Been a lurker for a couple of months, enjoy the site and have even corresponded with a few members by voice and email. In preparation for some more flying the Pac NW, both backcountry and asphalt to asphalt, I've been thinking hard about our current plane, an O-300 '63 C172 unmodified. We're a family of 3 (mom, dad and TALL 6-yr old daughter) and I fly a turbine amphib for a living, so I've been around some planes (no, I can't use the floatplane for personal use). I keep thinking a C182 (or variant) would fit us perfectly but then I pause and wonder if a 180hp C172 or even a PA-20 would be sufficient (having looked in a PA-12 I think it's too small in back for both mom and daughter), then I go back to thinking that in 10 years or less it's not going to be cool to be flying around with your parents and it would be back to my wife and me. Our current plane is doggie when it's hot but for the most part it gets us there cheaply, even climbing at 200'/min, and owes us nothing, and my wife says she doesn't even need to go faster she just wants to make sure we're going to leave the ground behind in a respectable manner. I'm ready to switch it out for more performance but then I see the recent posts about the C170 (basically the same plane as ours with one wheel switched) with the Sportsman STOL and seaplane prop, which has been suggested to me but I need a field approval and rubber stopper like used in AK, folks running all over the West in similar planes, etc. and I think "am I throwing the baby out with the bath water" by selling our current plane? A few mods here and there and it may work for both intended NW missions and I don't have all of startup costs, including the extra 10% of purchase price to make things right, of a different plane.

Do y'all have some thoughts? Thanks.

My thought in general is to make what you have work as well as it can unless doing so would cost more than the cost of getting into another plane. Sportsman cuff, exhaust upgrade, add up to a fair bit less than the likely cost of swapping planes, especially if there are any surprises.

If you are looking at bigger engines...a bigger engine mod on an older airplane will do more for you than a bigger engine on a newer airplane where the empty weight is probably a lot higher...

We've had a similar thought process. We can no longer get our entire family into the PA-22 due to the kids eating too much and turning into near-adults. But that means we have to take two trips to get places for a few years...then they will be gone and the PA-22 will serve us two just perfect. So we aren't switching it out and going broke to get a plane we won't need soon...

There are plenty of old 172's and 170's that do a pretty good job in back country flying. Especially for sport use as opposed to a "working" bushplane hauling gold miners or bear hunters. It fits in a perfectly valid niche for al ight to medium duty bushplane (when equipped properly and kept light). It's like having a 4 or 6 cylinder pickup truck instead of a V8 or a huge Cummins diesel. There is a niche for a smaller lighter pickup, and there is a niche for a lighter duty bushplane. If you outfit the airplane you already have for back country flying as much as can be done (within cost and reason), and if it still does not meet your needs after flying it for a while, then upgrade to a heavier duty airplane with a clear conscience.

EZ Flap - I see your way of thinking. It wouldn't be a heavy hauler, just for one or two trips or so to most of the known strips during the summer. But, even at 2300 lbs gross, which I'll need I just wondered if it was still possibly considering you're looking at 15.9 lbs/hp at that point. I could make it work but I'd have to bum a cast iron pot and some adult beverages off of someone already there. As I said, I have a tall daughter for starters.

Troy - PM sent

Thanks for the replies. If anyone else has thoughts I'd welcome.

My tall 6 year old daughter is now 12 and taller than her mother. And the 3 year old boy is now 9 and growing too. When I got the 170 just 13 short years ago, they weighed nothing at all. Funny how that works. Gotta plan for that kind of thing.

I'll throw in my two cents. If you're looking at doing a 180hp conversion, a 182 might pencil out better, maybe. Check out carefully if you can put a seaplane prop on the 172, there might not be enough clearance. Even so, that's more chance of hitting something.
The stol kit looks like the best bang for the buck.
The 172 will be a bit roomier than a PA 20.
How tall is your wife? Can she sit in back?
200 fpm is ok if you don't have any obsticals to clear such as trees, fences, small pets.

3 people in a 172 seems like pushing it to me though.

I have looked into a 180hp conversion but unless you have deep pockets at $52k it does pencil out better for a C182. I even asked at AirPlains when I inquired several months why anyone would do it, and the nice lady replied we're doing about one a week, which admittedly did include some IO550 upgrades for C182s.

I like to assign a horsepower-to-empty weight ratio for aircraft, so that you can abstract performance from utility. If you take for example, a Just Highlander that weights 770 lbs empty, and has 100hp, divide power/weight and you get a performance rating of .129. Take my old 170B at 1320 lbs empty, divided by 145hp, and you get .109. An early C182 wat about 1700 lbs / 220hp gets a .129 as well. A 1430lb 172 with 180hp is about .125. The large the ratio, the better your takeoff performance, all things being equal or disregarded, like wings/STOL kits, etc. That's what the aircraft can do with just you in it, that's as good as it will ever do.

That extra .20 performance is really the difference between confidently escaping an airstrip and chewing a hole in your seat with your sphincter. Add extra seats and you get more utility to haul stuff or extra meat, but also greater potential to reduce your performance. I sold my 170 because I was not comfortable with the performance safety margin operating in the places that I want to go, which tend to be higher elevation airstrips. With me and my dad, both weighing in at about 200 lbs, I was not comfortable with the takeoff and climb performance. We've all watched a few loaded 172's make some unimpressive takeoffs from Johnson Creek, so even that were very scary. There's not much margin there and you have to be VERY aware of density altitude, wet grass, moist air, etc. I learned a lot about the things that kill unaware pilots.

I'll be downgrading to a smaller plane that can haul less, but maintains a better power-to-weight ratio. To achieve that same power-to-weight ratio in an aircraft with load carrying utility, I'd have to upgrade to a 180. I can live with not hauling as much gear or a 3rd or 4th passenger, I'd rather have the takeoff performance.

Then the fuel economy enters into the equation. Basically, hauling more stuff is more expensive, so you have to decide what is more important: Performance or utility. To have both costs a lot more money. If I was rich I'd be operating a Skywagon or a Bearhawk and have it both performance and utility.

An O-300 is a great engine, very reliable, but in my opinion it's just not enough for backcountry ops when installed in a 172. For sea level valley flying, it's very economical and safe.

An old C182 with trimable tail will kick the dogshit out of any 180 horse C172 conversion out there.

Gump

Aaaaaannnnnnd, with a '63 172 you still got a tail that looks like you hit the bridge when you went under. I'm beginning to think that 180 horsepower is a minimum for any airplane. I think a 180 horse Avid Flyer would be ideal.....with some high compression pistons, flow balancing, and fuel injection.

That Carbon Cub has 180 horse for 5 minutes or something and can carry a lightweight like me with 5 gallons of gas and still stay LSA. Ideal!

Zane wrote: I like to assign a horsepower-to-empty weight ratio for aircraft, so that you can abstract performance from utility....

That's called the power loading, and is better expressed as weight/power or pounds per horsepower. The Highlander example is 7.7, the 170 is 9.1. IMHO it's actually better to work up a realistic loaded example, such as the 170 @ 1320#, pilot 170# (ha!), 30 gal fuel 180#, misc stuff 30# for a total of 1700# / 145hp= 11.7 lbs per hp. Highlander: 770 + 170 + 20 gallons 120# + 30# = 1090# / 100hp = 10.9. The old 170 comes off a little better here using loaded figures.
There's also the wing to factor in-- weight divided by wing area is the wing loading. Same 170 example: 1700# / 175 sq ft of wing = 9.7 lbs per sq ft. Highlander: 1090# / 108 sq ft = 10.1.
Combined power/wing loading for the loaded 170 example would be 21.4, the loaded Highlander would be 21.0 -- actually pretty close between the two, eh? Add a passenger & more gear & the 170 will end up leading the Highlander, on paper anyway. In real life?-- you tell me.
These sort of calc's don't take into account different airfoils, mods etc but can give you some sort of idea about the level of performance to expect. I think you have to do these sort of calc's using the loaded aircraft weight, notice that lightweight aircraft like the Highlander lose some of their (on paper) advantage when you add pilot, fuel, etc.

^^ Well put, Eric.

And like you say, the real life situation works out a bit differently. My dad and I in the 170 with our gear and half tanks resulted in a not-too-frightening takeoff roll from Johnson Creek (maybe 900 feet?) but the climbout really had me wishing for more power. Now, leaving JC last year in the Sport Cub, right at gross was more confidence inspiring. Same with my evening demo ride with Deadstick Steve in his original Highlander.

Anyway, fun hangar talk and a decently objective way of looking at these birds. People have told me time and again, "there's no replacement for displacement." You'll always wish you had more power. If you go the 180/182 class route, you'll always wish you had more money for fuel, I guess. I continue to struggle with the same decisions. Good luck.

The high horsepower guys will always argue (rightfully) that you can pull the power back and achieve whatever fuel flow you can afford. That is true of course, but I would bet that in the real world most 180/2 owners do not fly around at 170/2 speeds and fuel flows.

If you have the discipline (and patience) to pull the lever back, then you can have a good balance between power and economy. But the initial buy-in and maintenance is always gonna be higher on the bigger airplane. There also may be some validity to the idea that loafin around behind an O-470 at 1700 RPM will cause less engine wear than 75% cruise power on an O-300... but I'll let the engine experts verify or discredit that idea.

I personally would have about as much discipline and patience with a 180 throttle as I have when I'm near a box of chocolate

Apparently some pilots do have that sort of discipline. Today I intercepted a 180 guy I know flying through my airspace-- he was easing along at about the same speed as me (120-ish), and probably burning about the same amount of fuel as the 150XP (about eight).

My 63 P172D with a 180 hp Lycoming 360 and CS prop provides "just enough" power to pull out of places like Marble, CO with 2 adults and 77# dog aboard, or 1, same dog, and camping equipment. The only problem I have encountered (once) was when I had my head elsewhere and didn't let enough speed build in ground effect, so that I was trying to climb at less than the much higher Vx that exists at high DA--that doesn't work all that well. But if the speed is correct, I can count on a steady climb out at 300 fpm at a DA of around 10,500' or so, with a realistic service ceiling of about 15,000' DA.

My airplane has droopy tips (which aid low speed control but add drag) and flap gap seals (which reduce drag but do nothing for short field performance). So at 21" and 2400 rpm, I can count on burning 9.8 gph and cruise at 115 knots TAS. I just installed an Insight GEM, which may change the fuel flow some as I learn how to use it.

At high DAs, there certainly is no substitute for excess power, and as I said, IMHO I have "just enough", not excess. My airplane is fine for my purposes, but your needs may be a lot different.

Cary

I am 6'4" my wife is 6 foot we have a little one that rides in a seat. We have a c172 o300, horton stol, HD nose fork with 850s on the mains. So far we find it to be a very adequate plane. The sportsman I understand is the stol kit to get, (that said I can drive around at nearly full power full flaps stall horn blaring and indicating 0 on the airspeed). I can get 3 people plus some gear out of 900 feet. That said the strip was in good shape only a little soggy after a nights rain with no obstacles.

I would add a sportsman, full climb pitch or seaplane prop then see if it performs acceptably.

Lowcountry wrote:....I keep thinking a C182 (or variant) would fit us perfectly ....

That sounds like a pretty tough airplane to beat given your stated mission, and there are some real good buys on 182's out there these days. Frined of mine bought a nice 57 model, with fat tires, ext baggage, folding rear seats, & BAS harnesses-- $30K. It was out of annual & was hangared without flying for several years so needed a little remedial work, but nothing major. I've heard of some other similar deals recently-- the 182 shortfielder sold on ebay is a good example.