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). 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 Part 135 and departed MKE about 1557 with an intended destination of Willow Run Airport, 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.
The National Transportation Safety Board determined that the probable cause of this accident was the pilots' mismanagement of an abnormal flight control situation through improper actions, including failing to control airspeed and to prioritize control of the airplane, and lack of crew coordination. Contributing to the accident were Marlin Air's operational safety deficiencies, including the inadequate checkrides administered by Marlin Air's chief pilot/check airman, and the Federal Aviation Administration's (FAA) failure to detect and correct those deficiencies, which placed a pilot who inadequately emphasized safety in the position of company chief pilot and designated check airman and placed an ill-prepared pilot in the first officer's seat.
The safety issues discussed in this report include pilot actions and coordination, the need for image recording equipment on airplanes not equipped with flight data recorders, autopilot panel design, control yoke wiring installations, identification of circuit breakers for use in emergencies, aural and visual alerts to pitch trim-in-motion, aileron trim power and sensitivity, human factors in airplane design, FAA appointment of check airmen, the scope of Regional Aviation Safety Inspection Program inspections, avenues for expressing safety concerns to federal authorities, and the safety ramifications of an operators' financial health.
As a result of this investigation, the National Transportation Safety Board makes the following recommendations:
To the Federal Aviation Administration:
Require all 14 Code of Federal Regulations Part 91K and Part 135 operators to incorporate upset recovery training (similar to that described in the airplane upset recovery training aid used by many Part 121 operators) and related checklists and procedures into their training programs. (A-09-113)
Require Cessna to redesign and retrofit the yaw damper and autopilot switches on the autopilot control panel in Citation series airplanes to make them easily distinguishable and to guard against unintentional pilot activation. (A-09-114)
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. (A-09-115)
Issue an airworthiness directive mandating compliance with Cessna Service Bulletin 550-24-14, "Control Wheel Electrical Cable Replacement," which was issued on January 17, 1992. (A-09-116)
Require Cessna to modify all Citation series airplanes by incorporating an aural pitch trim-in-motion warning and contrasting color bands on the pitch trim wheel to help pilots recognize a runaway pitch trim condition before control forces become unmanageable. (A-09-117) (This recommendation supersedes Safety Recommendation A-07-52 and is classified "Open-Unacceptable Response.")
Require Cessna to replace all Citation series airplane pitch trim, autopilot, and any other circuit breakers for critical systems that a pilot might need to access during an emergency situation with easily identifiable and collared circuit breakers to aid a pilot in quickly identifying and easily pulling those circuit breakers if necessary. (A-09-118) (This recommendation supersedes Safety Recommendation A-07-54 and is classified "Open-Unacceptable Response.")
Require airplane manufacturers to develop guidance on the identification of circuit breakers that pilots need to identify quickly and pull easily during abnormal or emergency situations and to provide such guidance, once developed, to operators of those airplanes. (A-09-119)
Require operators to implement the manufacturer's guidance asked for in recommendation A-09-119 regarding which circuit breakers pilots need to identify quickly and pull easily during abnormal or emergency situations in their airplanes. (A-09-120)
Require Cessna to evaluate and limit the maximum aileron trim deflection on Citation series airplanes to that required to meet the certification control requirements for powered trim tabs, unless there is a design-justification to exceed those requirements. (A-09-121)
Require Cessna to reduce the aileron trim sensitivity (the unexpectedly significant aileron trim deflection that results from a relatively small amount of trim knob input) on Citation series airplanes to avoid sudden and excessive aileron trim deflections. (A-09-122)
As an interim measure (pending an available aileron trim system retrofit), notify Citation pilots and operators of the potential hazards related to the sensitivity and responsiveness of the airplane's aileron trim system. (A-09-123)
Revise check airman approval and oversight procedures to incorporate heightened surveillance during a probationary period and at other times, as warranted, for check airmen whose background evaluation uncovers a history of criminal convictions, certificate revocations, check-ride failures, or other performance-related deficiencies. (A-09-124)
Conduct a detailed review of the oversight provided to Marlin Air to determine why the oversight system failed to detect (before and after the accident) and correct Marlin Air's operational deficiencies, particularly in the areas of pilot hiring, training, and adherence to procedures. (A-09-125)
Based on the review described in Safety Recommendation A-09-125, revise the oversight system and Federal Aviation Administration Order 8900.1 as needed. (A-09-126)
Require all 14 Code of Federal Regulations Part 135 and Part 91K operators to provide their customers, when a business agreement or contract is finalized, with Federal Aviation Administration (FAA) contact information identified as specifically for use in expressing concerns about flight safety, thus providing customers with a clear means of communicating any safety concerns to the FAA. (A-09-127)
Require all 14 Code of Federal Regulations Part 91K and Part 135 operators to notify the assigned principal operations inspectors of specific adverse financial events, such as bankruptcy, court judgments related to nonpayment of recurring expenses, or termination of a credit agreement or contract by a vendor for reasons of late payment or nonpayment. Upon receipt of such information, inspectors should increase their oversight of operators who appear to be in financial distress. (A-09-128)
To the American Hospital Association:
Inform your members, through your website, newsletters, and conferences, of the Federal Aviation Administration's (FAA) role in aviation safety with respect to medical/air ambulance services and provide FAA contact information. Urge your members to communicate any safety concerns related to medical/air ambulance services to the FAA. (A-09-129)
Previously Issued Recommendations Reiterated and Reclassified in This Report
As a result of its investigation of this accident, the National Transportation Safety Board reiterates the following safety recommendations to the Federal Aviation Administration:
Amend the advisory materials associated with 14 Code of Federal Regulations 25.1309 to include consideration of structural failures and human/airplane system interaction failures in the assessment of safety-critical systems. (A-06-37)
Adopt Society of Automotive Engineers [Aerospace Recommended Practice] 5150 into 14 Code of Federal Regulations Parts 21, 25, 33, and 121 to require a program for the monitoring and ongoing assessment of safety-critical systems throughout the life cycle of the airplane. Once in place, use this program to validate that the underlying assumptions made during design and type certification about safety-critical systems are consistent with operational experience, lessons learned, and new knowledge." (A-06-38)
Safety Recommendations A-06-37 and -38 are reiterated in section 22.214.171.124 of this report. In addition, Safety Recommendations A-06-37 and -38 are reclassified "Open-Unacceptable Response."
Previously Issued Recommendations Classified in This Report
The following previously issued recommendations are classified in this report:
Safety Recommendation A-07-52 (previously classified "Open-Unacceptable Response") is classified "Closed-Unacceptable Action/Superseded" (replaced by Safety Recommendation A-09-117) in section 126.96.36.199 of this report.
Safety Recommendation A-07-54 (previously classified "Open-Acceptable Alternate Response") is classified "Closed-Unacceptable Action/Superseded" (replaced by Safety Recommendation A-09-118) in section 188.8.131.52 of this report.