NTSB · Safety Recommendation
Safety Recommendation A-76-116
Recommendation
REVIEW FUSELAGE NOSE ALTERATION APPROVALS ON ALL PA 23 AIRCRAFT AND DETERMINE THAT THE MODIFICATIONS ARE BASED ON APPROVED TECHNICAL DATA. (URGENT)
Safety Issue and Context
ON MARCH 28, 1976, NEAR PULLMAN, WASHINGTON, A PIPER PA23-250 C (N6199Y) STRUCK THE GROUND IN A HIGH SPEED SPIRAL. DURING ITS INVESTIGATION OF THE CRASH, THE NATIONAL TRANSPORTATION SAFETY BOARD DISCOVERED THAT A MAJOR STRUCTURAL ALTERATION HAD BEEN APPROVED AND ACCOMPLISHED WITHOUT PROPER ENGINEERING EVALUATION. THE MAJOR ALTERATION WAS AN EXTENSION OF THE FUSELAGE NOSE BY INSTALLING P/N 32958-00--SECTION ASSEMBLY - FUSELAGE NOSE. APPROVAL FOR THE INSTALLATION WAS GIVEN BY THE GENERAL AVIATION DISTRICT OFFICE (GADO)ON A "MAJOR REPAIR AND ALTERATION" FAA FORM 337, DATED MARCH 14, 1975.
THE BASIS FOR APPROVAL WAS THE PIPER SERVICE MANUAL.CHANGES IN WEIGHT WERE LISTED AND A STATEMENT THAT THE WEIGHT AND BALANCE DATA HAD BEEN REVISED WAS INCLUDED.
Response History
November 9, 1976 · Recipient Response · FAA
WE HAVE CONDUCTED A REVIEW OF THE REPORTS OF ACCIDENTS INVOLVING PIPER PA-23 AIRPLANES AND HAVE NOT FOUND ANY WHICH ARE ATTRIBUTABLE TO THE LONG NOSE INSTALLATION. THE PIPER COMPANY REPORTED THAT THEY HAVE SOLD 140 LONG NOSE AND RADOME ASSEMBLIES. MOST OF THESE ARE BELIEVED TO HAVE BEEN USED TO REPLACE DAMAGED ASSEMBLIES ON PRODUCTION LONG NOSE AIRPLANES. WE ISSUED AIRWORTHINESS DIRECTIVE (AD) 72-21-07 WHICH WAS ISSUED OCTOBER 19, 1972, TO COVER PRODUCTION AIRPLANES. WE REVISED THE AD ON APRIL 29 TO COVER THOSE MODEL PA-23-250 AIRPLANES WHICH HAD BEEN MODIFIED. IN VIEW OF THE ABOVE, WE DO NOT CONSIDER A COSTLY, TIME-CONSUMING SEARCH TO LOCATE MODIFIED AIRPLANES TO BE JUSTIFIED.