A. CARGO SYSTEMS
. The fire protection system consists of two sub-systems:
a) A dual loop smoke detection system:
Ionization-type smoke detectors are installed in cavities in the ceiling of each compartment. Each cavity contains two detectors. Detectors are controlled and operated by the Smoke Detection Control Unit (SDCU) as a dual loop system using and/or logic principle requiring that, in each compartment, signaling from two detectors is required to produce a smoke warning. With a detector failure, the system reverts to a single-loop operating condition.
Note: Smoke detectors: When combustion gazes enter the detector, they change the voltage of an ionization chamber, which the sampled air passes through. An electronic circuit inside the
Smoke detectors and Extinguishing nozzle
b) A Fire extinguishing system:
This system consists of two fire suppression bottles (just one bottle for the A320 family) which are installed behind the sidewall lining, one without flowmeter and the second with flowmeter. The discharged cartridges are electrically ignited by guarded switches located on the overhead panel. When the bottle content is discharged, a pressure switch activates lamps in the cockpit to confirm that the agent has been discharged. The extinguishing agent (Halon 1301) is discharged
SYSTEMS
B. FUEL SYSTEMS
FUEL SYSTEMS INTRODUCTION
This part describes general aspects of the aircraft fuel systems such as fuel capacities, fuel control computers as well as the impact on CG position (CG movement during refueling and CG movement in flight).
All Airbus aircraft fuel systems described in this part have some common characteristics, the most obvious being the location of the fuel tanks. These tanks are located in the wings, in the fuselage (center tank and additional center tanks . ACT) and in a trim tank located in the THS (except for A320 family and some A300/A310 aircraft). Due to some structural issues common to all aircraft, the refueling and defueling sequences follow the same guidelines. Fuel computers on board the aircraft manage the fuel sequence.
SYSTEMS
B. FUEL SYSTEMS
SYSTEMS
B. FUEL SYSTEMS
1. GENERALITIES
The main part of the aircraft weight and most particularly the payload is located in the fuselage. In flight, this weight is balanced by the lift created mainly on the wings. This distribution generates a bending moment around the wing root. This has a strong impact on the aircraft structure and leads to define a Maximum Zero Fuel Weight (MZFW) in order to limit the stress at these locations.
Bending moments
Weight
strain
=
mg
On the one hand, the weight of the fuel tanked in the wings balances the effect of the lift and thus reduces the bending moment. On the other hand, the fuel in the fuselage is an extra load the wings have to create lift for. So, fuel has to be kept in the wing as long as possible.
Bending moments
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本文链接地址：Getting to Grips with Aircraft Weight and Balance(19)
