@gulliBell
90% of the recurrent trainees I see don't do the after start hydraulic check properly, which makes me wonder why they were never taught properly from the outset, or since.
I fully agree with this but my experience tells me that the 99 % of the S76 pilots and instructors don't understand what they are checking. All our pilots have been type trained by a simulator company in Florida. Each crew member has had recurrent flight training in sim twice per year (6 months interval). This simulator training organization never pointed out how to do Stick Jump test properly (during the type rating course or during the 6 months recurrent flight training).
The Stick Jump Test is the hydraulic check of S76. The aim of the check is to verify that both hydraulic systems (HYD1 and HYD2) work well and at the same time as the HYD1 or HYD2 is OFF line that the Servo Actuators are checked by one servo channel one by one. This is commonly known, understood and performed.
My opinion is that these 99 % of the pilots and instructors are forgetting to do
or they don't know how to do the stick jump part of the test. The stick jump test's idea is to verify that the power of the Hydraulic System 1 and 2 and the power the Servo Actuator's channel #1 and #2 are on an equal level. To make this verification
during the check the pilot must keep the control stick moving at the same time when he or she switches over HYD #1 OFF to HYD #2 ON or reverse. If
during this cross over (together with the moving flight controls) from #1 to #2 or from #2 to #1
the stick should not make a jump. If the jump occurs it is an indication that the powers between the hydraulic systems are different or if the hydraulic power is equal between systems HYD1 and HYD2 then this is an indication that there is a difference between one or more of the three Servo Actuator's channel #1 and #2.
The common mistake during the test is that the pilot will stop the control stick movement at time when the pilot makes the HYD1/2 cross over (switch off and switch on).
When the stick doesn't be on move at time of switching over from HYD1 to HYD2, can't any stick jumps be detected.
The most likely the Stick Jump is caused by the increased Servo Actuator's internal leakage rate. This is the way find out a development that is a flight safety issue. This Stick Jump can't be identified in a case where the leakage rate has decreased parallel during the time on both channels #1 and #2. Even the power of the Servo Actuator power is poor (less that minimum acceptable) but if the both channel's leakage rates are on an equal level,
no Stick Jumps exists. This is a scenario where you could have unairworthy Servo Actuator installed but you are not able to pick it up by the Stick Jump Test, even the test is performed properly and within timely manner.
I have seen some endurance and continuity test reports which are proving that this is a kind of development that doesn't have to be developed in hours; this could develop within seconds.
I hope that some of the pilots and instructors will take into account the above, in their daily duties. I would like to receive some comments from the S76 line pilots and the line instructors are these things mention above something new for them? Please show up to the Forum.