CS Prop info

[Wyoming1]

I’m looking for information for a CS prop for a 170A with the Lycoming O-360. I’m sure this has been beat to death, but I can’t find a thread on it. Any suggestions?

[170driver]

I also have an ‘A’ with a 0360. Flew it with the 76’’ hartz, then the 80’’ b-hub hartz …but now have had a MT on it for quite a while now..95% off airport/backcountry ops - never looked back.

Pro/cons to each setup- but composite props paired up with a light A model with the big motor are in a class of their own

[Wyoming1]

That's what I'm looking at. Which MT did you go with?

[170driver]

83’’ expedition w/ nickel edges

[DaveF]

I’ve got an MT MTV-15-B/210-58, 83”. Far better than the Hartzell HC-C2YK-1BF/F7666-2 that it replaced. Made it a whole new airplane.

[ghostflyer]

Dave,
Can you supply any performance specs . I am very interested .

[DaveF]

David,

I didn’t do any before/after test flying, so I don’t have numbers. You could try asking the dealer, Flight Resource, if they have any.

I can tell you that the propeller improved every part of takeoff and climb, the prop control is now very effective at modulating descent rate in a glide, and the yellow RPM tach arc is eliminated, allowing efficient low RPM / high MP cruise operation.

I’m based at 5000 msl so high DA ops are important to me, and the propeller just keeps going where the Hartzell runs out of thrust.

20,000 feet:

[170driver]

https://media.mcfarlaneaviation.com/doc ... datar1.pdf

[GAHorn]

https://media.mcfarlaneaviation.com/doc ... datar1.pdf

That’s interesting data….. They operated it 250 over gross wt…. and claim a shortest ground roll with a 3 blade over a 2 blade… something out-of-the-ordinary. Usually 2-blade props outperform 3-blades in takeoff distance, noise level, and cruise speeds. I’m guessing this is because the blade profiles are not apples-to-apples.

[ghostflyer]

I have found Cessna 170,s fitted with Lycoming O-360 engines have no difficulty uplifting 250lbs over their weight . While it’s not legal ,and i am not recommending doing it , but had to under extenuating circumstances . I was full of fuel and had 3 very large passengers on board. I did ask what they did weigh and they were not truthful with their answers. I tried to do a W and B check but were well out of the graph. Cof G was ok but the weight was too much. Couldn’t defuel,as the fuel was needed . There was a density altitude issue also . The dirt /sandy strip i was using was over 3000ft long .
I was very pleasantly surprised the tail came up with not too much effort and the cross runway disappeared under our wheels . We were about 20 ft but climbing . Stall warning spluttered a couple of times and I just lowered the nose a fraction . We climbed to 2,500 ft easily [max power] but the climb to 4,500 ft took for ever . The climb rate was about 200 ft a minute . Aircraft handled normally ,but heaps of forward trim was required .
My issue is I am running fixed pitch Sensenich 76in with a pitch of 60in . A CS prop would have been great .

I was flying in the real outback of Australia and was asked could I pick up a couple of Pax on this dirt strip . No buildings or shade just this dirt strip .
They had been dumped there and their transport had returned to where they had come from. No cell phones and my radios didn’t work in this area. These latte siping city green horns didn’t have any water and one wasn’t wearing a hat. This trio had come to inspect a mine site . I was only helping a friend out . The temperature was well over a 100degs . My oil temp got to 210deg . Never seen it move pass 180 deg before.

[GAHorn]

The airframe certainly has the strength … anecdotally there’s a 150% design factor. The horsepower is the issue…. surprisingly long takeoff runs and frustratingly shallow climb-performance will be evident…. even frighteningly-so if you do this without consideration of Density Altitude….Flying a 170 overweight is certainly not unheard-of. I’ve unthinkingly done it myself… ….. in front of knowledgeable 170 owners. as I did in the event I’m recalling.

Can you spell “stoopid”…??

(I’m reminiscing about the time I agreed to “lead” a flight of 4 fellow Members on the migration from ILM to FFA at the ‘02 convention… and myself, Ol’ Gar, Jamie and Deanna hopped into 146YS …which had been refueled on arrival a few days earlier for the convenience of the FBO… and me simply not thinking…not giving Any Thought to the matter when I responded to Ol’Gar.

Subsequently, when the FLy-Out on Airport Day was presented….Ol’Gar asked if he and Deanna could ride-along with Jamie and Me…and brain-dead Me only wanted to accommodate him…. never giving a thought to what the airplane would weigh. We were about 2500 lbs I believe….it was a warm Summer Day…(high DA)…. and were still on the main wheels when all our gaggle were airborne behind us…awaiting me to lift-off and “lead” them to FFA.
Departure instructions from ATC were “Make an immediate Right Turn to HDG 090 (?) … climb to X-thousand feet… “

Since the entire convention-flight was camped-out nearby….we were assigned and we used the intersection for take-off…which had plenty of spare rwy….For THEM… 146YS and it’s Cruise-propeller used considerably More…and we departed the end of the rwy only a few feet above elevation. IAS was so low…that I dared-not make an “immediate Right Turn”…. so the 3 guys following their “leader”…. the ATP-rated “Pro” they’d signed-up-for to be on His Gaggle….. were undoubtedly wondering why I was deliberately ignoring ATC’s calls to us fussing about our disregard of Departure Instructions.

(we made that right turn about a mile later than ATC had wanted)

We eventually reached cruise altitude and had a smooth and enjoyable off-shore flight up the coast,…all the stress quickly passed..…we descended and landed at destination…and taxied in, parked.

To make matters Worse… Unbelievably… I accepted the arrival-FBO’s offer of a DIScount on Fuel if I “topped off”…..for the return trip!

I’m telling on myself to illustrate that it doesn’t matter who you are,… what your “qualifications” are,… your responsibilities are to your pax,… it takes an Active Mind and Conscious Pre-Flight Planning …and Integrity… to be a true Aviator. One Lapse…only One… can make you Embarrassed, Disrespected, Foolish, …or Worse.) BTDT.

There’s more than just poor and undocumented takoff/climb performance to consider as well. There’s unknown stall speed. …and unknown gust-load-factor margins…. The belief that a 170/172 is structurally sufficiently the same as an (underpowered) 180/182 …is common…but not justifiable. The fact a 182 wing can be transplanted to a 170B does not account for gauge of skins, or rivet-spacing, or reinforced attachments between and of varying SNs ..which may not interfere with fitment…but nevertheless exist for strength to support higher operating/gross wts of the later models. (I am not intimately familiar with specific examples…I am only regurgitating what knowledgeable airframe repairmen have noted to me.)

As Instructors want to say: “Do as I say….Not as I do.”