Cessna 185 vs. Cessna 206

[goingnowherefast]

Years ago, when I was working the dock, two private guys stopped by for fuel. One guy had a 185 with the 300hp engine. The other guy had a late model (long cabin) 180 with 230hp. They had just flown several hundred miles in loose formation, meaning identical speed. The fuel each one needed to refill the tanks was within 5 litres. For all practical purposes, you could say the fuel burn was identical.

There are also so many different varieties of 180, it's impossible to generalise. Early model short body 180s are basically a 170 with a bigger engine. In a late model 180 with an upgross kits and a bigger engine, you can carry as much as a 185.

The problem with the 206 is it's under powered and stalls too fast. The engine is rated at 300hp at sea level, standard atmosphere. However, you almost never operate there. You'll always be at 1000' asl, 25*c, with low pressure system moving in, Plus it's an older engine with compression falling a bit. Now you only have 270hp. If it was a turbo engine, you would have 290+ in the same situation.

Another option in the 206 to avoid the turbo is the IO-550 STC. It's rated at the same 300hp, but everybody knows it makes more.

[BeaverDreamer]

Another option in the 206 to avoid the turbo is the IO-550 STC. It's rated at the same 300hp, but everybody knows it makes more.

I would second this. The -520 is a complete dog at gross weights compared to the 550. Especially when you have to power back to max continuous shortly after takeoff. I was lucky enough to fly a -550 first and when I got into a 206 with a -520 I actually thought there might be a problem with the engine as I was struggling off the runway. Expect a mere 600-700 fpm with the -520 when loaded. Haven't flown either on floats but I imagine the difference would be clear as day.

[peterdillon]

Cant agree more with the votes for the 550. 520's were certified when they only had to make a certain percentage of power. Engine rebuilders will tell you that a 520 will seldom put out 300hp at 2850 and by the time you get back to max continuous you will be more like 270. On the other hand the 550 certification dictates it has to produce minimum 300hp and typically runs 305+. With the long blades on seaplane props the blades lose efficiency at the higher rpm further aggravating the problem as the 550 runs 2700 max. Combine a 550 with a good prop and and you will never look back. At the controls it feels more like an extra 75 hp. 185's are on the edge of cooling limits for long gross weight climbs but okay if the seals and fairings are good.
As to the very first post comparing the 185 to the 206 no matter what the Cessna specs say the 206 and 185 have the same engine and one has a wider heavier body so its pretty easy to figure out what the end results going to be. Turbos might be okay for wheels and private use but I have never seen a commercial float operator running one around this part of the world.

[TailwheelPilot]

On topic: As pointed out the 185 has slightly better performance that makes it better for short, bush strips or small lakes or rivers. 206s are not far behind, though, so it really depends on just how much performance you want/need (how short are the strips, what size margins are comfortable/acceptable for you). When you are not using the extra bit of performance, the 206 is generally the preferred plane - more volume for cargo, much more comfortable for passengers.

Straying off topic:
Once upon a time I flew a 520-powered 206 and a 550-powered 206 from big runways. The 550 was smoother and felt a little better on take off, the only negative about the 550 was that the starter did not crank the engine as well as whatever the 520s had. Never heard a bad thing about 550s at the time, in-person or online.

Recently I was told that one Whitehorse operator converted a 206 to a 550, had issues, then converted it back to the 520. A second operator has a 206 with a 550 but they change cylinders regularly, run it at 25"/2500 RPM for cruise (the only thing they found that helps with cylinder life), and the mechanics want to convert it back to a 520 to simplify their lives.

Are some STCs to convert to a 550 - or some models of 550 - more prone to needing cylinders repaired/replaced? Do the Whitehorse operators have bad luck? Any other theories why everyone seems to love 550s, so long as they are not in Whitehorse?

[Starboardwing]

Seems there are some knowledgeable 206 operators out there so i'd like to ask if anyone could offer some insight on this matter.

I flew a TU206C this past summer. Engine new as of a year ago. After engine break in period, i began noticing that on full power takeoff, that FF would show 35-38gph (redline 31). We operate with GEMs and this indication was corroborated by both a/c FF and GEM. High FF was consistent on first flight of the day. Subsequent takeoffs would show less than red line FF. however CHTs generally would stay under 400F. Hard to say whether aircraft was producing less than full power, given the tip tanks added lift and the generous power on takeoff.

I hear the turbo 206's can be finicky, but any ideas as to what might be causing the inconsistent FF on takeoff? I am reluctant to use partial power takeoffs to keep FF closer to red line. and while im more concerned about the lower fuel flow on subsequent takeoffs, the CHTs seem to be sitting at fairly decent numbers after takeoff, and without an appreciable differece in take off performance.... well maybe im looking into it more than i need to be!?

[SuperchargedRS]

. How do the service ceilings compare...?

They are unpressurized piston planes, never been a fan of flying above o2 range, shoving junk into my nose and hauling o2 tanks, homie don't play that game.


But to the topic, flown both, including light 206s (including u206s with 550s and extensions), I bought a A185F on edo amphibs, works great for my mission, if you know how to fly those floats you'll be able to get in most anywhere and still get a hair over 120ktas. On wheels she'll land damn near anywhere too.

Unless you really need that rear cargo door the 185 is the top dog.

[goingnowherefast]

Seems there are some knowledgeable 206 operators out there so i'd like to ask if anyone could offer some insight on this matter.

I flew a TU206C this past summer. Engine new as of a year ago. After engine break in period, i began noticing that on full power takeoff, that FF would show 35-38gph (redline 31). We operate with GEMs and this indication was corroborated by both a/c FF and GEM. High FF was consistent on first flight of the day. Subsequent takeoffs would show less than red line FF. however CHTs generally would stay under 400F. Hard to say whether aircraft was producing less than full power, given the tip tanks added lift and the generous power on takeoff.

I hear the turbo 206's can be finicky, but any ideas as to what might be causing the inconsistent FF on takeoff? I am reluctant to use partial power takeoffs to keep FF closer to red line. and while im more concerned about the lower fuel flow on subsequent takeoffs, the CHTs seem to be sitting at fairly decent numbers after takeoff, and without an appreciable differece in take off performance.... well maybe im looking into it more than i need to be!?

What is the manifold pressure on the first take-off? I have heard of turbo controller issues when the oil isn't completely and entirely warmed up. Basically you get a little extra boost, meaning more fuel flow too.

[geodoc]

Apparently "your mileage may vary". I flew a T206 amphib for a company for 4 years based in Portland in later 90's. It made it to TBO and never had a cylinder replaced during it's life (factory re-man). It was operated with a GEM engine monitor and had cowl flap extensions. It was, as an aside, a Wipaire landplane conversion w/ RH FWD door mod and mod(s) to remove the salt water ops limitation.

Violently expensive engine to overhaul though.

Fairly decent airplane, though kinda water-lovin compared to the 185. It was a little better after the Sportsman leading edge kit was installed.

The turbo charged 206 is very expensive to operate partly because of the high failure rate of cylinders.

It does not perform as well as a 185.

But it is comfortable.

The doors are a pain in the ass because of their positions.

If you don't care about cost the 206 is a good choice all things considered.

I have over 8oo hours on a 206 amphibian.

[edmanster]

Long time ago i asked same question to an oll-timer pilot 185/206.
His simple answer was do you want to make money? or u just wanna spice up ur logbook ..
The 206 has more volume capacity than the 185. & they carry approx the same payload. Its a lot more easier to convince a customer that 2 trips are required when you cannot fit anymore in a 185 than it is to convince same customer you're max-ed out on weight & half the cargo space is empty in a 206. What do you believe is the customer's first opinion of u ??? The 185 will takeoff with most everything you can place inside it .. The 206 will not. Check out the crash & burn statistics. There is a higher probability of pushing the aircraft limits to satisfy customer demands in a 206.