How Loud Are Twins?

Sinistar

Sinistar

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Brad
Seeing @Radar Contact and Barron Pilot flying twins made me wonder how loud they are inside compared to single engine planes?

Maybe to be more specific, let's limit to piston, non-radial non-pressurized. And let's throw out models with supersonic props (eg 185 with seaplane prop) and stick to more common models. Let's leave out the Skymaster from the twins too (maybe it beats the 185!)


So is a 310 or a Twin Barron louder inside than a 210, 206, Lance, Bonanza, etc. Are two engines located away from the cabin typically louder inside than just one engine right up front.
 
I find them to be a bit less loud. The engine isn’t two feet in front of you. Some say the opposite. I’ve flown in a whopping five twins so nothing scientific.
 
I actually find them to be *slightly* less loud.. surprisingly so, at least in Baron / Seminole / 400 series Cessna vs Bonanza/Cirrus/Archer/210

Agree with the poster above me.
 
Tantalum said:
I actually find them to be *slightly* less loud.. surprisingly so, at least in Baron / Seminole / 400 series Cessna vs Bonanza/Cirrus/Archer/210

Agree with the poster above me.
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I figured the 4xx Cessna were quieter due to pressurization...are some 4xx not pressurized?
 
Slightly less loud. But what can be bothersome is when the two noise sources are "out of synch" or "out of phase".

But a good pilot won't let this continue for two long as you can make slight adjustments to RPM and the noise appears to "mesh" together and sound more pleasant.
 
Sinistar said:
are some 4xx not pressurized
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the stuff Cape Air was flying wasn't pressurized, 402 I think?

Good point on pressurization

The quietest twin I've flown in, which, in my opinion was quieter than a PA28-140/160 and C172 was the Beech Travel Air
 
Seems then twins can be quieter by some amount. But still a need for headsets (hearing protection)?
 
It has been a few years so my memory may be a bit fuzzy, but from the inside the DA-42 was quieter than the DA-40 & DA-20.
 
+1 to the "slightly less loud" for unpressurized. You will still "know it" if your headset slips off of an ear. :D

I'd say from bonanza to baron, we're talking maybe 1-2 decibels quieter. If you picture it, the prop tips are where the noise comes from, right? So the tips on a single are pretty much at the same spot as the inboard tips on a twin. I think the difference is just noise from the firewall/exhaust which is further out.

There might be a larger gulf at, say, way low power settings (45% range) but I don't usually fly there. Something unscientific is making me believe that a baron may be like 5db quieter in descent than a bonanza. :dunno:
 
Slightly less loud ,my opinion from my Beech Travel Air
 
I received some dual in a T310 and I recall my experience being similar to the others - they are less noisy but still considerably loud. If the props are out of sync, you’ll have a reverberation that can be annoying. Nonetheless, the Citation CJ1 is a much quieter cockpit. :)
 
Jim Carpenter said:
401, 402, 404, 411.
The geared-engine models, 404, 411, and pressurized 421 can be a lot quieter, slower turning props.
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I’ve been flying the 421C for the last year or so and it is the quietest piston aircraft I’ve been in. Pressurized, and geared engines which turn the props at only 1800 rpm in cruise make for a no-headset-required cabin area for the passengers.
 
These twins certainly look pretty loud.
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Jim Carpenter said:
401, 402, 404, 411.
The geared-engine models, 404, 411, and pressurized 421 can be a lot quieter, slower turning props.
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A 404 even with 2 camera holes cut in the belly is no louder than a "trainer class" single. Those geared engines are nice
 
AKBill said:
I hear the C-337 purrs like a kitten...:rolleyes:
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I seem to remember someone on PoA saying that flying a 337 is like putting a bucket on your head and having someone beat the hell out of it with an aluminum baseball bat while you light wads of hundred dollar bills on fire. Heh!
 
kayoh190 said:
I seem to remember someone on PoA saying that flying a 337 is like putting a bucket on your head and having someone beat the hell out of it with an aluminum baseball bat while you light wads of hundred dollar bills on fire. Heh!
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Told by someone who has never ever flown a 337.

But hey, this is PoA, home of the OWT Perpetuation Society.
 
I've flown a push/pull Cessna and it didn't seem noisier than a single although it is a different sound. I've flown several other twins and they seem a bit quieter than singles. Also flew DC3s with windows open (spraying), they were noisy.
 
Doc Holliday said:
Told by someone who has never ever flown a 337.

But hey, this is PoA, home of the OWT Perpetuation Society.
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Actually in the OP I mentioned excluding the Skymaster. My wife has lots of time in the 337 and she said it was kind of loud as compared to a SEL, but different and perhaps a bit louder for back passengers . But nothing standard headset would overcome. Plus I was more curious when the engines are out on the wings. So that's mainly why I excluded it.
 
Sinistar said:
Actually in the OP I mentioned excluding the Skymaster. My wife has lots of time in the 337 and she said it was kind of loud as compared to a SEL, but different and perhaps a bit louder for back passengers . But nothing standard headset would overcome. Plus I was more curious when the engines are out on the wings. So that's mainly why I excluded it.
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What most people fail to realize is noise reduction is dependent on the type of insulation used, and windshield/window thickness.

You can take two identical airframes, one with the standard factory insulation, and the other with updated improved insulation and the reduction is quite remarkable. By adding a thicker windshield and thicker side windows will reduce noise even more.
 
Doc Holliday said:
What most people fail to realize is noise reduction is dependent on the type of insulation used, and windshield/window thickness.

You can take two identical airframes, one with the standard factory insulation, and the other with updated improved insulation and the reduction is quite remarkable. By adding a thicker windshield and thicker side windows will reduce noise even more.
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So for a pressurized plane is the reduced noise from the overall pressurization implementation? Or is the majority from just the thicker glass? I've never been in a P210 but would think it's also quieter than some of its HP single engine siblings.
 
P210’s are quieter than the unpressurized version. Same for P337 versus non pressurized.

But a properly insulated non pressurized single or twin will be noticeably quieter than a stock one.
 
The Beech's aren't that bad. A J-3 with the door open is worse. Any radial engined military trainer over time will cause hearing loss. The worst is turbine helos. there is a requirement in commercial service for a crew member to dismount during hot refueling or passenger loading/unloading to insure all doors are secured. Nothing ruins hearing better than a turbine. I've always used DC's and changed the pads several times each year. Can't stand noise attenuaters. My hearing test show no loss in high freq.
 
ktup-flyer said:
I didn’t know there was a single engine Baron
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The Baron and A36 share an almost identical airframe. The earlier Baron fuselages were manufactured on the same line as the Bonanza.

One of the Turbine Bonanza conversions uses a Baron airframe.
 
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