Flightcontrols check B737-500
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Flightcontrols check B737-500
How to move the control wheel when checking the flightcontrols ??
1. From neutral: aft, left, forward, right, aft, neutral
or
2. From neutral: left, right, neutral, forward, aft, neutral
There is no standard procedure given in the OM. Some pilots say, the no. 1 way is the best because this procedure check the FULL FREEDOM of movement in all the 4 corners.
BUT, I think:
Its only necessary to check the flight controls as in procedure 2, since there is NO corners on a standard control wheel in an airliner.
Motivation: The number 2 procedure is easier to do, and keeps the paper hanging on the control wheel map holder.
Does anyone know whether there is a technical reason to test flightcontrols like in procedure 1 - or if this is just "remains" from a time when aircraft had a stick instead of a control wheel ??
SAF
[This message has been edited by SAF (edited 29 May 2001).]
1. From neutral: aft, left, forward, right, aft, neutral
or
2. From neutral: left, right, neutral, forward, aft, neutral
There is no standard procedure given in the OM. Some pilots say, the no. 1 way is the best because this procedure check the FULL FREEDOM of movement in all the 4 corners.
BUT, I think:
Its only necessary to check the flight controls as in procedure 2, since there is NO corners on a standard control wheel in an airliner.
Motivation: The number 2 procedure is easier to do, and keeps the paper hanging on the control wheel map holder.
Does anyone know whether there is a technical reason to test flightcontrols like in procedure 1 - or if this is just "remains" from a time when aircraft had a stick instead of a control wheel ??
SAF
[This message has been edited by SAF (edited 29 May 2001).]
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The 1 method is a la Cessna and checks the controls as in the stick for full and free novement.
On the airliner the fact that you won't get your buckles caught is taken as read. What you're looking for is that as you turn the tops in elavator the control a) goes full deflection without feeling stiff or having any deadbands(think cars with knackered power steering) and b) comes back to dead centre. Same in Aileron and with rudder.
On the airliner the fact that you won't get your buckles caught is taken as read. What you're looking for is that as you turn the tops in elavator the control a) goes full deflection without feeling stiff or having any deadbands(think cars with knackered power steering) and b) comes back to dead centre. Same in Aileron and with rudder.
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Regarding teh recent Airbus incident where the controls were rigged the wrong way round, might be prudent to always make sure a visual confirmation of movement in the correct direction whenever possible. Could save you from a big embarrasment later on. Of course, this is standard flight training stuff, almost like lesson no.1 'Effect of controls', but still worth remembering.
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From: Ex-pat Aussie in the UK
The control check on the airbus (as I understand it) involves checking the sidestick movement with the control positions shown on the EICAM.
On light aircraft I used to teach students the control check as "UP, UP, UP" - where you turn the control wheel left, look left and see the aileron "up", pull the control wheel back and look behind for the elevator/stabilator to be "up", turn right, look right etc.
On the BAe 146 you have two spoiler position guages that can be used similarly for the aileron circuit, and you could feel the weight of the elevator.
I know that none of these is possible in the 733.
[This message has been edited by Checkboard (edited 31 May 2001).]
On light aircraft I used to teach students the control check as "UP, UP, UP" - where you turn the control wheel left, look left and see the aileron "up", pull the control wheel back and look behind for the elevator/stabilator to be "up", turn right, look right etc.
On the BAe 146 you have two spoiler position guages that can be used similarly for the aileron circuit, and you could feel the weight of the elevator.
I know that none of these is possible in the 733.
[This message has been edited by Checkboard (edited 31 May 2001).]
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On the MD80/90, only thing I can see is the glare of the position lights - at night. Only clue visible in the cockpit, as to the operations of flight controls is a message in overhead panel saying," spoiler deployed" when moving column left and right. Doesn´t say left or right!!!!!
Do I feel completely assured. Not really! Only consolation is, that I´ve flown all individuals in the fleet, and haven´t crashed yet. And if work has been done on the controls, A/C has been testflown and checked for the right cables going in the right direction. (No wires on this one
)
We just do your "method no. 2", and I feel it´s sufficient.
Sorry that I can´t comment on your subject, 735!
Do I feel completely assured. Not really! Only consolation is, that I´ve flown all individuals in the fleet, and haven´t crashed yet. And if work has been done on the controls, A/C has been testflown and checked for the right cables going in the right direction. (No wires on this one
)We just do your "method no. 2", and I feel it´s sufficient.
Sorry that I can´t comment on your subject, 735!
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The MD-90 etc might show a little drop in hydraulic pressure during aileron/spoiler check as during preflight (when checking ground spoiler extension).
Still off the topic, but years ago at a "lower budget" civilian repair/overhaul facility at Dothan (DHN), Alabama, a US Navy Reserve CV-580 (one of two based at the Navy side of Andrews AFB) crashed while returning to the runway, following a major overhaul. The facility had failed to thoroughly check the elevator control cables. On climbout, every time the pilots pushed the yoke forward, it could not be pulled back. There was some accidental linkage to either other control cables or other metal parts.
Fortunately for the bean counters, US Naval Aviation saved money using that repair facility-at least until the tragedy during base leg or the crew's "final approach".
Still off the topic, but years ago at a "lower budget" civilian repair/overhaul facility at Dothan (DHN), Alabama, a US Navy Reserve CV-580 (one of two based at the Navy side of Andrews AFB) crashed while returning to the runway, following a major overhaul. The facility had failed to thoroughly check the elevator control cables. On climbout, every time the pilots pushed the yoke forward, it could not be pulled back. There was some accidental linkage to either other control cables or other metal parts.
Fortunately for the bean counters, US Naval Aviation saved money using that repair facility-at least until the tragedy during base leg or the crew's "final approach".
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Hi spannerhead, well - if no.2 procedure is enough - why sit and do the slightly more time/effort demanding no.1 procedure for the next 25 years of flying???????
I also think, that a flightcontrols check should include visual checks if practical.
BUT:
I question whether a pilot of a conventional control wheel aircraft (boeing, atr, dash-8 etc.) is actually checking the flightcontrols better by using the no.1 procedure.
The no.1 procedure checks all the corners,BUT (this is my point) - THERE IS NO CORNERS TO CHECK!!, BECAUSE THE CONVENTIONAL CONTROL WHEEL ONLY MOVES FORWARD/REARWARD - however, on a control STICK (airbus and/or older aircraft, fighters, gliders etc.), the full deflection in the 4 corners can/should be checked.
Thats why I think, that no.1 procedure should be enough for checking flightcontrols on conventional control wheel aircraft (boeing, atr, dash-8 etc.)
The no.1 procedure is easier to do, and keeps the maps hanging proporly on the control wheel.
If I should think of a reason to check left aileron up and elevator up simultaniously and visa versa - it should be to check the hydraulic system response to the higher demand from the flight controls.. - maybe thats reason enough.
SAF
[This message has been edited by SAF (edited 01 June 2001).]
[This message has been edited by SAF (edited 01 June 2001).]
I also think, that a flightcontrols check should include visual checks if practical.
BUT:
I question whether a pilot of a conventional control wheel aircraft (boeing, atr, dash-8 etc.) is actually checking the flightcontrols better by using the no.1 procedure.
The no.1 procedure checks all the corners,BUT (this is my point) - THERE IS NO CORNERS TO CHECK!!, BECAUSE THE CONVENTIONAL CONTROL WHEEL ONLY MOVES FORWARD/REARWARD - however, on a control STICK (airbus and/or older aircraft, fighters, gliders etc.), the full deflection in the 4 corners can/should be checked.
Thats why I think, that no.1 procedure should be enough for checking flightcontrols on conventional control wheel aircraft (boeing, atr, dash-8 etc.)
The no.1 procedure is easier to do, and keeps the maps hanging proporly on the control wheel.
If I should think of a reason to check left aileron up and elevator up simultaniously and visa versa - it should be to check the hydraulic system response to the higher demand from the flight controls.. - maybe thats reason enough.
SAF
[This message has been edited by SAF (edited 01 June 2001).]
[This message has been edited by SAF (edited 01 June 2001).]
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Ignition Override,
Quite correct, but that still doesn´t tell me, if its the left spoiler going up when I´m moving control wheel left.
<font face="Verdana, Arial, Helvetica" size="2">The MD-90 etc might show a little drop in hydraulic pressure during aileron/spoiler check as during preflight (when checking ground spoiler extension</font>
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On the 737-800, it was also impossible to see the ailerons or even the wing tips from the flight deck. On our first (early) aircraft, we had to hope they were rigged the right way round, but on the later aircraft we were fitted with Control Position Indicators on the lower DU.
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I may be missing something but I get the feeling that some of the people here are concerned only about the external stick/yoke movement.
Consider whether the full and free check really isn't overly interested in what the pilot's bit is doing - rather it is to check the various control runs within the entire circuit to detect any restriction or interference, howsoever caused, which might prove to be an embarrassment in flight ?
The question of whether a particular bit goes up or down should only be terribly relevant after the control circuits have been upset during maintenance. The usual dual certification inspection and post maintenance test flight ought to protect the main body of troops against the spectre of things going in the wrong direction. Can happen, of course, if the system is bypassed or subverted somewhere.
[This message has been edited by john_tullamarine (edited 01 June 2001).]
Consider whether the full and free check really isn't overly interested in what the pilot's bit is doing - rather it is to check the various control runs within the entire circuit to detect any restriction or interference, howsoever caused, which might prove to be an embarrassment in flight ?
The question of whether a particular bit goes up or down should only be terribly relevant after the control circuits have been upset during maintenance. The usual dual certification inspection and post maintenance test flight ought to protect the main body of troops against the spectre of things going in the wrong direction. Can happen, of course, if the system is bypassed or subverted somewhere.
[This message has been edited by john_tullamarine (edited 01 June 2001).]
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From: Ex-pat Aussie in the UK
Thought I would throw in a story here.
Years ago I was instructing an aerobatic student in a C152 Aerobat. On completion of an aileron roll he said the controls were "a bit stiff" and "was this normal?", Taking ove, I found the controls locked in roll (at the neutral poition), but free in pitch.
I flew the aircraft back to the field using rudder and elevator, where it was discovered that the cotter pin on the end of the control column had snagged part of the radio wiring harness while at full left aileron and full forward pitch. This prevented the control wheel from turning to the right, and I was probably just lucky that there was enough play in the harness for the wheel to reach neutral, and not be snagged at full left roll. (Or unlucky that there was enough play in the harness to catch the pin in the first place, depending on how you view life)
A "four corners check" would have had a greater chance of catching the problem on the ground than a "forward back, left/right" check - which perhaps follows J.T.'s comment above about what you should be worried about.
As I said, I used to teach a four corners check, but have no idea whether the student did that on the ground or not now (it was quite a while ago.)
Years ago I was instructing an aerobatic student in a C152 Aerobat. On completion of an aileron roll he said the controls were "a bit stiff" and "was this normal?", Taking ove, I found the controls locked in roll (at the neutral poition), but free in pitch.
I flew the aircraft back to the field using rudder and elevator, where it was discovered that the cotter pin on the end of the control column had snagged part of the radio wiring harness while at full left aileron and full forward pitch. This prevented the control wheel from turning to the right, and I was probably just lucky that there was enough play in the harness for the wheel to reach neutral, and not be snagged at full left roll. (Or unlucky that there was enough play in the harness to catch the pin in the first place, depending on how you view life
)A "four corners check" would have had a greater chance of catching the problem on the ground than a "forward back, left/right" check - which perhaps follows J.T.'s comment above about what you should be worried about.
As I said, I used to teach a four corners check, but have no idea whether the student did that on the ground or not now (it was quite a while ago.)
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From: Ex-pat Aussie in the UK
Another story while I am at it, illustrating another perspective.
At around the same time, while I was an instructor in Melbourne, I was sitting in the instructor crew room drinking coffee. (I did a lot of that in those days) Looking out the window, which had a nice view of the runway approach path and touchdown zone I saw a Partenavia approach at a great rate of knots, slam onto the runway and lose some of its gear 
Apparently what had happened (all of this second had, and from memory, so don't quote me) was that a pilot had hired the aircraft from another school, but had returned it saying "That the controls check felt funny."
One of the instructors from that school jumped in, performed a control check and decided to fly a quick circuit. Getting airbourne he found no pitch response at all. He flew the rest of the circuit on the trim, with the touchdown mentioned above - all in all a pretty good display of aircraft handling.
It turns out that the clamp from the control run on the stabilator was loose, so while the elevator moved a bit on the ground, airbourne the aircraft had no pitch control at all. Again I don't know how the control check was performed - or even if you can see the elevator in a Partenavia, but I suspect so.
All the good stuff happens in G.A.
At around the same time, while I was an instructor in Melbourne, I was sitting in the instructor crew room drinking coffee. (I did a lot of that in those days
) Looking out the window, which had a nice view of the runway approach path and touchdown zone I saw a Partenavia approach at a great rate of knots, slam onto the runway and lose some of its gear Apparently what had happened (all of this second had, and from memory, so don't quote me
) was that a pilot had hired the aircraft from another school, but had returned it saying "That the controls check felt funny."One of the instructors from that school jumped in, performed a control check and decided to fly a quick circuit. Getting airbourne he found no pitch response at all. He flew the rest of the circuit on the trim, with the touchdown mentioned above - all in all a pretty good display of aircraft handling.
It turns out that the clamp from the control run on the stabilator was loose, so while the elevator moved a bit on the ground, airbourne the aircraft had no pitch control at all. Again I don't know how the control check was performed - or even if you can see the elevator in a Partenavia, but I suspect so.
All the good stuff happens in G.A.
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.. and another Oz example. Many decades ago a Chipmunk (and the two crew) was lost when a coin of the Realm became lodged in the front of an uncovered stick stub. This duly restricted forward stick movement and precluded recovery from whatever manoeuvre the intrepid pair were doing at the time. A long time since I read the crash comic report on the accident so the details may be a little vague - but the result was still fatal.
There have been numerous incidents of control runs snagging due to deterioration of one kind or another - if it can be found on the ground, then who really needs that kind of excitement in the air ?
There have been numerous incidents of control runs snagging due to deterioration of one kind or another - if it can be found on the ground, then who really needs that kind of excitement in the air ?
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In my company we always push the 737 cc forward FIRST then left/right before bringing it all the way back (beer gut permitting!) This way you don't smack the captain's knees etc when going left/right.
Does anybody look out the window at thie aileron when doing the check? - I've started doing it just to check it goes the right way!
Does anybody look out the window at thie aileron when doing the check? - I've started doing it just to check it goes the right way!
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Looking at the control surface movement is a good idea in a C152, maybe possible in a B737(not the rudder though, which at times is the more critical flight control; think EFACTO), but it is impossible on a B747.
There are stories of cables being crossed, and I bet there will continue to be more stories as such in the future. But, to physically check all the things that can go wrong ??? We'll never leave the ground that way.
Coming back to the original Q, whichever way your heart desires, just as long as you do it all the way to the control wheel stops, it shouldn't matter.
There are stories of cables being crossed, and I bet there will continue to be more stories as such in the future. But, to physically check all the things that can go wrong ??? We'll never leave the ground that way.
Coming back to the original Q, whichever way your heart desires, just as long as you do it all the way to the control wheel stops, it shouldn't matter.
