Here's my questions to Saavy and the answers I got back from the Man himself:
Hello I'm a MX Customer and I'm looking for some advice on operating my new airplane, a 1998 Piper Saratoga II TC. In my prior training aircraft (Piper Dakota) I followed Mike's advice regarding:
1. Operating with WOT with lower RPMs--Mike suggested the engine operations manual (rather than the POH) for a source on the limit of 'out of square' operation. But I am not able to locate this limit for my airplane, The plane is rated for 38"/2500 RPM and the critical altitude for the turbo is somewhere over 15,000'. The POH power setting tables specify only the following cruise settings: high performance 33/2400 or 32/2500, Normal 30/2300 or 29/2400, Economy 28/2200 or 27/2300, and Long Range 25/2200 or 24/2300. The only other advice is this placarded instruction: "Do not Exceed 26" of Manifold Pressure Below 2100 RPM,"
Question: Is it possible to run at high throttle in the Saratoga, and at high throttle how much can I safely pull back the RPMs?
2. LOP Operation. In the Dakota I would do the "big pull" to get quickly on the lean side of peak and then richen to a known fuel flow setting at around 50 degrees LOP. The Saratoga POH has an express prohibition against leaning above 34" of MP. At/under 34", leaning is allowed to PEAK TIT--Not to exceed 1650 degrees. The POH is from 1997 so I assume this isn't like the instructions in the old manuals (like Mike's plane) where they just didn't know any better?
Question: What would the recommendation be for leaning in high trottle/lower RPM scenario?
Mike's Answers : "For LOP cruise operation, I would suggest trying something like 34 inches and 2100 RPM. Do a rapid transition from ROP to LOP (“big pull“) and do not worry about momentarily exceeding TIT redline during the transition because you will and it won’t hurt anything. You should have a range of acceptable fuel flows LOP, limited on the lean side by the onset of engine roughness, and limited on the Rich side by CHT (don’t exceed 420°F) or TIT (don’t exceed 1650°F for more than a minute or so). I think this would be a good starting point, but don’t be afraid to experiment and find a powerplant management routine that feels good to you. Hope this helps. —Mike
I'm interested in forum member's reactions and responses to Mike's advice, and especially interested to hear from TIO-540 drivers. So far I've not run this plane LOP...just following the book numbers. Thanks for any thoughts or opinions on these issues. Robert.
Hello I'm a MX Customer and I'm looking for some advice on operating my new airplane, a 1998 Piper Saratoga II TC. In my prior training aircraft (Piper Dakota) I followed Mike's advice regarding:
1. Operating with WOT with lower RPMs--Mike suggested the engine operations manual (rather than the POH) for a source on the limit of 'out of square' operation. But I am not able to locate this limit for my airplane, The plane is rated for 38"/2500 RPM and the critical altitude for the turbo is somewhere over 15,000'. The POH power setting tables specify only the following cruise settings: high performance 33/2400 or 32/2500, Normal 30/2300 or 29/2400, Economy 28/2200 or 27/2300, and Long Range 25/2200 or 24/2300. The only other advice is this placarded instruction: "Do not Exceed 26" of Manifold Pressure Below 2100 RPM,"
Question: Is it possible to run at high throttle in the Saratoga, and at high throttle how much can I safely pull back the RPMs?
2. LOP Operation. In the Dakota I would do the "big pull" to get quickly on the lean side of peak and then richen to a known fuel flow setting at around 50 degrees LOP. The Saratoga POH has an express prohibition against leaning above 34" of MP. At/under 34", leaning is allowed to PEAK TIT--Not to exceed 1650 degrees. The POH is from 1997 so I assume this isn't like the instructions in the old manuals (like Mike's plane) where they just didn't know any better?
Question: What would the recommendation be for leaning in high trottle/lower RPM scenario?
Mike's Answers : "For LOP cruise operation, I would suggest trying something like 34 inches and 2100 RPM. Do a rapid transition from ROP to LOP (“big pull“) and do not worry about momentarily exceeding TIT redline during the transition because you will and it won’t hurt anything. You should have a range of acceptable fuel flows LOP, limited on the lean side by the onset of engine roughness, and limited on the Rich side by CHT (don’t exceed 420°F) or TIT (don’t exceed 1650°F for more than a minute or so). I think this would be a good starting point, but don’t be afraid to experiment and find a powerplant management routine that feels good to you. Hope this helps. —Mike
I'm interested in forum member's reactions and responses to Mike's advice, and especially interested to hear from TIO-540 drivers. So far I've not run this plane LOP...just following the book numbers. Thanks for any thoughts or opinions on these issues. Robert.
