Tow planes and transponders

Worldwide, what exemptions from transponder equipage apply to glider
tow planes (assuming built and certified with an electrical system)?.

How typical is it that tow planes are not equipped with a mode C or
mode S transponder?

Andy

In the US, there are no exemptions that I am aware of for Tow Planes.
14CFR 91.215 applies. It is rather extensive.
91.215 (b) All aircraft in airspace described in (b)(1) through (b)(5) must
have Mode 3A, C or Mode S.
(b)(1) All aircraft in Class A, B or C
(b)(2) All aircraft within 30nm of Appdx D airports .. (Mode C Veil) up to
10,000MSL
(b)(3) starts the exemptions..
(b)(4) above the ceiling of Class B, Class C up to 10,000MSL
(b)(5) All aircraft (except gliders, balloons, no electrical power).. etc
(b)(5)(I) above 10,000MSL

Bottom line, any aircraft , outside of 30nm from a "Class B airport" and
below 10,000MSL (or 2500AGL if higher) would not need a transponder.
A tow plane is not exempt just because it is towing.

If any aircraft flying more than 30nm from a Class B airport and outside of
Class C airspace, and stays below 10K, no transponder required.

"Andy" wrote in message
...
Worldwide, what exemptions from transponder equipage apply to glider
tow planes (assuming built and certified with an electrical system)?.

How typical is it that tow planes are not equipped with a mode C or
mode S transponder?

Andy

May we ask why the question?
If your tow location is more than 30nm from a Class B airport and tow stays
below 10K MSL, then transponder is not required.

We are within the 30nm ModeC Veil and need a transponder. When we know it
has failed, we have been able to call and get approval to tow, remaining
within 4nm and 5K AGL of the satellite airport.
BT

"Andy" wrote in message
...
Worldwide, what exemptions from transponder equipage apply to glider
tow planes (assuming built and certified with an electrical system)?.

How typical is it that tow planes are not equipped with a mode C or
mode S transponder?

Andy