Mechanical gyroscopes -- still used in airplanes?

[Abokoj]

I was a bit unsure where to post this, but this one seemed fitting enough.
I was wondering about the state of gyros in airplanes, like which type is being used today.
Are they all optik/fiber-based or are there mechanical gyroscopes at work. (By mechanical i mean the standard spinning wheel, not sure if it's the right definition. If there aren't when were they last used). I also know of the MEMS gyros but they don't seem quite in the airplane industry yet.
So yeah, I'd appreciate some clarification some example for a gyro would be great. Thanks

 

[Baluncore]

I believe that most mechanical gyros have been replaced by FOGs over the last 20 years.

Triaxial FOGs are available as a gyrocompass on ships to determine true north from sensing the Earth's rotation.

 

[SCP]

Older aircraft with "conventional" flight instruments (referred to in aviation, somewhat pejoratively, as "steam gauges") use mechanical gyros. This is still fairly common in single-engine and light twin-engine aircraft -- although it is becoming less so. Low-end Electronic Flight Information Systems (EFIS -- often referred to as "glass-cockpit") use an architecture called an "Attitude Heading Reference Systems" (AHRS - pronounced AE-hars), which uses MEMS gyros. High-end EFIS equipment uses ring-laser gyros. I haven't heard of FOGs being used in aircraft, but it's possible they are.

If you ever have a chance to fly up front in an aircraft that has steam gauges, when electric power is applied before engine start, you can hear a whining noise. That's the turn coordinator or turn & slip gyro spooling up. You won't hear the attitude indicator or directional gyro spool up because they are usually vacuum driven and require the engine to be running.