ONE GEAR UP LNDG.

Narrative

AFTER TOTAL REBUILD OF A P-51D MUSTANG; I TEST FLEW IT IN THE EXPERIMENTAL CATEGORY TO SHOW COMPLIANCE FOR CERTIFICATION IN THE LIMITED CATEGORY. UPON LOWERING THE GEAR FOR LNDG; I DID NOT GET A GREEN LIGHT ON THE L-HAND SIDE. AFTER EXHAUSTING ALL EMER PROCS; A LNDG WAS MADE WITH VERY LITTLE DAMAGE. AFTER DISASSEMBLY OF L-HAND GEAR ACTUATOR; IT WAS FOUND THAT SOME CHROME HAD FLAKED OFF OF THE PISTON AND GALLED THE SURFACE OF THE CYLINDER WALL AND PUSHED UP A RIDGE OF STEEL THAT THE HYD PRESSURE COULD NOT OVERCOME. THE OLDER P-51'S HAD AN ALUMINUM PISTON THAT SEEMS TO WORK BETTER. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR IS A CROPDUSTER BY TRADE AND FLIES THE P-51 AND A TBM IN EXHIBITIONS. THE ACFT IS BACK IN THE AIR AFTER 'VERY LITTLE' DAMAGE (L FLAP; L INBOARD GEAR DOORS; SCRAPES ON THE WINGTIP AND SCOOP; AND THE TIPS OF THE PROP BLADES). THE PROP BLADES HAVE BEEN TRIMMED AND ARE STILL IN USE. A FARGO FSDO REPRESENTATIVE CAME TO SEE THE ACFT AND RATED THIS AS AN INCIDENT. HE SEEMED TO BE MORE CURIOUS THAN ANYTHING. THERE WAS SOME QUESTION ABOUT A 'LETTER OF AUTHORIZATION' BEING REQUIRED TO FLY THE ACFT.