AN SMA TAXIES INTO POS ON THE ACTIVE RWY AND HAS HIS WING PASS UNDER THAT OF ANOTHER ACFT ALREADY ON THE RWY AT LAS.

Narrative

#3 BEHIND A LIGHT CESSNA AND TWIN TURBOPROP. TWR CLRED #2 CESSNA TO INTXN FOR POS AND HOLD ON RWY 19R. TWIN ACFT PARTIALLY BLOCKING 'HOLD SHORT' POS OF RWY 19R. TWR CLRS MY ACFT TO TAXI INTO POS AND HOLD RWY 19R. I TAXIED FROM BEHIND THE TWIN; ALONG SIDE OF HIM; AND MY L WINGTIP PASSED BELOW HIS R WING BUT NOT WITHIN 10-15 FT OF HIS PROP. AS I WAS AWAITING TKOF; PLT OF PLANE #1; THE TWIN; ASKED TWR WHY 2 OTHER ACFT WERE CLRED FOR TKOF AND NOT HIM. TWR ANSWERED THEY DID SO DUE TO HIS NOT ANSWERING TWR CALLS. THE PLT THEN ASKED TWR IF THEY KNEW THAT I HAD TAXIED UNDER HIS WING AND TWR REPLIED 'NO.' I FOLLOWED MY DEP CLRNC WITHOUT FURTHER TFC FROM THE TWIN. THE NEW HOLD SHORT LINE AT LAS RWY 19R IS NOT VERY WIDE. THERE IS AN INTXN ABOUT 50-75 FT BEFORE THIS HOLD SHORT AREA (WHERE THE CESSNA WAS CLRED TO ENTER RWY). I SHOULD HAVE QUERIED TWR AS TO WHETHER THEY WANTED ME TO TURN AROUND FOR THIS ENTRANCE BUT ANOTHER TWIN WAS ON MY TAIL. I HAD PLENTY OF ROOM TO TAXI PAST THE TWIN WITHOUT DANGER TO EITHER OF US.