Modification to Janet N654BA

This link has some information about a modification done to one of the Beech Janets (N654BA) It raises questions and provides no answers. C'est la vie.
www.lazygranch.com...

Grasping at straws, but found this:

UPD501 Antenna

Or perhaps:

NovaTel 501 GPS Antenna

N654BA was GPS equipped in 2003 by Banyan Air Service in Ft. Lauderdale, FL. I don't think it would be sniffing radar sites since that is not in the plane's mission.

What is baffling is the antenna is side mounted and on one side, so it won't work very well since at times the plane body will shield the antenna.

In Vegas, they also added two antennas at the back of the plane. I'll dig up the images and post them later.

I wish I had copied one of the links I was digging through yesterday.

The government in Australia was attaching round antennae like the 501 to helicopters and airplanes to dynamically map out wireless communications coverage over a large area.

From what I can remember they were looking at how high wireless 2.4Ghz network hotspots could transmit over different types of terrain. They were also looking at 800-900Mhz as well.

It might make sense given the recent ubiquity of wireless internet and folks running around with wireless laptops.

The only reason I would think that an antenna would be on the side of an airplane is so that it could circle an area and listen.

These guys were talking about using cherry-pickers and helicopters but the cherry-pickers couldn't go high enough and the helicopters were too expensive. They wanted to be at a certain altitude and linger there for a bit to measure signals, then move somewhere else.

Of course it could just be a miniature DirecTV antenna like they are putting on trucks and limousines these days. :-)

More links:

Boeing Broadband Satcom Network

BBSN Contract

Military Aircraft Broadband

This last one has tail and fuselage antennas. Still nothing that would be on the side of the airplane though.

finally a topic worth reading, not too much discussion anymore on the janet aircraft.

reply to post by emsed1


You may be onto something here with WIFI. Nellis uses wifi for plane maintenance. The service personnel can order parts via some notebook computer. I can't find the article on their website anymore. If you drive to the base and aim an external wifi antenna at it, the activity shows up with kismet. It is the 2.4G wifi

When I was at the Nut Tree Airport, I noticed a panel antenna on a pole by the gate
www.lazygranch.com...
www.lazygranch.com...
This could be the 5.4G wifi.

Maybe the pilots are filing flight plans via wireless.

The only thing that bugs me is that the one antenna is going on the side of the plane.

Maybe the commuters are watching HBO on those long flights!

If it is a wireless service, generally they create a mesh, i.e. transmit from multiple directions, so you wouldn't need the antenna on both sides. [If you did, you would need some sort of diversity scheme to pick the best site.] If you check out this photo
www.lazygranch.com/images/airshows/nellis2007/tbirds23.jpg
[Referring page
www.lazygranch.com/nellis20007_tbirds.htm ]
You can see a few wireless antennas. However, since I can get the Nellis wifi from Las Vegas Blvd, I expect there are transmitters on the far side of the base transmitting towards the street.