Question Why is the Carbon Cub FX-3 so deafening loud in the cockpit?

[Neal]

I remember back in my PPL days flying 152's and 172's not requiring hearing protection or even a headset, you could use the audio through the ceiling mounted speaker, although I did use a headset of some type. Now in the Carbon Cub FX-3 I'm amazed how loud it is in the cockpit. While I wear Bose A20's integrated into my former Air Force helmet, making it even more sound proof, it's not a big deal. But when flying my dog and her hearing protection slid off, I took off my headset to see how loud it was and was shocked, I air aborted to avoid causing my dog to go deaf. My Apple Watch often alerts on the sound levels.

Why is the FX-3 with IO-360 so incredibly loud in the cockpit?

 

[Cactus Charlie]

Why is the FX-3 with IO-360 so incredibly loud in the cockpit?

Because sound proofing adds weight and CC are obsessed with weight saving.

I'm sure it could be made much quieter with a thicker windshield, thicker firewall, thicker fire wall padding, and sound deadening material on the inside of the boot cowl. All that adds weight forward and would require more weight added aft to manage the CG.

If CC offered a heavy quieter FX-3 and a lighter noisier FX-3 which would you have purchased?

The early Husky used to be the noisiest aircraft I had flown but I think the FX-3 is worse. I like having the takeoff performance but power comes way back as soon as obstacles are clear.

 

[Neal]

If CC offered a heavy quieter FX-3 and a lighter noisier FX-3 which would you have purchased?

The numbers would be interesting to see. I am probably one of the heaviest FX-3's built with paint, BRS, cargo pod and my hoarding of stuff inside on the tacnets, etc. The weight difference would not change where I fly into or out of, I never intend to press the limits. No, I wouldn't want to be heavier than I am now at around 1300 dry but there are tradeoffs. If it were 20 lbs to drop 20-30 dB - yeah, I'd probably take it. If I wanted the light plane option I would have chosen the SS, and now we have the UL but as the UL came along a lot was learned in weight savings that could offset that's available now that wasn't years ago. (Oratex, titanium gear, EarthX, etc. etc.)

And yes, as my instructor taught me, getting 2500 RPM (or lower) after takeoff is being kind to the neighbors, the noise is something to consider.

 

[Neal]

So yeah, the FX-3 has a skylight, super thin flimsy side windows, and who knows on the windscreen. The skylight seems to be of thickness, I wonder what doubling the thickness of the side windows would do? Sound dampening on the firewall as well. Would small changes make a difference? Curious, but we'll never know.

 

[Waldom]

All light airplane cockpits are noisy enough to cause hearing damage. No one used headsets or any other hearing protection in them when I started flying sixty years ago and we all have the hearing loss to show for it. [I know, "walked to school through waist deep snow, uphill both ways".]

There are airplanes with noisier cockpits than the FX-3. No matter what kind of passive or noise cancelling headsets you are wearing in a DC-3, you will be not be able to understand any tower transmissions from the time you set takeoff power until reducing to climb power. In-cockpit calls for V speeds and configuration changes during that time are actually given with hand signals.

Even some jet cockpits can be louder than expected at cruise speed, largely due to airflow over the windshield of some designs. The Gulfstream II used the same forward fuselage as the slower turboprop powered Gulfstream I. For a jet, that cockpit was noisy at Mach .80. Gulfstream used vortex generators behind the top of the windshields in an effort to keep airflow attached and lessen the pressure pulses. They improved the design from the G-III onward and those cockpits were much quieter, although they still incorporated vortex generators above the windshield on those designs.

I doubt you ever flew the A-10 while wearing just a baseball cap, Neal . Due to the design of the armored windshield and the necessarily huge canopy, I imagine there was a lot of wind noise in that cockpit as well. It just wasn't as noticeable while wearing a helmet.

 

[Neal]

Valid points and yes, the A-10 with those high pitched turbofans were deafening, we had to wear ear plugs on the ramp before ever getting in the plane and we also wore ear plugs under the helmets which actually improved the ability to hear the radios. I tried that in my plane with the noise cancelling Bose A20's and that did not work well, the ear plugs were immediately removed.

I think I was just comparing my days where the trees and pictures were all black and white in the Cessna 150 to now and was curious the difference. Reminds me of my AA pilot friend that said how noticeable the change was going into the 787 and how the aerodynamics significantly reduced the wind noise and what a pleasure it was to fly.

Good points! Now to keep the ear muffs on my dog, trying rex specs next time instead of those mutt muffs that didn't stay on long.

 

[Waldom]

I'm a civilian pilot but have the greatest admiration for the design and the mission of the A-10. I'm afraid my tactical flying was limited to five years of crop dusting and we were rarely shot at.

The first time I saw a 787, what came to mind was how quiet the cockpit must be because of its exterior design.

 

[Neal]

I'm a civilian pilot but have the greatest admiration for the design and the mission of the A-10. I'm afraid my tactical flying was limited to five years of crop dusting and we were rarely being shot at.

That's amazing flying and you never know, you may have been shot at haha. Just like my admiration for those flying backcountry, the skills needed are commendable. It's not easy and I've enjoyed the challenge and never ending learning. If only I had a cub while flying in the Air Force it would have made me an even better pilot. Wish I had caught on to aircraft ownership back in those days. That would have been fun.

 

[Waldom]

I know I was shat at, but was hit only once.