Narrative:

Situation occurred aug/fri/05 approximately XA30Z; ZZZ. Flight conditions were VFR with 12000 ft ceiling; visibility clear 10 mi; and winds 290 degrees at 7-8 KTS. Asphalt runways 32 and 13 are 4200 ft by 100 ft without obstructions and/or field NOTAMS. I am a land; single engine airplane; VFR pilot with 148 hours total time with 20 hours of low wing; tri-gear experience; with most recent 3 hours in a piper tomahawk within the past 60 days. I purchased a 2004 zenair; zodiac 601HD experimental aircraft and it was certified as airworthy jul/sat/04 without expiration. My pre-purchase investigation revealed that zenair zodiacs have had a few incidents of canopy failure (flying off during takeoff or in-flight). No exact number of failures were available through the manufacturer of the zodiac kits or other sources. Zenair did report that some of the failures were due to inadvertent entrapment of the shoulder harness in the latch. Others were thought to be due to failure to secure the latch. However; at some point a latch modification was suggested to builders. The builder informed me that this modification was utilized in the construction of aircraft X. The exact nature of this modification is not known to me or my a&P. At the time of purchase; the wings were removed and the craft was transported by trailer to ZZZ without incident or damage. Aircraft was re-assembled; inspected; and test flown by my a&P. My a&P knew of a local zodiac owner who had a canopy failure in-flight in the local area. We inspected my canopy latching system; which was reported as poorly designed but not thought to be unsafe with careful latching. My insurance company required that I undergo 3 hours of dual time and 2 hours of solo time prior to carrying passenger. My first flight was with my CFI on aug/fri/05. Aircraft was new to me and my instructor; and we prepared as follows: on the day of the incident; my CFI and I reviewed the poh to include procedural and operational data. We reviewed the preflight inspection list in detail and carefully preflted the craft together. I reviewed the canopy latching system with my CFI. The preflight checklist calls for checking canopy latches 3 times before takeoff; and this was done by my CFI prior to his 1 1/2 hour solo. On my CFI's return; we preflted aircraft again together prior to our dual flight. We used the touch method to identify each check item. The checklist calls for latching the canopy prior to engine start and at runup. These checks were performed and the canopy was noted to be latched on both sides. We took off on runway 31 at approximately XA30 hours; rotated at 65-75 mph; and were climbing at approximately 80-95 mph when I felt a rush of air on my left leg. Despite trying to slow the craft; the canopy blew completely off; throwing us in a bad left wing down attitude at approximately 300-400 ft AGL. We pwred out and west were able to land the craft on the grass. In doing so; we hit a runway light causing mild damage to the underside of the left wing and belly of craft. The canopy struck the right rear stabilizer causing dents and a small hole on the leading edge with no loss of control. Other than the immediate effort to reduce speed to keep from losing the canopy; the time interval from feeling the rush of air and loss of the canopy was way too short for any other intervention. There was no vibration sensation or sound during runup or at takeoff until the rush of air. The design of the canopy precludes any attempt to grab it in an emergency situation because there are no handles either inside or outside the bubble. Therefore; there is no possible means to attempt to secure the latch at either engine startup; runup; at takeoff; or in-flight. We did not entrap either shoulder harness in the latch and we did check the canopy as per preflight checklist. We were not pressured for time or to clear the runway; as there was no other traffic. There is at least 1 significant contributing factor to the above incident as it relates to the canopy latching system design. The aft latch on both sides fits flush with the canopy cradle. However; the front latches do not. Therefore; there is not way to visually determine if the front latch is as far sideways as it can be. All one can do is apply additional force. There is no reassuring click or pop when the canopy is latched fore of aft. I think the canopy latching system is of poor design; as there is no means to confirm that the latches are; in fact; secured. I think a recall should be considered. Zenair now makes a forward anchored canopy system. I intend to have this installed with the addition of a grab handle if none is included. If not possible or too costly; one would hope that a new latching system with some method of 'lock confirmation' could be employed. Either way; there should be some visual and auditory means to confirm latch lock. Callback conversation with reporter revealed the following information: the reporter stated the modified canopy and latches will now be installed on the airplane and correct a poorly designed side latch problem. The canopy will have a forward latch to prevent lifting of the forward surface and have a positive lock indication.

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Original NASA ASRS Text

Title: A ZENAIR ZODIAC 601 ON TKOF CLB AT 400 FT THE CANOPY DEPARTED THE ACFT. ACFT MODEL HAS RECURRENT HISTORY OF CANOPY LATCH FAILURE.

Narrative: SIT OCCURRED AUG/FRI/05 APPROX XA30Z; ZZZ. FLT CONDITIONS WERE VFR WITH 12000 FT CEILING; VISIBILITY CLR 10 MI; AND WINDS 290 DEGS AT 7-8 KTS. ASPHALT RWYS 32 AND 13 ARE 4200 FT BY 100 FT WITHOUT OBSTRUCTIONS AND/OR FIELD NOTAMS. I AM A LAND; SINGLE ENG AIRPLANE; VFR PLT WITH 148 HRS TOTAL TIME WITH 20 HRS OF LOW WING; TRI-GEAR EXPERIENCE; WITH MOST RECENT 3 HRS IN A PIPER TOMAHAWK WITHIN THE PAST 60 DAYS. I PURCHASED A 2004 ZENAIR; ZODIAC 601HD EXPERIMENTAL ACFT AND IT WAS CERTIFIED AS AIRWORTHY JUL/SAT/04 WITHOUT EXPIRATION. MY PRE-PURCHASE INVESTIGATION REVEALED THAT ZENAIR ZODIACS HAVE HAD A FEW INCIDENTS OF CANOPY FAILURE (FLYING OFF DURING TKOF OR INFLT). NO EXACT NUMBER OF FAILURES WERE AVAILABLE THROUGH THE MANUFACTURER OF THE ZODIAC KITS OR OTHER SOURCES. ZENAIR DID RPT THAT SOME OF THE FAILURES WERE DUE TO INADVERTENT ENTRAPMENT OF THE SHOULDER HARNESS IN THE LATCH. OTHERS WERE THOUGHT TO BE DUE TO FAILURE TO SECURE THE LATCH. HOWEVER; AT SOME POINT A LATCH MODIFICATION WAS SUGGESTED TO BUILDERS. THE BUILDER INFORMED ME THAT THIS MODIFICATION WAS UTILIZED IN THE CONSTRUCTION OF ACFT X. THE EXACT NATURE OF THIS MODIFICATION IS NOT KNOWN TO ME OR MY A&P. AT THE TIME OF PURCHASE; THE WINGS WERE REMOVED AND THE CRAFT WAS TRANSPORTED BY TRAILER TO ZZZ WITHOUT INCIDENT OR DAMAGE. ACFT WAS RE-ASSEMBLED; INSPECTED; AND TEST FLOWN BY MY A&P. MY A&P KNEW OF A LOCAL ZODIAC OWNER WHO HAD A CANOPY FAILURE INFLT IN THE LOCAL AREA. WE INSPECTED MY CANOPY LATCHING SYS; WHICH WAS RPTED AS POORLY DESIGNED BUT NOT THOUGHT TO BE UNSAFE WITH CAREFUL LATCHING. MY INSURANCE COMPANY REQUIRED THAT I UNDERGO 3 HRS OF DUAL TIME AND 2 HRS OF SOLO TIME PRIOR TO CARRYING PAX. MY FIRST FLT WAS WITH MY CFI ON AUG/FRI/05. ACFT WAS NEW TO ME AND MY INSTRUCTOR; AND WE PREPARED AS FOLLOWS: ON THE DAY OF THE INCIDENT; MY CFI AND I REVIEWED THE POH TO INCLUDE PROCEDURAL AND OPERATIONAL DATA. WE REVIEWED THE PREFLT INSPECTION LIST IN DETAIL AND CAREFULLY PREFLTED THE CRAFT TOGETHER. I REVIEWED THE CANOPY LATCHING SYS WITH MY CFI. THE PREFLT CHKLIST CALLS FOR CHKING CANOPY LATCHES 3 TIMES BEFORE TKOF; AND THIS WAS DONE BY MY CFI PRIOR TO HIS 1 1/2 HR SOLO. ON MY CFI'S RETURN; WE PREFLTED ACFT AGAIN TOGETHER PRIOR TO OUR DUAL FLT. WE USED THE TOUCH METHOD TO IDENT EACH CHK ITEM. THE CHKLIST CALLS FOR LATCHING THE CANOPY PRIOR TO ENG START AND AT RUNUP. THESE CHKS WERE PERFORMED AND THE CANOPY WAS NOTED TO BE LATCHED ON BOTH SIDES. WE TOOK OFF ON RWY 31 AT APPROX XA30 HRS; ROTATED AT 65-75 MPH; AND WERE CLBING AT APPROX 80-95 MPH WHEN I FELT A RUSH OF AIR ON MY L LEG. DESPITE TRYING TO SLOW THE CRAFT; THE CANOPY BLEW COMPLETELY OFF; THROWING US IN A BAD L WING DOWN ATTITUDE AT APPROX 300-400 FT AGL. WE PWRED OUT AND W WERE ABLE TO LAND THE CRAFT ON THE GRASS. IN DOING SO; WE HIT A RWY LIGHT CAUSING MILD DAMAGE TO THE UNDERSIDE OF THE L WING AND BELLY OF CRAFT. THE CANOPY STRUCK THE R REAR STABILIZER CAUSING DENTS AND A SMALL HOLE ON THE LEADING EDGE WITH NO LOSS OF CTL. OTHER THAN THE IMMEDIATE EFFORT TO REDUCE SPD TO KEEP FROM LOSING THE CANOPY; THE TIME INTERVAL FROM FEELING THE RUSH OF AIR AND LOSS OF THE CANOPY WAS WAY TOO SHORT FOR ANY OTHER INTERVENTION. THERE WAS NO VIBRATION SENSATION OR SOUND DURING RUNUP OR AT TKOF UNTIL THE RUSH OF AIR. THE DESIGN OF THE CANOPY PRECLUDES ANY ATTEMPT TO GRAB IT IN AN EMER SIT BECAUSE THERE ARE NO HANDLES EITHER INSIDE OR OUTSIDE THE BUBBLE. THEREFORE; THERE IS NO POSSIBLE MEANS TO ATTEMPT TO SECURE THE LATCH AT EITHER ENG STARTUP; RUNUP; AT TKOF; OR INFLT. WE DID NOT ENTRAP EITHER SHOULDER HARNESS IN THE LATCH AND WE DID CHK THE CANOPY AS PER PREFLT CHKLIST. WE WERE NOT PRESSURED FOR TIME OR TO CLR THE RWY; AS THERE WAS NO OTHER TFC. THERE IS AT LEAST 1 SIGNIFICANT CONTRIBUTING FACTOR TO THE ABOVE INCIDENT AS IT RELATES TO THE CANOPY LATCHING SYS DESIGN. THE AFT LATCH ON BOTH SIDES FITS FLUSH WITH THE CANOPY CRADLE. HOWEVER; THE FRONT LATCHES DO NOT. THEREFORE; THERE IS NOT WAY TO VISUALLY DETERMINE IF THE FRONT LATCH IS AS FAR SIDEWAYS AS IT CAN BE. ALL ONE CAN DO IS APPLY ADDITIONAL FORCE. THERE IS NO REASSURING CLICK OR POP WHEN THE CANOPY IS LATCHED FORE OF AFT. I THINK THE CANOPY LATCHING SYS IS OF POOR DESIGN; AS THERE IS NO MEANS TO CONFIRM THAT THE LATCHES ARE; IN FACT; SECURED. I THINK A RECALL SHOULD BE CONSIDERED. ZENAIR NOW MAKES A FORWARD ANCHORED CANOPY SYS. I INTEND TO HAVE THIS INSTALLED WITH THE ADDITION OF A GRAB HANDLE IF NONE IS INCLUDED. IF NOT POSSIBLE OR TOO COSTLY; ONE WOULD HOPE THAT A NEW LATCHING SYS WITH SOME METHOD OF 'LOCK CONFIRMATION' COULD BE EMPLOYED. EITHER WAY; THERE SHOULD BE SOME VISUAL AND AUDITORY MEANS TO CONFIRM LATCH LOCK. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE MODIFIED CANOPY AND LATCHES WILL NOW BE INSTALLED ON THE AIRPLANE AND CORRECT A POORLY DESIGNED SIDE LATCH PROB. THE CANOPY WILL HAVE A FORWARD LATCH TO PREVENT LIFTING OF THE FORWARD SURFACE AND HAVE A POSITIVE LOCK INDICATION.

Data retrieved from NASA's ASRS site as of January 2009 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.