Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-00-098
Details
Synopsis: .In this letter, the national transportation safety board recommends that the Federal Aviation Administration (FAA) take action to address the following safety issues: air carrier pilot training in landing techniques and bounced landing recovery, training tools and policies that promote proactive decision-making to go around if an approach is unstabilized, the use of on board computers to determine the required runway length for landing, md-11 handling characteristics and structural integrity requirements, and hard landing inspection requirements. The safety board identified these issues in its investigation of the 1997 accident involving Federal Express flight 14 in Newark, NJ. This letter summarizes the Board's rationale for issuing these recommendations
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Review and, if appropriate, revise the DC-10 and MD-11 throttle resolver angle (TRA)-driven ground spoiler knockdown feature to ensure that it does not prevent ground spoiler deployment at moderate TRAs that could be associated with sink rate and airspeed corrections during the landing phase.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Newark, NJ, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA97MA055
Accident Reports: Crash During Landing Federal Express, Inc., McDonnell Douglas MD-11, N611FE
Report #: AAR-00-02
Accident Date: 7/31/1997
Issue Date: 8/25/2000
Date Closed: 7/29/2002
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Spoilers

Safety Recommendation History
From: NTSB
To: FAA
Date: 7/29/2002
Response: The FAA has completed the recommended review. Therefore, Safety Recommendation A-00-98 is classified "Closed--Acceptable Action."

From: FAA
To: NTSB
Date: 11/13/2001
Response: Letter Mail Controlled 11/19/2001 10:56:51 AM MC# 2010909: The FAA completed its evaluation of the throttle resolver angle spoiler knockdown limits for DC-10 and MD-11 aircraft to ensure that no safety issues exist with the current design. The FAA concluded that the current throttle position for spoiler knockdown should not be changed based on the following: * The FAA conducted a study of a number of Boeing airplanes including the DC-10, MD-10, MD-11, B-767-200, B-767-300 (with and without the full authority digital engine controls system), B-767-400, and the B-777. The knockdown position of most of the airplanes was located at approximately 18 to 24 percent of the forward thrust range (very similar to the MD-11 at the 24 percent location). * The design philosophy for providing a feature that knocks down the spoilers by forward motion of the throttle lever is to protect against possible inadvertent autospoiler deployment during takeoffs. A special circumstance that was considered for determining the throttle lever position for the spoiler knockdown was derated thrust takeoffs at low temperature. The throttle lever position under these conditions would be relatively closer to the idle position when compared to the normal thrust takeoff. The proposed safety recommendation to increase the throttle lever position for spoiler lever knockdown would be contrary to that design philosophy. A significant increase to the throttle position for spoiler knockdown would create a condition that the throttle lever can be positioned for takeoff at a point where it would be incapable of disarming a spoiler lever if the takeoff were continued after inadvertent deployment of spoilers. The current spoiler knockdown system for the DC-10 and MD-11 airplane does not knock down a spoiler lever when it is armed in the retracted position. Knock down by the throttle lever is possible only if the armed spoiler lever is in transition towards the ground spoiler position. This feature ensures that the throttle levers can be modulated during landing without interfering and inadvertently knocking down the armed spoiler lever until main gear touchdown. In addition, the MD-11 airplane flight manual states that the nonflying crewmember has the responsibility to monitor the spoiler lever and manually deploy the lever if it has not automatically deployed at wheel spin-up (touchdown). The FAA agrees with the Board's conclusion that the current MD-11 spoiler knockdown feature and the throttle lever position for spoiler knockdown did not contribute to the Federal Express MD-11 accident in Newark, New Jersey. In response to this safety recommendation, the FAA has concluded that increasing the throttle lever position for spoiler knockdown would have a negative effect on derated takeoff conditions. The FAA has also concluded that the current design allows the flightcrew greater throttle movement prior to touchdown with no effect on spoiler deployment/knockdown, and the DC-10 and MD-11 throttle lever position for spoiler knockdown is in the same range as other Boeing airplanes. I believe that the FAA has addressed the full intent of this safety recommendation, and I consider the FAA's action to be completed.

From: NTSB
To: FAA
Date: 6/13/2001
Response: Pending further information from the FAA on its course of action to respond to this recommendation, Safety Recommendation A-00-98 is classified "Open-Acceptable Response."

From: FAA
To: NTSB
Date: 11/13/2000
Response: Letter Mail Controlled 11/15/2000 3:27:59 PM MC# 2001695 The FAA is evaluating the throttle resolver angle spoiler knockdown limits for DC-10 and MD-11 aircraft to ensure that no safety issues exist with the current design. The FAA is also assessing the need for additional information and/or training to MD-11 pilots to increase their awareness of the ground spoiler knockdown feature and the possible effects on landing characteristics and performance. It is anticipated that the evaluation will be completed by May 2001. I will inform the Board of the FAA's course of action to address this safety recommendation as soon as the evaluation is completed.