AS350 levers and more
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AS350 levers and more
Hi guys
Watching a video on youtube about a guy named jazzpilot on how to start the astar, he was pointing at three different levers between the two seats: now taking into account that i am a plank driver who is familiar with turbine engines and with a very limited heli experience, still working on my addon in the r22, bug fascinated by any aircraft system, what are those levers for?
One, the long red lever, reckon is the Rotor Brake, i guess it morks in the same way as in the robbie where it must be disengaged prior to starting the engine.
The second, the short red lever, he mentions something about the fuel cut off, i am wondering if it controls a fso from the fuel system to the FCU of the engine or what?
The third one, the yellow one, he refers to as the FCU and has a button at the front: i believe the button controls the starter so that when pressed it energizes the starter imparting a rotary motion to the engine, cranking it up until it becomes self substaining: what is the lever controlling? Is it manually modulating the fuel delivered into the combustion chamber or to the FCU? and am i wrong or the fuel is introduced right away without waiting a minimum ng - i dont know, something like 10-12%?
One last question, hoping that i am not abusing yoir patience, is : is it normal to start an helicopter with the generator on? Cos in all the airplanes i have flown the generator was turned on only once the engine was started - even though i guess the GCU will prevent the generator from coming online until its output meet specific criteria, such as voltage output above but output.
Many thanks for your willingness
Baobab72
Watching a video on youtube about a guy named jazzpilot on how to start the astar, he was pointing at three different levers between the two seats: now taking into account that i am a plank driver who is familiar with turbine engines and with a very limited heli experience, still working on my addon in the r22, bug fascinated by any aircraft system, what are those levers for?
One, the long red lever, reckon is the Rotor Brake, i guess it morks in the same way as in the robbie where it must be disengaged prior to starting the engine.
The second, the short red lever, he mentions something about the fuel cut off, i am wondering if it controls a fso from the fuel system to the FCU of the engine or what?
The third one, the yellow one, he refers to as the FCU and has a button at the front: i believe the button controls the starter so that when pressed it energizes the starter imparting a rotary motion to the engine, cranking it up until it becomes self substaining: what is the lever controlling? Is it manually modulating the fuel delivered into the combustion chamber or to the FCU? and am i wrong or the fuel is introduced right away without waiting a minimum ng - i dont know, something like 10-12%?
One last question, hoping that i am not abusing yoir patience, is : is it normal to start an helicopter with the generator on? Cos in all the airplanes i have flown the generator was turned on only once the engine was started - even though i guess the GCU will prevent the generator from coming online until its output meet specific criteria, such as voltage output above but output.
Many thanks for your willingness
Baobab72
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you are pretty much correct; from left to right are rotor brake, emergency fuel cut-off (the stubby one is attached to a stop-cock just upstream from the engine - very simple), and the fuel flow control lever (throttle) which is attached via cable to the FCU (mounted to the engine).
in a turbomeca powered machine (excluding the B3) the pilot controls the amount of fuel introduced at start up with the position of the yellow lever. starts are generally initiated by pressing the button on the top of the throttle lever and after Ng reaches 10% advancing the throttle lever until light-off occurs. T4 (temp) is modulated to 700C and the button must remain depressed until Ng reaches 40-45%. as the engine speeds up T4 will drop of course but throttle must be advanced to 70% Ng which is idle.
in cold weather, the throttle can be advanced as soon as the button is pressed.
in the B2/BA the generator can be selected "ON" while starting. can't do that in Bell intermediates, at least according to the flight manual (i'm sure someone has tried it but i don't know how well it would have gone!).
hope this helps
fp
in a turbomeca powered machine (excluding the B3) the pilot controls the amount of fuel introduced at start up with the position of the yellow lever. starts are generally initiated by pressing the button on the top of the throttle lever and after Ng reaches 10% advancing the throttle lever until light-off occurs. T4 (temp) is modulated to 700C and the button must remain depressed until Ng reaches 40-45%. as the engine speeds up T4 will drop of course but throttle must be advanced to 70% Ng which is idle.
in cold weather, the throttle can be advanced as soon as the button is pressed.
in the B2/BA the generator can be selected "ON" while starting. can't do that in Bell intermediates, at least according to the flight manual (i'm sure someone has tried it but i don't know how well it would have gone!).
hope this helps
fp
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On the AS350 series, the gen button can stay in.
If the starter button is engaged, there is a cut-out relay that prevents the generator from generating.
Releasing the start relay will disengage the cut-out relay, which will bring it on line.
If the starter button is engaged, there is a cut-out relay that prevents the generator from generating.
Releasing the start relay will disengage the cut-out relay, which will bring it on line.
And just to change the start procedure slightly...... Common practice here is to move the FFCL to about the start position and THEN push the start switch.... Makes it easier.
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As350 levers
Many thanks for the answers.
Just for clarification what does the fuel cut off lever controls and when is it used - in case of a hot start for instance or in case of an engine fire?
What is the procedure in case of a malfunction during the start - no light off, hung start, hot start and so forth? You simply retard the FFCL and keep the button pressed in to motor the engine intilmthe T4 drops to below .... Or a time limit is exceeded?
Finally, is the ingnition system connected to the lever? cos i don t see the jazzpilot arming it?
Many thanks
Baobab72
Just for clarification what does the fuel cut off lever controls and when is it used - in case of a hot start for instance or in case of an engine fire?
What is the procedure in case of a malfunction during the start - no light off, hung start, hot start and so forth? You simply retard the FFCL and keep the button pressed in to motor the engine intilmthe T4 drops to below .... Or a time limit is exceeded?
Finally, is the ingnition system connected to the lever? cos i don t see the jazzpilot arming it?
Many thanks
Baobab72
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Indeed Gordy. Turbomeca and EC introduced that start a few years back. With everything off move the throttle until you read 27 degrees on the FCU. Make a mark on the quadrant next to the throttle and next start move the throttle to the mark and engage the starter-ala EC120 start.
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In case of a hung start or a high T4 you retard the FFCL all the way back and release the start button.Keeping that button pressed will continue to provide an ignition spark.There is another switch on the center console marked "crank". That is to be used if you just want to motor the engine without the ignition spark.That allows the excess fuel to be ejected and may reduce the high T4.
There is no arming the ignition system.Once the battery is on the button is "hot". The engine will start turning if the button is engaged at that point.
The only other interlock is a mechanical one.If the rotor brake is fully up and aft and in the slot (i.e engaged) there is a mechanical stop that prevents the FFCL from being moved forward.This prevents the rotors being turned and accelerated with the rotor brake "on".
Alt3
There is no arming the ignition system.Once the battery is on the button is "hot". The engine will start turning if the button is engaged at that point.
The only other interlock is a mechanical one.If the rotor brake is fully up and aft and in the slot (i.e engaged) there is a mechanical stop that prevents the FFCL from being moved forward.This prevents the rotors being turned and accelerated with the rotor brake "on".
Alt3
