Motores De Aviacion
Páginas: 13 (3144 palabras)
Publicado: 15 de abril de 2012
Smartcockpit.com
BOEING 737 SYSTEMS REVIEW
Page 1
FIRE PROTECTION
1. GENERAL
¡ Fire protection consists of overheat and fire detection sensors and fire extinguishers. ¡ Detection provides visual and aural indications of overheat and fire conditions in the engines, and fire conditions in the APU, main wheel well areas and 737-800 cargo compartments. ¡ The extinguishers provide a meansof extinguishing engines, APU and B737 NG cargo fires. ¡ Each lavatory is equipped with a lavatory fire extinguisher system and a smoke detection system.
2. ENGINE OVERHEAT AND FIRE DETECTION
¡ Each engine contains two overheat/fire detection loops (gas filled). Each of these loops consists of four detector elements. As the temperature of an element increases, the pressure within increases. Ata predetermined temperature, the element signals an overheat condition. At a higher temperature, the element signals a fire condition. ¡ The two overheat/fire detection loops are labeled A and B. An OVHT DET Switch for each engine, labeled A, B and NORMAL, permits selection of loop A, B or both A and B as the active detecting loops. Dual Loop System ¡ During normal operation, with the OVHT DETSwitch in NORMAL, an alert is initiated only if one of the detector elements in loop A & one of the detector elements in loop B signals an overheat or fire condition. ¡ Engine overheat alert indications result from dual loop indication of : - overheat/overheat - overheat/fire - overheat/fault. ¡ An engine overheat condition is indicated by illumination of : - the MASTER CAUTION Lights - the OVHT/DETSystem Annunciator Light - the associated ENG OVERHEAT Light. The light remains illuminated until the temperature drops below the onset temperature. ¡ Engine fire alert indications result from dual loop indication of : - fire/fire - fire/fault.
Copyright © Smartcockpit.com Ludovic ANDRE / version 00
Smartcockpit.com
BOEING 737 SYSTEMS REVIEW
Page 2
¡ An engine fire condition isindicated by illumination of : - the FIRE WARN Lights - the associated Engine Fire Warning Switch - the ENG OVERHEAT Light - the OVHT/DET System Annunciator Light and the sound of the alarm bell. The bell can be silenced and the FIRE WARN Lights extinguished by pressing either FIRE WARN Light or the Fire Warning Bell Cutout Switch on the fire panel. The Engine Fire Warning Switch remains illuminateduntil the temperature drops below the onset temperature. ¡ If both loops sense a fault, or the selected loop senses a fault, this is indicated by illumination of the FAULT light. When the test switch is positioned to OVHT/FIRE during the system test, and there is a single loop fault, the Engine Fire Warning Switch of the affected engine does not illuminate. Single Loop System ¡ The system alsocontains a fault monitoring circuit. If a malfunction in one loop occurs with the OVHT DET Switch in NORMAL, that loop is automatically deselected and the remaining loop functions as a single loop detector. ¡ If the system operates as a single loop system, either due to automatic deselection of a loop or the OVHT DET Switch in A or B, the single active loop initiates the overheat or fire indication.3. WHEEL WELL FIRE DETECTION
¡ A fire detection loop is installed in the main wheel well. The continuity of the loop is tested by sending an artificial electronic signal to the fire warning system. AC power must be available to test the system.
4. APU FIRE DETECTION
¡ A single fire detection loop (gas filled) is installed on the APU. As the temperature increases, the pressure within theloop increases. At a predetermined temperature, a fire condition is signaled. The Master FIRE WARN Lights and APU Fire Warning Switch illuminate, the fire warning bell sounds and the APU automatically shuts down. In the main wheel well, the APU fire warning horn sounds (on ground only), and the APU Fire Warning Light flashes. ¡ Silencing the aural warnings and activating the fire extinguisher can...
BOEING 737 SYSTEMS REVIEW
Page 1
FIRE PROTECTION
1. GENERAL
¡ Fire protection consists of overheat and fire detection sensors and fire extinguishers. ¡ Detection provides visual and aural indications of overheat and fire conditions in the engines, and fire conditions in the APU, main wheel well areas and 737-800 cargo compartments. ¡ The extinguishers provide a meansof extinguishing engines, APU and B737 NG cargo fires. ¡ Each lavatory is equipped with a lavatory fire extinguisher system and a smoke detection system.
2. ENGINE OVERHEAT AND FIRE DETECTION
¡ Each engine contains two overheat/fire detection loops (gas filled). Each of these loops consists of four detector elements. As the temperature of an element increases, the pressure within increases. Ata predetermined temperature, the element signals an overheat condition. At a higher temperature, the element signals a fire condition. ¡ The two overheat/fire detection loops are labeled A and B. An OVHT DET Switch for each engine, labeled A, B and NORMAL, permits selection of loop A, B or both A and B as the active detecting loops. Dual Loop System ¡ During normal operation, with the OVHT DETSwitch in NORMAL, an alert is initiated only if one of the detector elements in loop A & one of the detector elements in loop B signals an overheat or fire condition. ¡ Engine overheat alert indications result from dual loop indication of : - overheat/overheat - overheat/fire - overheat/fault. ¡ An engine overheat condition is indicated by illumination of : - the MASTER CAUTION Lights - the OVHT/DETSystem Annunciator Light - the associated ENG OVERHEAT Light. The light remains illuminated until the temperature drops below the onset temperature. ¡ Engine fire alert indications result from dual loop indication of : - fire/fire - fire/fault.
Copyright © Smartcockpit.com Ludovic ANDRE / version 00
Smartcockpit.com
BOEING 737 SYSTEMS REVIEW
Page 2
¡ An engine fire condition isindicated by illumination of : - the FIRE WARN Lights - the associated Engine Fire Warning Switch - the ENG OVERHEAT Light - the OVHT/DET System Annunciator Light and the sound of the alarm bell. The bell can be silenced and the FIRE WARN Lights extinguished by pressing either FIRE WARN Light or the Fire Warning Bell Cutout Switch on the fire panel. The Engine Fire Warning Switch remains illuminateduntil the temperature drops below the onset temperature. ¡ If both loops sense a fault, or the selected loop senses a fault, this is indicated by illumination of the FAULT light. When the test switch is positioned to OVHT/FIRE during the system test, and there is a single loop fault, the Engine Fire Warning Switch of the affected engine does not illuminate. Single Loop System ¡ The system alsocontains a fault monitoring circuit. If a malfunction in one loop occurs with the OVHT DET Switch in NORMAL, that loop is automatically deselected and the remaining loop functions as a single loop detector. ¡ If the system operates as a single loop system, either due to automatic deselection of a loop or the OVHT DET Switch in A or B, the single active loop initiates the overheat or fire indication.3. WHEEL WELL FIRE DETECTION
¡ A fire detection loop is installed in the main wheel well. The continuity of the loop is tested by sending an artificial electronic signal to the fire warning system. AC power must be available to test the system.
4. APU FIRE DETECTION
¡ A single fire detection loop (gas filled) is installed on the APU. As the temperature increases, the pressure within theloop increases. At a predetermined temperature, a fire condition is signaled. The Master FIRE WARN Lights and APU Fire Warning Switch illuminate, the fire warning bell sounds and the APU automatically shuts down. In the main wheel well, the APU fire warning horn sounds (on ground only), and the APU Fire Warning Light flashes. ¡ Silencing the aural warnings and activating the fire extinguisher can...
Leer documento completo
Regístrate para leer el documento completo.