'Problem' with Antares 20m?

[Ray Lovinggood]

From the following webpage:

http://www.aerokurier.rotor.com/akNachr/aeNewsE.htm


Antares too quiet
Lange Flugzeugbau faces an unusual hurdle with the
type certification of its electric glider, Antares.
The required noise level measurement according to Chapter
X was not possible. The noise emissions from the 20-meter
self-launching glider are so low that it can't be heard
above the ambient sound of the surrounding environment.
But the measurements are mandatory for the EASA certification.
Even a modified measuring process failed to produce
data that could be converted to values suitable for
compliance with Chapter X. It has simply never happened
before: An aircraft that is actually too quiet.

[Stefan]

You can read the full story here:
http://www.lange-flugzeugbau.com/htm/english/news/noise_measurement.html

BTW, the Antares has received EAS certification on the 14th of July.

Stefan

[Greg Arnold]

Ray Lovinggood wrote:
> From the following webpage:
>
> http://www.aerokurier.rotor.com/akNachr/aeNewsE.htm
>
>
> Antares too quiet
> Lange Flugzeugbau faces an unusual hurdle with the
> type certification of its electric glider, Antares.
> The required noise level measurement according to Chapter
> X was not possible. The noise emissions from the 20-meter
> self-launching glider are so low that it can't be heard
> above the ambient sound of the surrounding environment.
> But the measurements are mandatory for the EASA certification.
> Even a modified measuring process failed to produce
> data that could be converted to values suitable for
> compliance with Chapter X. It has simply never happened
> before: An aircraft that is actually too quiet.

I wonder if it makes enough noise for engine operation to be recorded by
the ENL function of a flight recorder.

[Andor Holtsmark]

The original story: http://lange-flugzeugbau.com/htm/english/news/
noise_measurement.html
(Note our brand new homepage. Much more info in it
now)

At 17:36 04 August 2006, Greg Arnold wrote:
>I wonder if it makes enough noise for engine operation
>to be recorded by
>the ENL function of a flight recorder.

Due to the RPM of the engine, the LE42 propulsion system
produses most of its noise on exactly the same frequence
which flight recorders pick up. There is no problem
recognizing powered flight.

cheers,

Andor