Mupp
13th Sep 2006, 09:51
Hello all, long time reader, first time poster.
I'm doing research on building myself an EC135 simulator. First and foremost, I'm not a pilot, so I apologize if my questions are stupid/out of place. The reason I'm building this thing is as much due to an interest in electronics/control theory/automation, as the more obvious love for helicopters. So, I was wondering if I could ask a few questions and hope for a few answers regarding this particular aircraft? I have a couple of questions of immediate interest, and if it's ok I'll revisit this thread when more arise.
First off, hardware, the cyclic: What are the spring forces in the force trim system, roughly? If, hypothetically, I were to move the force feel neutral fully left, what force would I have to put on the stick to put it fully right?
Secondly, hardware, hyd. failure: When suffering a hydraulic failure in one channel, what control forces could I expect respectively on the cyclic, collective and pedals (system 2)? What would be a good way to "emulate" this, a friction brake system acting on the controls, or some sort of damping system (counterforce prop. to speed of control movement)? What about a dual hydraulic failure? Can the controls be moved?
Final question, software (for me at least), the SAS: I've had the opportunity to skim through small parts of training material for this aircraft, and it states something like "after a corrective input, the actuator goes back to its neutral position to ensure full authority" about the basic SAS (not AP-provided, I sadly know nothing about that). Now, here's where my lack of knowledge potentially becomes really apparent, this is uncharted territory for me. If I've gotten this completely wrong, please tell me. But let's consider the yaw-SAS. For a short-term effect, say a gust of wind, I would imagine the SAS correction to go unnoticed by the pilot. What happens with a long term effect, say an increase in torque? Is the SAS a rate damper (always struggling to ensure 0 rotational speed around its axis) or an acceleration damper (always struggling to ensure a constant speed around its axis, i.e. 0 rotational acceleration). Will the SAS see the increase in torque as a prolonged gust of wind and put up a good fight, or will it merely lessen the impact of it, do a small correction to ensure a smooth start in the rotation around the yaw axis, and leave it to the pilot to stop the rotation? A short anecdote on how SAS changed the helicopter pilot's life ("there I was...") would be very valuable for me!
Please note that English is not my native language, if something is totally incomprehendable, I might be able to rephrase it.
Thanks!
I'm doing research on building myself an EC135 simulator. First and foremost, I'm not a pilot, so I apologize if my questions are stupid/out of place. The reason I'm building this thing is as much due to an interest in electronics/control theory/automation, as the more obvious love for helicopters. So, I was wondering if I could ask a few questions and hope for a few answers regarding this particular aircraft? I have a couple of questions of immediate interest, and if it's ok I'll revisit this thread when more arise.
First off, hardware, the cyclic: What are the spring forces in the force trim system, roughly? If, hypothetically, I were to move the force feel neutral fully left, what force would I have to put on the stick to put it fully right?
Secondly, hardware, hyd. failure: When suffering a hydraulic failure in one channel, what control forces could I expect respectively on the cyclic, collective and pedals (system 2)? What would be a good way to "emulate" this, a friction brake system acting on the controls, or some sort of damping system (counterforce prop. to speed of control movement)? What about a dual hydraulic failure? Can the controls be moved?
Final question, software (for me at least), the SAS: I've had the opportunity to skim through small parts of training material for this aircraft, and it states something like "after a corrective input, the actuator goes back to its neutral position to ensure full authority" about the basic SAS (not AP-provided, I sadly know nothing about that). Now, here's where my lack of knowledge potentially becomes really apparent, this is uncharted territory for me. If I've gotten this completely wrong, please tell me. But let's consider the yaw-SAS. For a short-term effect, say a gust of wind, I would imagine the SAS correction to go unnoticed by the pilot. What happens with a long term effect, say an increase in torque? Is the SAS a rate damper (always struggling to ensure 0 rotational speed around its axis) or an acceleration damper (always struggling to ensure a constant speed around its axis, i.e. 0 rotational acceleration). Will the SAS see the increase in torque as a prolonged gust of wind and put up a good fight, or will it merely lessen the impact of it, do a small correction to ensure a smooth start in the rotation around the yaw axis, and leave it to the pilot to stop the rotation? A short anecdote on how SAS changed the helicopter pilot's life ("there I was...") would be very valuable for me!
Please note that English is not my native language, if something is totally incomprehendable, I might be able to rephrase it.
Thanks!