Aqua 2400s and Cessna 175, opinions please

[skukum12]

Gang,

I am considering a Cessna 175 on Aqua 2400s. O-360, c/s prop.

This float flying is almost 100 percent new to me. I do have a handful of take offs and landings in a C180 on 2870s. I don't know what I don’t know.

Pros, cons? Run away? Run to the bank? Hit me!

 

[mvivion]

I have not flown Aqua 2400s on a 175, but I have flown them on a few other airframes, and they are good performing floats. So, they should do well enough on the 180 hp 175. Keep it as light as practical and should be a LOT of fun.

MTV

 

[supersport]

I have flown the same setup your talking about and I think it’s a great combo in my opinion.
Respect it for the plane it is and you will have a great flying machine with much lower operating costs than its big brother the 180.

 

[skukum12]

Thanks gentlemen. Will be doing a pre purchase inspection next week. Had a meticulous friend do a pre pre inspection and he gave it the thumbs up.

Mission for this plane is a float rating then off to explore some of the watery spots in Alaska. Fishing rod and camping gear always with me. I have a feeling someone will talk me into moving moose meat at some point.

 

[stewartb]

What’s gross?

If there’s a weakness it’ll be the rudder.

 

[mvivion]

What’s gross?

If there’s a weakness it’ll be the rudder.

Seriously? Rudder is nearly the size of a 180 rudder, if it’s an early one.



MTV

 

[RaisedByWolves]

Seriously? Rudder is nearly the size of a 180 rudder, if it’s an early one.

View attachment 62916

MTV

I have two customers with 175’s ones a straight tail and one is slant. They both have the 470. Say they run out of elevator. The 470 makes you put a bunch of lead in the tail

Did the annual on floats in the water. The flat tops are really nice.


Sent from my iPhone using Tapatalk

 

[mvivion]

I’ve flown one with the 470, and they are VERY nose heavy. Lots of power, though. Mine is a 58 with an O-360 Lyc.

MTV

 

[stewartb]

Seriously. On floats the rudder is weak. Weak for direction control on the hump and weak in crosswind taxi. Oversize water rudders help. It’ll keep you on your toes when taxiing on flowing water. Learn to anticipate the lag and know when to add throttle. Night and day compared to a 180 on floats.

 

[BC12D-4-85]

For comparison look at the rudder deflection angles for the C-175 vs C-180 in their TCDS. Yes they are different and generally the 175 has less deflection...some models even less on floats than conventional. A local has a C-175 on PK floats. He had turning issues in wind until he didn't. Said there was some adjustment required.

C-175 TCDS
C-180 TCDS

Gary

 

[mvivion]

For comparison look at the rudder deflection angles for the C-175 vs C-180 in their TCDS. Yes they are different and generally the 175 has less deflection...some models even less on floats than conventional. A local has a C-175 on PK floats. He had turning issues in wind until he didn't. Said there was some adjustment required.

C-175 TCDS
C-180 TCDS

Gary

Interesting limitation on floats, for sure. I wonder why that restriction...... ?

That said, having flown a J-3 on EDO 1320s with one water rudder and a Beaver on EDO 4850s with stock water rudders, both in Kodiak, there are ways to turn..... We did install 4930 water rudders on that Beaver after I whined enough, though.....

MTV

 

[BC12D-4-85]

There might be some relation between potential rudder deflection and subsequent longitudinal stability (Pete would know). Adding a ventral fin or dorsal forward extension to the vert stab might allow greater rudder swing? Maybe Cessna didn't have either when the C-175 was first certified on floats?

Gary

 

[john schwamm]

Baumanns on a 175 require a ventral fin, not sure on Aqua, but might help make a difference? Or could make it harder to turn?
John

 

[BC12D-4-85]

I "think" the original float for the C-175 was an Edo 248B-2440. Any floatplane rudder deflection might have been tuned to them. Maybe MTV can have a look at the flight manual to see what Cessna offered as optional equipment or if a fin/ fillet was required on floats. Also Aqua 2400's STC might include info on additional fins/fillets or rudder swing dimensions.

Gary

 

[mvivion]

Interesting….the TC provides required rudder deflection for “seaplane” version, yet there are no floats listed in the TC.

I assume that implies that any floats installed would have to be STCd, and the STC would specify any requirement for a ventral fin. That said, 180s on EDO 2960s required a ventral fin, if they were equipped with the early, low dorsal.

In any case, thanks Gary, now I have an excuse when I swerve all over a runway…..”Dang that rudder deflection!”.

MTV

 

[BC12D-4-85]

For later models (like C-185) Cessna put the equipment options like approved floats in the Flight Manual, with only references like installed float models, placards, and operating limitations in the TCDS. Check the FM for the C-175 and see what they have listed. If not Cessna's original work an STC would apply. The C-172-75 TCDS does list the Edo 248B-2440 floats for the C-172 around P. 17 of TCDS 3A17.

Gary

 

[skywagon8a]

I "think" the original float for the C-175 was an Edo 248B-2440. Any floatplane rudder deflection might have been tuned to them. Maybe MTV can have a look at the flight manual to see what Cessna offered as optional equipment or if a fin/ fillet was required on floats. Also Aqua 2400's STC might include info on additional fins/fillets or rudder swing dimensions.

Gary

EDO lists the model 338-2200 for the 175. The 172XP used the 248B2440. Both airplanes are approved on the same TC.

The model 175 rudder travel was reduced from 16* on wheels to 12* on floats. Then: on the model 175A & B the rudder travel was increased to 19*.

MTV,
Many years ago FAA stopped publishing the list of approved equipment on some TCs (not all). That doesn't mean Cessna didn't approve a set of floats on the TC. Other than being listed on the original equipment list, I'm not sure where to quickly find the approval.

 

[skukum12]

Seriously? Rudder is nearly the size of a 180 rudder, if it’s an early one.

View attachment 62916

MTV

1958, 2350 gross i believe

 

[skukum12]

I had a 54 180, ran out of rudder. Left crosswind takeoffs were an eye opener!

 

[stewartb]

A and B models got the swept tail so gave up some rudder authority. I'd bet the travel increase was to offset the tail change.

 

[BC12D-4-85]

There's a C-172 with a O-360 or 390 locally on Aqua 2400's. Does real good/owner is pleased. I see in the pic above for N9361B they installed a leading edge fillet to the vertical stabilizer. Good as a ventral fin maybe. Has to be a fun airplane to fly to a good fishing hole.

Gary

 

[mvivion]

For later models (like C-185) Cessna put the equipment options like approved floats in the Flight Manual, with only references like installed float models, placards, and operating limitations in the TCDS. Check the FM for the C-175 and see what they have listed. If not Cessna's original work an STC would apply. The C-172-75 TCDS does list the Edo 248B-2440 floats for the C-172 around P. 17 of TCDS 3A17.

Gary

No AFM for my airplane, per serial number: “The basic required equipment as prescribed in the applicable airworthiness requirements (see Certification Basis) must be installed in the aircraft for certification. This equipment mustinclude a current Airplane Flight Manual effective S/N R1722930 and on, S/N 172RG0001 and on.”

But, as Pete noted, later aircraft had floats listed in their equipment list. I just didn’t think the 175 was that “late” in that context.

MTV

 

[mvivion]

One thing to consider on the 175: They all have either 9 or 10 gallons of unusable fuel, depending on model year. That’s a lot of unusable weight to haul around. And, they seem to be fairly heavy.

MTV

 

[skywagon8a]

One thing to consider on the 175: They all have either 9 or 10 gallons of unusable fuel, depending on model year. That’s a lot of unusable weight to haul around. And, they seem to be fairly heavy.

MTV

Unusable fuel is determined during flight testing when the airplane is placed in unusual attitudes while simulating rough air. The amount remaining when the engine begins to run rough is declared to be the unusable fuel. So, while 9 or 10 gallons may be the official unusable amount, in reality if maintaining level smooth flight you may be able to use more of it. Not suggesting this is so, just that it is possible.

 

[skukum12]

One thing to consider on the 175: They all have either 9 or 10 gallons of unusable fuel, depending on model year. That’s a lot of unusable weight to haul around. And, they seem to be fairly heavy.

MTV

Any idea why so much?

 

[mvivion]

Any idea why so much?

I was told there’s only one fuel pickup in each tank. Not sure that’s true, and haven’t been motivated to find out, so take that as a rumor.

That said, Cessna did some things on these planes that make you wonder. Pilot side window opens, passenger side doesn’t. Duh, saved a lot of $ there.

MTV