Strange whining noise in cockpit

WillyCanuck

Hi there,
I'm scratching my head at this one. In the Turbine Duke after an hour I heard a strange high-pitched whining noise that kept fading in and out - It though my hearing was going lol.

The only thing I could think was it was either something with the engine or possibly the carbon monoxide detector (but that was flashing green).

It disappears in external view so it's definitely something in the cockpit.
Scoured the manual but couldn't find any reference to this noise.

brennan

Assuming you're airborne it's likely an overspeed warning - if you're near the barberpole then try rolling the throttle off and seeing if it stops. (ask me how I know)

zkiwi

Are you sure it is not the Copilot? :-)

Pondimus

You can always pull the stall warning horn circuit breaker and overspeed in peace. :) Not that I would ever do that. :P

WillyCanuck

naw no way it's an overspeed warning (I don't think) - but i'll bear that in mind if it happens again.

Allard

I noticed a very irritating high pith whine during descend. My assumption is that it was pressure related but the pressure warning light was off, and the pressure difference was within tolerance.
There were no warning lights and I had no failures.

When I levelled of the whine went away, but once I continued the descend the whine returned.
It only stopped sometime after landing.

Buzz

It's overspeed.

Allard

@Buzz said in Strange whining noise in cockpit:

It's overspeed.

Thanks for your reply.
According to the manual, the overspeed warning is a repeating beeping tone (page 113). That doesn't sound like the continuous whining noise I heard.
Next time I will try force an overspeed and find out whether the manual is wrong and the overspeed sound is not a repeating beep but a high pitch whine.

toby23

The overspeed warning is a high pitched tone. Check your airspeed indicator and just stay below 200 and you should be fine.

Allard

@Buzz said in Strange whining noise in cockpit:

It's overspeed.

@toby23 said in Strange whining noise in cockpit:

The overspeed warning is a high pitched tone. Check your airspeed indicator and just stay below 200 and you should be fine.

You are both correct. The continues whine is indeed the overspeed warning.
Because the manual says that the overspeed warning is "a repeating tone" I figured that it couldn't be that since what I heard wasn't repeating, it was continues.

Thanks for the help everyone.

Outermarker

@Allard You can mute it by pulling the circuit breaker for the stall horn on the copilot side.