Rotax air box - does it reduce noise? Some say yes - our measurements say no.

 Ultralight Aircraft News
Covering the World of Ultralight Aviation


Airfield By Appt Only
(by appointment ONLY)

Click here For Rotax Aircraft  
Engine Information

The L'il Buzzard, L'il Hustler, and L'il Hustler SS two place ultralight trainers and light sport aircraft.

Top 10 reasons to consider a
 L'il Buzzard, L'il Hustler or
L'il Hustler SS!

The World's first Lightsport and Ultralight Aircraft weekly web video webcast!

If you have high speed internet and Windows Media Player installed you can watch our weekly Light Sport and Ultralight aircraft webcast!

Each issue is 25 to 35 minutes in length and is live on the web for 7 days.
Click here for more information!

 Click here for this months specials!


Have you updated your Bing Carb! Failure to do so could result in an engine out! Click here for more information!

Our monthly newsletter
packed full of information about ultralight aviation!

Does the installation of an air box on a Rotax engine reduce noise?

Does a Rotax Air Box Work?

The following can be found at: 

This article is by Kevin Armstrong:

One discovery worth passing on, go out and buy an air - filter silencer, it knocks the horrible roar off when taking off on twin - carb models, and stops fuel dripping out of the pancake. Baffling fact:- despite having to fit a smaller jet-kit the climb rate and consumption is exactly the same, although I would have accepted a little performance penalty. Have cruised next to a Rapier with standard set up, speed is exactly the same.

It is a factory mod so you can fit it without any beurocracy, Roger (Mainair) will flog you a support - bracket.

The real reason I put one one was to 'encase' or shroud the carbs so that the heat from the air cooling vent didn't waste the air all over the place; it works, carbs are lukewarm.

Recent update from Kevin with pic.

503/582 twin carb with air-filter box from Rotax gives:-

  • 2.4 DeciBel sound reduction 

  • No change in performance I can detect despite smaller jetting

  • Warm carbs (they shroud the carbs and gather the heat from the cowling)

  • No fuel leaking out of the standard pancake

  • Mainair have it down as a factory mod, so no paperwork thank God.

  • (Air Création fit them as standard to the Fun Gt)
    Photos enclosed, actually looks good in the flesh

Editor's note : I am nervous about fitting one to my 582, as it would appear to block off the air flow to one of the radiators - anyone who has successfully fitted one please let us know how the temperatures behave.

Ultralight News:
I have measured the difference in sound from the ground at 500 feet with an aircraft using an airbox and one without and have found NO difference in the noise when using an air box to just using an air filter.

To reduce noise - use a higher ratio reduction ratio, and spin a larger multi-blade propeller slower.

Would you be able to hear one kid whispering in a crowd of kids screaming? The air noise passing the aircraft in flight, the exhaust, the prop are all louder than the noise from a carburetor with an airfilter on it!

Rotax Airbox

Rotax Air box.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28  Index for this section.

Make yourself visible to others when your flying...... Strobe lights make you visible! Click here for more information!

Ultralight News
Covering the World of Ultralight Aviation

Click here to contact us via email.

Use this box to search our sites or the web!


Ultralight Aircraft News Web Magazine Covering the World of Ultralight Aviation . You may link to these pages or print them out for your own personal use, but no part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic,  mechanical, manual, or otherwise,  without the written permission of Ultralight News. By copying or paraphrasing the intellectual property on this site, you're automatically signing a binding contract and agreeing to be billed $10,000 payable immediately. Copyright Ultralight News