Re: Icing
A full preflight - no. A quick-turn preflight - yes. Pitot-heat recheck for a VFR flight - no, we can reasonably assume that it is still operational because we checked it prior to the first fight of the day and haven't done anything that would have caused its failure, and can reasonably assume that no one damaged that system during the 5 minutes that we were in the FBO lobby.
Right--I'd do the same--but that's based on being a prudent pilot, not because there is a regulatory or manufacturer's requirement to do so.
Then why would you EVER have to do a pre-flight after you've done it once? I'm of the opinion that the FAA would ask if there were reasonable possibility that something happened to the aircraft in the interim that could affect its airworthiness? What guideline do YOU use to decide if the airplane needs a preflight and how extensive of a preflight it needs?
Exactly...it's all a judgment call.
Anyway, I didn't say it was "poor judgement" to skip the pitot heat check for a VFR flight, I said that the decision to do so may have unintended consequences. One of the consequences is that we may be teaching a primary student that we can pick and choose when to follow the regulations. I understand (now) that it is not your intention to circumvent a regulation, thus the reason for discussing 91.213 in detail before getting to this point.
Ok, I see where you're coming from. My premise is that the regulations basically leave the preflight inspection / equipment checks to the pilot's judgment, with the manufacturer checklist as nothing more than a recommended procedure. I believe if a piece of equipment will not be used during a flight, such as the pitot heat, it does not need to be checked. I'll explain why in my next line...
My premise is that the rules say that all equipment must be operational (or *properly* dealt with) prior to flight, and I also contend that there are reasonable expectations that we can make about how and when we need to verify this. I contend that it is not reasonable to assume that the pitot heat works if we haven't checked it and the aircraft has been out of our control for any extended period of time where others have flown the plane or handled it or otherwise had an opportuinity to cause damage unbeknown to us.
I agree with that, to a point. The logic for when a pilot should reasonably be expected to do a preflight check is dead on.
But here's the thing--do you check every single piece of equipment onboard the aircraft prior to flight? And I mean *EVERY* piece of equipment? You do a radio check with both COM1 and COM2 to verify you can transmit and receive? You check every interior cockpit light, even for day flights? You check both the pilot and co-pilot PTT switches? You check the fuel shutoff valve actually shuts off the flow of fuel?
See where I'm going with this? It's impractical to check every piece of equipment prior to each flight. Even a 172 has potentially hundreds of items to check, all of which might technically make the aircraft unairworthy if found to be inoperative yet not placarded.
Then I ask, what's the difference between checking the pitot heat and the co-pilot PTT switch? For a simple VFR flight in a 172, they both have about the same level of significance and impact on safety.
One might argue that the pitot heat is listed on the manufacturer's preflight checklist while the PTT is not, but we've already talked about how the manufacturer's checklist is not mandatory and is designed to be used at the pilot's discretion.
Does this make any more sense as to why I say it's not dangerous or illegal to selectively ignore certain equipment checks?
