PA 46 Pilot Quiz 1
The following questions apply to the piston-engine PA 46 airplanes only.
1) On PA 46s equipped with a cockpit stall sensor test button, on a flight with some icing potential, what is the ideal procedure for preflight testing the stall sensor if a second person is available?
2) How do you preflight test the in-tank fuel pumps?
3) On the PA 46 preflight, what is the proper procedure for checking the left exhaust pipe?
4) What is the turbocharger critical altitude for the PA 46-350P and what does critical altitude mean?
5) How many engine oil pumps does the PA 46 have?
Answers are shown below –
1) Turn on the battery master switch, with the second person out at the left wing, press the stall sensor test button in the cockpit. The second person should observe the stall sensor vane lift up by itself. Then turn on the sensor anti-ice heat and the second person should feel the sensor vane get warm. Then have the second person hold in the left gear door retraction sensor button an feel the stall sensor vane get hot. Then switch off heat and master switch.
2) Without the engine running, turn on the battery master switch and put the fuel selector on left tank (310Ps – switch on fuel pump switch) – listen for the pump, switch the fuel selector to the right tank – listen for the pump, then turn off the master switch.
3) Use a bright LED flashlight (even in bright sunlight) and shine the light up into the exhaust pipe. look for cracks and rust and look for coking and sludging at the point where the crank case breather tube merges with the exhaust. Check tightness and security of the pipe.
4) 20,600 feet. Turbocharger critical altitude for any airplane is either the max altitude that the turbocharger is capable of delivering redline manifold pressure or the max altitude that the turbocharger is allowed to deliver redline manifold pressure as a limitation imposed by the manufacturer. In this case, if you set redline manifold pressure while operating the PA 46 above the critical altitude, the turbocharger turbines would be spinning at excessive RPM trying to meet the demand with thinner air and damage or destruction of the turbochargers could result. On the PA 46-350, when you go above the critical altitude an desire to use maximum power, you must back off from redline manifold pressure at least 1.6″Hg for each 1,000 above critical altitude.
5) 3 pumps. The engine oil sump pump (primary oil pump), The turbocharger oil return scavenge pump and the propeller governor (the governor has its own internal oil pump).
How did you do? Please let me know if you find these tests useful. I will be adding more in the future. Posted June 6, 2015 by Steve Shaner
Since purchase of N9172V, I have a little over 200 hours in the PA-46 since April 2014.
I did not do well on your questions, scoring one out of five.
In addition, I never test the in-take fuel pumps as part of pre-flight. Always did this when switching tanks inflight.
Lots to learn.
Thank you for your comment James. A significant number of procedures that I teach on a variety of aircraft come from my research of thousands of accident reports, talking with highly-experienced mechanics, pilots, FAA and technical support personnel as well as my own experiences in aviation. I have “invented” a lot of procedures that I teach that I hope can improve the safety and efficiency of flight. For each type of airplane I fly, I produce a custom checklist that usually has 20% – 30% more steps in it than the manufacturer’s checklist. When I start the engine on an airplane, I typically start on the lowest level tank and remain on that tank for the pre-taxi and taxi phase. This gives me an adequate test of that tank feeding properly. When I arrive at the runup pad, I then switch to the fullest tank (the one I want to use for takeoff) and I conduct the complete pre-takeoff checklist and runup on that tank. This gives me an adequate test of that tank under the demand of runup power. I do this procedure even if both tanks are equal. I like my surprises to happen on the ground and not during flight, so I test what I can on the ground. I hope you get a lot of enjoyment from your Malibu Mirage – it is a great airplane!