National Transportation Safety Board
Aviation Incident Final Report

 

 

Location:

Des Moines, IA

Incident Number:

CEN12IA554

Date & Time:

08/15/2012, 0835 CDT

Registration:

N108EK

Aircraft:

CESSNA 560XL

Aircraft Damage:

Minor

Defining Event:

Flight control sys malf/fail

Injuries:

8 None

Flight Conducted Under:

Part 91: General Aviation - Executive/Corporate

Analysis

The flight crewmembers reported that, after about 10 minutes of cruise flight at 40,000 ft pressure altitude, they observed an autopilot pitch trim mistrim annunciation and an associated master caution indication. As they began to reference the applicable checklist, the autopilot automatically disengaged, the airplane suddenly pitched down, and the airspeed increased to about 30 knots over the redline. The flight crew regained control of the airplane and then leveled it at 33,000 ft pressure altitude. The flight crew subsequently landed the airplane without further incident. The autopilot was not used after the temporary loss of airplane control; however, the electric pitch trim was used after passing through 10,000 ft mean sea level, and it functioned normally. A postincident examination of the autopilot, pitch trim systems, and horizontal stabilizer did not reveal any anomalies consistent with a loss of control.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this incident to be:
A temporary loss of control during cruise flight for reasons that could not be determined because postincident examination of the autopilot, pitch trim systems, and horizontal stabilizer revealed no anomalies consistent with a loss of control.

 

Findings

Aircraft

Elevator tab control system - Malfunction (Cause)

Autopilot system - Malfunction (Cause)

Performance/control parameters - Not attained/maintained (Cause)

Factual Information

On August 15, 2012, about 0835 central daylight time, a Cessna 560XL, N108EK, diverted to Des Moines International Airport (DSM), Des Moines, Iowa, following a loss of control during cruise at Flight Level (FL) 400. The two pilots and six passengers were not injured. The airplane sustained minor damage. The aircraft was registered to New Heights Aviation LLC and operated by Elliott Aviation under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, which was operated on an instrument flight rules flight plan. The flight originated from Flying Cloud Airport (FCM), Eden Prairie, Minnesota, at 0748, with an intended destination of Arlington Municipal Airport (GKY), Arlington, Texas.

The flight crew reported that after about 10 minutes of cruise flight at 40,000 feet pressure altitude, they observed an autopilot pitch trim mis-trim (AP Pitch Mis-trim) annunciation and associated master caution. As they began to reference the applicable checklist, the autopilot automatically disengaged and the airplane suddenly pitched down to about 20 degrees. The airspeed increased to about 30 knots over redline. The flight crew recovered and leveled the airplane at 33,000 feet pressure altitude. They subsequently elected to divert to DSM and landed without further incident. The autopilot was not used for the duration of the flight. However, the electric pitch trim was used passing 10,000 feet mean sea level and it functioned normally. The flight crew noted that an "abnormally high amount of water" was observed to be draining from the tailcone during the postflight inspection.

The cockpit voice recorder (CVR) was downloaded and a summary of the recording was prepared. The CVR summary revealed that as the airplane was leveling at flight level (FL) 400, the co-pilot noted "it's not keeping up with it." He commented about referencing the checklist and added "R-five." About 30 seconds later, a high-pitched tone was recorded simultaneously with the sound of a "thunk" and rustling sounds. Two additional high pitched tones were recorded. These were followed by a beeping tone consistent with the overspeed warning, which lasted for 40 seconds. The flight crew discussed deploying the speed brake and declared an emergency. The flight crew regained control of the airplane and diverted to DSM. During the descent, the crew discussed that they would not use the autopilot for the duration of the flight. Based on further discussions recorded by the CVR, the pilots executed a full flap approach. They subsequently landed at 0844 without further incident.

The required pilot actions related to an AP Pitch Mis-trim annunciation were contained on page R-5 of the Pilots' Abbreviated Checklist – Emergency/Abnormal Procedures. The procedure called for: (1) AP Trim Disc Button – Press and Release (if elevator trim not in motion); Pitch Trim – Adjust (as required); and Autopilot – Engage (as desired).

A postincident examination of the autopilot, pitch trim systems and two-position horizontal stabilizer system did not reveal any anomalies. The left and right elevator electric trim actuators and the autopilot elevator drive servo were subsequently replaced. The airplane was returned to service without any further difficulties.

 

History of Flight

Enroute-cruise

Flight control sys malf/fail (Defining event)

Loss of control in flight

Uncontrolled descent

Attempted remediation/recovery

Emergency descent

Off-field or emergency landing

 

 

Pilot Information

Certificate:

Airline Transport; Flight Instructor

Age:

42

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Right

Other Aircraft Rating(s):

None

Restraint Used:

Seatbelt, Shoulder harness

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

Airplane Multi-engine; Airplane Single-engine; Instrument Airplane

Toxicology Performed:

No

Medical Certification:

Class 1 With Waivers/Limitations

Last FAA Medical Exam:

05/21/2012

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

07/22/2012

Flight Time:

7709 hours (Total, all aircraft), 620 hours (Total, this make and model), 5328 hours (Pilot In Command, all aircraft), 114 hours (Last 90 days, all aircraft), 58 hours (Last 30 days, all aircraft), 0 hours (Last 24 hours, all aircraft)

 

 

Co-Pilot Information

Certificate:

Airline Transport; Flight Instructor

Age:

58

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Left

Other Aircraft Rating(s):

None

Restraint Used:

 

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

Airplane Multi-engine; Airplane Single-engine; Instrument Airplane

Toxicology Performed:

No

Medical Certification:

Class 1 With Waivers/Limitations

Last FAA Medical Exam:

04/24/2012

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

07/22/2014

Flight Time:

8605 hours (Total, all aircraft), 2010 hours (Total, this make and model), 7025 hours (Pilot In Command, all aircraft), 87 hours (Last 90 days, all aircraft), 52 hours (Last 30 days, all aircraft), 0 hours (Last 24 hours, all aircraft)

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

CESSNA

Registration:

N108EK

Model/Series:

560XL

Aircraft Category:

Airplane

Year of Manufacture:

 

Amateur Built:

No

Airworthiness Certificate:

Normal

Serial Number:

560-5032

Landing Gear Type:

Retractable - Tricycle

Seats:

10

Date/Type of Last Inspection:

06/29/2012, AAIP

Certified Max Gross Wt.:

20000 lbs

Time Since Last Inspection:

595 Hours

Engines:

2 Turbo Fan

Airframe Total Time:

4510 Hours at time of accident

Engine Manufacturer:

P&W CANADA

ELT:

Installed, not activated

Engine Model/Series:

PW545A

Registered Owner:

New Heights Aviation LLC

Rated Power:

3372 lbs

Operator:

Elliott Aviation Flight Services Inc

Operating Certificate(s) Held:

On-demand Air Taxi (135)

Operator Does Business As:

Elliott Aviation

Operator Designator Code:

JEMA

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Visual Conditions

Condition of Light:

Day

Observation Facility, Elevation:

DSM, 958 ft msl

Distance from Accident Site:

20 Nautical Miles

Observation Time:

0954 CDT

Direction from Accident Site:

360°

Lowest Cloud Condition:

Few / 180 ft agl

Visibility

10 Miles

Lowest Ceiling:

None

Visibility (RVR):

 

Wind Speed/Gusts:

7 knots /

Turbulence Type Forecast/Actual:

/

Wind Direction:

200°

Turbulence Severity Forecast/Actual:

/

Altimeter Setting:

29.92 inches Hg

Temperature/Dew Point:

23°C / 15°C

Precipitation and Obscuration:

No Obscuration; No Precipitation

Departure Point:

Minneapolis, MN (FCM)

Type of Flight Plan Filed:

IFR

Destination:

Arlington, TX (GKY)

Type of Clearance:

IFR

Departure Time:

0748 CDT

Type of Airspace:

 

 

Airport Information

Airport:

Des Moines International (DSM)

Runway Surface Type:

 

Airport Elevation:

958 ft

Runway Surface Condition:

 

Runway Used:

N/A

IFR Approach:

None

Runway Length/Width:

 

VFR Approach/Landing:

Full Stop

 

Wreckage and Impact Information

Crew Injuries:

2 None

Aircraft Damage:

Minor

Passenger Injuries:

6 None

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

8 None

Latitude, Longitude:

41.533889, -93.663056 (est)

 


 


Administrative Information

Investigator In Charge (IIC):

Timothy Sorensen

Report Date:

02/23/2015

Additional Participating Persons:

James Konig; FAA -- Des Moines Flight Standards; Ankeny, IA

Theresa Jacobsen; Elliott Aviation; Des Moines, IA

Andrew Hall; Cessna Aircraft Company; Wichita, KS

Publish Date:

02/23/2015

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=84721