The International Cessna^® 170 Association

Bruce Fenstermacher wrote:This is another case where technology has surpassed the FARs. At least the definitions that are in the FARs. And so once again it's left up to the interpretation of the individual inspector and his interpretation of the FARs.

This is the problem, Bruce.

The definitions of many of these terms are not actually in the FARs and thus left to interpretation. ( In my dealings with another behemoth of a federal agency, the FDA, we always have a definitions section that provides unambiguous meaning to words so that the meaning of said words cannot change with time and is NOT left to individual inspectors determination of meaning or intent.)

Now we have FAA inspectors trying to fit the regulations and terms on which they were recently trained onto documents that were written before the inspector was born. There was no need for Cessna to call the rear seat optional or standard equipment on our type certificate 65 years ago. It wasn't the practice at that time. Yet some inspector freelances an excessively strict opinion that in this case it is a major alteration because it says its a 4 place airplane on the TC, even though every other four place Cessna single lists the backseat as standard (not required) equipment.

Sorry for the rant and the thread creep, but this freelance interpretation of regs is one of those things that is killing this industry.

Sure if you let it....I'll pass on further, back seat discussion but all markings on my plane are decals. They're permanent and as good as paint if not better. So sue me, threaten me and impress me with the regulations. If I had used plastic electrical tape as a substitute then maybe they have a beef.
Times change as does techniques, if you're following the intent of the regulations then I think you're good. All laws and regulations can be interpreted no different than the usual always having to interpret what the better half is saying. I'm sure you may run into a new model trying to save the world of aviation, likely his boss is smarter and sooner or latter he'll get there too.

Arayana, to the IDIOT that told you that you have to use permanent decals (there's no such thing) that aren't removable, I would point out that paint is not permanent and is removeable. Wouldn't that mean that paint is also not legal? I would consult your local FSDO and not the local village idiot for advice.

To get a relatively reliable answer, one might have to consult a number of FSDOs and average out the answers. It's not at all unheard of to find divergent answers from different FSDOs on a number of subjects. As a matter of fact, it is not at all uncommon to find that members of a given FSDO consult among themselves before giving an offisial answer for the group.

surrounded by idiots--- Trust me , I know the feeling.

FredMa wrote:Arayana, to the IDIOT that told you that you have to use permanent decals (there's no such thing) that aren't removable, I would point out that paint is not permanent and is removeable. Wouldn't that mean that paint is also not legal? I would consult your local FSDO and not the local village idiot for advice.

Part 45.421(c)(1) wrote:Except as provided in paragraph (d) of this section, be painted on the aircraft or affixed by any other means insuring a similar degree of permanence;

Paint can be cleaned off with MEK or lacquer thinner just like decals can. So, decals are of a similar degree of permanence as paint.

..at least until someone else doesn't think so.

How much contribution to the total thrust developed by the prop can be attributed to the portion populated by the vortilators? ...and, therefore, how much can the vortilators either help, or hurt, the propeller performance? (Answer: it's like snake oil.....it can only help prevent corrosion where it's applied.)

Sorry...couldn't restrain myself....

That's interesting. Of course, one would think that if vortilators re-attached airflow to the surface of the prop...that the resultant parasitic drag increase would result in RPM reduction...not increase. I suspect you are correct, the prop-tip mod is what produced the RPM increase. (Makes sense since, all other things being equal, a round-tip would offer less wetted area and less drag, and is one method sometimes suggested by McCauley for the purpose of increasing static RPM.)

It should be easy enough to test the effectiveness of the prop vorti-thingies. Install on only one blade and see if that one goes faster.

ah but then you'd get the prop out of sync with itself as the faster blade catches up to the slow one, and you'd have a C170 that sounded like a twin with un-synced props (wa-wa-wa)

Do this when needed with water base paint that will wash off