Microlighters

Can any of the clever okes enlighten me on what is required when changing a prop type on an existing plane.

A bit of background, when I bought the plane at 25 hours it had an incorrect spec prop (PProp) which was installed during the build, ie 70inch 50pitch instead of 72inch 50pitch. This resulted in over-revving of the 582, ie at cruise it was 6400rpm and more. I subsequently opted to replace the wood prop with a composite 3-blade ground adjustable prop (Kiev) with excellent results. In order for me to make the change 'legal' can the AP/Manufacturer just sign off in the plane's logbook or do the okes from Midrand (read CAA) need to be involved with mod reports, proving flights, etc.....

Due to having too many flying toys I want to sell the plane but would first need to get the documentation sorted and legal. If it appears to be a major exercise I would rather buy a new correct spec prop and flog the composite. Any views on rather going this route.

Please advise.

PS: The Kiev prop is approved for both the 582 and 912 motors but I am not sure approved for the actual plane hence my enquiry

Hi,

Interesting question on who must be involved in this process. I am also interested in info. Is it the manufacturer of the aircraft that specifies the prop or is it props specifically approved for Rotax, Lycomings, etc...?

If a "mod approval" has to be filed, what is the process and how pain(full)less is the process?

Jacques

Technically a prop change outside of Proving Flights is seen as a modification. The reason is that your POH was written with a certain setup. Now with a new prop the performance changes for the better or worse and it needs to be documented in the POH for the next unsuspecting pilot going to fly or buy your plane. So at the very least an AP has to document and check the removal and installation of the new prop and send copies of the changes to RAASA or CAA for their records. If you are pedantic pilot you will also revise your POH and send a copy to CAA

As Stefan said.

I damaged a wooden Geo Kelly, and replaced it with a Warp Drive on my 503 Windlass, and nothing more complicated than the AP signing it off and updating RAASA's records.

Dobbs wrote:As Stefan said.

I damaged a wooden Geo Kelly, and replaced it with a Warp Drive on my 503 Windlass, and nothing more complicated than the AP signing it off and updating RAASA's records.

If a prop is certified to fit on your trike why do you have to get an Ap to sign it out ?????? All this unneccesary paperwork has taken the fun out of flying.Its a lot easier for you guys living close to the cities but when your nearest Ap is a 3 hour drive away makes it a lot more difficult.One may as well buy a certified aircraft with the way Trike flying is going.One of the reasons I have sold my trike.

If a prop is certified to fit on your trike why do you have to get an Ap to sign it out ?????? All this unneccesary paperwork has taken the fun out of flying.Its a lot easier for you guys living close to the cities but when your nearest Ap is a 3 hour drive away makes it a lot more difficult.One may as well buy a certified aircraft with the way Trike flying is going.One of the reasons

In every sport there are rules. These rules are there for a number of reasons but mostly so that the sport is safe and enjoyable. Unfortunately in aviation most of these rules were written in blood. Think of your answer from an AP's point of view. Remember that the AP signed the trike out at the annual inspection, you now decide that you want to change the prop. You go flying with your kids or whoever, the prop goes flying on it's own and you land in the bushes upside down. People get hurt or worse somebody dies. Now who will be held accountable for that prop that came loose because you didn't locktite or wire tied the bolts or the carb that fell off because you didn't know that the clamp only needs to be tightened to a certain point. The list goes on and on.

Some guys are competent to do their own work, others think they know. The law is there to draw that line. A little bit of knowledge is far more dangerous than none at all.