You should be able to identify all the antennae on your airplane.
(I don't care if you call them antennas: I just like Latin
plurals). They show up more clearly on a real airplane then they do at 75 dpi
on a web page, just look for them on your next preflight inspection and ask
your instructor to verify your identification.
You should see one or two metre-long antennae sticking up and
back out of the roof of the cockpit. These are the antennae for your
VHF communication radios, the ones you use to talk to traffic
and to control towers. You'll have at least as many of these as you have
radios. (If you have more, your airplane used to have more radios).
Another spindly antenna should stick out of you airplane above
where your ELT is installed, assuming you fly an airplane with a fixed
ELT. Flight training airplanes aren't required to have ELTs but most do.
If you have your own airplane, it's a good idea to periodically check that
your ELT is actually attached to this antenna by doing an ELT check in conjunction
with someone parked at the other end of the field: sometimes corrosion damages
the connection and ELT transmission range is drastically reduced. Remember
that ELT checks are restricted to the first five minutes of an hour.
A USAF C130 pilot wrote to tell me that his aircraft uses the
VHF antenna depicted above as an ELT antenna. That makes perfect sense, as
an ELT transmits on a VHF frequency, and the comment serves as a reminder
that your aircraft equipment may look different but do the same job.
If you have a VOR installed in your airplane, you should have
two antenna extending back from the top of your tail. Together the two form
a horizontal V, making it easy to remember that they form the VOR antenna.
The ADF sense antenna does not show up well in photographs,
because it's a long skinny wire that goes from the top of the tail to the
roof of the cabin. I have marked the picture below to show where the antenna
The sense antenna works in conjunction with an ADF loop
antenna, a flat square box mounted on the belly of the airplane, shown
If you wonder why it's called the loop antenna, look at the
picture of the DC-3, with its loop antenna circled in red. I spotted this
one hanging from the ceiling at the Air and Space Museum of the Smithsonian
Institute in Washington DC, and spent quite a while hanging over a balcony
trying to get a properly lit shot. You can see that the old style ADF was
clearly a loop. There's still a loop inside that flat belly box; the avionics
engineers have just figured out how to make it more compact.
The OAT probe marked on the Piper in the third picture above
is not an antenna, but a temperature sensor (OAT stands for Outside Air Temperature).
The OAT probe on a Cessna is located inside the wing root opening for the
right side overhead cabin air vent.
You can see a picture of one sort of transponder antenna on
the vents page of this section. A transponder antenna
can also look like a little shark fin sticking down out of the belly, about
4 inches long. If you have two shark fins, the other one is probably a DME
A GPS antenna is usually a little pod, about the size of your
hand, flat on the top of the aircraft. Other (portable) GPS units attach their
antennae to the inside of the windscreen with suction cups.
Jim Weir posts some antenna physics
for pilots that explain why some antennae are vertical and some are horizontal.
He also has some better antenna
pictures than I do.
I've done some editing to this page to stop the pictures and
text from overlapping in some browsers. Please let me know if you have any
problems viewing it.
This page written 11 November 2003 by Robyn Stewart.
Last updated 20 February 2004.
Copyright 2003 Flying Start