# SAIB NM-05-68: - Type: Special airworthiness information bulletin (advisory, not mandatory) - Status: Current - Revision: 0 - Issued: July 8, 2005 - Products: Learjet Mutiple models - Product type: Aircraft, Large Airplane - PDF: https://openairdocs.org/files/sha256/e0/06/e0069eef4950370bd4106539418940e0d645feb58e57f66e373aa93f248c18b6 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D18F1B25BE43B9B78625721F0052EB7D.0001 - Page: https://openairdocs.org/saib/NM-05-68 ## Text **SPECIAL AIRWORTHINESS** **INFORMATION BULLETIN** Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration NM-05-68 July 8, 2005 http://www.faa.gov/aircraft/safety/alerts/ This is information only. Recommendations aren’t mandatory. Introduction This Special Airworthiness Information Bulletin alerts you, owners and operators of certain Transport Category Airplanes (listed in Table 1), that the design is such that mechanical advantage enables the capability of opening the exit when significant differential pressure exits between the cabin and the outside. In some cases, this differential may be sufficient to push the person operating the exit through the exit opening. Airplanes with this potential include, but aren’t limited to, the following aircraft in Table 1. TABLE 1 Manufacturer Model ATR42 ATR72 Aerospatiale (S.N.I.A.) SN-601 "Corvette" A318 A319 A320 A321 A330 Airbus (Industries) A340 737-600/-700/-800/-900 Overwing exit Boeing Company 747-300/-400 Upper deck exit Bombardier Inc. (Canadair) BD-100-1A10 (Challenger) BD-700-1A10 (Global Express) CL-600-1A11 (CL-600 series) CL-600-2C10 (RJ 700 series) CL-600-2D24 (RJ 900 series) DHC-3 DHC-4 DHC-6 Bombardier Inc. (continued) DHC-7 550/560 560XL 650 Cessna Aircraft Company 750 Fan Jet Falcon Mystere-Falcon 20 Mystere-Falcon 200 Mystere-Falcon 50 Mystere-Falcon 900 Falcon 900EX Falcon 2000 Dassault- Aviation Falcon 2000EX 328-100 AvCraft Aerospace GmbH (Fairchild Dornier) 328-300 F.28 Fokker Services F.28 Mark 0070/Mark 0100 Airstair door 24 25 31 35 36 55 Learjet Inc. (Gates) 60 2 Background The National Transportation Safety Board (NTSB) has recommended that manufacturers design fuselage doors on future airplanes so that they can only be opened when there is limited differential pressure between the cabin and the outside. This recommendation was based on incidents and accidents where persons were pushed through an exit when it was opened under high differential pressure. We have issued airworthiness directives to address the airplanes on which this occurred because of the severity of the condition. The NTSB also recommended that operators implement a way of notifying persons that the exit can be opened with differential pressure and to exercise caution. During our investigation, we concluded that the majority of airplanes on which opening with significant differential pressure is possible are the smaller transports, which have several mitigating features. • They are low to the ground, they have relatively small cabin volumes, and will thus equalize pressure very quickly. • They are usually operated by persons familiar with the airplane. Even so, there is some potential for injury and we want to make you aware of it. • In the other airplanes, the exits are either primarily emergency exits and aren’t used for boarding or loading of supplies, or are already equipped with an indication for opening in non-emergency conditions. • We expect that the situation would occur only rarely as there is generally only significant differential pressure on the ground following failure(s) in the cabin air pressurization or venting systems. Recommendation We agree with NTSB and recommend that you implement a means to notify persons that doors or exits on the identified airplanes can be opened with significant differential pressure and that in the event you feel resistance in opening the door, you should proceed with caution. For example, you may elect to install placards or indication systems near or on the affected exits. For Further Information Contact Jeff Gardlin, Aerospace Engineer, FAA Transport Airplane Directorate, Standards Staff, Airframe/Cabin Safety Branch, 1601 Lind Ave. SW, Renton, Washington 98055; phone: (425) 227-2136; fax: (425) 227-1149; email: jeff.gardlin@faa.gov --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.