October 25, 2009

Soundproofing and Installing the Steps - 4.0 Hrs.

A while back, I found something on someone else's website that really impressed me. This guy was installing some soundproofing in his RV. The benefits not only go toward reducing some of the noise inside an airplane, but provide some insulation and vibration reduction, too. I did some research and some reading, and finally ended up ordering some material from Aircraft spruce. There's a 12-page booklet called "Soundproofing an Aircraft" that you can read online, available for free. You can also read some of the archived forum discussions by searching using key words like sound deadening, etc. There are mixed opinions, of course, but there's at least some consensus that much of the noise in an RV comes primarily through two places; the floor and the firewall. It seems obvious to me, if you think about it. An airplane is like a big aluminum drum. And you're sitting inside while the propwash, exhaust, and airstream are beating on the drum. There's lots of vibration going on. I decided that for a very minimal weight penalty, I could install this material on the floor under the seats, baggage area, and forward floor. It's one of those creature comforts that I think will be an improvement. I found it interesting to learn that headsets don't really protect your hearing from damage from the loudness inside the cockpit, according to this booklet. I think this will be valuable to me, personally.

This material comes in various thicknesses. It's a closed-cell vinyl nitride foam with self-adhesive backing. It's FAA approved for fire safety, too! You can go crazy if you wish and put in 2" thick layers and really deaden the sound. I ordered the 1/4" material for minimal weight while still gaining a lot of benefit (I hope!). I can always pull the stuff out later if I don't like it.

Anyway, I decided to install a few pieces in the baggage area first, before installing the steps. The material needs to go in first because it will lie under the step tubings. I used some paper pressed into the bays to make templates, and then cut out the foam and installed it. The foam cuts easily with a pair of scissors, and weighs almost nothing. I'm carefully keeping track of how much weight I'm adding. So far, the 3 panels on each side that you see below weigh a total of 6.8 oz. total. Not bad. I may forego putting carpet in the baggage area, which should more than compensate for the weight of this material.

I have 3 pieces installed in each side, in between the ribs.

I'll be putting side pieces in place before the baggage side walls are installed.

Next, the steps were installed for the final time. I mixed up some proseal to seal each plate against the fuselage against water leaks into the aircraft. The white blocks were bolted, torqued, and sealed in place.

These guys are finally ready to rivet into place! I hope to be able to get that done tomorrow.

<< Previous | Home | Next >>

Contact me: swayze "at" europa.com (replace "at" with the @ sign... no spaces... you know the deal)