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If I am looking to stetch range on a long flight, yes, I climb lean of peak. I usually do it around 2-3000 MSL. I lean to around 50-100* LOP in these cases with FF around 11 -12 in the RV-10. Throttle is WOT and RPM 2500. I also advance ignition when LOP. CHTs WAYYYY lower than ROP climb.
You throttle back at 200 feet? It seems if you think that you are being nicer to your engine and helping it last longer, I feel that you are doing exactly the opposite by doing that! It seems that most engine failure happen during a power change, are you ready to have the engine come apart at 100 to 200 feet? I would touch NOTHING until you are at pattern elevation or in a position to handle an engine out situation. Then if you want the busywork of throttling back to climb at 25 square, have at it. I think most of us leave it firewalled all the way to altitude, maybe trimming off some RPM for noise, but at the expense of power and climb rate. Some Continental engines come to mind where there’s a time limit RPM (2 minutes or 5 minutes?) but the Lycoming can run 2700 all day every day to TBO and beyond.
Doesn’t sound like you have done any formation flying.
You do have DATA to support this statement? (I was going to say, myth, but will hold off for now)
Yes, I understand doing element takeoffs mean working the throttle on the takeoff roll. That’s an incurred risk that we take for formation takeoffs. No I don’t have any real data to back up that engine failures occur on power changes, maybe that’s just an old wives tale, but on my non element takeoffs, I don’t pull throttle or prop (or even turn off the fuel pump) until I’m in a position to handle an engine failure.
No I don’t have and data to back it up, that’s why I stated that I ”feel” that you are not doing the best for your engine. I thought it was common knowledge that it’s safer and better for your engine to get to pattern altitude as quickly as possible. I thought there were people smarter than me that said reduced power takeoffs expose the plane to a more risky situation for longer, while reducing the power also isn’t the best thing to do at 200 feet.. but I guess I’ll shut up and let you do you I guess.
If you meant full throttle sea level takeoffs I’d hardly call best power mixture ‘conservative’. Every POH I’ve ever seen calls for full rich in this circumstance, for detonation margin.
Of course. Still hung up on folks talking about leaning with no discussion of field elevation. They kind of go hand in hand in my book.
A quick internet search came up with an article from the CAA, the New Zealand FAA.
www.aviation.govt.nz
I did. I said that I leaned at 2-3000 MSL.
Spent the night at Rawlings WY (KRWL) with field elevation at 6,817 MSL. The takeoff in the morning, I added full throttle for takeoff and my constant speed prop did not get full RPM, as the airplane was moving forward on the runway, I screwed the mixture back till it came to full RPM. This took a few seconds and added 200 to 300 feet to my takeoff roll.
Those POHs are ultra conservative. THe FAA certification tests runs these engines at redline temps for 100+ hours at full rated power and best power mixture. Any detonation beyond light (i.e. no damage) results in failure. They are ultra conservative because many planes have no instruments and even fewer pilots understand what they are telling them.
I did my primary training at an field elevation of 4500ft. The flight school usually kept the tanks full and I'm not light. On a warm day if we didn't lean for best power that poor tired little C-150 may not have gotten out of ground effect lol.
That sounds like what Gary described previously. I would be at 1800 and that’s a fast taxi, if I need to taxi after run up. I think both methods get you rich of peak but still near best power.
That doesn’t guarantee that the mixture is where it needs to be at WOT. I prefer to have an idea where your EGTs would be if you were talking off at sea level, full throttle, full mixture. Take note where your EGTs are, doesn’t matter which one, just pick one. Then if you are talking off from a high DA airport, start your takeoff and if you can glance over at the EGTs, dial back to that same value. That should be safe. Another technique is to go high enough where your power is less than 65% so that you can slowly explore the peak EGTs without fear of hurting anything.. at 12,500 or so, you can’t burn up anything and you can really take your time. After you get good info on your peak, you can know that taking off you should be 200 degrees or so ROP.
I'd think the method I described would get you a better starting point than eyeballing a knob from memory days later. With all the new parameters being monitored by the new avionics toys I'm surprised no one has started putting an O2 sensor in the exhaust. You could treat every flight like a dyno tuning session.
Setting the best power mixture from 1500 to 1700 rpm doesn’t mean that it’s still best power at WOT. I mean it’s probably in the ballpark, but then having an idea where your EGTs need to be and tuning from there is better.
Bingo! I was taught in piston, and still use in turbine aircraft "reduce HP/thrust when your ready for the engine to fail" Of course, now I'm flying a tree-holer, so an engine failure is just an "abnormal" procedure, but still.... good habit.
I was taught many things from my original instructor 40+ years ago and one of them was to not touch any power setting until pattern altitude. For my first airplane (182RG) he transitioned me and told me to never run over square. Need 22 inches manifold set RPM to 2,200. Sounds simple. But that has also changed it seems. I am just asking is there real data (Besides someone just saying there is statistical evidence and not providing the stats) that shows reducing power is asking for a problem? Any NTSB report that sights "Pilot made first reduction in power and engine failed? ", etc. The industry is famous for urban legends and was only asking for real data if it's out there. If not that's ok and I will go with what I "feel" is correct. (From an engineering viewpoint)
I don’t think so. Assuming a carburetor, the lean until rough, enrich to smooth procedure should put you near peak EGT. But a full rich takeoff has you richer than best power egt - for lower CHTs, more detonation margin. And low egt.BTW, if you lean until engine rough, then enrichen until the engine runs smooth again you will notice that the EGT will be close to the temperature you had at the sea level full rich take off and during the climb.
Notice I said close, not exact, and yes it assumes carb not injection.
Some have. I've been running one for 1000 hours already.
I misunderstood, or over understood, this approach. Tried it at several fields above 6k. Worked like a charm. Some adjustment to target EGT’s needed but for me close enough to have good performance at gross weight.
You're climbing slower LOP - so to be fair you need to pick a point somewhere further down the flight path where you will be stabilized at altitude either way, and compare fuel burn to get there. ROP you burn it faster in the climb, but climb faster. LOP you are burning less in the climb, but climbing longer. Personally, I've never tested it but have wondered...
Has that time all been on the same sensor? Do you run leaded or unleaded? Been wanting to do the same but I’d heard the sensors don’t appreciate leaded fuel.
The sensors are sensitive to lead, I run mostly unleaded 93E10. I've been getting somewhere between 50 and 100 hours of leaded fuel use from the sensors before they die. Takes about 5 minutes to change one out and they cost $40 on amazon. I've heard rumor of some sensors that would have much better life with lead exposure but I haven't found one or tried it.
I confirm the (very) short lifespan of O2 sensors when leaded fuel is used.
I put a timer on my PLX system that's set for 2 mins after the engine is started. That seems to help improve the life of a sensor when using 100LL. Without the timer was getting about 25 hours or one oil change. Now get 100 to 150 hrs. Others I know have clipped the power lead to the sensor. No data on that method. As riseric states the O2 sensor not really needed but nice to have as confirmation of the lean assist.
