FAR 91.215-- may an aircraft with no electrical system and no transponder overfly Wheeler AAF at 9500' MSL? Here are some of the airspaces where FAR 91.215 requires aircraft to have transponders--


  (b) ...
  
  (2) All aircraft. In all airspace within 30 nautical miles of an
  airport listed in appendix D, section 1 of this part from the surface
  upward to 10,000 feet MSL;
  
  (3) Notwithstanding paragraph (b)(2) of this section, any aircraft
  which was not originally certificated with an engine-driven electrical
  system or which has not subsequently been certified with such a system
  installed, balloon or glider may conduct operations in the airspace
  within 30 nautical miles of an airport listed in appendix D, section 1
  of this part provided such operations are conducted -
  
  (i) Outside any Class A, Class B, or Class C airspace area; and
  
  (ii) Below the altitude of the ceiling of a Class B or Class C
  airspace area designated for an airport or 10,000 feet MSL, whichever
  is lower; and


Consider the airspace near Honolulu International Airport (now Daniel K Inouye International Airport), HNL/ PHNL.  (Link to sectional chart.)

May an aircraft with no engine-driven electrical system operate at 9500' MSL directly over Wheeler AAF (HHI/PHHI)?

This airspace is within one of the 30-nm Mode C veils described in FAR 91.215 (2).  

The intent of the question is to ask whether the "Below the altitude of the ceiling of a Class B or Class C airspace area" clause of 91.215(3)(ii) applies only within the actual lateral boundaries of (i.e. within, above, or below) Class B or C airspace, or throughout the 30-nm circle.  Wheeler AAF is within the mode C veil for HNL, but beyond the actual lateral boundaries of any of the Class B airspace.  The ceiling of the Class B airspace at HNL is 9000' MSL.

See also related question FAR 91.215 (b)(3)(ii) -- transponders-- does the &quot;or below 10,000&#39; MSL&quot; clause have any practical significance?
Yes, the following statement indicates that aircraft without electrical systems may penetrate the mode C veil at any altitude (presumably excluding cases where the penetration would immediately bring them into Class B or C airspace, or would immediately place them above underlying Class B or C airspace):


  "The practical effect of paragraph (b)(3) with respect to your
  question is that it allows non-equipped aircraft to enter the
  30-nautical mile circles surrounding Appendix D, Section 1 airports
  between the surface and 10,000' MSL and to operate beneath the floors
  of the associated Class B airspace..."


From this page 2 of this 2006 interpretation from the FAA Office of the Chief Counsel.