The Horsham Land Reuse Authority has asked the federal government for a three-month extension on its deadline for submitting a plan to redevelop most of the former Willow Grove Naval Air Station property. The original deadline was December 18, but Authority Executive Director Mike McGee says he believes the extension will be granted. A draft plan calls for mixed residential, retail and office uses and open space preservation. Nonprofit and governmental entities and the Hatboro-Horsham School District will also be considered for free or low-cost land, but keeping the runway open for any kind of aviation is now out of the picture. Any actual redevelopment construction is more than two years away.