Rotating beacon noise

[Eyon]

I've just got involved in a new group and I really like their aircraft. However, one of them, my personal favourite, foxtrot charlie, has recently been getting electrical noise through my headset from the lights.

Obviously strobes can be switched off in good conditions, landing lights only when landing and taking off, but the beacon should be kept on when the engine is running, right?

I had to turn it off in flight the other day, no big deal if you ask me, it was CAVOK so I'm not sure a little red light would make me more visible. It just got so irritating to hear this beeeep beeeep beeeep noise.

I've not had this before, what could be causing it? Using a DC H10-13.4 headset.

[mad_jock]

There will be some earthing straps come off somewhere.

Its a right pain tracking it down.

[Eyon]

Ah good, so it's the plane at fault and not something I'm doing.

Good to hear!

[tecman]

It is indeed often to do with missing earths, or poorly thought out installations. Individual items like the strobe should have their own ground returns and these should not be shared with the avionics, or be forced to find opportunistic grounds via the fuselage. Unfortunately, many light aircraft have had 'incremental' installations over the years, and good practice is not always observed. As EH has found, newer gear is sometimes more sensitive than older models. In the case of a comm set, and assuming that there is no actual obvious fault with the interfering device, you might cure or reduce the noise with an in-line power filter. Strictly though, it'd be better to fix the installation issue. If you're flying someone else's aircraft and you have noise in your passive headset, about all you can do is encourage them to get it sorted out.

[The_Pink_Panther]

I've had the same noise on and off in various aircraft, 'tis annoying, but whatever you do don't turn it off in flight as you suggested. That little flashing light is your anti-collision light and must be operational at all times:

"A UK-registered aircraft fitted with anti-collision lights must display this light in flight both day and night..."

[FlyingKiwi_73]

I flew two PA38's which had noticeable 'beacon noise' through the radio, it was pretty noticeable on the ground and but at higher RPM's blended into the noise, at cruise power and in clear airspace on those longer xcountry flights it was like a contstant friend... a comforting tick :-)

It never bothered me enough to ask maintenance to look at it... but i do believe you need that beacon on from before start up till last thing on shutdown, i usually include it in my OFF checks.

FK

[twelveoclockhigh]

Replacing the old fashioned rotating beacon with a modern red strobe might work.

[phiggsbroadband]

Hi Eyon, although the light flashes, it is a bit funny that the rotating motor noise is intermittent and not continuous. You would think that the motor would run continuously, maybe there is some commutator wear that is causing the beeeep beeeeps.

The electrically driven gyros, have a speed controller that sends bursts of current to the gyro. These can cause a significant arcing sound on the radios.

[Monocock]

I've had the same noise on and off in various aircraft, 'tis annoying, but whatever you do don't turn it off in flight as you suggested. That little flashing light is your anti-collision light and must be operational at all times

Funny isn't it, how Permit aircraft don't need to have these silly little red lights (that don't do anything at all for collision avoidance in daytime flying) and as a group of aircraft, they're hardly banging into each other and raining debris down over our green and pleasant land.

[joec]

Non-permit aircraft don't need them either. They only have to use them if they are fitted.

[Monocock]

Didn't know that. Thanks Joe.

So, can one choose to 'unfit' one if one has one fitted on one's tail? :}

(Ie take the fuse out if it's being a pain in the @rse).

[The_Pink_Panther]

Monocock "(Ie take the fuse out if it's being a pain in the @rse)."

No, as previously stated:

"A UK-registered aircraft fitted with anti-collision lights must display this light in flight both day and night..."

also joec "They only have to use them if they are fitted."

If they're fitted you have to use them.

[Blind Squirrel]

...it's legal to leave it off until the very end of the take-off roll, and turn it on right at the moment of rotation.

Stick it to the Man!

[Blues&twos]

So, I wonder what would be the outcome if the light was turned off in flight " for safety reasons"? I know in this particular case the fault should be rectified before flight as it is known about....but if the light started to interfere with the comms or was a major distraction to the pilot common sense would dictate that it was turned off.Legally, in the event of an incident, though....??

[mad_jock]

Well commercially we can have them broken and still fly.

And as you don't have any time limits on GA aircraft put it in the techlog. Collar the CB and go flying.

The next time it goes for a check with a licensed engineer it will have to be working again unless you have one who is happy to ignore it.