 feet for the accident region. Pilot reports in the area near the time of the turbulence event indicated moderate levels of turbulence above 10,000 feet. The preflight weather information obtained by the flight crew did not include available information about the turbulence forecasts or the pilot reports of turbulence.

## Factual narrative

On February 13, 2010, about 0830 mountain standard time, a Cessna 680 airplane, N606CS, was substantially damaged during an encounter with turbulence while in cruise flight near Eagle, Colorado. The two airline transport pilots were not injured. The airplane was owned by DEC Leasing, LLC, and operated by Citationshares Management, LLC. Visual meteorological conditions prevailed at the time of the accident and an instrument flight rules (IFR) flight plan had been filed for the 14 Code of Federal Regulations Part 91 repositioning flight. The airplane had departed Centennial Airport (APA), Denver, Colorado, about 0819 and was en route to Eagle County Airport (EGE), Eagle, Colorado. The airplane was flying at 16,000 feet mean sea level (MSL) in clear air on top of lower clouds. Because of light to moderate turbulence the flight crew members reported that they requested and were cleared to climb to 18,000 feet MSL. While leveling off at 18,000 feet, the airplane encountered extreme turbulence which caused the autopilot to disengage and the flight crew members were briefly unable to keep the wings level, maintain altitude, or maintain airspeed. The extreme turbulence encounter lasted less than a minute and the airplane then made an uneventful descent and landing at EGE. A postflight inspection of the airplane revealed overstress damage that caused wrinkling and debonding of portions of the top skin on both wings. Surface stations along the mountain range near the upset location registered high sustained winds with significant gusts during the times surrounding the event. Wind speeds approached 40 knots with gusts at 50 knots. Directions of the winds were generally perpendicular to the orientation of the mountain range. An Airmen's Meteorological Information (AIRMET) in-flight weather advisory, issued at 0145, was active for moderate turbulence, icing, and mountain obscuration for the upset location and altitude. Low Level Significant Weather charts, valid during the time surrounding the accident, advised of moderate or greater turbulence below 20,000 feet for the accident region. Numerous aircraft in the area relayed turbulence information that indicated a significantly turbulent atmosphere over the central portion of Colorado during the times surrounding the accident. Pilot reports in the area near the time of the turbulence event indicated moderate levels of turbulence above 10,000 feet. A copy of the preflight weather briefing for the accident flight was provided by the operator. This briefing, accessed via FlightPlan.com, included winds aloft estimates, surface observations, station forecasts, notices to airmen (NOTAMS) and pilot reports (PIREPS) for selected sites. The preflight weather briefing did not include available information about active AIRMETS, recent PIREPS, or Low Level Significant Weather (SIGWX) charts.

## Aircraft

- Registration: [N606CS](https://openairdocs.org/deregistered/N606CS-2015-07-24), registration cancelled 2015-07-24, S/N 680-0061, built 2006 (OpenAirDocs)
- Reported make and model: CESSNA 680
- Registry model: [Cessna 680](https://openairdocs.org/model/cessna-680) (registry code 2076811) (OpenAirDocs)
- Registry engine: [Pratt & Whitney PW300 series](https://openairdocs.org/engine/pratt-whitney-pw300-series) (registry code 52128, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 680-0061
- Airframe hours: 3746
- Engines: P & W PW300 Series 5680 lbs thrust turbo fan
- Damage: Substantial damage
- Flight: Executive/Corporate, Part 91
- Operator: Citationshares Management LLC, doing business as Citation Air
- Registered owner: DEC Leasing LLC
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, February 4, 2010
- Departed: APA, Denver, CO
- Destination: EGE, Eagle, CO
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 69; injuries: none; flight engineer, commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review January 29, 2010; seat: left; flight hours: 26,300 total, 3,000 in this make and model, 15,000 as pilot in command, 150 in the last 90 days, 50 in the last 30 days, 8 in the last 24 hours
- Co-pilot; age 56; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review January 20, 2010; seat: right; flight hours: 5,700 total, 97 in this make and model, 2,200 as pilot in command, 97 in the last 90 days, 48 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 260° at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: 5,000 ft overcast
- Temperature: 27 °F, dew point 21 °F
- Altimeter: 30.07 inHg
- Observed at: EGE, 50 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 20100213034249A](https://openairdocs.org/incident/20100213034249A), Feb 13, 2010: Cessna 680, Denver, CO, Substantial damage. At flight level 180 aircraft experinced severe turbulence.

## Docket (5 files)

The files NTSB released with the investigation on November 23, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75759. 10.9 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Captain's Statement (item 1, .PDF, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40330522&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Captain%27s%20Statement-Redacted.PDF
- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - First Officer's Statement (item 2, .PDF, 332 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358416&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20First%20Officer%27s%20Statement-Redacted.PDF
- Operator's Flight Logs, Trip Itinerary, and Preflight Weather Briefing Data (item 3, .PDF, 388 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358400&FileExtension=.PDF&FileName=Operator%27s%20Flight%20Logs,%20Trip%20Itinerary,%20and%20Preflight%20Weather%20Briefing%20Data-Redacted.PDF
- Meteorology 5 - Factual Report of Group Chairman (item 4, .PDF, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358194&FileExtension=.PDF&FileName=Meteorology%205%20-%20Factual%20Report%20of%20Group%20Chairman-Master.PDF
- Pre-accident Photo of N606CS (Internet Photo from www.flickr.com) (item 5, .PDF, 165 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358399&FileExtension=.PDF&FileName=Pre-accident%20Photo%20of%20N606CS%20%20(Internet%20Photo%20from%20www.flickr.com)-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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