Get Rid of the Noise

[DonMuncy]

Comparing airplanes and cars is an exercise in futility. Sure we can make a plane as quiet as a car, but when we get through, it will weigh A LOT more, which means we will need A LOT bigger engine, which means A LOT more fuel, which means we need more lift, which means we need larger wings, which means a heavier plane ....

[OR75]

suggest to have Mooney and Bose or Lightspeed or other .... to cooperate and develop an ANC cabin

[N201MKTurbo]

This is what we need:

http://www.wolfeaviation.com/aircraft_quiet_flight.html

[BigTex]

suggest to have Mooney and Bose or Lightspeed or other .... to cooperate and develop an ANC cabin

That or something like from the TV show Get Smart... Dome of silence.

[Piloto]

suggest to have Mooney and Bose or Lightspeed or other .... to cooperate and develop an ANC cabin

 

I saw an ANC system at the Le Bourget Air show and it never convinced me. The problems is that as you move your head you end up with nulls and peaks. At certain head positions you get noise cancellation but at other positions you get intensified noise. This is  due to the wide spectrum that noise have. Still ANC does not address farts when taxing nearby others on the ground.

 

Just imagine the comments from guys on the ramp when a no fart  Mooney comes by:

 

"Wow"

"Is that electric"

"Is that on pedals"

" I want one of those"

 

José 

[Piloto]

Comparing airplanes and cars is an exercise in futility. Sure we can make a plane as quiet as a car, but when we get through, it will weigh A LOT more, which means we will need A LOT bigger engine, which means A LOT more fuel, which means we need more lift, which means we need larger wings, which means a heavier plane ....

 

You are right Don. Currently Mooneys are not fart restricted. You can fart all what you want and nobody will hear it. But with the $10K "No Fart Option" everyone onboard will hear yours. Tough decision.  

 

José 

[Piloto]

Even the Germans during WWII address this noise issue:

 

Watch this:

 

José

[Cody Stallings]

It is obvious that noise is annoying to pilots. The very fact of the big headset market and intercoms just proves that. Some are willing to spend over $10K on ANRs and intercoms for just to talk to the passengers. The very first thing that a pilot in traing purchase is a headset. Have not seen this for driving cars. So yes noise is annoying to all here, that is why you have headset.

 

And yes noise comes from the engine. Just turn it off and see the difference. You do not even has to be inside the plane to notice the difference.

 

What is in your Mooney and others is merely a flame arrester not a muffler or silencer like in a car. There is simply no room in the engine compartment for silencer, neither on cars. That is why in cars the muffler/silencer is below or the back end of the exhaust pipe.

 

If Mooney wants to have an edge over the competition it needs to look into this before the competition does. Otherwise they are going to run in the same scenario as before with the same airplane. Being fastest has proven not to appeal to the majority. After all when have you purchased a car based on maximum speed, is not even on the specs.

 

The first thing that appeal to a prospective buyer is plane looks on the ground. Mooney and others have pretty much the same appeal on this. But Mooney can make an impressive show on the ground when it does not fart like the others. After all who like farts. It is easier to impress a crowd of 100 on the ground than three onboard. Particulary when comparing to your competitor on the ramp.

 

José

when was the last time you drove a car where there were no speed limits?

[Awful_Charlie]

Well, I drove yesterday and there weren't any speed limits, but the most I could get was somewhere around 220kmh, which is only 120knots or so, and that was certainly noisier than the Bravo with noise cancelling headsets. I'm not sure the fuel consumption was significantly better either!

 

Some of the Robins around here have a long exhaust under the fuselage with a silencer at the end, and on the ground the noise is less, unless you happen to be at the angle where the prop noise overwhelms the whole lot, which seems to be just forward and just aft of dead abeam, and that is on the ground at 1000RPM or so. I dread to think what the feds would say about putting that inside the body - can you imagine the hassle every 50hr check to have to do a leak/crack/corrosion verification.

 

Rather than quieter, I'd go for the speed, or better payload - lobbing 20lbs of silencer on the end of another 10lbs of pipe isn't going to help. Similarly, putting more noise insulation might help a bit, but at what cost on payload? It's not as though Mooneys are particularly well endowed in this respect anyway.

 

If you look at the competition, even the Meridians/Jetprops and similar require headsets, and that is something pressurised, so it's going to need to be something very innovative to improve on that - and at what cost? Given the 'high end' SEP market is already competitive (Cirrus, Columbia/Cessna, Malibu etc), 4AMUs on headsets is going to be a lot more achievable.

 

As for the list, sorry, I just disagree on all of it!:

1. Trip is not long enough to justify higher altitude

It's probably not long enough to justify a Mooney either! if you don't need the seats, a Piper Cub would do the job too (and get in and out of shorter fields)

2. They like to have the oxygen tank full than half full

Those are the one that probably fly everywhere with full tanks too - you can't train some people

3. The head winds at altitude are stronger

But so are the tailwinds! And when you get a headwind you can punch through it more easily. The increase from 150KTAS to 200KTAS is more valuable when there's 50kts on the nose

4. Burn more fuel climbing to the FLs

and less fuel per mile when you get there, and you get a part of it back in the descent

5. Build ups in the summer are over 20,000ft high.

But much less frequent at FL250 than FL150

6. I am not going to pay $100 for a refill at the FBO.

It costs me 70CHF (about 80USD) for a cylinder that will do 3 complete fills, and a couple of partial fills. Given that a fill does something like 40 man hours at FL200 it's a lot less than a dollar an hour

7. My cannula is plugged with nostrils stuff.

Ugh. Blow your nose and get rid of that before you put a cannula on, and then go up into the nice clean pollution free air!

[Jerry 5TJ]

I think Jose is on the right track, at least in his suggestion that noise reduction would be a big plus for new Mooney market differentiation.

 

I know the M20C I fly is quite a bit louder in the cabin than the P46T.   

Comparison is 'interesting' at least, tho I am not claiming any definitive conclusion:

1. Prop in P46T is about 7 feet in front of me, vs about 3 feet in the "C" and has 4 vs 2 blades.   Less "pulse" noise apparent in the P46T in the front seats.
2. Prop diameters are about the same, but the P46T spins its prop at 2200 RPM versus 2400-2700 for the Mooney, so the Mooney's tip speed is higher.  There's something to be said for a geared engine.
3. TAS for the "C" is about 60% of the P46T so the latter has a lot more 'wind noise.'
4. The 550HP engine is not louder just by virtue of its greater power.
5. The Mooney has a muffler but the PT6 does not, unless you count the power turbine as a muffler of sorts.
6. At 160 KIAS with the engine at running at idle and the prop feathered (yes, it will do that) the sound in the P46T is mostly from the air flowing past the cabin.  While doing so it is nearly as loud in the cabin as when the engine is pulling the plane through the air in level flight at 160 KIAS (250 KTAS).   From that I assume even if the engine is silent there's considerable noise due to speedy air flowing around the airframe.
7. Pressurization clearly makes the plane "tighter" and quieter.   And heavier, etc.
8. Airframe vibration from the engine is easily noticeable and audible in the "C" but much less discernible in the P46T. 
9. The noise cancelling Bose headsets are MORE effective in the "C" as the rhythmic engine beat is ideal for active electronic cancellation.   The noise cancelling effect is still strongly felt in the P46T using the same model headset.
10. A three-hour leg in the P46T with a cabin altitude of 8,000' is considerably less wearing on me than the same length flight in the "C" at 8,000' MSL.   Noise is a big part of that difference, I believe. 

 

PS: There is a speed limit aloft - 250KIAS below 10,000' and subsonic over the CONUS.   Keep it down, you guys.

 

[carusoam]

The O does a bit better than my C did.

There was no insulation in My C.

And the prop is way out front on my O.

Either one is more friendly than a jet on take off...

Best regards,

-a-

[Hank]

Jerry--

 

We don't need to worry about the speed limit in our Mooneys. Mine redlines at 200 mphi; even the TN only reaches 242 KIAS, but only when well above 10,000. So no speed limit that matters--our planes won't reach it.

 

I don't find my C to be intolerably loud, but then again, it's nicer with my Halos than it was with my old student headset. I'm not fond of the ANR hiss, and I don't want to have to carry a box of AA batteries around.

[Bob_Belville]

I don't find my C to be intolerably loud, but then again, it's nicer with my Halos than it was with my old student headset. I'm not fond of the ANR hiss, and I don't want to have to carry a box of AA batteries around.

ANR hiss? My DC H10-13X ($580) uses a 9V which lasts several months.

[DonMuncy]

I have my Headsets, Inc. ANRs hardwired in. Unless the plane's battery fails, the ANRs get power.

[Piloto]

BTW all this noise issue was started by my wife nickname for my M20J "El tira pedos" because of the way it sounds.

 

I found that many non-aviation enthusiast are not comfortable in a Mooney after two hours due to unfamiliar noisy environment. That is why Boeing and others has put so much effort in passenger comfort. After all company revenues comes from the paying passengers not from the crew.

 

Like my wife says "if you cannot hear your own pedos, it is too noisy" Lets use a new standard for noise: "The pedo standard".

 

José 

[Hank]

Hmmm . . . I didn't even know I had a pedos . . . 

[N201MKTurbo]

The fart ripper?

[Danb]

maybe she could afford a new Boeing

[Piloto]

The fart ripper?

 

You got it.

 

The new quiet Mooney brochure slogan "Only in the new quiet M20-Q you will be noticed" "Free first bottle of Gas-X included"

 

I'll bet you that will attract buyers. I can't wait for Aviation Consumers review "It is true, is quiet as a pedo!!!"

 

On the new M20-Q you can only go ROP (Restrain Of Pedos) or you will be noticed. Never go out LOP (Let Out Pedos) or everyone onboard will be looking at you. On my M20J I just go LOP, nobody will notice.

 

Sorry guys I think I am having too much Fish Oil.

 

José