CLASS D AIRSPACE AND OR RESTR AREA ENTRY WITHOUT CLRNC.

Narrative

I WAS FLYING R SEAT IN THE WWII BOMBER THAT I HELP CREW (OPERATING LIMITATIONS REQUIRE 2 PLTS) ON A PAX SIGHTSEEING FLT WHILE SUPPORTING A LCL WWII MEMORIAL MUSEUM. SEVERAL OF THE PAX WERE VOLUNTEERS FROM THE MIL VEHICLE MUSEUM LOCATED NEARBY. WE DEPARTED HEF TO THE SW AND ON THE RETURN TO HEF THE PIC WANTED TO CIRCLE THE FARM WHERE THE MIL VEHICLE RESTORATIONS ARE CONDUCTED. AS COPLT; MY JOB AMONG OTHERS WAS NAV AND COM. I WAS USING A CURRENT SECTIONAL CHART TEAMED WITH MY RECENT EXPERIENCE FROM A PREVIOUS FLT IN THE AREA TO HELP WITH THE DR; THIS WAS VERIFIED BY MY HANDHELD MOVING MAP GPS. AS LUCK WOULD HAVE IT THE RESTORATION FACILITY THAT THE PLT WANTED TO CIRCLE WAS IMMEDIATELY ADJACENT TO A RESTR AREA TO THE S AND THE HEF CLASS D AIRSPACE TO THE N. THE CTLRS AT HEF WERE BUSY AND WHEN I CALLED THEM WE WERE TOLD TO REMAIN CLR OF THE CLASS D AIRSPACE. THE AIRSPACE BTWN THESE 2 BOUNDARIES IS APPROX 1.5 MI AND IN THE ENSUING CIRCLES WE DID PENETRATE THE HEF CLASS D AIRSPACE BY .5 MI (VERIFIED BY THE ONBOARD VFR GPS). THE SINGLE BIGGEST CONTRIBUTING FACTOR WAS THE PLT'S INDIFFERENCE TO A 'SLIGHT' AIRSPACE INTRUSION BY THE PIC. THE ACFT IS ADEQUATELY EQUIPPED WITH NAV EQUIP. IN THIS CASE THE ACFT INSTALLED GPS SHOWED HEF AT 4.5 MI. THIS WAS POINTED OUT TO THE PIC. MY VERBAL WARNINGS TO 'TIGHTEN UP THE TURNS' PROMPTED BY WHAT I SAW ON MY HANDHELD MOVING MAP GPS WERE UNHEEDED. WHEN TFC AT HEF DID PERMIT US TO ENTER CLASS D AIRSPACE FOR LNDG AT HEF; THE CTLR MADE NO MENTION OF THE TRANSGRESSION. SUPPLEMENTAL INFO FROM ACN 481721: I HAD SOME DISTANT PAST FAMILIARITY WITH THE AREA; BUT THE ACFT OWNER (COPLT) ASSURED ME THAT HE WAS FAMILIAR WITH THE AREA FROM THE PREVIOUS DAY'S FLTS AND THAT AFTER TKOF ON RWY 34R; A TURN TO DOWNWIND; AND THAT AFTER PASSING ABEAM OF THE END OF THE RWY A HDG OF 210 DEGS WOULD TAKE US OUT OF THE HEF CLASS D AIRSPACE AND KEEP US N OF RESTR AREA R6608A. THE COPLT WAS NAVING AND HAD A CURRENT SECTIONAL CHART IN FRONT OF HIM. LACK OF DISTINGUISHING LANDMARKS; LESS THAN ADEQUATE DR NAV SKILLS; AND A DIRECTIONAL GYRO THAT WAS PROBABLY A FEW DEGS OFF; WERE ALL POSSIBLE CONTRIBUTING FACTORS LEADING TO OUR INADVERTENT ENTRANCE INTO R6608B. I RECOGNIZED THE ONE AND ONLY LANDMARK THAT I WAS FAMILIAR WITH; A SMALL WATER TOWER NEAR WHAT LOOKS LIKE A RIFLE RANGE. I KNEW THAT THAT WATER TOWER WAS ON THE EDGE OR JUST INSIDE OF THE RESTR AREA AND MADE AN IMMEDIATE R TURN TO THE NW TO CLR OR REMAIN CLR OF THE AREA; AT THE SAME TIME I GRABBED MY HANDHELD MOVING MAP GPS TO HELP VERIFY MY POS. IT TOOK A FEW SECONDS FOR THE GPS TO COME ON LINE; AND WHEN IT DID; IT SHOWED OUR POS AS CLR OF THE RESTR AREA. I'M NOT SURE IF INDEED WE PENETRATED THE RESTR AIRSPACE OR NOT; BUT IT WAS DEFINITELY CLOSE AND NOT A GOOD FEELING.