Heated Prop on a 201

[Steve Dawson]

Does anyone have a heated prop on your 201? How do you like it, is it worthwhile and do you know the cost?

[Cody Stallings]

Don't think a J is TCed with anti-ice on the propeller. There are also no provisions on the spinner backplate for a Slipring or Dripring.

[201er]

May I ask a dumb question? What's the point of a heated prop if the rest of the plane isn't deiced?

[Cody Stallings]

I think so the propeller is running smooth all the way to the ground....

[DonMuncy]

Maybe they think if you prop is working really well, maybe you can climb through the ice up to clear air.

My 231 has a hot prop, but keeping it operating is a pain. It is disconnected at this time.

[201er]

Are you saying that prop ice is considered to be a greater problem than wing ice? Or just a more easily solvable one?

[Cody Stallings]

I really don't understand it..... I have been told when the prop gets loaded up, just push the blue knob forward for a second an it sheds it. Where is the blue knob for the wings an tail?....

[DonMuncy]

I really have no idea. I have often wondered myself. I was just looking for some logic the engineers might have used.

[Super Dave]

A small radius leading edge will acumulate ice at a greater rate than a leading edge with a larger radius. Tails build ice faster than wings, props build ice faster than tails.

[201er]

Tails build ice faster than wings, props build ice faster than tails.

At least it keeps the CG in the right place!

[chrisk]

I've never had ice on my Mooney, but I haven't flown it in the winter yet. My last flight was at 8,000 ft and the temps were near 20C.  

 

I have had ice on a Cessna 172 before.  Once the prop gets iced up, it vibrates very badly and you have to throttle back.    There is no climbing after that.   I assume the behavior would be similar on a Mooney?  I would think a hot prop would help, possibly giving the option to climb.  And of course, the best option is not to get ice on the plane in the first place.

[Steve Dawson]

I've read that ice on a prop can vibrate the engine enough to break a mount.

20 years ago I had ice on the prop of a Cherokee 6-300 and tried to get it off by varying the RPM, It eventually came off but I wasn't sure if it was because we went into a warmer altitude or just from varying the prop RPM.   

[hoppetool]

I too would like to put a hot prop on my Acclaim.  The advantage is that even though the airframe has ice (heavy), the engine/prop will make the same amount of thrust thus aiding the airframe ice issue.  I have a hot prop on my Bonanza and it also does not have de-ice on the wings.  If the prop ices up, there's no thrust.  Add to an iced up airframe and you've got serious trouble.  I'd prefer a de-iced prop to what amounts to swinging a baseball bat in the wind trying to get thrust..... All that said, the question still remains.  Does anyone know of STCs  for hot props on modern Mooneys?

[rocketman]

I too have a de-icing prop on my Rocket. Why? No answer. Maybe because it is cheaper, easier and more effective than trying to deice the other larger leading edges. Kind of leads you into a sense of false security. I guess they thought that the TSIO-520 turbo charged big bore Continental could muster its way through ice better if the prop was clear - NOT. It is obviously better than nothing but sometimes nothing is better than something. Hmmm - something about nothing to think about.

[201er]

Question (possibly ignorant): even with deiced prop, won't you still be at a loss of power to an extent because of induction icing across the intake filter? Even if most air is going through it, doesn't that reduce engine effectiveness regardless of icing on the blades?

 

As for the alternate air:

 

-Does it work as all or nothing or in stages? If filter is partly clogged, does alternate air let some in to make up or does it only open when no air is coming through the normal intake?

-Isn't it bringing in warm air so also less power?

-Are you sure it works? How do you know when it is operating?

[JohnL]

An interesting note for the discussion: according to my POH, the hot prop costs 6 mph airspeed. Wow!

Has anyone done a before / after comparison when adding a hot prop and measured the drop in airspeed?

Can I gain 6 mph by removing my hot prop? (I would not consider this)

 

My experience with ice is that you can typically climb or descend to get out. Without a hot prop, the climb option becomes compromised.

[carusoam]

The TopProp is available with electric heat. I briefly researched the option when searching out replacement props.

I believe an additional STC is required, possibly significant amperage requirement as well.

My research ended with go FIKI or stay away from ice the old fashioned way. There doesn't seem to be any room for going halfway.

I believe FIKI uses liquid on the prop. This makes the heated prop a no go for me.

Maybe somebody knows better than me.

Best regards,

-a-

[jlunseth]

I have a hot prop on my 231, but rarely use it.  Hot props were put on our aircraft generally before any other deice systems were available, so they were what there was.  Now they are not certified for flight into known ice, so it is generally not legal to fly where you are going to need to use one. 

 

The main purpose of the hot prop is to eliminate vibration caused by differential buildup of ice on the two blades.  You can find yourself in a situation where the only two choices are turn the engine off, or leave it on and risk it coming off in flight, which is worse?  But frankly, you should not ever get yourself in an icing situation severe enough to need it.  If you do, you have most likely broken a half dozen FARs already.  The old method of climbing through to the top does not qualify as legal any longer.