Piper Arrow IV Landing Gear System Operation Overview

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Piper Arrow IV Landing Gear System Opera8on Overview St. Louis Flying Club 2/9/16 WARN GEAR UNSAFE AUTO EXT OFF Gear down and locked lights Panel Light Dimmer switch ThroJle Posi8on Gear Up/Down Switch Landing Gear System Switches and Indicators 2 Power & Lights • Hydraulically operated, up and down. Hydraulic pressure holds gear up (there are no gear up-­‐locks) • For emergency extension, hydraulic pressure holding gear up is “dumped” to allow gear to freefall to extended posi8on. • Lights – Three green light means all gear are down and locked – No lights means gear retracted • Or in daylight with the panel lights on, the gear lights will be too dim to see. – Yellow “Auto Extend Off” light on panel – Blinks on & off when Auto Extend System is in override or “Off” – Red “Warn Gear Unsafe” light on panel • Will light during normal gear retrac8on and extension to indicate gear is in transit. – If one green down and locked light is out, try switching bulbs. 3 Normal Retrac8on & Extension • Retrac8on – Do not retract above 109 KIAS – Takes about 7 seconds – Red “Warn Gear Unsafe” light should illuminate while gear is in transit. Light goes out when gear fully retracted • Extension – Not above 130 KIAS for normal extension – Takes about 7 seconds to extend – Extended gear acts as speed brakes – Glide ra8o seriously decreased with gear extended 4 Automa8c Gear Extension System • Designed to automa8cally extend gear when power is reduced and air speed is at or below approx 87 KIAS (unless system is turned off with override lever) • Triggered by differen8al air pressure sensed by high pressure/sta8c source mast on led side of fuselage and a diaphragm ac8vated mechanism. Note: This mast is also heated when the Pitot heat switch is on to prevent icing. Icing would restrict pressure port causing the system to think aircra; speed is low and gear would automa<cally extend. 5 High Pressure Air Line Sta8c Air Line Hydraulic Pressure Dump Valve Diaphragm Actua8ng rod AJached to the Diaphragm System located under Passenger Seats Auto-­‐extend System Pressure & Sta8c Mast. Note: If Red ground Cover is accidently le; on mast during flight, System thinks Airspeed is zero. Must override system to raise gear Manual Emergency Extension • Emergency gear “dump” by pushing red lever down to release hydraulic pressure ader slowing to < 87 knots. Nose gear is helped down against airflow with a spring. – Note: If Auto extend is in lockout Posi<on, li; red lever slightly to allow lockout pin to slide out and then the lever can be pushed all the way down • Yaw plane if needed to get down and locked green lights for main gear 6 Push Lever Down for Manual Emergency Gear Extension 6 Rela8ve Wind Rela8ve Wind If Led gear not down; Yaw to the led If Right gear not down; Yaw to the right YAW Aircraft to help move gear down to down and locked position Gear down & Locked lights Gear down & Locked lights 7 8 8 3 Posi8ons for Override/Emergency Lever Auto-­‐Extend Override or “OFF” Posi=on – Held up by Auto-­‐Extend Lockout Pin. Auto-­‐Extend “On” Posi=on. Gear will automa8cally come down when airspeed decreases to approx 87 KAIS Push Down for Manual Emergency Gear Extension Below 87 KAIS Use posi8on for take-­‐off, prac8cing stalls, Or if engine out to improve glide ra8o Use posi8on when in cruise flight to provide auto-­‐gear extend capability Use manual gear extension to extend gear if auto extend fails to lower gear. AUTO EXTEND OFF “AUTO EXTEND OFF” light will blink on and off when lever is in override posi8on Override Gear Extension System When • Taking off (otherwise gear does not want to come up during normal climb out speeds) • For maximum glide in an engine out situa8on • Prac8cing stalls with gear up • Best prac8ce is to remove the override and ac8vate the automa8c extension system once set-­‐up in cruise and leave it on when entering the traffic paJern and landing • If doing touch and goes, once you lower the gear for landing, put the lever in override posi8on so you can raise the gear when you want ader touch and go. 9 Landing Gear Warning System • Steady horn and red “Warn Gear Unsafe” light comes on during the following condi8ons: – Gear is up and power is very low; approx 14” of MP – Auto extender system puts the gear down and the gear handle is s8ll raised – Gear handle is raised when the plane is on the ground 10 Other Things to Know • The gear is held up with hydraulic pressure. If in cruise you hear/feel the hydraulic pump come on, this is usually an indica8on there is a small leak in hydraulic system which lets the hydraulic pressure drop. The pressure switch will automa8cally turn the pump on to bring hydraulic pressure back to the specified amount. • Contact maintenance ader flight to troubleshoot the system if you hear/feel the hydraulic pump come on during cruise. 11 12 Gear Down 13 Gear UP Ques8ons? 14