Checklist speeds - help needed

How to keep the Cessna 170 flying and airworthy.

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dstates
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Joined: Sun Jun 30, 2019 5:50 pm

Checklist speeds - help needed

Post by dstates »

I'm new to my 170A and am working on my own checklist based on one from a past owner and one I used for a Piper Archer in the past. I'm having some trouble finding some values in the owners manual/AFM. Any help would be appreciated.

On a zero flap takeoff, what is a good rotation speed?
What about short field takeoff (2 notches of flap), what is a good rotation speed? What is a good climb speed with 2 notches of flap?

What are good approach speeds for with and without flaps?

What is best glide speed?

Thanks ahead of time!
Doug
N1235D - 1951 170A - SN: 20118
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wabuchanan
Posts: 147
Joined: Sun Nov 02, 2014 2:51 am

Re: Checklist speeds - help needed

Post by wabuchanan »

Doug,

All your answers are in the 2 page AFM. That's it. We choose to fly OLD airplanes built during a time when the V speeds really did not exist in the form they are currently published in.

Your AFM shows you various climb speeds listed for altitude, temperature, etc. as well as a 76mph climb speed to clear a 50 ft obstacle.

From those you can roughly correlate a good set of speeds to use as Vx/ Vy. On my A model, I can get the aircraft into ground effect on a STOL take off at 45mph's with 2 notches of flap, and climb out with one notch until obstacles are cleared, generally using 70 as Vx (and Best Glide speed). I generally use 80-85 as my Vy speeds.

Approach speeds will be specific to your aircraft, but I usually use 80-60 in the pattern, final at 60 generally, and 50 for a very short field landing. These have been practiced at altitude many many times to know exactly the stall characteristics of my plane. All of our planes have their own idiosyncrasies based on how straight they are, how many times the wings and tails have been repaired and rebuilt etc. By example, my planes stalling characteristics without flaps is a rather dramatic drop of the right wing. Using at least one notch of flaps tames all my stalls into nice stable descents without any wicked or dramatic characteristics.

As for flap use in the pattern, I use 1 or 2 notches initially entering the pattern and 4 on base and final. I find the 3rd notch essentially useless on the A model. BUT, these were arrived at by flying in all regimes for 2-3 years figuring out what worked best for me. You did ask about no flap landings. I always use a minimum of 2 notches myself, but 70 seems to work well.

For general rotation speeds, I have learned to let the airplane choose it's own speeds to lift off at, which is generally around 55-60 mph's. It depends on whether I am choosing to take off in a 3 point attitude, or tail high.

If you PM me I would be happy to send you a basic check list I use on my A model which I made from 3 other checklists and the particular avionics/equipment in my plane.

Bill
1950 170A N5776C SN:19730
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