170 Roll Rate Compared to an 172S

[morrisond]

Hi,

I'm an recently licensed Pilot and am thinking of rebuilding an 170 with an 0-360 or IO-360.

All my time is on on 172S's. One of the tings I don't like about the 172S is the somewhat slow roll rate, which in my mind makes it slow to correct wing drop in turbulence.

Does the 170 have the same Wing/Aileron as the current 172? Are there any mods available to improve the Aileron effectiveness of the 170?

I am told that more affective Ailerons have made the Husky a much more pleasant Aircraft to fly in turbulence as it takes very little to correct wing drop.

Would minimizing weight on the 170 help to alleviate this issue? The 172S i'm flying has an empty weight of close to 1800 lbs. I'm guessing that if you rebuilt an 170 from scratch you could get the weight to well under 1300 lbs. VFR only, no vacumn system, 0-360 with an fixed pitch prop. What about some of the Stol kits? Would they help Aileron effectiveness at High speeds?

Thanks

[tshort]

Here is my completely unscientific opinion...

I own a '48 170 and a 1997 172R (basically the same airplane as the S model, minus a different prop / tach / etc.).

My impression and "feel" is that the 170 is far more responsive and lighter on the controls than the skyhawk. A lot of the time I correct wing drop with a little rudder - that almost works just as well.

I haven't actually done anything to compare the roll rates, but the 170 feels much more responsive to me...

Just my .02

Thomas

[morrisond]

Thanks Thomas,

That would confirm what I was thinking in retrospect that of course the Ailerons would be more effective at a lower weight.

So the goal would then be to see how light you could make one of these.

I've read on the forums that the 0-360 saves 30 lbs.

Are there light weight starters/altenators and batteries approved for 170's?

I would want an B, for the more effective flaps, and would strip out the interior, redo with light weight materials, and rebuild the panel with basic instruments, no vacum system.

Is there an Wood Prop STC for the 180/170?

Thanks

[mrpibb]

From flying my 48 with the occasional flight in the schools 172, i have drawn the following comparison. the 48 170 has a lighter feel, same roll rate if not a little less, and not as effective at the lower speeds as a 172 or a 170 A or B for that matter. Being I have a straight wing my airplane feels more responsive initially but throw in some dihedral like the B models and 172's you get a more stable flying aircraft, and this stability is what you initially have to overcome to initiate a roll.
As for Wood propellers, the are lighter but the loss of performance dose not make up for the savings in weight IMHO.

[4583C]

I always thought the "keel" effect of the nosewheel slowed the roll rate of the 172's

[blueldr]

Morrisond,
I suggest you ask the factories what their empty weight is on their engines. I seriously doubt that there will be a 30 pound difference between the Cont. O-300 and the Lyc. O-360.

[morrisond]

I got that number from reading other posts on this website.

Does anyone know the Website for Del-Air?

[alaskan99669]

Morrisond,
I suggest you ask the factories what their empty weight is on their engines. I seriously doubt that there will be a 30 pound difference between the Cont. O-300 and the Lyc. O-360.

O-300 = 268 #'s
O-360 = 284 #'s

According to : http://www.aviator.cc/aircraft_engine_weights.html

[rupertjl]

If anyone wants to be a weekend test pilot, here's the way to test for roll rate safely in our airplanes...

get into a 20-30 AOB right and apply a constant yoke input to the left. Hold that input and have your data taker in the copilot's side time from wings level to 20-30 degrees in the other direction. then do the simple math and get your degrees per second roll rate. Also remember, large yoke inputs produce large roll rates, smaller inputs produce smaller roll rates. Importatn thing is to make it a constant yoke input, you want a a steady state roll rate developed before you time from wings level to the opposite angle of bank.

Please do not go out and do full yoke inputs and end up on your back...any good test pilot knows biuld-up is important and the safe way to go about it.

I've been thinking that once I get out of Test Pilot School that I would do an evalaution of my 170 and see how it compares to what Cessna said in the owners manual and what mine will acutally do. But of course my time right now is very milimted because TPS wants me to do that stuff with their airplanes instead of mine (and they grade me on their stuff!)

v/r,
Jud

[GAHorn]

The ragwing (170) has smaller ailerons (from the 120/140 actually) and does not have the roll-rate of the metal wing A/B models.
The A/B models have slightly faster roll rates than late model 172's for two reasons: sector-gearing in the 170A/B is faster, and momentum due to fuel load and location is less in the 170A/B than later 172s.
None of the 170 series suffers from lack of roll response in turbulence. Neither does the 172, in my opinion. However any airplane will "wallow" if coordinated rudder is not fed simultaneously with aileron.