I have recieved a copy of the incident report on latest problem with the Astar.
The pilot, while doing water sampling in northern ontario had a problem with rate limiting on the servos(cyclic has some resistance when trying to move fast). Temperature had warmed to -36 'C, had been running on ground at full throttle while waiting for customers when occured(had already been flying for about one hour). He "stirred the soup" and the problem went away. The rate limiting was somewhat more fore and aft(makes sense as only one servo for fore and aft movements is actuated). After he took off his cyclic seemed to go stiffer and he turned off the hydraulics and attempted a hyd off landing, when 30'agl the cylic forces to the left made it impossible for him to keep a/c level and he then turned on the hydraulics and made a run on landing.
There was no mention as to the length of time the pilot flew without hydraulics or why he not able to hold cylic level, maybe he was of slight build or flew too long without hyd and was tired, my experience is the a/c wants to go right until aispeed is bled off and t/r thrust pushes the a/c left which has to be compensated for with right cyclic(maybe he was severe crosswind,,,wtfk). But my first reaction to this is that there was a slight loss of hydraulic pressure, slight as the light and horn weren't on, they come on at ~32 bars. If there was a problem with a servo the rate limiting would have been much more noticable on one servo not all three as was reported by pilot. Normal operating pressure of system is ~43 bars which allows for a good deal of pressure loss before warning system is activated(maybe this should be looked at). Loss of pressure could be various things such as the belt slippping, ice in filter, 'o' ring in relief valve torn..... why not look at that. Was there an improvement to performance when a/c was warmed. what about the swashplate? Was it shimmed too tight, or excess ice or snow somewhere there shouldn't be? When the a/c first came out they had to put snow/ice shields over the pilot valves on servos, the pilot was running on ground fair bit and maybe too much ice formed somewhere it shouldn't have. He was worried about cycle counting on engine thus left a full rpm, this should not be done as it just circulates snow which does no good on any type.
It is my assumtion(bad I know) that this incident will cause as sorts of feedback from TC. TC faxed the incident to a bunch of operators but with no follow up, talk about scare tactics, I tried to get more info but had no luck.
My experience with this type has ranged from the Yukon at -40'C to south america. There have been occurances with the type but let's not go off half cocked, it seems as though there is a great lack of knowledge on this type's hydraulic system, which makes the drivers out there nervous as hell. I could go one and one about 206 contamination problems let alone the switch location issues they had, finger pointing is immature and unprofession. Get into the books(maintenance and flight manuals) read all you can, ask questions of your boss, get him or her to ask people that know the answers. Get HAC involved more. Penticton has been doing hydraulics off training since the a/c was introduced into their fleet, to my knowledge there has not been any incident doing hydraulics off landings ever. My opinion is that by limiting hydraulics off training is wrong and has done nothing to increase the safety level in the type, infact the opposite has happened, pilots are nervous and NEED more training NOW. Maybe tc should involve the industry more or get a professional outside organisation such as the royal test pilot school or AETE to work on this, so we can get on with providing the public with safe pilots, and safe a/c. Not the extreme head in the sand attitude prevailing now of parking pilots and a/c. Spend some money get a qualified test pilot and go to different aircraft around Canada and try flying them without hydraulics, maybe there is a problem with non-training a/c, doubt it but hey do something.
The pilot, while doing water sampling in northern ontario had a problem with rate limiting on the servos(cyclic has some resistance when trying to move fast). Temperature had warmed to -36 'C, had been running on ground at full throttle while waiting for customers when occured(had already been flying for about one hour). He "stirred the soup" and the problem went away. The rate limiting was somewhat more fore and aft(makes sense as only one servo for fore and aft movements is actuated). After he took off his cyclic seemed to go stiffer and he turned off the hydraulics and attempted a hyd off landing, when 30'agl the cylic forces to the left made it impossible for him to keep a/c level and he then turned on the hydraulics and made a run on landing.
There was no mention as to the length of time the pilot flew without hydraulics or why he not able to hold cylic level, maybe he was of slight build or flew too long without hyd and was tired, my experience is the a/c wants to go right until aispeed is bled off and t/r thrust pushes the a/c left which has to be compensated for with right cyclic(maybe he was severe crosswind,,,wtfk). But my first reaction to this is that there was a slight loss of hydraulic pressure, slight as the light and horn weren't on, they come on at ~32 bars. If there was a problem with a servo the rate limiting would have been much more noticable on one servo not all three as was reported by pilot. Normal operating pressure of system is ~43 bars which allows for a good deal of pressure loss before warning system is activated(maybe this should be looked at). Loss of pressure could be various things such as the belt slippping, ice in filter, 'o' ring in relief valve torn..... why not look at that. Was there an improvement to performance when a/c was warmed. what about the swashplate? Was it shimmed too tight, or excess ice or snow somewhere there shouldn't be? When the a/c first came out they had to put snow/ice shields over the pilot valves on servos, the pilot was running on ground fair bit and maybe too much ice formed somewhere it shouldn't have. He was worried about cycle counting on engine thus left a full rpm, this should not be done as it just circulates snow which does no good on any type.
It is my assumtion(bad I know) that this incident will cause as sorts of feedback from TC. TC faxed the incident to a bunch of operators but with no follow up, talk about scare tactics, I tried to get more info but had no luck.
My experience with this type has ranged from the Yukon at -40'C to south america. There have been occurances with the type but let's not go off half cocked, it seems as though there is a great lack of knowledge on this type's hydraulic system, which makes the drivers out there nervous as hell. I could go one and one about 206 contamination problems let alone the switch location issues they had, finger pointing is immature and unprofession. Get into the books(maintenance and flight manuals) read all you can, ask questions of your boss, get him or her to ask people that know the answers. Get HAC involved more. Penticton has been doing hydraulics off training since the a/c was introduced into their fleet, to my knowledge there has not been any incident doing hydraulics off landings ever. My opinion is that by limiting hydraulics off training is wrong and has done nothing to increase the safety level in the type, infact the opposite has happened, pilots are nervous and NEED more training NOW. Maybe tc should involve the industry more or get a professional outside organisation such as the royal test pilot school or AETE to work on this, so we can get on with providing the public with safe pilots, and safe a/c. Not the extreme head in the sand attitude prevailing now of parking pilots and a/c. Spend some money get a qualified test pilot and go to different aircraft around Canada and try flying them without hydraulics, maybe there is a problem with non-training a/c, doubt it but hey do something.
