Mesa Airlines E175 Systems Study Guide QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 202, Exams of Space Flight Mechanics

Download Mesa Airlines E175 Systems Study Guide QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 202 and more Exams Space Flight Mechanics in PDF only on Docsity! Mesa Airlines E175 Systems Study Guide QUESTIONS WITH COMPLETE 100% VERIFIED SOLUTIONS 2024/2025 How many engine driven generators? Rating? 2 IDGs (Integrated Drive Generators) 115VAC, 400Hz, 40KVA What kind of APU? Rating? Sundstrand APS 2300 115VAC, 400Hz, 40KVA What is the RAT rated at? 115VAC, 400Hz, 15KVA What is the Normal AC Electrical Priority? - Onside (IDG) - Inside (APU) - Outside (GPU) - Cross-side (Opposite IDG) When does the RAT automatically deploy? Loss of all AC power in flight (electrical emergency) What are SPDAs and what do they do? (Secondary Power Distribution Assemblies) - 2 Total - Electrical load management unit - Receives power from ICCs - Distributes power according to system logic What are ICCs and what do they do? (Integrated Control Center) - 4 Total - Collects & confirms power is safe - Sends power to SPDAs What's on DC HOT BUS 1? - Engine 1A/2A Fire Extinguisher - Engine Fuel Shutoff Valve 1 - Hydraulic Shutoff Valve 1 - Engine 1 oil level indication - Courtesy/Service Lights - DC Ceiling Lights What's on DC HOT BUS 2? - Engine 1B/2B Fire Extinguisher - Engine Fuel Shutoff Valve 2 - Hydraulic Shutoff Valve 2 - Engine 2 oil level indication - CMC (Central Maintenance Computer) - Panel Refuel - Water & Waste System How many networks make up the electrical system on the airplane? Why? - 2 independent networks - Redundancy and fault isolation What happens if a power generating source fails? Bus ties automatically connect to provide no system degradation What components power the AC system? - 2 Integrated Drive Generators (IDG) - Auxilliary Power Unit (APU) - Ram Air Turbine (RAT) - AC GPU receptacle - Inverter What components power the DC system? - 2 NiCad batteries - 3 Transformer Rectifier Units (TRU) - DC GPU receptacle How does the IDG maintain a stable power output? A Constant Speed Drive (CSD) attaches the IDG to the Accessory Gear Box (AGB) What monitors and controls the IDGs? Each IDG has a Generator Control Unit (GCU) Can one IDG supply the entire electrical system? Yes What will cause the amber IDG light on the electrical overhead panel to illuminate? - High oil temperature - Low oil pressure If an IDG is manually disconnected can it be reconnected by the flight crew? No. This is a maintenance function What is the primary purpose of the AC generators? What is the purpose of the fuel crossfeed? - Allows fuel to both engines from one tank - Used to correct fuel imbalance What powers the refueling and defueling panel? Powered by DC HOT BUS 2 or DC BUSES How many fuel tanks does the airplane have? 2 integral tanks Where is fuel tank temp taken? Left tank What is the primary ejector pump? - Venturi pump with no moving parts and no electrical power used by the respective engine - Powered by motive flow What is the purpose of the ACMP? - Backup pump in case primary ejector pump fails - Engine start - Crossfeed operations What is the purpose of the DCMP? Used for APU start if AC power or the ACMP is not available What is the purpose of the scavenge pumps? Maintains fuel level in the collector box What pump is used once an engine is started? Associated primary ejector pump What is the surge/vent tank? - Collects fuel during wing-down maneuvers and returns it to the main tanks once the wings are level - Equalizes tank pressure with atmosphere in flight and during refueling Can fuel be transferred from tank-to-tank or be dumped overboard? No What happens when the crossfeed switch is selected to LOW 1? - Crossfeed valve is opened - Commands the ACMP 2 to "ON" to provide fuel from the right tank to both engines What is the only way to close the engine fuel SOV? Pull the associated engine fire extinguishing handle When will the FUEL 1(2) LO LEVEL EICAS be presented? 660lbs of fuel remaining in the associated tank How many different ways can fuel be supplied to the APU? - DCMP (Right tank) - ACMP (Right tank) - Primary ejector pump (Right tank) - Left tank primary ejector pump via X-FEED - Left tank ACMP via X-FEED What airplane systems have fire detection and protection? - Engines - APU - Cargo Compartments - Lavatories Are the cockpit and cabin protected from fire? - Yes - Cockpit: 1 hand-held Halon fire extinguisher - Cabin: 3 hand-held Halon fire extinguishers (1 fwd & 2 aft) - Cabin: 1 hand-held Water fire extinguisher How are the engines and APU protected from fire? - Engines: 2 Halon fire bottles - APU: 1 Halon fire bottle dedicated to the APU Can both engine fire bottles be used for one engine if needed? Yes What is the power source for engine and APU fire detection and protection? - Engine Detection: DC ESS - Engine Protection: HOT BATT - APU Detection: DC ESS - APU Protection: DC ESS Describe the engine and APU fire detection system? - Engine: 8 pneumatic fire detectors (2 loops) per engine - APU: 2 pneumatic fire detectors (2 loops) What happens when an engine fire handle is pulled? - Closes engine fuel SOV - Closes engine hydraulic SOV - Closes engine bleed SOVs (EBV & HSV) What is an indication of an APU fire? - Fire bell - Red stripe in the EMER STOP button - APU FIRE is displayed on the EICAS Will the APU automatically shut down if a fire is detected? Only on the ground What happens if the APU EMER STOP button is pushed after a fire has been detected? - APU shuts off immediately without a 1-minute cool-down - APU fuel SOV closes - APU FIRE EXTG button illuminates What happens if the APU EMER STOP button is not pushed after a fire has been detected? After one minute the APU FIRE EXTG button illuminates Will the APU fire extinguisher automatically discharge? No How many smoke detectors are installed in the cargo compartments? - 3 detectors in the FWD compartment - 2 detectors in the AFT compartment What happens to the forward cargo compartment in the event smoke is detected? - Recirculation fan shuts off - Ventilation outflow valve closes What is the purpose of the forward cargo compartment recirculation fan shutting off and the ventilation outflow valve closing when smoke is detected? - Prevents oxygen from entering the compartment - Prevents Halon agent from escaping into the aircraft's cabin How many extinguishing bottles are installed for the cargo compartments? - 2 bottles used for both compartments - 1 high-rate bottle and 1 low-rate bottle What is the difference between the (cargo compartment) high-rate bottle and the low-rate bottle? - High-rate bottle saturates the compartment immediately - Low-rate bottle maintains saturation over a duration of time How long will the (cargo compartment) low-rate bottle remain active in the compartment? 60 minutes Can one bottle be used for one compartment and the other bottle for the other compartment? No. Only one compartment may be selected (FWD or AFT) What happens when a cargo extinguishing button is pushed if smoke has been detected? - High-rate bottle discharges immediately - Low-rate bottle discharges after one-minute if the airplane is in flight - If airplane is on the ground (WOW) the low-rate bottle will NOT automatically discharge During flight, can the low-rate bottle be discharged before the minute is up? Yes, by pushing the extinguishing button again - Flight controls - Spoilers - Landing gear - Nose wheel steering - Wheel brakes - Thrust reversers Can hydraulic fluid be transferred between each system? No How many hydraulic pumps are on the airplane? 6 total: - 2 EDPs (Engine Driven Pumps) - 4 ACMPs (AC Motor Pumps) What are the basic components of the hydraulic systems? - Reservoir - Pumps - Accumulators What is the purpose of the accumulator? - Helps to maintain constant pressure by covering transient demands - Helps to avoid pump cavitation What are some important items controlled by HYD system 2? - Landing gear - Nose wheel steering - Inboard brakes What is a PTU? - Power Transfer Unit - Mechanical pump that uses HYD 1 power to provide HYD 2 pressure What is the primary purpose of the PTU? To allow landing gear retraction in the event of an engine 2 or EDP 2 failure When will the PTU automatically activate? During takeoff and landing with flaps >0, if; - Engine 2 fails, or; - EDP 2 fails How is single eng taxi possible if nose wheel steering is on HYD 2? Releasing the parking brake automatically activates ACMP 2 What is the primary purpose of HYD 3 system? Back-up for the flight controls Why are HYD ACMP 3A and 3B switch positions different, "ON" & "AUTO" respectively? - HYD ACMP 3A is primary and has no automation - HYD AMCP 3B is a back-up and automatically activates if ACMP 3A fails Which, if any, HYD ACMP will function if the RAT is the only power source? HYD AMCP 3A only During an electrical emergency what provides hydraulic pressure to the flight controls until the RAT comes online? - HYD 3 accumulator - After 8 seconds the RAT will power ACMP 3A In an electrical emergency can HYD 3 system power requirements overload the RAT? No. A flow limiter valve is used to reduce hyd fluid flow and limits pump electrical power draw to prevent a RAT stall How many brake applications does the hydraulic accumulator provide? ~6 applications List the things that the Air Management System (AMS) is used for? - ECS (Environmental Control System) - Engine Start - Pressurization - Anti-Ice - Water pressure - Hot air leak detection What is the primary use for APU bleed air? - ECS on the ground - Engine starting on the ground - Electrical source (<FL330) - Assist with engine start (<FL210) - Bleed source for pressurization, heating, and cooling (<15,000 ft. MSL) How many AMS controllers are installed? One controller with 2 channels which control the respective onside system What happens if a channel fails in the AMS controller? The remaining channel is able to control the entire AMS What provides air for the AMS? - Engine bleeds - APU bleed -External pneumatic source What is bleed air used for? - ECS (heating & cooling) - Engine start - Engine & wing anti-icing - Water pressurization What is external pneumatic air used for? - ECS on the ground - Engine start on the ground Where is the external ground source pneumatic panel located? Lower fairing between the wings Can engine bleed air flow-back to the APU? No. A check valve prevents flow-back Where is bleed air tapped from the engines? - 6th and 10th stage compressors (EBV and HSV respectively) - System alternates between valves to regulate an adequate and safe pressure What is normal pressure for any engine operation? 45 psi What is the purpose of the pre-cooler? Cools the bleed air coming from the engine to the AMS What cools the pre-cooler? - Ground N1 fan - Flight N1 fan or ram air What does the overheat detection system (ODS) observe? - Engine bleeds and packs - APU bleed - Plumbing for the wing & eng anti-icing systems Do both loops in the AMS overheat detection system have to function in order to detect an overheat condition? Yes, but if one fails the other will work alone to detect an overheat How many ECS packs are on the airplane? What provides air for the packs? - 2 independent packs (Pack 1 and Pack 2) - Each engine provides bleed air to its respective pack Can a single pack provide adequate temp control and pressurization? Yes, up to FL310 - Engine lips - 3 outboard slats (on each wing) What uses electric heat for ice protection? - Air Data Smart Probes (ADSP) - Total Air Temperature (TAT) probes - Windshields - Water lines - Pressurization static port If an engine fails does the opposite wing and engine receive ice protection? - Yes. The crossbleed valve opens to provide symmetrical ice protection for both wings - The failed engine does not receive heat to the engine lip How many ice detectors must be working to have icing detection? One. There are two for redundancy How long will the de-icing system remain on after icing is no longer detected? 5 minutes If ICING on the MCDU is set to "OFF" and on takeoff roll icing conditions are encountered, will the de-icing system turn on? (Selector knob is in "AUTO") Not until 1,700ft. or 2 minuites after takeoff (whichever happens first) Can the APU be used to provide bleed air for de-icing? No. What components are protected from ice & rain? - Engine inlets - Wing leading edge - Smart probes and TAT probes - Windshields - Water & waste drain systems Is the ice protection system automatic? Yes, under normal conditions Can the pilot override the automatic system? Yes How is ice detected in flight? - 2 ice detectors - Vibrating sensor element changes frequency when ice builds up around it - Once ice is detected, the sensor element heats, the ice melts, the normal vibration characteristics are restored, and the heating process stops. Cycle repeats as ice rebuilds on the probes What compressor stage is bleed air tapped for anti-icing operations? 10th High stage valve (HSV) How is bleed air directed for pneumatic anti-ice? - Engines are independent - Wings from onside bleed What happens if there is a single bleed source failure? The crossbleed automatically opens What should the MCDU be set to if there are icing conditions present on the ground between 5- 10C? Below 5C? - <10C "ENG" - <5C "ALL" What does selecting "ALL" on the MCDU provide? - Engine anti-ice "ON" when engines are running - Wing anti-ice "ON" at 40 kts wheel speed If "OFF" is selected on the ground, at what point will the anti-ice system become automatic? 1,700 ft. AGL or 2 minutes after takeoff (whichever happens first) If "ALL" is selected on the ground, at what point will the anti-ice system become automatic? 1,700 ft. AGL or 2 minutes after takeoff (whichever happens first) How does the failure of one of the two power sources affect the windshield heating system? - On ground inhibited - In flight Left side is heated (Right heats if Left has failed) What does the "TIMER" selection on the windshield wiper switch do? Activates the associated wiper in 8-second intervals What happens if the wiper is operated on a dry windshield? - The wiper will stop - To reset wiper move switch to "OFF" When do the smart probes heat? When an engine is running Is there a test for the anti-ice system? Yes, but maintenance performs this test How should the aircraft be configured for de-icing? - Bleeds....................OFF - Packs......................OFF - Stab trim...............Full nose down - Flaps.......................UP - Engines & APU...ON or OFF What type of engines are on the aircraft? - Two General Electric CF34-8E5 - High-bypass, 2-spool, axial-flow, turbofan What is the max thrust produced by the CF34-8E5? 14,200 lbs (ISA) How is each FADEC powered? - ESS powered below 50% N2 - PMA powered above ~50% N2 How many channels does each FADEC have? Each FADEC has 2 channels (active and standby) What does the cyan N1 tick represent? Max N1 for selected engine thrust mode What does the green N1 tick represent? Max N1 allowed for current thrust rating and current operating conditions What does the N1 moving arc represent? Value requested based on TLA (Thrust Lever Angle) Describe in detail the normal engine start sequence? - N2 Rotation - 7% N2 Ignition - 20% N2 Fuel flow (light off within 5 secs) - Normal acceleration & oil pressure - 50% N2 Ignition off & Starter cut-out - Normal acceleration & stabilization (27% N1, 460C ITT, 62% N2, 550 lb/hr FF, Oil pres >25 psi) What does Automatic Takeoff Thrust Control System (ATTCS) do? What controls the ATTCS? - Provides max thrust reserve (RSV) according to current rate previously selected via the MCDU - Controlled by FADEC What will trigger an ATTCS event? - N1 difference >15% between engines - Engine failure during takeoff or go-around (TOGA) - Windshear detected The FADEC will prevent fuel flow during ground start until ITT is at or below___? 120C Describe N1 spool? - Single-stage fan - 4-stage LP turbine