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Permalink Reply by Jonathan Porter on August 28, 2014 at 6:32am

We have not found it necessary.   If you fly out of balance the airframe shouts back at you, but otherwise, with a decent headset on, and the right engine up the front, it is any noisier than any other plane I have flown.  (NB We tried on one to use special foam on the firewall, and carpets, but it really made no difference - other than materials for the local insects to chew on - so we removed it after 2 years... )

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Permalink Reply by John Austin on August 28, 2014 at 7:28am

I've been told by other 750 pilots my 750 is much quieter than average. I lined the backside/cabin side of the firewall with aluminum faced ceramic blanket from Spruce and sealed all the edges with 3M Firestop caulk. All the sidewalls, floor between the seats and the heel rest, baggage area roof, and the fuselage skin under the seats were lined with "QIC" foam from Hi Tech Foam. (I don't think they list it on their website, but call them - they have it!). This foam is really remarkable - it's about 1/2" thick and has an attractive "skinned" surface on one side (looks like slightly wrinkled black leather) and a very sticky adhesive on the other. The adhesive side molds and conforms to irregularities, which makes it great putting it down over rivet heads/ends, etc. ... and it does not come loose! The best part is that it is burn-certified safe, the skinned surface looks good enough to leave as a finished surface, and a huge roll seems virtually weightless! Once it is stuck and conformed to an aluminum panel, it changes a rap on the outside from a sharp pop to a dull thud!  The best way I found to install it was to make poster board templates of the area I wanted to apply it to, mark the template outline on the foam with a Sharpie, and then cut it out with heavy straight shears. The foam is plenty durable for the sidewalls, but probably would not hold up well under your feet, so I put down thin floormats over the foam made of the baggage area carpet and secured with Velcro.

In the baggage area, I wanted something that was scuff and stain resistant, so I found some aircraft carpet on Ebay - I'm afraid this is a "no-name" item, so I can't point to another definite source, but it shows up on Ebay occasionally. It looks to me like the carpet used in an airliner aisle between the seats. The carpet is also burn certified and has a simulated carpet texture but actually appears to be some sort of plastic laminate - it is impervious to fluids, stains, etc. It is backed with a thin, dense foam backing and has to be installed either with an adhesive or carpet tape. Spruce sells a burn certified carpet tape that supposedly comes up cleanly if you ever need to remove it and I used that. The downside of this carpet is that since the foam is so dense, it is heavy and that's why I only used it in the baggage area. I also covered the rear baggage panel that extends to the ceiling with it as this panel acts as a giant resonator for sound. Covering it with the carpet totally stopped the resonating noise! Here's a pic that shows the black foam on the sidewall and the back/gray carpet in the baggage area:

And although I even have a pair of Bose ANR headsets, the reason I went to this extent is that a lifetime of rock and roll, shooting, and flying has left me with some hearing loss and a fairly severe case of tinnitus and I'm trying to preserve what hearing I have! 

John

N750A

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Permalink Reply by Wayne Tyson Jr on August 28, 2014 at 5:31pm

John, you could sell those templates for a pretty penny.

Did you put carpet down over the foam?

"Sounds" like the carpet is a much better sound-deadener than the foam . . . ?

Wayne

N750MV

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Permalink Reply by Kevin Lippert on August 29, 2014 at 5:06pm

Thanks John, looks great. I'm going to definitely use some (or most) of your ideas.

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Permalink Reply by Samuel McNair on January 23, 2015 at 7:50pm

I put down the thick Rhino liner truck bed liner on my floors. Durable, light, dampens sound, and with removable plugs in the floor it makes it easy to wash the dirt out if you have been playing in the mud.

 

You can by an aluminized plastic sheet bubble insulation from Lowes. It is fire rated for direct exposure in a house. about 5/16 thick, aluminum on both sides, tough. I covered it with fire retardant cloth glued on with 3M upholstery glue. HD velcro on the back makes it easy to remove and install. Weighs close to nothing. One $40 roll insulaetd my entire garage door, the plane, the dog house and baout 1/2 of it left over.

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Permalink Reply by Bob Jones on January 28, 2015 at 2:26pm

Johnathan, I use dynamat TAC- MAT, it is a thin foam and sound deadiner , available from some auto supply, and aviation approved, it is a cockpit liner and cost effective  

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