Utilization Figure 004 
R  EFF :  001-049, 055-061, 101-105,  Page 735-31-00 Config-3 May 01/05
 CES 

 FLIGHT CREW PORTABLE DEVICES - DESCRIPTION AND OPERATION
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 1. General
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The flight crew portable oxygen will supply one crew member with protected breathing oxygen. It is used when fighting a fire and against the emission of smoke and noxious gas. It will also supply one crew member with emergency oxygen if a failure of the fixed oxygen system occurs when there has been a loss of cabin pressurization.

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The flight crew emergency breathing hood system provides protection to the eyes and respiratory system for crew members. It is used when fighting a fire, against the emission of smoke and noxious gas and in case of cabin pressurization loss (hypoxia). The breathing hood ensures a total duration of 15 minutes, and is in compliance with the regulation TSO C116.

 A.
 Breathing Hood System

 (1)
 Component location (Ref. Fig. 001) The breathing hood container is installed in the cockpit on the console forward of the rear panel 120VU. The container is provided with a good-condition indicator and tamper seal used for the preflight inspection.

 (2)
 Storage The complete hood is vacuum-packed in a transport/storage container. The breathing hood is stored under vacuum in a specially designed sachet. The sachet is mounted inside a box in such a way that, after opening the box, the hood is removed and the vacuum protection is automatically opened with a single movement.

 (3)
 Box description
 This box made of polycarbonate is composed of two parts:

 (a)
 The cover equipped with:

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A good-condition indicator on the lid (operational color: green).

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A handle

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A hinge for jointing with the container

 (b)
 The container provided with:

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A fastener which closes the cover on the container.

 -
A pictogram which describes the utilization procedure.

 -An identification plate, located at the back of the container which gives the date of its manufacture.

 Breathing Hood Container
 Figure 001

 CES  To gain access to the aluminized bag it is necessary to break the lead seal and open the box cover.

 B. Protective Breathing Hood
 (1)
 The protective breathing hood equipment is composed of three main parts:

 (a)
 The internal hood Has two compartments, one for the head the other being used as a lung. The separation membrane (1) is made of self-extinguishing impervious polyurethane. It includes a collar seal (6) at the level of the neck, made of self extinguishing neoprene. It is sealed internally and externally with bands of PVC.

 (b)
 The external hood Is made of welded polyester coated on both sides with a fire proofing PVC. It includes:

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A visor (3) made of polycarbonate, sealed onto it and treated with an anti-fogging compound.

 -
A pressure control valve (7).

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A phonic membrane (4).

 -
A carbon dioxide absorption system (2).

 -An annular container (5) full of compressed oxygen equipped with a lever (8) automatically opens the flow when donning.

 (c)
 The over hood Is made of polyphenolic material ensuring fire protection. It cover and holds the annular container at level of the external hood.

 (2)
 Technical Characteristics:

 -duration: 15 minutes.
 -Oxygen capacity: 39l (NTPD).
 -Filling pressure: 150 bars relative (2175 psig).
 -Inspiratory flow: 30l/mn (BTPS).
 -Maximum operating altitude: 40,000 ft.

 2. Operation/Control and Indicating
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 A. Operation When donned the annular container in the hood releases the amount of oxygen the user needs in sustained activity. A slight noise is heard by the wearer. When the noise of oxygen flow stops the hood should no longer be used. The operation is ensured by gas circulation generated by the inspirations and expirations of the user. The hood has two compartments, one for the head, the over being used as a lung. During inspiration, some gas flows from one compartment to the other through the absorption system. The absorption system traps the carbon dioxide contained in expired gas through a layer of soda lime, without using a mechanical system. A pressure control valve avoids overpressure in the hood (set pressure 2 mbar). A phonic membrane allows the users to communicate easily.
　
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