Is this allowable under EASA rules? The need for an STC attracts attention.
Balance, if badly fitted?
Some time back I met a retired engineer who’s job when he was working, was looking after the props on Hovercraft. They were fitted with rubber covered leading edges. He said using similar rubber we could have this fitted to our prop and stop stone strikes.This we did, but over a period of 18 months had to have the rubber reapplied twice. The propblem was the adhesive. We just could not get the rubber to bond. In the end we gave up and are as careful as possible to avoid stony ground.
A few years ago I used to help (I say “help”, probably more like “get in the way of”) a guy restore a beautiful old Piper Comanche, which had been sitting in a field rotting for years. He fixed it up enough to ferry to his airfield where he then worked on it over a period of a few months. If I remember correctly it had these boots along the leading edges, and he would curse them on a regular basis for messing up otherwise decent props. They were bubbled, blistered and peeling off at the edges. Like I said, the aircraft had been sitting outside in the elements for a period of time that probably didn’t contribute well to the overall state of things.
I personally wouldn’t bother after seeing that, but I am not an aircraft owner and probably never will be so don’t know of the ins and outs of propeller care. Don’t you usually stick to relatively well prepared and maintained airports most of the time?
Balance, if badly fitted?
When you look at how little weight is added during prop balancing, I reckon balance would certainly be a problem if the tape came off one blade, but probably not enough to cause a hazard.
Is this allowable under EASA rules? The need for an STC attracts attention
It will depend on what your CAMO is happy to see (or not)… they are the final arbiter in practice.
Because of this “grey area” in a lot of the aircraft mod scene, the unwillingness of mechanics to stick their neck out, and the illiteracy of many (unable to read the pretty simple FAA guidelines for Minor v. Major Alterations) there is a big drive in the USA for manufacturers to get STCs for stuff which is unquestionably Minor. These “marketing” STCs are now widespread. Same with Concorde batteries…
I don’t think there is an EASA STC for any of this however. Nobody does those unless they can sell them on and make some money, and most smaller US manufacturers are not interested in the European market and its impenetrable regulatory intricacies.
Would you not loose speed by adding things?
Would you not loose speed by adding things?
I don’t think there is supposed to be any speed loss, but that is a part of why I asked.
If there was a performance change then the aircraft POH would need amending and that is an instant Major Alteration which would need an STC if you wanted to sell it openly.
Don’t you usually stick to relatively well prepared and maintained airports most of the time?
Yes, that’s what most people with “nice” planes do, even if they don’t admit it openly, because avoiding grass gets you labelled as a sissy 
If we do a fly-in to a grass runway, about 1/3 will immediately drop out.
My instructor in SA considered them mandatory for operating on gravels strips.
