BE35 at cruise began to shake after penetrating light turbulence. Return to land. Inspection showed ...

Attributes
ACN	344220
Time
Date	199608
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sff
State Reference	WA
Altitude	msl bound lower : 1953 msl bound upper : 6500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sff
Operator	general aviation : personal
Make Model Name	Bonanza 35
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 2 flight time total : 600
ASRS Report	344220
Person 2
Affiliation	Other
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During cruise flight the aircraft began to shake. After penetrating light turbulence, I slowed the aircraft and returned to the airport (approximately 10 mi). Looking into the tail section I found that bulkhead 256.9 located in the tail had cracked in 4 places. After a representative of beechcraft dismantled the tail, he concluded that the bulkhead was too light and needed to be replaced with the later doubled bulkhead. This problem exists on the early bonanzas 35, A35, and early B35 with single bulkheads. Callback conversation with reporter revealed the following information: reporter states the factory sent their people to dismantle the aircraft and could find no reason for the failure. There have been 7 of these same failures in 12 months and beech is very interested in checking out the problem. The aircraft is very well maintained and that is why they are so interested. The other aircraft they could account for some of the cracking due to rigging and less maintenance. The factory has been very good at keeping in touch with reporter and keeping him aware of any progress. They are very eager to find out what is causing the problem. The FAA is involved as well. This is a straight 35 model.

Original NASA ASRS Text

Title: BE35 AT CRUISE BEGAN TO SHAKE AFTER PENETRATING LIGHT TURB. RETURN TO LAND. INSPECTION SHOWED TAIL SECTION BULKHEAD CRACKED IN 4 PLACES.

Narrative: DURING CRUISE FLT THE ACFT BEGAN TO SHAKE. AFTER PENETRATING LIGHT TURB, I SLOWED THE ACFT AND RETURNED TO THE ARPT (APPROX 10 MI). LOOKING INTO THE TAIL SECTION I FOUND THAT BULKHEAD 256.9 LOCATED IN THE TAIL HAD CRACKED IN 4 PLACES. AFTER A REPRESENTATIVE OF BEECHCRAFT DISMANTLED THE TAIL, HE CONCLUDED THAT THE BULKHEAD WAS TOO LIGHT AND NEEDED TO BE REPLACED WITH THE LATER DOUBLED BULKHEAD. THIS PROB EXISTS ON THE EARLY BONANZAS 35, A35, AND EARLY B35 WITH SINGLE BULKHEADS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THE FACTORY SENT THEIR PEOPLE TO DISMANTLE THE ACFT AND COULD FIND NO REASON FOR THE FAILURE. THERE HAVE BEEN 7 OF THESE SAME FAILURES IN 12 MONTHS AND BEECH IS VERY INTERESTED IN CHKING OUT THE PROB. THE ACFT IS VERY WELL MAINTAINED AND THAT IS WHY THEY ARE SO INTERESTED. THE OTHER ACFT THEY COULD ACCOUNT FOR SOME OF THE CRACKING DUE TO RIGGING AND LESS MAINT. THE FACTORY HAS BEEN VERY GOOD AT KEEPING IN TOUCH WITH RPTR AND KEEPING HIM AWARE OF ANY PROGRESS. THEY ARE VERY EAGER TO FIND OUT WHAT IS CAUSING THE PROB. THE FAA IS INVOLVED AS WELL. THIS IS A STRAIGHT 35 MODEL.

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.

BE35 at cruise began to shake after penetrating light turbulence. Return to land. Inspection showed tail section bulkhead cracked in 4 places.