Heated Pitot necessary?

[BobTurner]

Originally Posted by h&jeuropa

While pitot heat is nice, it is not as necessary today as it was 20-30 years ago because today we have GPS which will provide a "ball park" airspeed (and altitude) even if the pitot is iced over. Prior to GPS you were out of luck!

Jim Butcher

Every builder needs to carefully consider their choices in some detail. For example, you can still buy used EFIS units that require pitot data to reach an attitude solution.
As to the other question: no TSO is required for a VOR/ILS.
OTOH, a TSO or other approval is required for a gps used under IFR. So while there are a lot of high accuracy gps boxes out there, they are not legal as the primary nav source under ifr without the approval. Most don?t have databases, either.

[RFSchaller]

My definition of a good IFR airplane is one that is stable so you can spend 10 or 15 seconds looking at a chart and when you look up everything still looks good on the AI. My Cherokee is like that and very stable. The RV-12 has an empty weight half of the Cherokee so it gets pushed around more and seems a little less hands off stable. I would recommend the AP if you are serious about flying the RV-12 in IMC.

[rongawer]

Originally Posted by R7237

Thank you for taking the time to comment. As I am also putting a ULPower 350iS on the 12, I am glad to get your input. Based on the thread, "properly equipped" means 1) Heated Pitot 2) Autopilot and 3) TSO'd navigation source with a 4) sign off on the pitot static system.

You're welcome. I agree with having a heated pitot, AP and pitot/static check, 91.411, and then there is also a separate check for the transponder, 91.413 that is required. I would also include the items listed in 91.205(c) for night flying, which I do often. And then there is everything by 91.205(d) that will be required by operating limits as well. All of that, meets my definition of "properly equipped".

I personally have a GTN625 , which is TSO'd under C146, which is the WAAS TSO; it's a fine unit and I recommend it. I see Van's is now offering a similar avionics package for IFR training. However, you can fly IFR with a GPS TSO'd under C129 (non-WAAS) with some restrictions. You cannot fly IFR with a non-TSO'd GPS using that as your primary means of navigation - but that is way off topic and already discussed at length in other threads.

Prior to entering any form of precipitation and OAT is <=45ºF, I turn on my pitot heat. Thermal layers can change quickly in IMC and ice may form, so I recommend having the heated probe, and use it.

A pro-tip for Garmin G3X users is that the regulated GAP 26 probe has a discrete output that can be configured to alert you when OAT is <45º and your probe temp is less than 77ºF and/or your power to the probe is off; a very nice feature.

Originally Posted by RFSchaller

My definition of a good IFR airplane is one that is stable so you can spend 10 or 15 seconds looking at a chart and when you look up everything still looks good on the AI. My Cherokee is like that and very stable. The RV-12 has an empty weight half of the Cherokee so it gets pushed around more and seems a little less hands off stable. I would recommend the AP if you are serious about flying the RV-12 in IMC.

Getting "pushed around" isn't just about gross weight, but includes wing surface area for wing loading determination - the higher the wing loading, the less the plane will be affected by thermal activity. Depending on which Cherokee you have, the wing loading at gross weight has about 13.4 pounds per square foot (2150lbs / 160 sqft), whereas the E-LSA RV-12 has 1320 pounds and 127 sqft for 10.4 lbs/sqft. Three pounds is a difference, but not so much that I would say it gets pushed around noticeably more than my brother's warrior, that I've flown on the same day, in the same conditions. For comparison a B58 Baron is 27 lbs/sqft, which is significantly different, or a 747 which has about 133 lbs/sqft. When trimmed out, an RV-12 is quite stable and an excellent IFR training platform, IMHO, although I wholeheartedly agree with having an AP - not for stability, but for flying IFR single pilot.

P.S. Congrats R7237 on the UL350iS install. I'm happy to share my lessons learned or just compare notes if you want.

EDIT: I just remembered, my 12 has fuel out in the wings, not in the baggage, which may contribute to its stability more so than fuel at the centerline.

[Driftdown]

Originally Posted by RFSchaller

About 20 years ago I was flying IFR from PHX to SAF in November. Went into IMC and my airspeed indication went to zero. Sure was nice to flip on pitot heat and get it back in 10 seconds. I’ve been flying 35 years and that is the only time I needed it, but when you need it, you need it.

Glad it worked out for you, but that's way too late to be turning it on.
That pitot heater should have been turned on well before the actual icing event. Why?
Because the pitot heater is not an "ice-removal device." It is however, an "anti-icing device." That means it prevents ice from forming, instead of removing icing which is already there. If icing is severe enough, there are circumstances where the ice accumulation could far exceed the capabilities of the pitot heater to remove the ice. Therefore, prevention is far superior than removing with this piece of equipment.
Unless it is turned on during taxi-out for an anticipated IFR flight (observing operating limits) . . . a good rule of thumb is to make sure it is on, when encountering visible moisture with an OAT less than +50ºf or +5ºc.
Had that rule of thumb been followed, the indicated airspeed would probably not have gone to zero.

[RFSchaller]

No argument there, Driftdown. Sometimes you just miss something, and that was one of them.