Symptoms of prop ice

[Morne]

Since I don't have any deice equipment I don't play with icing. But curiosity forces me to ask, "Since you can't see the ice building on your prop how can you tell it is getting ice?"

 

[gprellwitz]

Vibration? Ice striking the windshield as it breaks off?

 

[CJones]

Well, since your prop is essentially a 'spinning' wing, it should show the same effects of decreased 'lift', which for a prop means decrease in airspeed for the same RPM.

 

[Ted]

I do have de-iced props, so I use them.

I've never noticed any issues from the ice building on the props specifically. It has come off (and hits the nose - it wouldn't hit the windshield on a single as it will be flung outwards), but never caused a discernible imbalance. If you were in ice bad enough to build up significantly and then lose the ice from one blade, I would expect a more noticeable imbalance and have heard reports as such.

If you do end up in icing inadvertently, a good first step on many planes is to shove the props all the way forward. This has a few functions. First, increased RPM will help prevent ice accumulation and aid in shedding - this is why props only have the inner bit covered with a boot. Second, it gives you more power on tap.

In the Aztec it was especially important. The prop governor was located in front of the #2 cylinder, and the first thing to happen in icing was that the prop cable would freeze up right at the governor and you'd be unable to move it. Obviously this was not ideal.

 

[flyingmoose]

If its on the wings, its most likely on the prop. But like they said before it will affect the efficiency of the prop so you will see a decrease in performance.

 

[Fearless Tower]

If you are in a twin you'll know when the ice starts to fling off the props against the side of the fuselage.

 

[Ted]

If you are in a twin you'll know when the ice starts to fling off the props against the side of the fuselage.

First time that happened to me I was solo in the Aztec. It was quite loud, and I found myself yelling "What the **** was that?!?!" I realized pretty quickly.

 

[bobmrg]

If its on the wings, its most likely on the prop. But like they said before it will affect the efficiency of the prop so you will see a decrease in performance.

Since ice accretion begins first on small-radius surfaces, unless you have a really, really skinny wing (or fat props), the prop will ice up first. The outer third of the prop is the part that flexes the most, so changing RPM occasionally will flex the prop and help with an ice problem if one exists.

As noted, first clue will be a reduction in speed with a constant power setting.

Bob Gardner

 

[Baron2PG]

As others have mentioned, speed loss is the 1st indication of airframe icing. It part of my SOP to dial in the TAS and monitor it during the flight. I know what TAS to expect for various configurations. If my TAS isn't correct (too fast, too slow) then you know something is wrong such as dragging a cowl flap, fuel flow incorrect, or in this case ice building on the airframe.

It doesn't take much ice to cause a noticeable drop in TAS. And yeah, the ice banging on the side of the nose really gets your attention!

 

[Piloto]

As others have mentioned, speed loss is the 1st indication of airframe icing. It part of my SOP to dial in the TAS and monitor it during the flight. I know what TAS to expect for various configurations. If my TAS isn't correct (too fast, too slow) then you know something is wrong such as dragging a cowl flap, fuel flow incorrect, or in this case ice building on the airframe.

It doesn't take much ice to cause a noticeable drop in TAS. And yeah, the ice banging on the side of the nose really gets your attention!

If you though it was loud in a Baron try in an Aerostar. It sounds like a machine gun on your head.

José