What are the pros and cons of covering the fuselage interior?

[DavidGA2]

What are the pros and cons of covering the fuselage interior? I am building a 4-place, and I am at the point of covering the fuselage. Particularly in the cargo area I wonder what the advantage is to cover the inside. Questions:
1. Does covering the inside walls make the cockpit quieter? What about more comfortable temperature wise?
2. I am installing a see-through panel in the ceiling all the way back to the cargo area. I was thinking of leaving that short section in the cargo area ceiling uncovered on the inside.
3. I was thinking the inside covering in the cargo area would help protect the outer covering from cargo damage. I do have bolt tabs welded on in the bottom of the cargo area where I could install lower aluminum protective panels. I would put an offset at the bottom to cover the rudder cables.

Thanks for your insight. I have been pulling my hair out trying to figure out what is right for my build.

[Bcone1381]

I covered my interior because that is what Bob's Patrol had. I now I predict my single layer of medium fabric by itself will be damaged when I go camping...a bit fradgil. We'll see.

I like the appearance of no interior fabric cover. I think double covering (research a double cover video by Stewarts System instructor John Hanson) the area would improve the fabric strength more than 100% for very little effort and time. I think the interior cover that I have can provide a good platform and base for a stronger material.......Kevlar? Carpet that is attached with adhesive or velcro maybe? I'm trying to be open minded and creative.

[AKKen07]

Hi David -
short version: 1) not unless you invest a lot of effort and weight in sealing and insulating the whole cabin, which is hard on a BH. 2) I wouldn’t bother with the ceiling if you don’t want the look. 3) sound logic there- my personal opinion is that the lighter fabric will do the job without aluminum “armor” but that’s up to your priorities.

longer version: nice work getting to covering! I was danged excited at that point. I think having something on the inside will be beneficial whether it’s the covering fabric or some other method - but there are places it is a bigger benefit than other places. I could see leaving it bare where you don’t see the likelihood of cargo or people kicking, poking, gauging, etc. I think the biggest non-superficial benefit is just like you said- protecting your functional outside skin from “oopsies” on the inside. I double covered the entire outside of my plane then did the same in the lower half of the cargo compartment to toughen it up. Aluminum would protect better but would be heavier. Otherwise, depending on how you do it the sound and temperature insulation value will vary from small to negligible - unless you go all in and add real (heavy) insulation which doesn’t sound like the direction you’d go. Me either.
I use my Max takeoff weight and volume fairly often - that is to say that I value all the pounds I saved but don’t think the weight of the interior added up to anything worth regretting. The biggest downside is having to do the installation and painting that adds a little time to the build.
more superficially it looks more finished and that increases the confidence of my passengers, and that boosts my fragile my ego a bit too .

[Bissetg]

I didn’t Oratex my internal cabin because I was worried about the damage I thought I’d do with stuff getting poked into it and damaging it. I went with 3mm coreflute plastic board instead.

The advantage of the coreflute is that the panels can be an easily removed, cleaned or replaced. The reality is I’ve never had to do that, hence I would go with Oratex if I was doing it again.

Hope that helps.

[rodsmith]

I went with the same medium fabric that the exterior is covered with. It is tougher than I believe most people think, as mentioned earlier it is a lot of extra work. I prefer the more finished look vs looking at the inside of the exterior fabric. The problem in the baggage area would be sharp objects that can slide or bounce around in turbulence. I have tie downs in all the corners and will probably use netting to secure large amounts of cargo. Going off script does the tagline Radial Desert Hawk indicate you are building a radial engine Bearhawk?

[Jhankins]

Rod I had the same question, radial or not? We need to know!

[whee]

image.jpgI’m not real keen on fabric in the interior, but it’s just a personal preference. I put 3/8” foam on the inside of the exterior fabric and I’ve been very please. Idk how much thermal or sound insulation it provides but I like how it looks and functions.
image.jpg

[DavidGA2]

Very interesting comments. Looks like covering the inside gives a more finished look and some manner of oopsie protection, but little in sound and temperature protection. That gives me a lot to think about.

FYI - I am finishing a build started by Rob Gaddy and Kevin Deutscher. The 4-Place fuselage was re-engineered per an idea put forward by Budd Davisson in 2000. The fuselage is longer, wider, and taller than a 5-Place and this one is built to receive a M-14PF engine. It has been a great project for me as nothing much is per the plans, and I am learning a lot. I have completed a set of A Quick Build wings and have a much-updated engine in build that should put out 430 takeoff horsepower. The engine rotates backwards so the rudder is kicked the other way as well as the firewall. I realize this will make me test pilot. Kevin has the same airplane ready to fly, but with a Continental IO-470 engine. Mine should climb like a scalded dog!

[rodsmith]

That's great! I wondered what had happened to that project, glad to see it is still going forward.

[Battson]

I used a single layer of lightweight fabric to cover the interior. It has held up very well with no damage from routine use in 10 years and almost 1100 hours. I am certainly happy with it, and I recommend it above the other solutions I have seen.

Pros:
Protects exterior fabric effectively. Surprisingly strong, just be careful with sharp pointy objects.
Probably lighter than many covering alternatives, certainly lighter than using metal or plastic sheeting.
Flexible, tidy, easy to work with. Forms to any shape with the touch of a hot iron. Great introduction to fabric work if you're new to it.
Avoids having to work with more fiddly plastic-board solutions, which can be harder to get right.
Seems to help reduce drafts / air circulation.
Looks professional and "finished" compared to leaving uncovered - the non-pilot public expect an aircraft to have more structure and strength than they actually require. Having some kind of interior covering makes non-pilot passengers feel more comfortable.
Easy to clean.

Cons:
Heavier than leaving the interior bare.
Not as durable as heavier interior coverings.
Could be challenging to repair, if major damage occurred.

Rudder cables don't need covering in the cargo area and passenger seating area. No issues occur from leaving them bare. Covering them makes inspection harder.

Sometimes the front seat pax catch the cables with their foot - but they can also touch the rudder pedals.... so.... passenger briefing.

[Battson]

2. I am installing a see-through panel in the ceiling all the way back to the cargo area. I was thinking of leaving that short section in the cargo area ceiling uncovered on the inside.

You probably know this already, but just to be on the safe side: Be sure to attach that skylight really well, the roof is a lifting surface, and a large skylight coming loose in flight could potentially destroy the control surfaces.

[Bcone1381]

Whee, You've got a ton of stuff there!!! Can you show us your tie down fittings and they are secured to the airframe?

Group! I'm glad others endorse what I was concerned about in post #2. I've not flown yet and have a fabric repair from a dropped screwdriver in my exterior fabric.