Mine is bigger than yours

[FenderManDan]

C'mon don't think about that.... I am talking about the exaust on this c172. It seems very draggy, why would someone change the original design?

[Rudy]

They probably got tired of washing the belly.

[sidestick stirrer]

I think some experimenting was done in Europe to reduce cabin noise and they tried extending the exhaust exit past the cabin.
That left the noise of internal combustion events amplified by the bell-shaped cylinders and the individual power pulses from the propellor blades beating against the windshield.

[Beefitarian]

I suspect it works pretty good. I know full length exhaust on race cars makes a huge difference even without mufflers.

[jamesel]

Looks like an early version of the Golmozig exhaust silencer out of Germany, Amazingly quiet. Saw and (barely) heard one installed on a Robin Towplane at Wasserkuppe years ago. Fitted with a 4 blade prop, and at idle, from 30 metres away, the loudest noise was the sound of the valves & tappets. On take off, starting from 100 m away it sounded like your neighbors electric lawnmower. I gather there is about a 8% loss of thrust, but man, it is quiet.

[MUSKEG]

10 to 1 there's a camera port in the belly. Saw something similar and asked about it and was told it kept the hot exhaust fumes from screwing up photos.

[3-Green]

Saw a 206 with the duel exhaust extension this past summer, it had a glass camera port in the belly. Would be a waste of money and thrust putting on extra exhaust to save a bit of sound when you can buy a noise cancelling head set for under $1000.

[Beefitarian]

Looks cheaper than $4000 to me.

[rigpiggy]

Europe is really aviation averse, the noise fines even on small a/c can be quite high. they want hunters to use suppressors, that says alot about noise mitigation

[skypirate88]

As a few have said it is likely to do with a camera set up. My previous place of employment made a modification very similar to a 206. Keeps the exhaust from distorting the images.

[sidestick stirrer]

I recall that the European noise police tried to make airplane owners switch to geared engines, so the propellor tip speeds would be less( think Beaver/Harvard/185)

[Nark]

Ran into the goggle earth 206 in Alabama a few weeks ago.
Funny exhaust just like this one. It was to deflect the hot gas away from the camera lens.

[FlyHigh13]

It's due to the camera's in the back. If you look, there's also holes on the side for camera's as well. Look at the baggage door.
Keeps exhaust gases from dirtying lenses, and distorting images like others have said.

[GyvAir]

You call that a pipe?? That's not a pipe... that's a pipe!



A little mod installed to bypass heat and soot so that the IR camera can reveal the difference between the signatures of corn plant and pot plants. Or perhaps, alternatively, to make it easier to capture the glow of a mayoral crack pipe out behind the high school?