You may be trying to access this site from a secured browser on the server. Please enable scripts and reload this page.
Turn on more accessible mode
Turn off more accessible mode
Skip Ribbon Commands
Skip to main content
Top Link Bar
NEWS & EVENTS
Speeches & Testimony
Most Wanted List
The Investigative Process
Data & Stats
General Aviation Safety
Assistance to Families & Victims
Operations & Policy
Administrative Law Judges
Strategic Plans & Reports
Safety Recommendation Details
The Investigative Process
Data & Stats
General Aviation Safety
On June 4, 2007, about 1600 central daylight time, a Cessna Citation 550, N550BP, impacted Lake Michigan shortly after departure from General Mitchell International Airport, Milwaukee, Wisconsin (MKE).1 The two pilots and four passengers were killed, and the airplane was destroyed. The airplane was being operated by Marlin Air under the provisions of 14 Code of Federal Regulations (CFR) Part 135 and departed MKE about 1557 with an intended destination of Willow Run Airport (YIP), near Ypsilanti, Michigan. At the time of the accident flight, marginal visual meteorological conditions prevailed at the surface, and instrument meteorological conditions prevailed aloft; the flight operated on an instrument flight rules flight plan.
TO THE FEDERAL AVIATION ADMINISTRATION: Identify airplanes other than the Cessna Citation with autopilot control panel designs that may lead to inadvertent activation of the autopilot and require manufacturers to redesign and retrofit the autopilot control panels to make the buttons easily distinguishable and to guard against unintentional activation.
Original recommendation transmittal letter:
Closed - Unacceptable Action
Milwaukee, WI, United States
Loss of Control and Impact with Water, Marlin Air Cessna Citation 550, N550BP
Addressee(s) and Addressee Status:
FAA (Closed - Unacceptable Action)
General Aviation, Instruments
Safety Recommendation History
The NTSB notes that the FAA completed its review of accident and incident data associated with the issues in this recommendation. We further note that the FAA did not identify any significant issues attributed to the location and design of the autopilot and yaw damper engage switches and that the autopilot controller installed in the Cessna 550 and other similarly designed controllers have been used in numerous airplanes by many manufacturers for over 30 years. The FAA conducted flight tests on a Cessna Citation 550 and found that the autopilot control panel provides acceptable annunciation of the autopilot and yaw damper engage status. In addition, the FAA believes that an appropriately trained and qualified Cessna Citation 550 flightcrew member is able to distinguish between the autopilot and yaw damper switches and engage them properly. The FAA determined that the yaw damper and autopilot switches on the autopilot control panel in Cessna Citation series airplanes are in compliance with all standards and requirements in effect at the time the airplane was certificated, including 14 CFR Part 25, Section 25.777. The NTSB has previously indicated our belief that the location of the switches is not in compliance with Section 25.777. As a result of its investigation, the FAA does not plan to take the actions in either Safety Recommendation A-09-114 or -115. In the NTSB’s November 17, 2010, letter concerning these recommendations, we stated the following: Although the FAA plans to examine the service history associated with these types of designs, as well as crew indications that alert them to improper switch selection and pilot training, the NTSB believes that the location and arrangement of these switches violate fundamental human factors principles in cockpit design….regardless of the findings related to service history and pilot training, an acceptable response to these recommendations will require revisions to the autopilot controller to bring it into compliance with good human factors design practice. However, the FAA has indicated that it does not plan to take the recommended actions; consequently, Safety Recommendations A-09-114 and -115 are classified CLOSED—UNACCEPTABLE ACTION.
From J. Randolph Babbitt, Administrator: The Board's November 17. 2010, letter to the FAA states"... as the letter that transmitted these recommendations to the FAA indicated and as the FAA stated in its response, the location and operation of the switches on the autopilot controller arc not in compliance with 14 CFR Part 25, Section 25.777.” It was the FAA's intent in our initial response to agree to conduct a review, which has been completed. We did not find, nor did we state, that the location and operation of the switches are not in compliance with § 25.777. Our response to recommendation A-09-115 follows the extensive FAA study or the autopilot control panel design for recommendation A-09-114, which concluded that the Cessna Citation autopilot control panel complies with § 25.777. We concluded that other airplane types using the same controller and controllers of similar design offered by other manufacturers, also comply and do not warrant redesign or retrofit. I believe the FAA has effectively addressed this safety recommendation and I consider our actions complete.
The NTSB notes the FAA's statement that the autopilot controller used on the Sperry/Honeywell autopilots installed on the Cessna Citation is used on numerous airplanes by many manufacturers and that the design and grouping of the autopilot and yaw damper switches is a standard design used on many other Sperry/Honeywell autopilot systems. Although the FAA plans to examine the service history associated with these types of designs, as well as crew indications that alert them to improper switch selection and pilot training, the NTSB believes that the location and arrangement of these switches violate fundamental human factors principles in cockpit design. In addition, as the letter that transmitted these recommendations to the FAA indicated and as the FAA stated in its response, the location and operation of the switches on the autopilot controller are not in compliance with 14 CFR Part 25, Section 25.777. The review that the FAA has initiated is a necessary first step in issuing the requirements recommended, but regardless of the findings related to service history and pilot training, an acceptable response to these recommendations will require revisions to the autopilot controller to bring it into compliance with good human factors design practice and Section 25.777. Accordingly, pending completion of the actions recommended, Safety Recommendations A-09-114 and -115 are classified OPEN – ACCEPTABLE RESPONSE.
Letter Mail Controlled 5/5/2010 12:17:19 PM MC# 2100167 - From J. Randolph Babbitt, Administrator: The FAA concurs with the intent of this recommendation. Current FAA regulations, specifically 14 CFR part 25 section 25.777, require that each cockpit control be located to provide convenient operation and to prevent confusion and inadvertent operation. In addition to reviewing the design of the specific autopilot system related to this accident, the FAA specialists will review autopilot control panel design on other aircraft for similar characteristics and determine if an unsafe condition exists. I will provide an update on the progress of this safety recommendation by March 2011.
Strategic Plan, Performance & Accountability Reports & More
Directions to Conference Center
Web Policies & Notices
Annual Review of Aircraft