Safety Recommendation A-01-012

Notation 7360A: The National Transportation Safety Board has reviewed your notice of proposed rulemaking (NPRM), “Airworthiness Directives; Airbus Model A319, A320, and A321 Series Airplanes,” published in 69 Federal Register 75273-75275 on December 16, 2004. The NPRM proposes to require a new modification for telescopic girt bars on escape slide/raft assemblies, which would terminate the repetitive functional tests required by existing Airworthiness Directive (AD) 2001-16-14, amendment 39-12383.

Specifically, the Federal Aviation Administration (FAA) proposes installing a newly designed, larger trigger on telescopic girt bars to prevent their inadvertent retraction, which could result in a slide being unusable during an emergency evacuation. The proposed AD would also expand the applicability of the existing AD.

The proposed rule is the FAA’s latest effort to address the safety issues identified in the Safety Board’s investigation of a slide/raft failure during the evacuation of a Northwest Airlines A320-200 on March 17, 2001. As a result of its investigation, the Board issued Safety Recommendations A-01-27 and -28 on May 16, 2001, requesting that the FAA issue ADs to ensure that all girt bars conformed to design specifications and to repair or replace any girt bars that did not meet specifications or could not pass a functional test.

The FAA determined that modifying the girt bar would be a better course of action than an inspection and functional test and issued AD 2001-16-14 on August 16, 2001, requiring the installation of a U-shaped reinforcement strip on the girt bar as an interim action.

On January 3, 2002, the Safety Board classified Safety Recommendations A-01-27 and 28 “Closed—Acceptable Alternate Action,” with the understanding that the FAA’s action was considered an interim solution while Airbus redesigned the trigger mechanism. On September 6, 2002, Airbus issued Service Bulletin (SB) A320-52-112, Revision 2, which described how to install the new larger trigger. The Direction Générale de l’Aviation Civile (DGAC), France’s airworthiness authority, issued AD 2002-637(B) on December 24, 2002, mandating the actions specified in the SB for applicable airplanes in France.

The Safety Board agrees that the proposed modification of the girt bars with a larger trigger will be a permanent solution to the problem of inadvertent girt bar retraction. However, the Board disagrees with the proposed compliance time of 48 months from the effective date of the final rule. Although the DGAC imposed a similar compliance schedule when it issued its AD 2 years ago (requiring compliance by December 31, 2006), the Board notes that the modification was developed several years ago and is immediately available for implementation on U.S. carriers. The Board sees no reason to prolong implementation simply because the FAA did not issue the proposed AD more quickly.

The Safety Board notes that the FAA published the final rule concerning Airworthiness Directive (AD) 2004-02-08 in the Federal Register on January 30, 2004. This AD requires the replacement of the hinge assemblies on escape slide compartments of the forward doors of Boeing 737-300 through -500 series airplanes with new, stronger hinge assemblies.

This AD meets the intent of Safety Recommendation A-01-12, which was to prevent forward door escape slides from inadvertently falling out of their compartments and possibly inflating inside the cabin. Accordingly, Safety Recommendation A-01-12 is classified "Closed--Acceptable Action."

AD 204-02-08 was published in the Federal Register on 1/30/04.

The FAA reports that on June 28, 2002, it issued a notice of proposed rulemaking to adopt an airworthiness directive (AD) to require that all operators of Boeing 737-300 through -500 series airplanes replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of 737 NG airplanes. Pending issuance of the AD, Safety Recommendation A-01-12 remains classified "Open--Acceptable Response."

Notation 7343A: The National Transportation Safety Board has reviewed the Federal Aviation Administration’s (FAA) Notice of Proposed Rulemaking (NPRM), “Airworthiness Directives, Boeing Model 737-300, -400, and -500 Series Airplanes,” which was published in the July 9, 2002, Federal Register (Volume 67, Number 131). The NPRM proposes adoption of Airworthiness Directive (AD) 2001-NM-88-AD, which requires operators of Boeing Model 737-300, -400, and -500 series airplanes to replace hinge assemblies on certain escape slide compartments of the forward doors with new, stronger hinge assemblies.

The actions specified by the AD are intended to prevent forward door escape slides from falling out of their compartments into the airplane interior and inflating, which could impede an evacuation in the event of an emergency.

On March 5, 2000, at 1811 Pacific standard time, Southwest Airlines flight 1455, a Boeing 737-300, overran runway 08 after landing at the Burbank Glendale Airport, Burbank, California. The airplane collided with a blast fence and an airport perimeter wall, then left the airport property, coming to rest on Hollywood Way Boulevard. The nose gear collapsed, and the airplane sustained extensive damage during the accident. Before the airplane came to rest, the escape slide at the forward service door (1R) slid out of its container and inflated inside the cabin.

The slide extended across the entry area, blocking the aisle from the passenger cabin to both forward door exits and preventing two flight attendants from assisting in the evacuation.

As a result of its investigation, the Safety Board issued Safety Recommendation A-01-12 on December 19, 2001, asking the FAA to issue an AD requiring that all operators of Boeing 737 300 through -500 series airplanes replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of Boeing 737 600 through -900 series airplanes. The AD proposed by NPRM 2001-NM-88-AD would meet the intent of Safety Recommendation A-01-12.

The Safety Board fully supports adoption of the proposed AD and believes that it will help to eliminate inadvertent slide deployments on B737-300 through -500 series airplanes. The Safety Board appreciates the opportunity to comment on the proposed AD.

Letter Mail Controlled 08/22/2002 3:52:56 PM MC# 2020777 On June 28, 2002, the Federal Aviation Administration issued a notice of proposed rulemaking (NPRM) proposing to adopt an airworthiness directive (AD) to require that all operators of Boeing 737-300 through -500 series airplanes replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of 737 NG airplanes. I have enclosed a copy of the NPRM for the Board's information.

Pending issuance of the NPRM and the AD, Safety Recommendation A-01-12 remains classified "Open--Acceptable Response."

Letter Mail Controlled 01/03/2002 2:16:29 PM MC# 2020009 The Federal Aviation Administration (FAA) agrees with the intent of this safety recommendation and plans to issue a notice of proposed rulemaking (NPRM) proposing to adopt an airworthiness directive. The NPRM will propose to require that all operators of Boeing 737-300 through -500 series airplanes replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of 737 NG airplanes. The FAA had planned to issue the NPRM by October 2001.

However, there has been a delay in issuing the NPRM because of other more immediate regulatory safety issues that need to be addressed. The FAA now plans to issue the NPRM in response to this safety recommendation within the next few months. I will provide the Board with a copy of the NPRM as soon as it is issued.

Pending issuance of the NPRM and the AD, Safety Recommendation A-01-12 is classified "Open--Acceptable Response."

Letter Mail Controlled 06/26/2001 10:10:14 AM MC# 2010516 The Federal Aviation Administration (FAA) agrees with the intent of this safety recommendation and will issue a notice of proposed rulemaking (NPRM) proposing to adopt an airworthiness directive to address this recommendation. The NPRM will propose to require that all operators of Boeing 737-300 through -500 series airplanes replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of 737 NG airplanes. The FAA anticipates issuing the NPRM by October 2001. I will provide the Board with a copy of the NPRM as soon as it is issued.