PA-28R-201 Systems Andy Philbin
Objectives Arrow Fuel System Arrow Propeller System Arrow Landing Gear Oxygen Systems and Pressurization Arrow Preflight
Fuel System Components Two Fuel Tanks – 72 Usable Gallons 75 Total / 50 to Tabs – Vents – Sumps – Gasket Fuel Selector – Three Position Fuel Filter – Gascilator Low Point Sump Engine Driven Fuel Pump Boost Pump Fuel Control Unit / Servo Regulator Flow Divider Fuel Flow Gauge Fuel Injectors
Fuel System Components
Fuel Pumps Engine Driven – Driven off of the Accesory Case of the Engine / Diaphragm Type Pump Electric Boost Pump – Electric Driven Vane Type Pump
Fuel Control Unit / Servo Regulator Fuel Control Unit / Servo Regulator Same Component Fuel Control Unit Point of Mixture Control – Variable Orifice Servo Regulator Uses Differiential Pressure to Determine a Fuel Value Fuel Diaphragm Air Diaphragm Ball Valve Servo Regulator also has Internal Throttle Body – Attached to Throttle (Butterfly Valve)
Servo Regulator Normal Operations Mixture Control Idle Mixture Control Idle Speed Control Differential Pressure and how it controls fuel value
Flow Divider Normal Operations Outlet to Fuel Flow Gauge Outlet to Servo Regulator Outlets to the Injectors Shut Down Operations Vapor Lock – How the Flow Divider Helps Prevent It
Fuel Injectors Filter Screen Principles of CIS Emulsion Chamber How this affects the spray pattern
Piper Arrow Propeller System Propeller Control Lever Speeder Spring Pilot Valve Fly Weights Governor Pump Propeller Hub – Piston return Spring Spinner
Prop Overspeed TO OIL SUMP TO PROPELLER
Prop Underspeed TO OIL SUMP TO PROPELLER
Piper Arrow Gear System Electro Hydraulic Fully Reversible Fluid Used – MIL-H-5606 – Red in color Normal Operations Hydraulic Electrical Emergency Operations Caution and Warning Systems
Gear Extension
Gear Retraction
Emergency Extension
Gear Extension
Gear Retraction
Arrow Gear Common Questions Why is Vlr Different then Vle? What is the purpose of the Snubber Orifice? What is the purpose of the orifice on the nose wheel? What does the 020 Diameter Bleed Hole Do? Why do we have to slow to 87 to manually extend the gear? How would you trouble shoot gear that failed to extend? Retract? When does the gear horn go off? Why doesn’t the nose wheel bind when you move the rudders with the gear retracted? What turns off the hydraulic pump? Extension? Retraction?
Oxygen Systems and Aircraft Pressurization
Why do we need oxygen systems? Flight at higher altitudes – favorable winds, better aircraft economy (ram recovery with turbine aircraft) Regulatory Requirements – 91 and 121 Emergency Systems – failure of aircraft structure or pressurization systems
Oxygen Regulations Part 91 91.211 – 12,500 – 14,000, 14,000, 15,000 Pressurized Aircraft – Above 25,000 10 min supply for all passengers Above FL350 One crew member must wear or have a system able to supply O2 while wearing if cabin altitude exceeds 14,000 feet., or if both pilots at controls and both have quick don type masks and below FL410. If one pilot leaves then the other must put on the mask.
Part 121 Oxygen Requirements 121.333 – 120 min rule – 10 min descent from cruise and 110 min of cruise at 10,000 10 min supply for 10% of the passengers 15 min supply for cabin attendants wherever they are when the decompression occurs.
Types of Oxygen Systems Continuous flow – Usable up to FL250 or FL180 with nasal canula. Dilluter Demand – Good up to FL350 Pressure Demand – Up to FL410 Theories of operation
Why do we need pressure demand oxygen systems? Dalton’s Law – Partial Pressure’s of Oxygen Law of Gaseous Diffusion and how respiration works With a low partial pressure of oxygen in the cabin with each breath we take in even breathing 100% oxygen we can rob our bodies of O2 due to a greater pressure differential Pressure breathing allows higher partial pressure in the lungs and the O2 to pass through the alveolar membrane
Methods of Oxygen Storage High Pressure Bottles – 1800-1850 PSI Low Pressure Bottles – 400-450 PSI LOX Chemical Oxygen Generators Oxygen Generating Systems
Oxygen Storage and Usage Safety Graham’s Law – As temperature increases the pressure increases Leaving tanks out in the sun the could quickly become empty Hoses crack after exposure to extremes of temperature Use of petroleum based products is not recommended due to extremely flammable nature in pure O2 Environment.
Oxygen Preflight Check S – Supply C – Connections R – Regulator E – Emergency Equipment A – Adjustments M - Mask
Types of Pressurization Isobaric Control Differential Pressure Control
Pressure Differential Theory SL 14.7 psi 4000 12.7 psi 8000** 10.9 psi 10,000 10.1 psi 14,000 8.6 psi 20,000 6.8 psi 30,000 4.4 psi 41,000 2.5 psi 2.5 psi 10.9 psi 10.9 Cabin - 2.5 Ambient 8.4 Differential