Narrative:

Banner tow training had been completed. Made a normal approach for landing. Wind was gusting from south to southeast. Made full stall landing and ran about 30 ft on sod runway. A gust put the plane into the air with nose high attitude. Gust stopped and plane again landed harder than normal, at which time the 5/16 inch nuts that hold the main landing gear on, pulled off the bolts. The wheel departed, the landing gear spring dug into the dirt, and the aircraft flipped over the nose and onto its back. No injuries. We know of other crashes where this make and model main gear has come off with similar circumstances. The plane is a bellanca scout 8GCBC and has 4 5/16 inch bolts with nyloc nuts (an) that hold the gear on. The nuts strip out leaving the thread material on the bolt. Callback conversation with reporter revealed the following information: reporter states his company has been in touch with the manufacturer and they indicate they have never heard of this problem. However, this seems strange to reporter who knows of 3 incidents himself. The nuts were found and FAA has taken them for study. They also requested reporter to fill out a report on the malfunction. Nothing has been heard from FAA. The aircraft, a BL28 bellanca scout, now known as american champion, is a 1975 model. The planes owned by this company are all between 1974 and 1978 models. There is a tremendous amount of stress placed on these 5/16 inch nuts with the momentum of the landing aircraft. Part 43 maintenance regulations allow for repairs to 'go as good or better in replacing a part.' company has asked what the FAA would do if they do a line check and find a 3/8 inch nut and twice as many on the aircraft. This is the solution which company would prefer. So far, FAA has not given a definitive answer. The company is reluctant to just go ahead with such a repair and have their aircraft grounded when an inspection is made. They operate 8 aircraft and do not wish to ruin another one if they can avoid it.

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Original NASA ASRS Text

Title: BANNER TOWING ACFT HAS NUTS RELEASE FROM MAIN GEAR AFTER HARD LNDG. WHEEL SEPARATES, ACFT NOSES OVER ONTO BACK.

Narrative: BANNER TOW TRAINING HAD BEEN COMPLETED. MADE A NORMAL APCH FOR LNDG. WIND WAS GUSTING FROM S TO SE. MADE FULL STALL LNDG AND RAN ABOUT 30 FT ON SOD RWY. A GUST PUT THE PLANE INTO THE AIR WITH NOSE HIGH ATTITUDE. GUST STOPPED AND PLANE AGAIN LANDED HARDER THAN NORMAL, AT WHICH TIME THE 5/16 INCH NUTS THAT HOLD THE MAIN LNDG GEAR ON, PULLED OFF THE BOLTS. THE WHEEL DEPARTED, THE LNDG GEAR SPRING DUG INTO THE DIRT, AND THE ACFT FLIPPED OVER THE NOSE AND ONTO ITS BACK. NO INJURIES. WE KNOW OF OTHER CRASHES WHERE THIS MAKE AND MODEL MAIN GEAR HAS COME OFF WITH SIMILAR CIRCUMSTANCES. THE PLANE IS A BELLANCA SCOUT 8GCBC AND HAS 4 5/16 INCH BOLTS WITH NYLOC NUTS (AN) THAT HOLD THE GEAR ON. THE NUTS STRIP OUT LEAVING THE THREAD MATERIAL ON THE BOLT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES HIS COMPANY HAS BEEN IN TOUCH WITH THE MANUFACTURER AND THEY INDICATE THEY HAVE NEVER HEARD OF THIS PROB. HOWEVER, THIS SEEMS STRANGE TO RPTR WHO KNOWS OF 3 INCIDENTS HIMSELF. THE NUTS WERE FOUND AND FAA HAS TAKEN THEM FOR STUDY. THEY ALSO REQUESTED RPTR TO FILL OUT A RPT ON THE MALFUNCTION. NOTHING HAS BEEN HEARD FROM FAA. THE ACFT, A BL28 BELLANCA SCOUT, NOW KNOWN AS AMERICAN CHAMPION, IS A 1975 MODEL. THE PLANES OWNED BY THIS COMPANY ARE ALL BTWN 1974 AND 1978 MODELS. THERE IS A TREMENDOUS AMOUNT OF STRESS PLACED ON THESE 5/16 INCH NUTS WITH THE MOMENTUM OF THE LNDG ACFT. PART 43 MAINT REGS ALLOW FOR REPAIRS TO 'GO AS GOOD OR BETTER IN REPLACING A PART.' COMPANY HAS ASKED WHAT THE FAA WOULD DO IF THEY DO A LINE CHK AND FIND A 3/8 INCH NUT AND TWICE AS MANY ON THE ACFT. THIS IS THE SOLUTION WHICH COMPANY WOULD PREFER. SO FAR, FAA HAS NOT GIVEN A DEFINITIVE ANSWER. THE COMPANY IS RELUCTANT TO JUST GO AHEAD WITH SUCH A REPAIR AND HAVE THEIR ACFT GNDED WHEN AN INSPECTION IS MADE. THEY OPERATE 8 ACFT AND DO NOT WISH TO RUIN ANOTHER ONE IF THEY CAN AVOID IT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.