GS

Why large aircrafts generally use Hydraulic Powered Actuation Systems?. High hydro-mechanical stiffness and associated high frequency response is relevant for flight control actuation. Additional typical factors are response time and efficiency but not reliability and robustness, when compared with another Systems. Water hammer is negligible in hydraulic system pipe installation. Hydraulic Pumps generally used in aircraft hydraulic systems are gear type and capable to provide roughly same pressure at any flow demand (if below specified max flow demand). High flight Control and LG actuation stiffness and power response time. High Power transmission vs system weight. High efficiency. Robust & Reliable. General design is to adopt a common shared Power Generation System. Hydraulic Pumps generally used in aircraft hydraulic systems are variable displacement piston-type and capable to provide roughly same pressure at any flow demand (if below specified max flow demand). The emergency braking system must have differential control.çontrol.

Generally, with regards to the number of hydraulic systems used in a civil type certified large aircraft under Part 25 – EASA Airworthiness Regulations: There is no any aircraft using two hydraulic systems. If any primary flight control is required to be hydraulically powered, definitively three hydraulic systems are required. If the aircraft's hydraulic system supplies all the primary (PFC) and secondary (SFC) flight controls and there is no manual reversion, then usually a minimum of three hydraulic systems will be required. If hydraulic system supplies no primary flying controls, then usually only a single main hydraulic system is required. (Any single failure of the hydraulic system would not prevent the aircraft from safely completing the flight).

Select the correct response(s): Water hammer is negligible in hydraulic system pipe installation. Hydraulic Pumps generally used in aircraft hydraulic systems are gear type and capable to provide roughly same pressure at any flow demand (if below specified max flow demand). High hydro-mechanical stiffness and associated high frequency response is relevant for flight control actuation. Additional typical factors are response time and efficiency but not reliability and robustness, when compared with another Systems. Hydraulic Pumps generally used in aircraft hydraulic systems are variable displacement piston-type and capable to provide roughly same pressure at any flow demand (if below specified max flow demand). The emergency braking system must have differential control.

If the aircraft hydraulic system supply the services that control the direction of the aircraft on the ground (e.g. nosewheel steering and differential braking): The emergency braking system must have differential control. In case of hydraulic system failure, the Rudder will be able to keep directional control through the complete stop. Nosewheel steering and normal brakes should be supplied from different hydraulic systems.

Common use Aerospace Hydraulic Pumps: Either Engine Driven or Electrical Motor Driven, are normally located in Engine Nacelle. Has a response time required by standard of 0.05 secs. This fast response time is provided by the a servo-compensator which actuates yoke piston plate angle. When engine driven, are installed in engine gearbox. Its suction line and fire shut-off valve in suction line are fire proof tested.

Common use Hydraulic Reservoirs : Do not need pressurization. Vented type reservoir is sufficient whenever located above the pump. There shall be no hydraulic reservoirs located in a designated fire zone. The interior pressure must be enough to avoid pump cavitation at Pcrit. All are pressurized (bootstrap) type. Generally are bootstrap type and air pressurized, but not limited to.

The RAT (Ram Air Turbine) is a device that, when deployed, acting as ram air generator. In case of Total Engine Flame Out (TEFO), can provide hydraulic power to the essential systems to ensure the aircraft control during its descent just before touch down.

Select the correct response(s): The “Priority Valve” is a device typically used to isolate the power supply to general services (utility subsystems) when it is required to preserve the supply to critical services (generally, primary flight controls). Fuse (two types: quantity and flow fuses): This component typically senses the flow rate and/or fluid volume through it so that if the rated value is exceeded, the fuse will close. Typically used in the wheel braking system (exposed area to stones, tire debris and with risk of fire). Fuse is calibrated to limited amount of fluid (quantity type). Electrically Operated Shutoff Valve: Electrically operated (e.g. signaled by the hydraulic reservoir quantity sensor through computer monitoring system).

CFG main advantages compared with VFG are: Less weight. Better reliability. Mechanic simplicity. Constant frequency output not dependent on engine speed. Lower probability of overvoltage. Consumers input stage optimised. Efficiency and capability is the same in all the frequency range. More simple and reliable. Cheaper and several suppliers able to design and produce them. Less volume and weight for the same power delivered.

The emergency system shall power the services necessary to complete a flight and make a safe landing. The services to be powered must include: Those required for descent, approach and Lansing. Continued controlled flight. Immediate safety.

New high voltage levels (270 Vdc and 230 Vac) are applicable to civil and military electrical systems since they permit to: Reduce electrical power demand. Increase hydraulic Systems. Increase generated power for a defined size of generator. Decrease losses in feeders and distribution wiring. Reduce current level. Reduce cross section of wire (save weight -> fuel saving). Voltage drop in lines is reduced.

Electrical power quality is determined by: The interactions of all the electrical generation and supplied equipements. The electrical power generation equipment. The electrical consumers.

Li-Ion battery technology main advantages compared with Ni-Cd one are: Maintenance free and higher service life. High power capability. Lower weight. Better control of the SoC.

LED technology main advantages compared with HID one are: Higher maximum operating temperature.

What of the following exterior lights have their illumination performances covered by the EASA Part 25 requirements?. Taxi lights. Position Lights. Anti-Collision Lights. Landing Lights. Wingtip Navigation Lights. Wing Inspection Lights.

The biggest problem in humans associated to exposure at high altitudes is: Reduction in temperature. Reduction in pressure -> hypoxia. decompression sickness DCS. cold injury.

What is the type of hypoxia due to exposure at high altitude: Hypemic.

Minimum standard ventilation to maintain CO2 levels in enclosed spaces is (at SL, 15°C) according to ASHRAE: 0,5 kg/min of air. 7,21 L/sec of air. 15,28 ft^3/min of air. 15 kg/min of air. 1,5 kg/min of air. 1 kg/min of air.

Redundancy in cabin pressurization outflow valves is requested: Sometimes. Never. Always.

What will be the minimum differential pressure in an aircraft designed with a ceiling at 25 kft: 5 psi. 34.5 KPa. 40 KPa.

In a wing profile section, ice accretion impingement limits will be most extended in the following case: Thin profile, high speed, big droplets. Thick profile, high speed, big droplets. Thin profile, low speed, big droplets.

A deicing system is basically sized to limit quantity of ice accreted. What is the worst flying condition in terms of design: High Speed, high Outside Ambient Temperature. Low speed, high Outside Ambient Temperature. Low Speed, Low Outside Ambient Temperature. High Speed, low Outside Ambient Temperature.

Which two of the conditions below are equivalent in terms of water catch: 0.5 grm/m3@20m/sec and 0.1 grm/m3@50m/sec. 0.1 grm/m2@20m/sec and 0.5 grm/m3@50 m/sec.

What is the worst flying condition in terms of design of an evaporative thermal anti-ice system: Danger of Run Back ice. Low speed, low Outside Ambient Temperature. Low speed, high Outside Ambient Temperature.

What is the purpose of the compensation valve in the oxygen mask: Holds the pressure in the mask cavity when the pressure at which breathing gas is provided by the supply system is increased. Ensure unidirectional gas flow through the ports of the mask. Facilitate breathing to the user. To provide low breathing resistance.

A pressure demand oxygen pressure regulator will be more appropriate: To provide low breathing resistance. Pressure demand: gas is delivered pressurized for use at altitudes above 35 Kft. Never.

Which is the engine technology most extensively used today, for aircraft auxiliary power units?. Turbomachinery / Jet Engine Technology. Gas turbine engine. Diesel Engine.

Which of the following are functions of the APU systems used in AIRBUS Aircrafts? : To supply full hydraulic power to the aircraft systems up to 42000Ft. Las APU son capaces de presurizar hasta cierto techo. (en A350 hasta 22500ft). To provide additional thrust power under main engine failure cases. To supply electrical & pneumatic power to the aircraft systems while in flight. To supply electrical & pneumatic power to the aircraft systems mostly on ground. Power A/C systems and operational. To run the A/C systems, thus relieving or supplementing the main engines on that function. To assist the Main Engines Re-start in windmilling 2022. On Ground Electrical & pneumatic Demands from the A/C systems. To provide enough energy without any external means on ground during 12 hours. In flight Electrical & pneumatic Demands from the A/C systems and Main engines re-start in windmilling.

Which of the following is an A350 APU requirement? : The A350 shall be capable to start any engines - regardless of engine starting sequence or engine type ( RR or GE ) - on ground using battery power supply. The APU in its installed configuration shall have an adequate inflight start reliability (not less than 95%) throughout the flight envelope taking account of all approved fuel types and temperatures. The APU shall be operative without permanent presence of operator. The APU shall be capable to pressurize the aircraft and maintain an adequate cockpit and cabin environment in one-engine inoperative cruise conditions, taking into account one engine operative requirements, up to 30,000 ft. The A350 shall be able to take-off and land in manual operation with steady crosswind 35 kts gusting to 40 kts. The A350 shall be capable of transporting maximum passengers from Bangkok to Heathrow using IATA 1 and 2 ( Alternatives to L888 airway ).