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Safety Recommendation Details

Safety Recommendation A-01-072
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 Part 121 on an instrument flight rules flight plan.
Recommendation: TO THE NATIONAL WEATHER SERVICE: Eliminate the Automated Surface Observing System lockout feature as soon as possible.
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: 4/27/2011
Addressee(s) and Addressee Status: United States Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service (Closed - Acceptable Action)
Keyword(s): Weather, Weather Equipment/Products/Reports

Safety Recommendation History
From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service
Date: 4/27/2011
Response: The NTSB recently learned that problems that the NWS initially encountered in 2003 when it was attempting to implement the recommended change were fully resolved when software version v2.79D was fully fielded on January 11, 2007. The NWS has now completed the action recommended; consequently, Safety Recommendation A-01-72 is classified CLOSED – ACCEPTABLE ACTION.

From: United States Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service
To: NTSB
Date: 6/3/2003
Response: Received via email from NWS staff: The updated ASOS version should be available early next Summer. The explanation for this new time period is below, as well as a description of an option. There have been slippages due to problems with the software for the new processor. The new processor is required for the SPECI at any time change. Right now we are hoping to get the SW to the contractor by the end of August. The earliest we would expect to have it back from the contractor would be February. Some budget cuts could delay this date. After receipt from the contractor the system and Operational Acceptance Testing would have to occur. In a perfect world this would have the new software available for implementation early next Summer. There is a possibility that an interim load containing the SPECI at any time would be available for testing in September. We had hoped that we would not have to go to an interim load, but due to recent delays, this option will have to be considered. We would know more about this towards the end of June.

From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service
Date: 7/22/2002
Response: The NWS reports that it believed the problem of the observation lockout had been resolved through software modifications built into ASOS software version 2.80. However, problems surfaced regarding the ability of the existing ASOS computer hardware to handle the increased workload. The NWS states that it decided to replace the processor with an improved version, which will allow for the future hosting of ASOS software version 2.80. The NWS further reports that it has worked with the FAA to acquire the processor board replacements and is now in the operational acceptance test phase. The NWS states that it will replace ASOS software version 2.60 with version 2.80 shortly after deploying the new processors. Pending full deployment and implementation of the hardware and software improvements necessary to operate ASOS software version 2.80, Safety Recommendation A-01-72 is classified OPEN -- ACCEPTABLE RESPONSE.

From: United States Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service
To: NTSB
Date: 3/8/2002
Response: Letter Mail Controlled 05/21/2002 10:51:36 AM MC# 2020527 - From John J. Kelly, Jr., Director: As reported previously in an e-mail exchange on June 26, 2001, between Rainer Dombrowsky, Chief, Observing Services Division, NWS, and Don Eick, lead NTSB investigator, NWS believed the problem of the observation lockout had been resolved through software modifications built into ASOS software version 2.80. However, problems with the existing ASOS processor board's ability to handle the increased workload surfaced. Therefore, we decided to replace the processor with an improved version which will allow for the future hosting of ASOS software version 2.80. We worked with the FAA to acquire the processor board replacements, and are now in the operational acceptance test phase. Shortly after deploying the new processors, we will replace ASOS software version 2.60 with version 2.80. As mentioned in our June 2001 reply to the NTSB, the steps for replacing the ASOS processor and hosting ASOS software version 2.80 may extend into the fall of 2002. Full deployment is projected to be completed no later than December 2002. When completed, we will update the NTSB on this effort.