# NTSB ERA11IA184: Cessna 560XL, N588QS, Haynesville, VA, March 10, 2011

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: March 10, 2011, 08:56 local (13:56 UTC)
- Place: Haynesville, VA
- Coordinates: 37.935753, -76.668326
- Nearby events: https://openairdocs.org/map.md?lat=37.9358&lon=-76.6683&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-climb to cruise: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report February 6, 2012
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- Parties: Cessna Aircraft Company, FAA/FSDO, Netjets Aviation, Inc.
- NTSB case key (mKey): 78529
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11IA184
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78529/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78529
- Page: https://openairdocs.org/ntsb/ERA11IA184

## Probable cause

The manufacturer's inadequate design fix for previously known tailcone stinger water ingestion and retention.

## Findings

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

- [Flight control system: rudder control system](https://openairdocs.org/ntsb-findings/01022720): Aircraft › Aircraft systems · Inoperative (probable cause); cases with it: [Cessna 560XL, 3 cases](https://openairdocs.org/ntsb-findings/01022720/cases.md?model=2076702), [All aircraft, 93 cases](https://openairdocs.org/ntsb-findings/01022720/cases.md)
- [Ceiling/visibility/precip: rain](https://openairdocs.org/ntsb-findings/03035035): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Cessna 560XL, 1 case](https://openairdocs.org/ntsb-findings/03035035/cases.md?model=2076702), [All aircraft, 56 cases](https://openairdocs.org/ntsb-findings/03035035/cases.md)
- [Design: equipment design](https://openairdocs.org/ntsb-findings/04011010): Organizational issues › Development · Manufacturer (probable cause); cases with it: [Cessna 560XL, 1 case](https://openairdocs.org/ntsb-findings/04011010/cases.md?model=2076702), [All aircraft, 35 cases](https://openairdocs.org/ntsb-findings/04011010/cases.md)

## Sequence of events

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

- [Enroute-climb to cruise: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Cessna 560XL, 3 cases](https://openairdocs.org/ntsb-events/333/sequence.md?model=2076702), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md)

## Analysis

After a flight earlier in the day, the airplane sat on a ramp in moderate rain for about 1 1/2 hours before departing. During the departure, the airplane encountered light to moderate rain, and, while climbing through about 28,000 feet, the crew found that the rudder was frozen in the neutral position. The crew continued the climb to 40,000 feet and, based on discussions with the company, diverted to an en route airport. Descending through 13,000 feet, normal rudder operation returned, and the subsequent approach and landing were uneventful. After the crew disembarked, they noticed water dripping from the belly of the airplane, and subsequently found ice in the bottom of the tailcone stinger, through which the rudder and elevator control cables ran. About 4 months prior to this incident, two other airplanes had similar incidents that resulted in the manufacturer issuing an alert service letter (ASL). The ASL stated, in part, that the tailcone stinger may not drain water, which could allow ice to form around the rudder cables and pulleys. The ASL required inspection of the two existing drain holes to ensure they were the right size, sealing an existing drain hole, and adding another drain hole in the aft canted bulkhead. This incident airplane had incorporated the ASL prior to the incident. Subsequent flight testing by the manufacturer revealed that, with the tailcone stinger drain hole sealed per the ASL, air could still enter the tailcone through seams at the bottom of the stinger with enough force to splatter water onto the rudder cables and pulleys, which could then freeze. Testing also revealed that air emanating from the new hole in the aft canted bulkhead also resulted in water splattering onto the rudder cables and pulleys and that, after large quantities of water were introduced, water would only drain forward through the new hole only if large quantities were introduced. As a result, the manufacturer issued a service bulletin, in addition to the ASL (which must be completed) that requires the installation of a seal and another drain.

## Factual narrative

On March 10, 2011, at 0856 eastern standard time, while climbing through approximately 28,000 feet near Haynesville, Maryland, a Cessna 560XL, N588QS, operated by NetJets Aviation, Inc., experienced stuck rudder controls. There was no damage to the airplane, and the two pilots and one passenger were not injured. Visual meteorological conditions prevailed. The airplane was operating on an instrument flight rules flight plan from Baltimore/Washington International Thurgood Marshall Airport (BWI), Baltimore, Maryland, to Lynden Pindling International Airport (MYNN), Nassau, The Bahamas. The personal flight was being operated under the provisions of 14 Code of Federal Regulations Part 91, Subpart K. According to the company's director of aviation safety, the incident flight was the second of the day for the airplane, with the first being a positioning flight from Malcolm McKinnon Airport (SSI), Brunswick, Georgia to BWI. The airplane departed SSI at 0520, flew at an en route cruise altitude of 37,000 feet and landed at BWI at 0702. Other than encountering light to moderate rain upon arrival, the flight was uneventful with no anomalies noted with the airplane. While the airplane was on the ground at BWI, there was occasionally moderate rain at a temperature of 9 degrees C. The airplane departed the ramp at 0831 for MYNN with the copilot at the controls, flying from the right seat. During the departure, the airplane again encountered light to moderate rain. As the airplane was climbing through approximately 28,000 feet, the copilot noted that the yaw damper was "not functioning properly." The copilot disconnected the autopilot and yaw damper, and as he exercised the flight controls, he found that the rudder was "frozen" in the neutral position. The crew continued the climb to 40,000 feet, and based on the captain's discussions with the company, then diverted to Myrtle Beach International Airport (MYR), Myrtle Beach, South Carolina. Descending through 13,000 feet, normal rudder operation returned, and the subsequent approach and landing were uneventful. After the crew disembarked, they noticed water dripping from the belly of the airplane. Panel 321ABC was subsequently removed, and water and ice were found in the bottom of the compartment, through which, also ran the rudder and elevator control cables. On December 1, 2010, another Cessna 560XL, N607QS, had landed without damage after the crew experienced rudder binding during the landing flare. According to the preliminary report for NTSB incident investigation CEN11IA087, a postflight examination of the inside of the tailcone stinger revealed an accumulation of ice that interfered with the rudder control cables and pulleys. It also noted that the airplane had previously been parked in light rain and subsequently departed in light to moderate rain before breaking out of clouds at 14,000 feet en route to a final altitude of 40,000 feet. On December 13, 2010, another Cessna 560XL, N498AB, had landedwithout damage after the crew experienced rudder binding in flight. According to the preliminary report for NTSB incident investigation CEN11IA111, a postflight examination of the inside of the tailcone stinger revealed an accumulation of ice around the rudder control cables and pulleys. The report did not provide atmospheric conditions. On January 21, 2011, Cessna issued Alert Service Letter [ASL]560XL-53-08, "Fuselage – Aft Canted Bulkhead Drain Installation," which stated, in part, that the tailcone stinger "may not drain water, and in turn, could allow ice to form around the rudder bias cable pulleys." The ASL provided instructions to inspect two 0.201 inch diameter drain holes in frames immediately forward and aft of access panel 321ABC and drill them if necessary, to seal an existing 0.201 inch diameter drain hole in the tailcone stinger, and to add a 0.75 inch diameter drain hole in the aft canted bulkhead. According to the NetJets director of aviation safety, on March 7, 2011, another Cessna 560XL, N691QS, had landed in Canada without damage after the crew experienced rudder binding in flight after having parked in and taken off during rain. Ice was again found in the tailcone stinger that bound the rudder controls, but the ASL had not yet been incorporated into the airplane. On March 15, 2011, the NTSB issued Safety Recommendation A-11-16, which recommended that the Federal Aviation Administration (FAA) issue an airworthiness directive to mandate that all Cessna 560XL operators comply with the ASL. According to maintenance records, the ASL requirements were completed on N588QS on January 31, 2011. Subsequent to the rudder binding of N588QS, Cessna, with FAA oversight, conducted further testing. According to an FAA response to the NTSB Safety Recommendation, flight testing occurred on another Cessna 560XL that had also incorporated the requirements of the ASL, and was modified with onboard video cameras, tufts to indicate ventilation, light sources, and tubing for the introduction of water to the stinger area during flight. Flight tests revealed that even though the previously existing tailcone stinger drain hole had been sealed per the ASL, air was still coming through seams at the bottom of the stinger with enough force to splatter water onto the rudder cables and pulleys. Testing also revealed that air emanating from the new hole in the aft canted bulkhead also resulted in splattered water onto the rudder cables and pulleys, and that after large quantities of water were introduced, water would only drain forward through the hole. As a result of the testing, Cessna issued Service Bulletin [SB]560XL-53-16, "Fuselage-Stinger Drain Installation" on October 4, 2011. The stated purpose of the SB was to reduce the amount of water entering the tailcone stinger and to improve drainage by installing a seal and an additional drain. The SB also noted that the ASL was to be completed prior to, or in conjunction with the SB. The Cessna 560XLreceived FAA certification in April 1998; however, except for the events listed in this report, no previous documentation of rudder control binding due to internal tailcone stinger icing could be found in either the FAA Service Difficulty Report database or the NTSB accident database

## Aircraft

- Registration: [N588QS](https://openairdocs.org/aircraft/N588QS), registered now, S/N 560-5721, built 2007 (OpenAirDocs)
- Reported make and model: CESSNA 560XL
- Registry model: [Cessna 560XL](https://openairdocs.org/model/cessna-560xl) (registry code 2076702) (OpenAirDocs)
- Registry engine: [Pratt & Whitney Canada PW545B](https://openairdocs.org/engine/pratt-whitney-canada-pw545b) (registry code 52186, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 560-5721
- Airframe hours: 3141
- Engines: P&W CANADA PW545B 4119 lbs thrust turbo fan; P&W CANADA PW545B 4119 lbs thrust turbo fan
- Damage: No damage
- Flight: Personal, Part 91 subpart K
- Operator: Netjets Aviation, Inc.
- Registered owner: Netjets Sales, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, January 25, 2011, 153 hours before
- Departed: BWI, Baltimore, MD
- Destination: MYNN, Nassau
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review January 28, 2011; seat: left; flight hours: 10,000 total, 3,473 in this make and model, 104 in the last 90 days, 38 in the last 30 days, 3 in the last 24 hours
- Co-pilot; age 35; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review November 5, 2010; seat: right; flight hours: 7,412 total, 1,744 in this make and model, 147 in the last 90 days, 63 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 130° at 6 knots
- Visibility: 4 statute miles
- Lowest ceiling: 1,300 ft broken
- Temperature: 52 °F, dew point 48 °F
- Altimeter: 30.01 inHg
- Observed at: NUI, 15 nm away

## Docket (9 files)

The files NTSB released with the investigation on December 14, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78529. 8.8 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357233&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Cessna Alert Service Letter ASL560XL-53-08 (item 2, .PDF, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357249&FileExtension=.PDF&FileName=Cessna%20Alert%20Service%20Letter%20ASL560XL-53-08-Master.PDF
- Maintenance Record of Implementation of ASL560XL-53-08 (item 3, .PDF, 460 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357250&FileExtension=.PDF&FileName=Maintenance%20Record%20of%20Implementation%20of%20ASL560XL-53-08-Master.PDF
- NTSB Safety Recommendation A-11-16 (item 4, .PDF, 2 photos, 534 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357253&FileExtension=.PDF&FileName=NTSB%20Safety%20Recommendation%20A-11-16-Master.PDF
- FAA Response to NTSB Safety Recommendation A-11-16 (item 5, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357257&FileExtension=.PDF&FileName=FAA%20Response%20to%20NTSB%20Safety%20Recommendation%20A-11-16-Master.PDF
- Cessna Service Bulletin SB560XL-53-16 (item 6, .PDF, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357260&FileExtension=.PDF&FileName=Cessna%20Service%20Bulletin%20SB560XL-53-16-Master.PDF
- Statement of Party Representatives to NTSB Investigation (Cessna) (item 7, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357235&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20(Cessna)-Redacted.PDF
- Statement of Party Representatives to NTSB Investigation (Netjets) (item 8, .PDF, 788 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357237&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation%20(Netjets)-Redacted.PDF
- Photo - Ice Remnant Found by Crew in Tailcone Stinger (Courtesy Netjets) (item 9, .PDF, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358003&FileExtension=.PDF&FileName=Photo%20-%20Ice%20Remnant%20Found%20by%20Crew%20in%20Tailcone%20Stinger%20(Courtesy%20Netjets)-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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