Air Filter

[flyingfool]

I did some searching on this site.

It appears that there at one time was a "kit" that you could convert the airmaze frame to accept a bracket air filter.

Does anybody know where I might be able to buy one of these kits? Or know what parts are needed to make it up? How much would something like this cost? Is it worth the front end cost?

I don't see a reason to pay $75 for an airmaze filter when you can get a bracket at 1/10th the cost. If that is, the upfront cost isn't too high?

Is there some disadvantage to the bracket filter or advantages of using an airmaze?

[Nathan K. Hammond]

An Airmaze's life span is indefinite; I replaced mine after 15 years only because I tried to clean it with bleach and dissolved the filter media. A bracket element must be replaced at EVERY annual inspection.

Figure a Bracket will cost $50 for the unit and $10 for an element; versus $80 for an Airmaze. In 3 years, you'll be paying more for a Bracket.

And they both filter the air equally well.

nkh

[joea]

I would agree with Nathan up to a point. A new AirMaze will filter as good as a Brackett when the AirMaze is new.

Let it get a few years down the road and my guess is that the Brackett starts to way out-filter the other filter. Once the "fuzzy stuff" on the AirMaze is not new am guessing that big chunks can get through.

I have a Bracket on my airplane because I operate in a dirty and dusty area and feel that it does a much better job. Back East where there is grass and so on it might not be as important but its worth it to me.

[Tim Juhl]

Back in the 1980's I converted an airmaze filter frame to accept a BA 4108 filter using such a kit. In a subsequent conversation with the late Bob Brackett I learned that the FAA had pressured them to stop selling the kit.

In order to convert the frame you need a piece of expanded steel grill for the back along with the front filter retainer such as would be used in a current production brackett filter. You'll also need a couple of rivnuts. The expanded steel grill is brazed into the airmaze frame while the front grill attaches by machine screws into the rivnuts. I can email you a copy of my 337 if you decide to do it.

Bear in mind that when finished the legal route is to have your A&P write up a 337 and request your local FSDO for a field approval. I got mine approved by the Detroit FSDO without any difficulty. It did require a visit from an inspector and cost me lunch That said, there are a lot of undocumented brackett filters in use.

Tim