For Immediate Release
October 1, 2004
Contact: Les Dorr/Paul Takemoto
Nov. 15, 2001: Rudder Pedal Use Safety Letter
The FAA issued a letter to all affected operators notifying them about National Transportation Safety Board (NTSB) concerns regarding the need for industry-wide pilot knowledge and training on proper use of rudder pedals. The letter also addressed the potential consequences of some maneuvers that might exceed the structural limits of the vertical tail.
Nov. 16, 2001: Airworthiness Directive (AD) 2001-23-51
Based on preliminary findings from the American 587 accident investigation, the FAA issued an emergency AD mandating a one-time visual inspection to detect possible damage of the vertical stabilizer and rudder attachment area within 15 days on all Airbus A300-600 and A310 airplanes.
- Inspections of the U.S. fleet found no significant structural problems.
Feb. 15, 2002: FAA Notice to Operators
The FAA issued a notice to its aviation safety inspectors providing information for air carriers regarding operational use of the rudders and the subsequent effects on the vertical stabilizer. This notice was provided to operators.
March 2002: Inspection Method
The FAA, Airbus and the DGAC (the French civil aviation authority) implemented an established supplemental inspection procedure which uses an ultrasonic inspection method to detect possible problems in composite tails that would not have been found by visual inspection required by AD 2001-23-51. A300/A310 service histories were extensively reviewed to identify planes that had experienced upset events, severe turbulence, abnormal conditions (e.g., thrust reverser deployment, engine-out maneuvering) or loss of control.
- This inspection method was used on the tail attachment fitting lugs of six A300/A310 aircraft (three U.S.-registered, three foreign) that had experienced high vertical tail load events within the last 20 years.
- There were no findings of damage on five of the airplanes and only a small amount of damage on the sixth. This damage was judged to have little or no impact on the fundamental strength of the tail, but the tail was removed from service and retained for further evaluation and study. This activity provided confidence in the continued airworthiness of the A300-600/A310 fleet.
- The FAA continues to support NTSB and NASA studies and testing to evaluate the strength of the tail and, using the tail removed from service, the effect of in-service damage.
March 15, 2002: AD 2002-06-09
The FAA issued an AD ordering supplementary structural inspections of the vertical tail on all A300-600/A310 airplanes which may experience an in-flight incident of significant lateral loading in the future.
- If the lateral load factor is less than 0.3 g, no report is necessary and the airplane can continue in service.
- If the lateral load factor was 0.3g but less than 0.35g, the operator must perform a detailed visual inspection defined in the AD before further flight. The operator also must send a report to Airbus, which will then recommend supplementary inspections, if necessary.
- If the load factor was 0.35g or greater, the supplementary inspections must be done and a report sent to Airbus before further flight.
- Since issuance of AD 2002-06-09, one U.S. operator experienced in-flight turbulence with corresponding lateral load factor determined to be 0.32g. The operator inspected the aircraft in accordance with the AD with no findings. For this airplane, the FAA concurred with the conclusion of an Airbus loads assessment that supplemental inspections were not necessary since the resultant loads were below limit and there was no damage found in accomplishment of the specified AD inspections.
April 2002: Certification Loads Review.
The FAA met with representatives from Airbus, DGAC and the NTSB in Toulouse, France during the week of April 15, 2002. The agencies reviewed the Airbus load analysis methods used during certification of the A300-600 and A310. The team concluded that the Airbus methods were consistent with industry practices and produced designs that fully comply with applicable FAA regulations.
August 2004: Revision to Upset Recovery Training Aid
Shortly after the AA 587 accident, the FAA requested that Boeing and Airbus take the lead in a working group with the FAA to develop specific training programs for rudder usage on all transport category airplanes. As a result, the "Airplane Upset Recovery Training Aid Revision 1," was released in August 2004 and distributed to all operators for incorporation into their training programs.
Continuing Activity: FAA Response to NTSB on Flight Data Recording Filtering.
In a letter to the FAA, the NTSB expressed concern that some flight control data was "filtered" (smoothed out) on the accident airplane, making re-creation of the flight conditions more difficult. The FAA has requested all manufacturers of transport category aircraft to identify what flight control parameters are filtered and if the data can be readily retrieved.. The manufacturers have responded indicating that the Airbus A310, A300-600, and the A319/320/321 contain a few flight control parameters that are filtered. The FAA is currently working with industry to resolve this issue.
Continuing Activity: FAA support for AA587 Investigation:
FAA accident investigators and propulsion and airframe specialists traveled to the accident scene to support the NTSB. The FAA has continued to support the NTSB investigation with specialists assigned to the NTSB's structures, performance, operations, systems and Digital Flight Data Recorder groups.
Continuing Activity: Interpretation of Design Maneuver Speed
The FAA tasked an FAA/industry group to develop a clarifying note to add to the definition of "Design Maneuver Speed," which is required to be in the Airplane Flight Manual (AFM) Limitations section. This note would caution that rapid and large alternating control inputs — especially in combination with large changes in pitch, roll, or yaw (e.g., large sideslip angles) — may result in structural failures at any speed, even below design maneuver speed. This task is complete, and with FAA concurrence, the major transport airplane manufacturers have agreed to voluntarily revise the AFM Limitations section with the new text for airplane types currently in service.
Continuing Activity: High Load Events Working Group
An FAA-industry working group is determining appropriate practices for detecting high-load events and the appropriate maintenance procedures to be followed. The working group output is to be a "Best Practices Guide".
Continuing Activity: FAA Studies
The FAA began a series of rudder control and airplane handling quality related studies (pilot surveys, simulations, service data collections) in 2002. The studies are needed to evaluate the key factors that may need regulations to ensure safe handling qualities in the yaw axis throughout the flight envelope, including limits for rudder pedal sensitivity.