Curious if anyone else here may have experienced this before.  When we hit the starter on a B3e, there is a very loud static noise...it lasts for about 5-10 seconds before going away.  To make things more interesting, the static noise does not occur if starting from a start stick or other external power source. 

The static can't be traced to a single audio source, as it occurs regardless of which audio source is selected.  The only way to silence the static is to unplug my helmet/headset. 

We are stumped...anyone else experience this before?  Thanks in advance. 

Replace Starter / Generator as it will fail soon.

Replacing the starter or generator will fix it. High load during initial start sequence really hits generator hard. Ba weak starter will increase generator load. Have seen this in many different aircraft. 

Starter-generator brushes and armature first, if possible.  Remember, generators can start fires inflight!!

Agree with Been There 100%...starter generator.

Watch your voltage on the start, how low is it dropping during a battery starts vs a start stick vs a power cart.  If all 3 are appx same voltage drop then the starter is probably not the problem as it should make the same noise during the start.  When the static goes away note the NG speed and voltage, see which one is a constant for when the static goes away.  Check the main ground to airframe connection in the rear baggage, its behind the sheet metal but right where the EPU socket is, take grounds off, clean and retighten.  Be absolutely sure you know if the static is heard on all headset jack positions vs just the pilots.  Verify its on the ICS and not any radio circuits but having all sources selected off and rotary mic selector to a position that has no radio.  What model audio panel do you have, digital or analog? Are there 2 or 3 audio panel heads installed? Im guessing only 2 since its an AS350.

the Jr avionics tech above.

Allow the Guru to speak.

W-T-F are you cranking up with Avionics powered on for?  Every helicopter I ever worked on had a Radio Master switch that should not be set on until you are stabilized on the start and the GENERATOR is TURNED ON.  You are asking to fry some radios.....

If you don't have a Radio Master switch.....I suggest you find a competent avionics shop and have them install one.  Don't go replace a perfectly operating Starter/Gen because some Retard did your avionics package and didn't install a Radio Master switch.....unless you enjoy spending lots of money for no reason at all.

many aircraft have power to the intercom when the battery is turned on but yeah you're the guru lol

Well the youngsters check in. Seems younger pilots aren't taught to turn off every electrical demand that's not part of the start procedures anymore.

 All my check list include all avionics off. 

Bro, you are no helicopter guru.

Thanks for the suggestions...will give all this a shot with our Mx crew tomorrow. 

The static noise comes through the ICS regardless of which radio(s) are selected for Rx or Tx (Jupiter Avionics JA94 audio controller). 

And to answer the Guru...master avionics switch is off for start...however, the JA94 audio controller is powered when the master pwr button is turned on. 

Thanks for all other thoughts and suggestions.  We'll get to the bottom of it eventually.  I hope. 

I told you but you're the guru! lol

Why would you need to talk thru ICS before the engine is started?

Why would you need to listen to anything thru ICS before the engine is started?

Your installer screwed up.

Pull the C/B or install a switch on the ICS and then turn that on only after the engine is up and gen is on.

You people are daft.

when you fly something bigger than an r22, you may need to talk to the people in the back before start. that you are unaware many large AND small aircraft are set up this way tells the world you are nothing but a fraud and a poser.

Loud ststic in the headset ... Eventually traced it to a fuel pump...  spent thousands and thousands trying to diagnose it and replaced avionics.  mechanic randomly found the fuel pump was causing the noise while troubleshooting something else. 

Ok...our Mx crew figured it out.  Wasn't the brushes....those are new.  Doing some more troubleshooting and digging into Dunston Notes, turns out there are filter capacitors inside the terminal block of the Start-Gen...then confirmed by testing the filter capacitors.

One of ours is bad (circled in image below).  Unfortunately it sounds like those filter caps aren't readily replaceable and must be dealt with at overhaul.  (note:  I'm not an A&P and am doing my best to regurgitate this). 

Mystery solved and maybe this will help someone else out down the road.