Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-98-098
Details
Synopsis: On January 9, 1997, an Empresa Brasileira de Aeronautica, S/A (Embraer) EMB-120RT, operated by COMAIR Airlines, Inc., crashed during a rapid descent after an uncommanded roll excursion near Monroe, Michigan. The flight was a scheduled, domestic passenger flight from the Cincinnati/Northern Kentucky International Airport, Covington, Kentucky, to Detroit Metropolitan/Wayne County Airport, Detroit, Michigan. The flight departed Covington with 2 flightcrew, 1 flight attendant, and 26 passengers on board. There were no survivors. The airplane was destroyed by ground impact forces and a postaccident fire. IMC prevailed at the time of the accident, and the flight was operating on an IFR flight plan.The probable cause of this accident was the FAA's failure to establish adequate aircraft certification standardds for flight in icing conditions.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Require all manufacturers of transport-category airplanes to incorporate logic into all new and existing transport-category airplanes that have autopilots installed to provide a cockpit aural warning to alert pilots when the airplane's bank and/or pitch exceeds the autopilot's maximum bank and/or pitch command limits.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Unacceptable Action
Mode: Aviation
Location: MONROE, MI, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA97MA017
Accident Reports: In-Flight Icing Encounter and Uncontrolled Collision with Terrain, Comair Flight 3272, Embraer EMB-120RT, N265CA
Report #: AAR-98-04
Accident Date: 1/9/1997
Issue Date: 11/30/1998
Date Closed: 7/8/2009
Addressee(s) and Addressee Status: FAA (Closed - Unacceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 7/8/2009
Response: In a June 4, 2001, letter, the FAA informed the Safety Board that it had published a final policy statement, titled Improving Flightcrew Awareness During Autopilot Operation, which met the intent of this safety recommendation for new and significantly modified transport-category airplanes. On April 11, 2006, the FAA published a final rule implementing the recommended requirement for new and significantly altered airplanes, and, on July 17, 2006, the FAA published Advisory Circular 25.1329-1B, which provided guidance necessary for complying with this revised regulation. In its June 4, 2001, letter, the FAA stated that it had concluded that the lack of bank or pitch angle alerts was not an inherently unsafe condition and, consequently, did not intend to mandate changes to existing airplanes. On September 19, 2001, the Board disagreed with this conclusion and classified the recommendation Open Unacceptable Response. In its current letter, the FAA stated that it had reconsidered its position regarding existing airplanes. As part of this reconsideration, it had reviewed upset and unusual-attitude accident and incident data for scheduled transport-category aircraft for the period from January 1993 through April 2008. The FAA’s review found 74 significant accidents and incidents that had occurred during this period. The FAA considered whether these accidents and incidents would have been prevented if the recommended revisions to the autopilot had been made, dividing the data into those that would have been prevented, those that would not, and those for which the outcome could not be determined. The FAA determined that the recommended revision would not have prevented 69 of the 74 events. Among the events that the FAA did not believe would have been prevented by the alert was the Comair flight 3272 accident that prompted this recommendation and the loss of control and ground impact in icing conditions involving American Eagle flight 4184 over Roselawn, Indiana, on October 31, 1994. The FAA believes that, in these events, the alert would have sounded simultaneously with the loss of control, providing no advance warning and therefore no safety benefit. After completing this review of the data, the FAA continues to believe that it is unwarranted to require the retrofit of all existing transport-category aircraft with the recommended alert logic in their autopilots. The Safety Board thanks the FAA for providing the data and results of the analysis that formed the basis for the FAA’s decision. The Board believes that the set of data analyzed was appropriate, but we disagree with the FAA’s determinations regarding whether an accident or incident would have been prevented by a cockpit aural warning to alert pilots when the airplane’s bank and/or pitch exceeds the autopilot’s maximum bank and/or pitch command limits. In the Comair flight 3272 accident, the autopilot was providing inputs to the airplane’s control surfaces to keep the airplane in a stable flight environment, yet the situation continued to deteriorate without the pilots’ knowledge until the airplane entered an uncontrollable situation and the autopilot subsequently disconnected. The Board believes that the autopilot should have alerted the pilots to this developing situation before it suddenly disconnected. However, the FAA has concluded that this accident does not support the need for the recommended action and does not intend to require that existing airplanes include the same safety feature now required for new aircraft. Consequently, Safety Recommendation A-98-98 is classified CLOSED—UNACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 10/16/2008
Response: Letter Mail Controlled 11/3/2008 10:32:10 AM MC# 2080660: Robert A. Sturgell, Acting Administrator, FAA, 10/16/08 In our letter dated June 4, 2001, the Federal Aviation Administration informed the Board that we published a final policy statement entitled “Improving Flightcrew Awareness During Autopilot Operation,” that accomplished the full intent of this safety recommendation for new and significantly modified transport-category airplanes. In that letter, the FAA also agreed to revise 14 Code of Federal Regulations (CFR) 25.1329 and Advisory Circular (AC) 25.1329-1A. These actions were reiterated at the Safety With A Team meeting in February 2004. The FAA published a final rule (enclosure 1) on April 11, 2006, and also published AC 25.1329-1B (enclosure 2) on July 17, 2006. As stated in our 2001 response, the FAA concluded that the lack of bank or pitch angle alerts is not an inherently unsafe condition, and we do not intend to mandate changes to existing transport-category airplanes. In the Board’s response, dated September 19, 2001, the Board disagreed with the FAA’s conclusion, citing one incident and one accident involving excessive bank angles, and requested the FAA reconsider its position. In reconsidering its position, the FAA reviewed upset and unusual attitude accident and incident data for scheduled transport-category aircraft from January 1993 through April 2008. This data was obtained from the Board’s Accident and Synopses Database (www.ntsb.gov), the Aviation Safety Network database (www.aviation-safety.net), and an aircraft accident database provided by Flight Simulation Systems, Inc. (www.fss.aero). This review showed 74 significant accidents and incidents involving scheduled airline operations in transport-category airplanes. Part 91 accidents were excluded except for ferry and maintenance flights by a part 121 or part 135 operator. Flights that resulted in an accident or incident because of pilot incapacitation, structural failures, midair collisions, or criminal acts were also excluded. This review is summarized in Table 1. The rows labeled “Yes” in Table 1 are situations where an alert would have had an effect on the event and are those instances where the condition was slowly developing because of inattention, distraction, or unrecognized spatial disorientation. The corresponding events to these rows are the upset incident to Delta Flight 106 and the accident to Crossair Flight 498. The rows labeled “Uncertain” account for events where the outcome may have been affected by the proposed addition of bank and/or pitch aural alerts. The corresponding events were the accidents to ATI Flight 805, China Flight 676, and Gulf Air Flight 72. The rows labeled “No” reflect the balance of the events. These events either occurred on airplanes that had a bank alert (e.g., Adam Air Flight 574 or Kenya Flight 507) or the crew would have been aware of the occurrence as a result of an abrupt upset. In particular, the icing-induced upsets, as in American Eagle Flight 4184 and Comair Flights 3272 and 5054, would likely not have been prevented by such an alert, as the alert would have sounded simultaneously with the loss of control, providing no advance warning. Two accidents of interest in recent years, Flash Airlines Flight 604 and Adam Air Flight 574, occurred in situations where the pilot flying had an aural cue of excessive bank. In the Flash event, the copilot was repeatedly calling both the over-bank and the incorrect direction of the turn. In the Adam Air event, the airplane had a bank angle annunciation audible on the cockpit voice recorder. The crews on both flights failed to respond appropriately and the result was an accident. The FAA reviewed its previous position along with the accident and incident data and its conclusions remain unchanged based on the following rationale: • The FAA has no authority to issue an airworthiness directive (AD) requiring modifications to existing type-certificated airplanes unless an unsafe condition exists, meaning the airplane design poses a hazard to its safe operation. A review of 15 years of accident and incident data does not support issuing an AD; • The absence of a cockpit aural warning to alert pilots when the airplane’s bank and/or pitch angle exceeds the autopilot’s maximum bank and/or pitch command limits is not an unsafe condition because multiple, redundant indications of the hazardous condition are already required by 14 CFR part 25. Crew inattention or incorrect reaction to properly functioning indications of a hazardous condition is not indicative of an unsafe airplane design; and • An aural alert of excessive bank and pitch angle is considered to be a safety enhancement as it improves crew situational awareness. It is for this reason that the FAA implemented the policy and rulemaking changes to 14 CFR 25.1329 requiring this feature for new airplane designs. Consequently, the FAA concludes it is unwarranted to require all manufacturers of transport-category airplanes to incorporate the recommended alert logic into all existing transport-category airplanes. I believe that the FAA has effectively addressed this safety recommendation and consider our actions complete.

From: NTSB
To: FAA
Date: 9/19/2001
Response: The Safety Board is pleased that the FAA acknowledges the safety benefit of the recommended action, but is disappointed that the FAA has implemented a policy statement that only applies to newly certificated designs. The FAA states that it does not plan to mandate this change for existing airplanes; however, the Board believes that the recommended action is needed for existing airplanes as well as new airplanes. In the Monroe, Michigan, EMB-120 accident that prompted this recommendation, and the Evergreen 747 incident cited in this recommendation, if the autopilot or other alerting system had alerted the flight crew to the developing problem, these accidents and incidents might have been avoided. Further, the Safety Board disagrees with the FAA's conclusion that the lack of bank or pitch angle alerts is not an inherently unsafe condition. The FAA's conclusion is based on the assumption that AC 25.1329-1A's pilot performance premises are always attainable under real operational conditions. Specifically, the AC's premise that "at least one pilot [should] monitor the behavior of the airplane and associaed autopilot performance at all times" is unrealistic for certain events that occur with subtle indications such as slow angular rates and control deflections. The incident and accident history of the part 23 and 25 fleets, as well as the FAA's "current certification standards" section of its March 2, 2001, Federal Register discussion of its proposed autopilot policy, indicates that this premise is not valid and that the lack of bank or pitch angle alerts constitutes an inherently unsafe condition. Pending the FAA's reconsideration of the recommended action, Safety Recommendation A-98-98 is classified OPEN—UNACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 6/4/2001
Response: Letter Mail Controlled 06/08/2001 7:11:13 PM MC# 2010479: On February 22, 2001, the Federal Aviation Administration (FAA) published a policy statement entitled "Improving Flightcrew Awareness During Autopilot Operation" in the Federal Register. The policy statement advises the public, manufacturers of transport-category airplanes, and manufacturers of automatic flight control (autopilot) systems that the FM, when certifying automatic pilot installations, intends to evaluate various items that will improve the flightcrew's awareness during autopilot operation. The policy statement does specify a cockpit alert for unusual and/or potentially hazardous conditions during autopilot operations. The FAA believes that the policy statement accomplishes the full intent of this safety recommendation and has the same effect on the manufacturers as an advisory circular (AC). I have enclosed a copy of the policy statement for the Board's information. In order for the FAA to require manufacturers of transport-category airplanes to incorporate a bank or pitch angle alert into existing airplanes, it would have to determine that the lack of such an alert is an inherently unsafe condition. The FAA does not consider this to be the case. Cues already exist to alert flightcrews of excessive pitch and bank angles (like attitude indicator and position of cockpit flight controls). When the flightcrew is not manually performing a specific flight path control function, the flightcrew is expected to be aware when this function is not being performed safely and to take appropriate and timely corrective action. The certification guidelines presented in AC 25.1329-lA, for example, state "...at least one pilot [should] monitor the behavior of the airplane and associated autopilot performance at all times." Therefore, the FAA does not consider it appropriate to mandate changes to existing transport-category airplanes as requested by this safety recommendation. The FAA acknowledges that such an alert represents an additional safety enhancement for future airplanes and is taking several actions to address this. The Aviation Rulemaking Advisory Committee (ARAC) Flight Guidance Systems Harmonization Working Group has addressed the issue of mandating an alert in the cockpit in developing recommendations to revise AC 25.1329-1A and 14 CFR 25.1329. The Flight Guidance Systems Harmonization Working Group's recommendations for revising 14 CFR 25.1329, in conjunction with the details included in the recommended revision to AC 25.1329-lA, are consistent with this safety recommendation. The recommended revision to AC 25.1329-1A specifies that the alert discussed in the policy statement should be installed in the flight deck of all new transport-category aircraft to increase the level of safety. The FAA agrees with the working group's recommendations and plans to proceed with a revision to 14 CFR 25.1329 and AC 25.1329-1A. The conditions (as defined in the proposed revision to AC 25.1329-1A) that will cause this alert to be annunciated while an aircraft is being operated with an autopilot engaged are listed below: *The autopilot is holding a sustained lateral or longitudinal command, possibly nearing the limit of the autopilot authority, which indicates an abnormal situation for which the autopilot is compensating. *The airplane experiences roll or pitch attitudes in excess of the autopilot design limits for pitch and roll angles. The ARAC is working to revise the AC and regulation referenced above. However, the policy statement published on March 2, 2001, accomplishes the full intent of this safety recommendation and has the same effect on the manufacturers as an AC. Consequently, I consider the FAA's action to be completed in response to this safety recommendation.

From: NTSB
To: FAA
Date: 3/12/2001
Response: The actions being taken by the FAA are responsive to this recommendation. Pending issuance of a final policy statement concerning the recommended action that augments AC 25.1329-lA and the issuance of a revised autopilot rule and AC that address the subject of this recommendation, Safety Recommendation A-98-98 remains classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 9/25/2000
Response: Letter Mail Controlled 10/02/2000 3:16:36 PM MC# 2001437 The FAA has initiated a survey of existing autopilot installations on transport-category airplanes to determine whether an unsafe feature exists and whether revisions of autopilot certification criteria were needed. Industry chose not to provide data in response to the FAA survey. I have enclosed a copy of the survey and responses that were received for the Board's information. Despite the lack of responses to the survey, on September 9, 1999, the FAA published a policy statement entitled "Improving Flightcrew Awareness During Autopilot Operation" in the Federal Register. A copy of the policy statement was provided to the Board on December 20, 1999. The public response to the policy statement was substantial, and the disposition of the comments has not been completed. The FAA plans to complete the disposition of comments and issue the final policy statement by the end of this year. The final policy statement will augment Advisory Circular 25.1329-lA. The ARAC Flight Guidance Systems Harmonization Working Group, in addition to several other issues, is addressing flightcrew alerts for several conditions during autopilot operation. The working group had originally planned to provide its recommendations to the FAA in June 2000. There has been a milestone slippage in this effort. The ARAC Flight Guidance Systems Harmonization Working Group has drafted language for the recommended advisory circular that states that flightcrew alerts should be provided for several conditions, including bank and pitch angles that exceed those expected for autopilot operation. The ARAC working group has made significant progress, but has not completed its task to recommend a revised autopilot rule and advisory circular. The working group anticipates completing its task and providing a recommendation to the FAA by mid-2001. I will keep the Board informed of the FAA's progress on this safety recommendation.

From: NTSB
To: FAA
Date: 3/9/2000
Response: Pending further FAA action, A-98-98 is classified OPEN—ACCEPTABLE RESPONSE, the Safety Board would appreciate a copy of the results of the FAA's proposed survey.

From: NTSB
To: FAA
Date: 2/16/2000
Response: A review of this document shows that, as stated by the safety board, certain failures of the autopilot system can cause changes in attitude at rates imperceptible to the flight crew and remain undetectable until the airplane reaches significant attitude deviations. Pending the results of the ARAC working group and subsequent action by the FAA to implement its recommendations, A-98-98 is classified OPEN--ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 12/20/1999
Response: Letter Mail Controlled 03/02/2000 3:04:36 PM MC# 991531 On 9/9/99, the FAA published a policy statement entitled "improving flightcrew awareness during autopilot operation" in the federal register. This document notes that certain failures of the autopilot system can cause a roll at rates imperceptible to the flightcrew. The policy statement addresses several topics, including advisory guidance that certain autopilot failures can result in changes in attitude at rates imperceptible to the flightcrew and remain undetectable until the airplane reaches significant attitude deviations. I have enclosed a copy of the policy statement for the board's information. The final policy statement will augment advisory circular 25.1329-1a. The aviation rulemaking advisory committee flight guidance systems harmonization working group, in addition to several other issues, is addressing autopilot and alerting system design and plans to provide its recommendations to the FAA in June 2000. I will keep the board informed of the FAA's progress on this recommendation.

From: FAA
To: NTSB
Date: 2/26/1999
Response: The FAA is initiating a survey of existing autopilot installations on transport-category airplanes to determine whether or not an unsafe feature exists and whether or not revisions of autopilot certification criteria are needed. The FAA plans to issue interim autopilot certification policy in fall 1999 that may be affected by the findings of this survey. The FAA has also tasked the APAC to harmonize and update 14 CFR part 2s automatic flight control and guidance rules and ac. Among many other issues, the flight guidance systems harmonization working group is addressing problems in the interface between flightcrews and autopilot systems, including alerting features. The working group will consider this safety recommendation specifically and propose related certification requirements to be incorporated in the comprehensive revision of 14 CFR part 25 automatic pilot rule and AC.