AD 2006-13-13 Airworthiness Directives; Boeing Model 737 Airplanes

Models named: 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to all Boeing Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800 and -900 series airplanes, certificated in any category.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Revising the Airplane Flight Manuals (AFMs) (f) Within 60 days after the effective date of this AD, revise the Cabin Pressurization procedures in the Normal Procedures section of the AFMs for Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800, and -900 series airplanes to include the following procedure: “For normal operations, the pressurization mode selector should be in AUTO prior to takeoff.” (g) Within 60 days after the effective date of this AD, revise the Emergency Procedures section of the AFMs for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, or the Non-Normal Procedures section of the AFMs for Model 737-600, -700, -700C, -800, and -900 series airplanes, as applicable, to include the following procedure: “Warning Horn—Cabin Altitude or Configuration Recall Condition: An intermittent or steady warning horn sounds: • In flight an intermittent horn indicates the cabin altitude is at or above 10,000 feet • On the ground an intermittent horn indicates an improper takeoff configuration when advancing thrust levers to takeoff thrust • In flight a steady horn indicates an improper landing configuration. If an intermittent horn sounds in flight:       Oxygen Masks and Regulators on, 100% Crew Communications Establish Do the Cabin Altitude Warning or Rapid Depressurization checklist. If an intermittent horn sounds on the ground: Assure proper airplane takeoff configuration. If a steady horn sounds in flight: Assure proper airplane landing configuration.” Optional Action for Certain Requirements of AD 2003-03-15 R1 and AD 2003-14-08 (h) For Model 737-100, -200, -200C, -300, -400, and -500 series airplanes: Using the phrase, “If the intermittent cabin altitude/configuration warning horn sounds in flight:” in place of the phrase, “If the cabin altitude warning horn sounds:”, in the revisions to the “Cabin Altitude Warning or Rapid Depressurization” procedure specified in Figures 2 and 3 of AD 2003-03-15 R1, is acceptable for compliance with the requirements of paragraph (a) of AD 2003-03-15 R1. All other requirements of AD 2003-03-15 R1 remain unchanged. (i) For Model 737-600, -700, -700C, -800, and -900 series airplanes: Using the phrase, “If the intermittent cabin altitude/configuration warning horn sounds in flight:” in place of the phrase, “Condition: The cabin altitude warning horn sounds:”, in the revisions to the “Cabin Altitude Warning or Rapid Depressurization” procedure specified in Figure 1 of AD 2003-14-08, is acceptable for compliance with the requirements of paragraph (a) of AD 2003-14-08. All other requirements of AD 2003-14-08 remain unchanged. Alternative Method To Revising the AFM (j) The AFM revisions specified in paragraphs (f) and (g) of this AD may be done by inserting a copy of this AD into the AFM. (k) When statements identical to those specified in paragraphs (f) and (g) of this AD have been included in general revisions of the AFM, then the general revision(s) may be inserted into the AFM, and the copy of the AD may be removed from the applicable revised sections of the AFM. Alternative Methods of Compliance (AMOCs) (l)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. Material Incorporated by Reference (m) None. Issued in Renton, Washington, on June 15, 2006. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 06-5585 Filed 6-21-06; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports that airplanes have failed to pressurize, and that the flightcrews failed to react properly to the cabin altitude warning horn. We are issuing this AD to prevent failure of the airplane to pressurize and subsequent failure of the flightcrew to recognize and react to a valid cabin altitude warning horn, which could result in incapacitation of the flightcrew due to hypoxia (lack of oxygen in body) and consequent loss of airplane control.