So I'm sitting in a hotel in the middle of cross country time building at ATP. I just got a call from my fiance who is a FA at United and just got back from Osaka. (She's also a PSEL Instrument pilot.)

Apparently one of the FO's challenged her to ask a "smarter question" when she about when a bunkie is needed.

She asked him what a Fan Marker is, and while he had heard the term he didn't know what it was and she couldn't explain it well enough to end the debate.

So now I'm trying to find her proof, can y'all help me find:

a) a good explaination of what one is (I've read a discription which makes it sound like all marker beacons are fan markers)

b) a list of some approaches with one in the approach

Thanks!!

"Fan Marker" is a generic term. OM, MM, and IM are special types of fan markers.

A generic fan marker lights up the white indicator light (the IM light) and has a audio sound which is different from the IM sound.

They were originally used on airways to mark certain points, but I doubt there are few of those left (DME and GPS work better). That's why you have the high sensitivity selector, to detect them from cruise altitudes if needed. They are also used on some approaches to mark a point that has some significance other than the OM, MM, or IM.

I think the ILS approach into MSO has one.

KSEE in San Diego CA. has a FM on the LOC approach. The intro section of the Jepp plates talk a little about it, the AIM doesn't have anything too good on the topic either. To my understanding they are a less precise marker beacon which has a larger signal area. Used for non precision approaches, mainly back course approaches to identify a fix, and I think DME has pretty much taken it's place. Email your FSDO and you should get an exact answer within a few days, they are pretty good about that.

VOR 21 at Parkersburg, WV (PKB)

There are lower mins. for Fan Marker or DME using the Marietta, Ohio Fan Marker.

http://204.108.4.16/d-tpp/0713/00646V21.PDF

Lower mins are also available with the fan marker on the SDF to RWY 10 at Ashland, KY (DWU)

http://204.108.4.16/d-tpp/0713/05099S10.PDF

Thanks for the help!

A fan marker is a radio navigation aid which operates in the 75mhz region. It is called a fan marker because the antenna is designed to emit the signal in only one plane. If one could see the signal emmited, it would look like an old (V shaped) folding hand fan perpendicular to the course flown.