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#1
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Folks:
You will not yet find this on any accident/incident reports. There were no fatalities. A pilot called me to relay this story. The SZD-50-3 Puchacsz was bought used from Europe and imported to the US with ~1900 hours. The glider was given a US airworthiness inspection, and licensed by an FAA inspector last week Thursday or so. It went into legal service before the weekend. On Saturday, following only a few flights, the pilot felt some restriction in rudder movement, and asked the front seat passenger to adjust the length of rudder stirrups for more freedom of movement. The passenger complied, and free movement was "restored." The flight continued in nice lift, and some mild maneuvers for perhaps twenty five more minutes prior to landing. As the glider came to a halt, the ground personnel roared up to the cockpit and informed the pilot that there was no rudder on the machine. All parties were amazed. A search by air for the missing rudder were fruitless. I have not seen the Puchacsz. I do not have pictures or links to any photos. I cannot comment on the mode of departure. I do not know if the cables or swedges and thimbles are on the machine, nor if the vertical hinges are in place on the rear face of the vertical fin. I do know there was a mandatory service item to replace the rudder stop elastic nut on the bottom bolt with a castelated nut and safety key. I cannot say if this was done, found, gone or otherwise on the machine in question. I do know that you should look at the attachments of controls and moving parts fully and carefully on each pre-flight inspection. Things change and move over time. The pilot in this case asked me to put the information out to the soaring community, PRIOR to any formal incident investigation, to prevent any possible similar occurrence. Cindy Brickner Southern California www.caracole-soaring.com |
#2
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On Sep 6, 6:50*pm, CindyB wrote:
Folks: You will not yet find this on any accident/incident reports. There were no fatalities. *A pilot called me to relay this story. The SZD-50-3 Puchacsz was bought used from Europe and imported to the US with ~1900 hours. The glider was given a US airworthiness inspection, and licensed by an FAA inspector last week Thursday or so. *It went into legal service before the weekend. On Saturday, following only a few flights, the pilot felt some restriction in rudder movement, and asked the front seat passenger to adjust the length of rudder stirrups for more freedom of movement. The passenger complied, and free movement was "restored." The flight continued in nice lift, and some mild maneuvers for perhaps twenty five more minutes prior to landing. As the glider came to a halt, the ground personnel roared up to the cockpit and informed the pilot that there was no rudder on the machine. All parties were amazed. A search by air for the missing rudder were fruitless. I have not seen the Puchacsz. I do not have pictures or links to any photos. I cannot comment on the mode of departure. I do not know if the cables or swedges and thimbles are on the machine, nor if the vertical hinges are in place on the rear face of the vertical fin. I do know there was a mandatory service item to replace the rudder stop elastic nut on the bottom bolt with a castelated nut and safety key. *I cannot say if this was done, found, gone or otherwise on the machine in question. I do know that you should look at the attachments of controls and moving parts fully and carefully on each pre-flight inspection. *Things change and move over time. The pilot in this case asked me to put the information out to the soaring community, PRIOR to any formal incident investigation, to prevent any possible similar occurrence. Cindy Brickner Southern Californiawww.caracole-soaring.com There is a mandatory service bulletin/AD to replace the lower rudder mount bolt. If the nut on the old bolt unscrews, the rudder can fall off! The cables drive a plate with vertical pins that fit into the rudder. The cables are not connected directly to the rudder. This and several other AD's and service bulletins should have been checked on the annual inspection. Another biggie is to replace the aluminum turn- buckles that are bolted directly to the rear rudder pedals with steel turn-buckles and an 8" cable to get them off the rudder pedals where rear pilot can/will kick and bend ..............do that a few times and the aluminum turn-buckle breaks.....................then you are in a world of hurts! Who did the annual? JJ JJ |
#3
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On Sep 6, 6:50*pm, CindyB wrote:
Folks: You will not yet find this on any accident/incident reports. There were no fatalities. *A pilot called me to relay this story. The SZD-50-3 Puchacsz was bought used from Europe and imported to the US with ~1900 hours. The glider was given a US airworthiness inspection, and licensed by an FAA inspector last week Thursday or so. *It went into legal service before the weekend. On Saturday, following only a few flights, the pilot felt some restriction in rudder movement, and asked the front seat passenger to adjust the length of rudder stirrups for more freedom of movement. The passenger complied, and free movement was "restored." The flight continued in nice lift, and some mild maneuvers for perhaps twenty five more minutes prior to landing. As the glider came to a halt, the ground personnel roared up to the cockpit and informed the pilot that there was no rudder on the machine. All parties were amazed. A search by air for the missing rudder were fruitless. I have not seen the Puchacsz. I do not have pictures or links to any photos. I cannot comment on the mode of departure. I do not know if the cables or swedges and thimbles are on the machine, nor if the vertical hinges are in place on the rear face of the vertical fin. I do know there was a mandatory service item to replace the rudder stop elastic nut on the bottom bolt with a castelated nut and safety key. *I cannot say if this was done, found, gone or otherwise on the machine in question. I do know that you should look at the attachments of controls and moving parts fully and carefully on each pre-flight inspection. *Things change and move over time. The pilot in this case asked me to put the information out to the soaring community, PRIOR to any formal incident investigation, to prevent any possible similar occurrence. Cindy Brickner Southern Californiawww.caracole-soaring.co Who do you blame for this incident? The glider or the inspector? Jacek |
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How could you fly a glider without a rudder and not be able to tell
something is very wrong???? Was the yaw string missing too? Boggs |
#5
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On Sep 6, 9:09*pm, GARY BOGGS wrote:
How could you fly a glider without a rudder and not be able to tell something is very wrong???? Was the yaw string missing too? Boggs Some students wouldn't know if the rudder fell off, because they never use it anyway! It (the rudder) must weigh a good 20 pounds or so and that much weight lost way back there would surely shift the CG out of the forward limit. OK as long as speed is sufficient to keep elevator authority. No Guy, my Puchacz went to Brazil and all the ad's were complied with! Cheers, JJ |
#6
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On Sep 7, 1:09*am, GARY BOGGS wrote:
How could you fly a glider without a rudder and not be able to tell something is very wrong???? Was the yaw string missing too? Boggs I agree with Gary.. How could the pilot not notice the rudder is gone? Our club DG200 had the rudder pop out on a winch launch and it fell back and hung from the rudder cables. The pilot felt both pedals go forward and get stuck. He completed the launch and from the ground he was told that his rudder came off so he made gentle turns and landed without trouble. A few days later we got the AD calling for a larger washer on the lower hinge bolt... With no rudder he could only make very gentle, shallow turns without having the yaw string all over the place. Regards, Juan Carlos |
#7
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At 04:09 07 September 2010, GARY BOGGS wrote:
How could you fly a glider without a rudder and not be able to tell something is very wrong???? Was the yaw string missing too? Boggs My thoughts exactly! Whilst not wishing to undermine the obvious safety message about ensuring the rudder is firmly attached to the aircraft, this missive has the distinct odour of urban myth... If I recall correctly, one of the very first lessons in gliding is the secondary effects of using the controls. This includes adverse yaw due to aileron movement without rudder! |
#8
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Going on some years of experience maintaining three high-time Puchaczes,
I'd say these are your options: - Rudder not properly installed after maintenance. The only thing holding the rudder in place is a castelled nut (visible from the underside of the fuselage, behind the tailwheel). To remove the rudder for maintenance, remove the split pin and castelled nut, and the rudder may be lifted off upwards. The rudder cables are attached to a rudder drive - butterfly shaped - that automatically connects when the rudder is refitted. Lovely system, actually. Now, sometimes people do not take out the lower (castelled) nut, but the nyloc nut that holds the bottom rudder hinge pin to the rudder itself. That saves some time fiddling with splitpins (while working upside down), but also creates the hazard of rehanging the rudder without fitting this nut, and to a quick inspection from the underside of the aircraft it looks OK (bottom castelled nut properly fitted), while it is actually loose in the aircraft (top nyloc missing). I had one of these when I did an annual after maintenance, lovely situation to catch in time... - Service Bulletin BE-058 not complied with, not checked or improperly done. It says to check the bottom nut. If another type of nut is there (e.g. nyloc), it needs to be replaced by a castelled nut. Shortly afterwards, a Puchacz in the UK lost its rudder: it had a nyloc replaced by a castelled nut, but the inspector in question had overlooked that a hole for the splitplin was already there when he drilled a new one, weakening the bolt which subsequently failed. All other SB's relating to the rudder system, were regarding the attachment of the cables to the rudder pedals (which were a completely different although very important problem altogether). - A structural problem. There's two known weakpoints in the Puch's rudder attachment. First (a minor one) is the plywood (vertical) support under the rudder cable drive (the butterfly shaped thing). The glued joint on the topside (to the horizontal plywood mount of the butterfly lever) tends to fail sometimes. However, this alone should not result in the rudder to depart the aircraft, or even the rudder controls to become difficult. Then there's also the problem the GFA alerted the world about (but which has not yet made it into an SB or AD) of cracks found in the horizontal support plywood of the butterfly lever. This however, should result in the rudder becoming inoperable, but it should remain on the aircraft since the mounting is not affected. Then there's always the chance of a different hitherto unknown structural problem altogether... Just giving you information to work out the problem at hand. Not pointing fingers here (which is a pointless thing to do anyway). Eric |
#9
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On 9/7/2010 11:10 AM, Eric Munk wrote:
Going on some years of experience maintaining three high-time Puchaczes, I'd say these are your options: - Rudder not properly installed after maintenance. The only thing holding the rudder in place is a castelled nut (visible from the underside of the fuselage, behind the tailwheel). To remove the rudder for maintenance, remove the split pin and castelled nut, and the rudder may be lifted off upwards. The rudder cables are attached to a rudder drive - butterfly shaped - that automatically connects when the rudder is refitted. Lovely system, actually. Now, sometimes people do not take out the lower (castelled) nut, but the nyloc nut that holds the bottom rudder hinge pin to the rudder itself. That saves some time fiddling with splitpins (while working upside down), but also creates the hazard of rehanging the rudder without fitting this nut, and to a quick inspection from the underside of the aircraft it looks OK (bottom castelled nut properly fitted), while it is actually loose in the aircraft (top nyloc missing). I had one of these when I did an annual after maintenance, lovely situation to catch in time... - Service Bulletin BE-058 not complied with, not checked or improperly done. It says to check the bottom nut. If another type of nut is there (e.g. nyloc), it needs to be replaced by a castelled nut. Shortly afterwards, a Puchacz in the UK lost its rudder: it had a nyloc replaced by a castelled nut, but the inspector in question had overlooked that a hole for the splitplin was already there when he drilled a new one, weakening the bolt which subsequently failed. All other SB's relating to the rudder system, were regarding the attachment of the cables to the rudder pedals (which were a completely different although very important problem altogether). - A structural problem. There's two known weakpoints in the Puch's rudder attachment. First (a minor one) is the plywood (vertical) support under the rudder cable drive (the butterfly shaped thing). The glued joint on the topside (to the horizontal plywood mount of the butterfly lever) tends to fail sometimes. However, this alone should not result in the rudder to depart the aircraft, or even the rudder controls to become difficult. Then there's also the problem the GFA alerted the world about (but which has not yet made it into an SB or AD) of cracks found in the horizontal support plywood of the butterfly lever. This however, should result in the rudder becoming inoperable, but it should remain on the aircraft since the mounting is not affected. Then there's always the chance of a different hitherto unknown structural problem altogether... Just giving you information to work out the problem at hand. Not pointing fingers here (which is a pointless thing to do anyway). Eric I don't normally like to repeat an entire post, but (and speaking as someone who has never actually seen a Puchacz in the flesh) this one deserves it IMHO. Thanks, Eric, for an informed, informative and hugely useful post in response to a (we can hope!) isolated if bizarre incident that could fairly easily have ended badly. If I ever buy (or see) a Pooch, I know one area where I'll be peering more intently, now! Regards, Bob W. |
#10
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On Sep 7, 7:46*am, JC wrote:
On Sep 7, 1:09*am, GARY BOGGS wrote: How could you fly a glider without a rudder and not be able to tell something is very wrong????...clip... Boggs I agree with Gary.. How could the pilot not notice the rudder is gone? Our club DG200 had the rudder pop out on a winch launch and it fell back and hung from the rudder cables. The pilot felt both pedals go forward and get stuck. He completed the launch and from the ground he was told that his rudder came off so he made gentle turns and landed without trouble....clip... We don't recognize when something has gone wrong with the rudder because a - we normally don't practice not having a rudder b - really don't understand, in the seat of our pants, what it feels like not to have one So -- all we know at first is that *something is wrong*. (Note that Juan Carlos points out that the pilot was TOLD his rudder was off.) What that *something* is, ain't all that obvious. This is true for MOST airplane malfunctions, not just rudder malfunctions. And the emotional upset ("alarm") that we feel during the event hinders rational analysis. I speak as an expert, having once many years ago flown a Blanik L-13 with the rudder cables reversed. All I could tell was the rudder *wasn't working*. So I put my feet on the floor. Which worked fine until they quietly snuck back onto the pedals during the turn from base to final. My personal mantra, "Speed is my friend" saved the day. (Then, after the repair, one of us five guys who'd all missed the rudder reversal, found the safety missing from the castellated nut underneath the elevator bell crank and saved someone's life. An airplane flies awkwardly but safely without a good rudder, but the pilot dies without an elevator.) DJ |
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