Noise !

[mikezen]

Hi,
Would anyone know about noise mesures on take of for a P337 ?
Does any noise comparison exist with other classical piston twins (B 58, SENECA,...) ?
The Skymaster is known as a noisy aircraft : reality or legend ?

[patrolpilot]

If you are talking about a cabin noise comparison, I've not seen it. With noise-canceling headsets, it's a bit of a moot point! I couldn't help myself.

A document establishes various noise levels produced by different aircraft, AC 36-1H. It lists the 337H, and P337H yet shows them having the same engine, the TSIO-360-G. The AC does record the RPM at which the noise was measured; 2600 RPM for the 337, but not at the MAX RPM of 2800.

The AC was published on 11/15/01, twenty years after the end of the 337s production, so I suspect there is no specific information other than this. Here is a data chart for some other Cessna's and the Seneca.

[wslade2]

dBa looks comparable to some common others. so much for the claim that skymaster is noisier.

[mikezen]

Hi
Thanks for your answers !
I'm sorry I wasn't clear enough, I meant noise measured from the ground when the aircraft is processing patterns or low patterns !
I suppose it isn't an issue in the USA, as the country is so wide, but here in France, because of the complains of people living near airports, the DGAC (equivalent FAA) has normalized noise measures for many type of general aviation aircrafts : https://calipso.dta.aviation-civile....terne/#aeronef
They have created 4 classes, from A (low noise) to D (high noise) (application CALIPSO).
I suppose the skymaster must be in class D, because of its 2 blades propellers, but I can't find any skymaster in CALIPSO, as this aircraft is very rare in France.
Anyway, I wonder if the measures are relevant, as you can find CESSNA 172 in all the 4 classes !

[kbecker]

These levels were measured with the planes at 1000 ft AGL

[patrolpilot]

The FAA Advisory Circular (AC 36-1H) I referenced is provided for such use in the US.

[cjordan]

I think most assume louder due to unique sound from centerline thrust.. not sure they are any louder. Ever hear a beech 18 take off �� only thing civilian better is maybe an Mu-2 or unhushed Lear 20 series!!!����

[patrolpilot]

Liked the Learjet reference, my first jet was the 25B. The key to beating the noise sensors at airports like KSNA is to keep the tailpipes pointed at the center of the airport as the sensors are beyond the airport. The Learjets are one of a few that can climb at that angle.

[mshac]

RVSM and noise restrictions killed the 20 series in North America.

Saw one in great shape for $175k, but no rsvm and no hush kit.

If I lived in South America or Africa where these restrictions are far less, I'd own one in a minute.