Ask the airport manager if he requires that all transient aricraft have
the airport as named insured before using the airport... If not, then
they are discriminating among users of a public airport, which is a
violation of federal law..
The reality is that if someone gets injured, say by walking into a
prop, it doesn't make any difference if the plane has been sitting
there 90 seconds or 90 days... The airport's risk level is the same...
The other reality is that the airport is the landlord for renters and
the renters will probably have to compromise in the end, but by keeping
their feet to the fire you can keep their demands down to a reasonable
level...

My situtation is a bit different as I own my hangar - which sits on
land leased from the airport... Still, the County tried to force me to
abrogate my insurance with them as additional named insured.. I
politely declined..
Well actually and more accurately, the airport manager handed me a
sealed envelope on a Saturday morning, inside was this contract with
numerous underlined, blank areas that I was to sign and after I signed
they would fill in the blanks... He said he had to have it within 5
business days... I read through it briefly, laughed loudly to get the
attention of the other pilots/owners milling around, wadded up the
contract and tried for a 3 pointer into the waste basket... I missed
and it skidded under the vending machine... I was still chuckling as I
walked out... He told me later that two guys who had signed their
contract and put it on his desk, after seeing my little act of defiance
then grabbed their contract back and tore it up... The airport wound
upwith a full blown revolt and only the FBO's signing the new airport
contract... Be aware that this airport does not have a five year
waiting list for a hangar... AIrports in major urban centers probably
can play hard ball...

denny