Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-10-120
Details
Synopsis: On November 12, 2001, about 0916 eastern standard time, an Airbus A300-605R,1 N14053, operated as American Airlines flight 587, crashed into a residential area of Belle Harbor, New York, shortly after takeoff from John F. Kennedy International Airport, Jamaica, New York.2 Following an encounter with wake turbulence from a preceding Boeing 747 (747), the first officer made a series of full alternating rudder pedal inputs before the airplane’s vertical stabilizer and rudder separated in flight; both were found in Jamaica Bay about 1 mile north of the main wreckage site.
Recommendation: TO THE EUROPEAN AVIATION SAFETY AGENCY: After the yaw axis certification standard recommended in Safety Recommendation A-10-119 has been established, review the designs of existing airplanes to determine if they meet the standard. For existing airplane designs that do not meet the standard, the European Aviation Safety Agency (EASA) should determine if the airplanes would be adequately protected from the adverse effects of a potential aircraft-pilot coupling (APC) after rudder inputs at all airspeeds. If adequate protection does not exist, EASA should require modifications, as necessary, to provide the airplanes with increased protection from the adverse effects of a potential APC after rudder inputs at high airspeeds.
Original recommendation transmittal letter: PDF
Overall Status: Open - Acceptable Response
Mode: Aviation
Location: Belle Harbor, NY, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA02MA001
Accident Reports: In-Flight Separation of Vertical Stabilizer American Airlines Flight 587, Airbus Industrie A300-605R, N14053
Report #: AAR-04-04
Accident Date: 11/12/2001
Issue Date: 8/4/2010
Date Closed:
Addressee(s) and Addressee Status: European Aviation Safety Agency (Open - Acceptable Response)
Keyword(s): Rudder

Safety Recommendation History
From: NTSB
To: European Aviation Safety Agency
Date: 8/1/2014
Response: The ARAC Report also contained a recommendation that retrofit of existing transport airplanes should be considered on a case-by-case basis and any potentially unsafe conditions found should be addressed in airworthiness directives (ADs). As part of its work on the report, the FCHWG reviewed several airplane designs but found none to be unsafe. In the report, the FCHWG stated its belief that a review of the existing fleet is important to ensure safety. Although the review was conducted for a representative sample of the Part 25 aircraft designs currently in service and no further retrofit evaluation was determined to be needed for the models evaluated, the report pointed out that designs that were not considered might need to be evaluated for acceptability. We acknowledge that a case-by-case analysis is an appropriate response to Safety Recommendation A-10-120 and that issuance of an AD is an appropriate means of addressing any designs identified as needing revision. However, we disagree with EASA that the work to satisfy our recommendation is complete. Analyses similar to those performed by the FCHWG are needed for existing designs that were not evaluated by the FCHWG, and ADs will need to be issued for any designs identified as unsafe. Pending EASA’s taking that action, Safety Recommendation A-10-120 remains classified OPEN—ACCEPTABLE RESPONSE.

From: European Aviation Safety Agency
To: NTSB
Date: 6/4/2014
Response: -From John Vincent, Deputy Director for Strategic Safety, Executive Directorate: EASA participated in the Aviation Rulemaking Advisory Committee (ARAC) Committee Flight Controls Harmonization Working Group (FCHWG) (Reference: Federal Register I Vol. 76, No. 59 I Monday, March 28, 2011 I Notices) tasked to consider whether changes to Part 25 are necessary to address rudder pedal sensitivity and rudder reversals. The report recommends an evolution of the yaw axis certification standards. One of the conclusions was that these new standards should be applicable only to new designs. For existing transport aeroplanes, EASA in accordance with conclusions from FCHWG believe that design reviews and retrofit of modifications should be considered on a case by case basis and that the normal continuing airworthiness of type design process should apply for any potentially unsafe condition that might be identified. It has to be noted that none of the aeroplanes reviewed as part of the FCHWG deliberations were found to have an unsafe condition.

From: NTSB
To: European Aviation Safety Agency
Date: 7/9/2013
Response: We are encouraged that, in response to Safety Recommendation A-10-119, EASA is working with the US Federal Aviation Administration to address flight controls harmonization and that you will determine the basis for reviewing the designs of existing airplanes after completion of this work. Pending completion of the recommended action, Safety Recommendation A-10-120 remains classified OPEN—ACCEPTABLE RESPONSE.

From: European Aviation Safety Agency
To: NTSB
Date: 3/26/2013
Response: -From John Vincent, Deputy Director for Strategic Safety: For transport aircraft, within the US Aviation Rulemaking Advisory Committee (ARAC) Committee there is a Flight Controls Harmonization Working Group (HWG) (Reference: Federal Register/ Vol. 76, No. 59/ Monday, March 28, 2011 / Notices). The working group has the task to consider whether changes to Part 25 are necessary to address rudder pedal sensitivity and rudder reversals. EASA participates in the working group with the aim of developing harmonised material that can be proposed as a change to Certification Specifications for Large Aeroplanes (CS-25). EASA will determine the basis to review the designs of existing aeroplanes after the above tasks are completed.

From: NTSB
To: European Aviation Safety Agency
Date: 12/21/2011
Response: These recommendations are very similar to Safety Recommendations A-04-56 and -57, which we issued to the FAA as a result of the AA587 accident investigation. EASA stated that it is supporting the FAA’s study to determine how existing certification standards should be revised. On June 17, 2011, in response to Safety Recommendations A-04-56 and -57, the FAA wrote to us that its Five-Part Rudder Study to better understand the issues associated with rudder usage on transport airplanes is complete, and that it had tasked its Aviation Rulemaking Advisory Committee (ARAC) to develop recommendations for new standards and guidance based on the study. On March 28, 2011, the FAA published a notice in the Federal Register about the formation of an ARAC subcommittee to respond to this task. The FAA indicated that the ARAC will include foreign certification authorities, which we believe includes EASA. The FAA further indicated that the ARAC report, scheduled to be completed by August 2012, will include specific consideration of Safety Recommendations A-04-56 and -57. Pending appropriate revisions being made to the certification standards based on the five-part study, the application of all criteria developed as a result of that study to existing airplane designs, and appropriate actions being taken for airplane designs that do not meet the new standards, Safety Recommendations A-04-56 and -57 were classified “Open—Acceptable Response.” The NTSB is encouraged by EASA’s continued participation in the FAA’s activities to revise and apply to in-service airplanes the certification standards concerning yaw handling characteristics, including rudder pedal sensitivity. Pending EASA’s completing the recommended actions, Safety Recommendations A-10-119 and -120 remain classified OPEN—ACCEPTABLE RESPONSE.

From: European Aviation Safety Agency
To: NTSB
Date: 7/27/2011
Response: CC#201100306: Patrick Goudou, Executive Director: Thank you for your letter sent on 23 May 2011 and emphasizing the NTSB’s deep interest in the follow-up given on the accident to the Airbus A300-600 registered N14053 operated by American Airlines on November 12th, 2001. The Agency shares also your concern that pilots' training cannot alone be trusted as a sufficient response to the issue of pilots' commanded sequential opposite-rudder inputs (rudder reversals) on large transport-category aeroplanes. It is the reason why the EASA and Airbus reviewed several options for a design change to address that concern. As a consequence, the purpose of the design change to be implemented on Airbus A300-600 and Airbus A310 is to provide increased protection from potentially hazardous rudder pedal inputs at high airspeeds as requested in recommendation UNST-2004-063 (A-04- 63). Following the initial study of reduced pedal travel limiter unit for the A300-600 and A310, the Agency informed you in our letter dated January 14, 2011, that the development of a Stop Rudder Input Warning (SRIW) system was also alternatively evaluated. The SRIW system monitors rudder inputs and triggers flight deck deterring aural instructions, voiced by the message 'STOP RUDDER INPUTS', combined with Visual warnings (by means of red lights in the glare shield just above the Primary Flight Displays) as soon as one dangerous rudder doublet Is detected, thus preventing: a further increase of the aerodynamic loads on the fin. A thorough evaluation of this SRIW system is currently taking place and, as usual in the frame of a certification process and in line with the EU-US validation process, the FAA responsible authority in that matter, is fully involved; thus ensuring that the proposed change satisfies both parties. In addition to the certification exercise, an FAA evaluation of the crew training aspects has been retained prior introduction of the proposed modification into US-registered aeroplanes. In accordance with the framework on cooperation in the regulation of civil aviation safety, technical data is shared with the FAA who is also part of the tests validating the benefit as well as the non-regression. With regards to recommendations UNST-2010-119 (A-10-119) and UNST-2010-120 (A10-120), EASA is supporting the FAA study in order to determine whether and how existing certification standards could be revised. In parallel, following the A320 ACA190 wake vortex encounter at high speed, Airbus has completed an aircraft level evaluation of the single aisle design in terms of sustainable loads. Airbus is working with EASA on the definition of a design change that would provide increased protection from potentially hazardous rudder pedal inputs. Several design options are currently under feasibility study (warning, reduced rudder travel limitation unit, pedal travel limitation unit).

From: NTSB
To: European Aviation Safety Agency
Date: 5/23/2011
Response: As EASA indicated in its letter, these recommendations are very similar to Safety Recommendations A-04-56 and -57, which were issued to the United States Federal Aviation Administration (FAA) on November 10, 2004. Since the issuance of these recommendations, the FAA has been evaluating its certification standards for the yaw handling characteristics of transport category airplanes. The FAA has both briefed NTSB staff and written to us to describe its activities in response to Safety Recommendations A-04-56 and -57. The FAA is currently completing a five-part study of the associated issues and has indicated that, based on the results of the study, it plans to make appropriate revisions to FAA certification standards. In addition, after these standards have been revised, the FAA will implement Safety Recommendation A-04-57, applying the revised standards to in-service aircraft and requiring modifications to existing airplanes where appropriate. In its current letter, EASA acknowledges that the FAA study is appropriate and indicates that EASA will work with the FAA to determine whether and how existing certification standards should be revised, based on the FAA’s analysis. Although the NTSB has not yet had the opportunity to perform a detailed review of the FAA’s five-part study, based on the information and results that we have reviewed, it appears to be responsive to Safety Recommendation A-04-56. However, we recently cautioned the FAA that the ACA190 event demonstrates that, because of the similarity of the rudder control system designs of the A320 series and A300-600/A310 aircraft, the A320 family is also susceptible to potentially hazardous rudder pedal inputs. The five-part study may not constitute an acceptable response to Safety Recommendation A-04-56 unless the study recognizes what we believe to be similarities and addresses the potential for hazardous rudder pedal inputs on the A320 series of aircraft. In its January 14, 2011, letter, EASA acknowledges that both the AA587 accident and the ACA190 event were triggered by a wake vortex encounter at high airspeed, but EASA believes that crew reactions were very different in the two events. EASA stated that, in the ACA190 event, the crew inputs combined side-stick and pedals and were not aggressive, whereas, in the AA587 accident, the crew reaction reflected the negative training from American Airline’s advanced aircraft maneuvering program. EASA concluded that, if a crew is caught unaware in a wake vortex, they may react by making control inputs, but they would not necessarily make the type of repetitive aggressive input in the AA587 accident. The NTSB requests that EASA reconsider the relevance of the ACA190 event. As described in the letter that transmitted Safety Recommendations A-10-119 and -120 to EASA, the flight data recorder in the ACA190 event showed that, in response to the wake vortex encounter, the flight crew had made three to four alternating rudder pedal inputs over 15 seconds, and Airbus’s analysis indicated that these pilot reactions to the wake vortex encounter were responsible for exceeding the limit load on the vertical stabilizer by 29 percent. Regardless of whether pilot reactions are characterized as aggressive, the yaw handling characteristics of the A319 aircraft in the ACA190 event were such that the pilots seriously overloaded the airframe. The NTSB notes that, despite the widespread publicity that had occurred and the training revisions that had been implemented after the AA587 accident, the ACA190 pilots still made alternating rudder inputs while at high airspeed. Accordingly, pending (1) completion by the FAA of the five-part study and (2) EASA’s making appropriate revisions to its certification standards based on the findings of the study and on the AA587 and ACA190 accident investigations, Safety Recommendation A-10-119 is classified “Open—Acceptable Response.” Pending application of all criteria developed in response to Safety Recommendation A-10-119 to existing airplane designs and EASA’s taking appropriate actions for airplane designs that do not meet the new standards, Safety Recommendation A-10-120 is classified OPEN – ACCEPTABLE RESPONSE.

From: European Aviation Safety Agency
To: NTSB
Date: 1/14/2011
Response: CC# 201100047: - From Patrick Goudou, Executive Director: Thank you for your letter of 3rd August 2010 in response to EASA letters dated 19th March 2010 and 6th April 2010, in which EASA provided its position with respect to NTSB recommendation UNST 2004-063, addressing NTSB concerns about Potential Effects Following Inappropriate Pilot Rudder Pedal Inputs resulting from their investigation of the accident of Airbus A300-605R, registration N14053 on 12/11/2001 at New York. The NTSB reiterates Safety Recommendation A-04-63 and asks for further details about the PTLU. The NTSB has also raised in this letter 2 new Safety Recommendations to EASA (A-10-119 and A 10-120), which repeat recommendations previously made by NTSB to the FAA reference A-04-56 and 57. EASA notes the FAA initial response to A-04-56 and -57 in which the FAA indicated that the current standards in FAR Part 25 may need to be redefined and that it was evaluating these and conducting a study to identify critical rudder control system parameters and human interaction with those controls. EASA acknowledges that such a study is appropriate and we would be willing to work with the FAA to develop the research already conducted in order to determine whether and how existing certification standards could be revised. When the study concludes that Certification Standards need to be revised, a new task will be introduced in the EASA rulemaking programme and it will be developed following the usual rulemaking procedure, which includes a regulatory impact assessment to set the priority and schedule, and the best harmonisation with the FAA. At this stage it is worth noting that our general objective, when amending existing or developing new certification standards, is to identify clearly the safety objective to be met by the applicant and wherever possible to avoid making the standards too prescriptive. With this in mind, our general approach to this particular subject would be to consider the pilot, flight control and aircraft interactions, including the structural capability of the airframe to withstand an abuse case, rather than to focus too closely on specific parameters within an individual control circuit design. Regarding progress on the development of the reduced pedal travel limiter unit for the A300-600 and A310, EASA has received an overall engineering certification and embodiment programme from Airbus, which shows that such a solution will take several years to develop, certify and embody. Airbus has in parallel proposed a new alternative design which is aimed at de-coupling the pilot input. Airbus has included in its proposal a development, certification and embodiment plan which is considerably shorter than for the R-PTLU. The new design monitors rudder input parameters and triggers flight deck visual and aural warnings, which would reqUire the pilot to release the pedals, thus preventing an escalation of the coupling. EASA is carefully evaluating the new concept and has started the certification process of the associated design change, in coordination with the FAA. In respect of the A320 family, which is mentioned in the NTSB letter, EASA has previously acknowledged that there are some similarities between the Air Canada flight 190 event and the American Airlines flight 587 accident; both were triggered by a wake vortex encounter at high airspeed. It is however important to restate that the crew reactions were very different. In the AC 190 event the crew inputs combined side-stick and pedals were not aggressive whereas in the AA587 accident the crew reaction reflected the negative training from the AAMP. This difference indicates to us that if a crew is caught unaware in a wake vortex encounter there is a possibility that they would react by making control inputs, but they would not necessarily make repetitive aggressive inputs. Consistent with our approach to the rulemaking review, we have tasked Airbus with conducting an aircraft level evaluation of the A320 design to ensure that the design as a whole is robust enough to withstand such a low probability event.