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Flight Frequency vs Total Hours considering Total Service

wawrzynskivp

Well Known Member
From another post I saw Savvy recommending the engine be flown as frequently as possible. This seems a very well proven common prescription for obtaining the most hours. But those are engine hours and not longevity in terms of total age.

If I can get 2000 hours TBO from my engine if I run it 5 hrs/wk (total made up number) then I get to TBO in 7.69 years and may have to do some extra flying just for the sake of flying.

If I run my engine for 1 hr/wk and only get 1000 hrs TBO I get 19 years of service. Again, totally made up numbers. Assuming I am a geezer who is no longer padding the logbook I can save money on the unburnt fuel. In this case it would be somewhere around $50,000 not including oil and other consumables.

As you cut the hrs/wk down, the longevity will increase to a point then start decreasing again owing to hangar rot. Or hanger rot depending on what you use to maintain.

Are there numbers out there that show the sweet spot for total longevity?
 
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I shall use my time

If you're operating your airplane with the principal objective of longevity, you're kind of missing the point of aircraft ownership.
 
From the articles/posts I've seen on camguard and other corrosion testing (Ken Sutton's articles in Twin Cessna in 2012 comes to mind), at least flying every 15-30 days or so is ok from a corrosion perspective and probably in the realm of most longevity for minimum use. Like most things, too much or too little, with a just right in-between. Mike Busch says, most of our aircraft are not flown enough and the resulting corrosion is the mechanism for end of engine life. Which goes back to just fly as much as you can and enjoy!

If you want the best chance at longevity, do oil changes once every 3-4 months and/or 20-30hours whichever is first, use an AD type oil with an anti-corrosion additive, use an engine dehydrator, and preheat when cold, are the best things besides flying in my opinion.
 
This raises the inevitable question around frequently flying your airplane versus the need for anti-corrosion additives. I don’t know the right answer, but I’ve always wondered if you fly your airplane weekly, do you really need to use those additives (like Camguard)…especially if you live in a low humidity environment (like the Southwestern US). Additives aren’t cheap, but I suppose you’re buying “peace of mind” if nothing else.

From the articles/posts I've seen on camguard and other corrosion testing (Ken Sutton's articles in Twin Cessna in 2012 comes to mind), at least flying every 15-30 days or so is ok from a corrosion perspective and probably in the realm of most longevity for minimum use. Like most things, too much or too little, with a just right in-between. Mike Busch says, most of our aircraft are not flown enough and the resulting corrosion is the mechanism for end of engine life. Which goes back to just fly as much as you can and enjoy!

If you want the best chance at longevity, do oil changes once every 3-4 months and/or 20-30hours whichever is first, use an AD type oil with an anti-corrosion additive, use an engine dehydrator, and preheat when cold, are the best things besides flying in my opinion.
 
This raises the inevitable question around frequently flying your airplane versus the need for anti-corrosion additives. I don’t know the right answer, but I’ve always wondered if you fly your airplane weekly, do you really need to use those additives (like Camguard)…especially if you live in a low humidity environment (like the Southwestern US). Additives aren’t cheap, but I suppose you’re buying “peace of mind” if nothing else.

Probably not or at least the data would be different (most likely longer days to visible corrosion on all fronts). Ken’s test was only a few data points, but it’s more then I have tested!

You are right, each person makes their own judgement based on their perspective and experiences, but sometimes it’s cheaper to trust others data then the alternative.
 
this is a really great OP and thread. It's the kind of question I have wondered about a lot. To the post that said "you're kind of missing the point of aircraft ownership", i would disagree - different aircraft owners have different purposes. for me, the occassional x-country trip is why i love having an aircraft. But those trips are not frequent enough to keep the airplane healthy. so I do a lot of maintenance flying just to keep things moving. But that maintenance flyign is not pure joy, and it' s not the reason i built an airplane. So the OP has a very valid question I think.
 
Just don’t forget that if you are saluting a TBO of 2000 hours, then for the same rationale, you should salute the “or 12 years, whichever comes first….” Part of the Lycoming overhaul interval - at least for planning purposes.

Or just forget both those numbers, do good maintenance, enjoy the airplane, and overhaul on condition of you ever get there.

Remember that, depending on how you do the math, it is cheaper to rent an airplane if you fly less than 120(ish) hours per year….but where’s the fun in that?
 
Remember that, depending on how you do the math, it is cheaper to rent an airplane if you fly less than 120(ish) hours per year….but where’s the fun in that?
I really love this kind of discussion becuase it's at the heart and soul of "why should i build/own an airplane... is it worth it?"
The thing about your comment about the relative cost of renting is that it ignores the convenience factor. I can walk outside on any given morning and say "it's a beautiful day, i feel like going to Waterloo for a night, or to see my Dad in Chatham." Renting, that would requires planning ahead, booking the plane etc.
In terms of "worth it", last year i invested a siginficant (to me) amount of money to ugrade the plane to IFR. At the end of the day, this is not "worth it" by any quantifiable measure. But the IFR training has added a dimension to my life and re-invigorated my enthusiasm for flying through a new challenge. That is priceless.
 
Assuming I am a geezer who is no longer padding the logbook I can save money on the unburnt fuel.

We all have a finite number of days left to fly. But many of us are 'geezers' and at our age they are quickly dwindling! :eek:

I vote to use up the engine and airframe!
 
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Are there numbers out there that show the sweet spot for total longevity?[/QUOTE said:
I know of 2 flight schools that get 3500 to 4000 hours between overhauls on their fleet aircraft. These planes fly about 1000 hrs per year each. Oil/filter changes are done every 50 hrs. Most flights are 1hr or more in duration. No dehydrators or additives but pre-heat in the winter.

For me, I average about 120 hrs/year. I use Camguard, a dehydrator, oil/filter changes at 45-50 hrs and pre-heat in the winter. Needs a litre of oil every 25ish hrs. So far, 690 hrs in almost 6 years of trouble free flying. Will see if the engine or I have the longer life....
 
Pop-corn thread… nevertheless.

We all have a finite number of days left to fly. But many of us are 'geezers' and at our age they are quickly dwindling!

Good call Carl :)
Let’s fly and enjoy as long as we can.
 
“or 12 years, whichever comes first….” Part of the Lycoming overhaul interval - at least for planning purposes.
Interesting, i didn't know about that. My very expensive IRAN (4 replaced cylinders, replaced crankshaft and other parts) was very close to 12 years after first flight (12 years plus 4 months). But i had ECI Cermanil cylinders which I suspect was partly to blame for my piston-ring failure.
 
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Remember that, depending on how you do the math, it is cheaper to rent an airplane if you fly less than 120(ish) hours per year….but where’s the fun in that?

Paul, I agree 100%. “Owning versus renting” is a mathematical road few should travel on since you’re trying to logically (via cost analysis) justify the emotional desire to own your own airplane. Keep it simple…if you want to have your own airplane AND you have the financial means to do so, then do it…regardless of the math…and enjoy yourself!😀😀😀
 
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