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Safety Recommendation Details

Safety Recommendation A-01-068
Details
Synopsis: On June 1, 1999, at 2350:44 central daylight time, American Airlines flight 1420, a McDonnell Douglas DC-9-82 (MD-82), N215AA, crashed after it overran the end of runway 4R during landing at Little Rock National Airport in Little Rock, Arkansas. Flight 1420 departed from Dallas/Fort Worth International Airport, Texas, about 2240 with 2 flight crewmembers, 4 flight attendants, and 139 passengers aboard and touched down in Little Rock at 2350:20. After departing the end of the runway, the airplane struck several tubes extending outward from the left edge of the instrument landing system localizer array, located 411 feet beyond the end of the runway; passed through a chain link security fence and over a rock embankment to a flood plain, located approximately 15 feet below the runway elevation; and collided with the structure supporting the runway 22L approach lighting system. The captain and 10 passengers were killed; the first officer, the flight attendants, and 105 passengers received serious or minor injuries; and 24 passengers were not injured. The airplane was destroyed by impact forces and a postcrash fire. Flight 1420 was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 121 on an instrument flight rules (IFR) flight plan.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Conduct research activities to determine if recent technological advances would enable submerged low-impact structures and other nonfrangible structures at airports to be converted to frangible ones.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: LITTLE ROCK, AR, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA99MA060
Accident Reports: Runway Overrun During Landing, American Airlines Flight 1420, McDonnell Douglas MD-82
Report #: AAR-01-02
Accident Date: 6/1/1999
Issue Date: 12/10/2001
Date Closed: 7/2/2013
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 7/2/2013
Response: We note that the FAA analyzed the suitability of using low-impact resistant structures in areas subject to flooding and made appropriate revisions to FAA order 6850.2A, “Visual Guidance Lighting Systems.” These actions satisfy Safety Recommendation A-01-68, which is classified CLOSED—ACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 5/21/2013
Response: -From Michael P. Huerta, Administrator: The Federal Aviation Administration (FAA) completed its analysis of the fiberglass low-impact resistant (LIR) structures in areas subject to flooding (i.e. floodplains) . We determined that it is technically feasible to install LIR structures in a floodplain. LIR structures are also known as frangible structures and the FAA may use frangible structures to convert non-frangible structures. However, the installation of frangible structures is not advisable for every floodplain design. At a minimum, each floodplain must be evaluated against historical weather considerations, flood water velocity, 100 year flood evaluation, and floodwater conditions. The FAA completed the revision to FAA Order 6850.2A, Visual Guidance Lighting Systems, and released version Bon August 20, 2010. The revision added paragraph 212, Floodplain Low-Impact Resistant Installation, that refers to guidance provided in Appendix D, to address Safety Recommendation A-01-68. FAA Order JO 6850.2B can be found at the following address: http://www.faa.gov/documentLibrary/media/Order/FINAL%20FAA%200rdefl/o206850.2B.pdf I believe the FAA has effectively addressed this safety recommendation and consider our actions complete.

From: NTSB
To: FAA
Date: 3/28/2003
Response: The Safety Board notes that the FAA has been working with a team of government and industry specialists familiar with approach lighting systems and runway safety area frangibility requirements and that a preliminary analysis indicates that the typical fiberglass low-impact resistant pole may be able to survive high water flooding. The FAA plans to evaluate the design's potential operational stability and maintainability issues, as well as the impact to installation standards. The FAA's preliminary analysis and evaluation are responsive to the recommendation. Pending the final results of the evaluation and analysis, Safety Recommendation A-01-68 remains classified OPEN -- ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 2/20/2003
Response: Letter Mail Controlled 3/3/2003 10:36:30 AM MC# 2030112 - From Marion C. Blakey, Administrator: The FAA has been working with a team of government and industry specialists familiar with approach lighting systems and runway safety area frangibility requirements. The team is reviewing the FAA low-impact resistant frangible structure design standard, as well as the current operational expectations and maintenance policy. The review includes analysis of full-scale impact tests that have been previously conducted on the low-impact resistant structures by the FAA and the National Institute of Standards and Technology and survival load tests recently conducted by the manufacturer to verify the maximum allowable loads. A preliminary analysis indicates that the typical fiberglass low-impact resistant pole may be able to survive a certain level of high water flooding. If this is determined to be technically acceptable from a survival perspective, we will evaluate potential operational stability and maintainability issues, as well as the impact to the installation standards. A change in FAA policy to install approach light structures within a floodplain would need to be coordinated on a site-specific basis with the local district office of the U.S. Army Corp of Engineers, the Federal Emergency Management Agency, and local officials authorized to provide floodplain management. I will keep the Board informed of the FAA's progress on this safety recommendation.

From: NTSB
To: FAA
Date: 10/17/2002
Response: Pending the results of the FAA's review of technological advances that may enable submerged low-impact structures and other nonfrangible structures at airports to be converted to frangible ones, Safety Recommendation A-01-68 is classified OPEN -- ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 2/19/2002
Response: Letter Mail Controlled 02/21/2002 7:49:04 PM MC# 2020178 - From Jane F. Garvey, Administrator: Since 1979, the FAA has been steadily replacing rigid structures with low-impact resistance structures that break on impact. This replacement has been done slowly because of limited funding. Every new Approach Lighting System (ALS) that was installed since 1979 features low-impact resistance structures. The FAA currently uses frangible systems to the extent possible for its ALS and considers safety its number one objective when doing so. However, the FAA often encounters extenuating circumstances like rapidly changing terrain or other design challenges when it is designing frangible systems. When extenuating circumstances are encountered, design options may be limited by the functional need of the system or the jurisdiction of other governing bodies such as the Corps of Engineers or local ordinances. Typically, the FAA uses lightweight metallic tubes for the light bars that are less than 6 feet high, and low-impact fiberglass structures for light bars between 6 and 40 feet high. Normally both of these light bars are installed outward from the runway threshold. However, for light bars over 40 feet high and in some special cases like piers, flood plains, rapidly changing terrain, and steep-sided terrain, only the upper 20 feet of the structure is required to be low-impact resistant. These structures are referred to as "semi-frangible" structures. Semi-frangible structures are only installed when it is necessary to mitigate the following circumstances: § to resist the motion of moving flood or tidal waters and external forces like moving debris and ice; § to support the weight of the technician, as well as provide a safe environment for maintaining the lights (these towers in many cases are up to 128 feet above ground); and § to withstand wind velocities of up to 100 miles per hour. The installation of the ALS on runway 22L at Little Rock is an example of a flood plain installation. In order to install the ALS, it was necessary to extend the light stations into the flood plain of the Arkansas River. The support structure for the ALS at Little Rock was outside of the published runway safety area, which extends from the threshold outward to 450 feet. It should be noted that all light bars within the safety area at Little Rock are low-impact resistant. The support structure for the ALS system at Little Rock was originally designed and installed by the City of Little Rock and maintained by FAA personnel. The structure was designed to be below the elevation of the runway threshold and in accordance with the mandatory requirements of the United States Army Corps of Engineers. The FAA will undertake two initiatives to address this safety recommendation. First, the FAA will review recent technology to be applied to submersible structures to make them more frangible. In 1984, the Board issued Safety Recommendation A-84-36, which asked that FAA establish the feasibility of submerged low-impact resistance support structures for airport facilities, and promulgate a design standard, if such structures are found to be practical. After years of studying the feasibility of submerged low-impact resistance support structures, the FAA and the National Institute of Standards and Technology concluded that given the current technology, any structure deemed frangible would most likely be destroyed by wave motion. The FAA will reexamine its previous analysis and findings and determine whether or not any advances in technology might be applied. The FAA will include industry representatives in this effort. The second course of action is to accelerate the completion of the Approach Lighting System Improvement Program. This program was initiated to replace nonfrangible support structures with frangible land-mounted facilities. Currently, there are over 100 approach lighting systems to be converted. The FAA will expedite this program as funding permits.