How to do a Positive Control Check?

[ContestID67]

A recent accident (disconnected aileron) got me thinking about
positive control checks. I searched the RAS archives and didn't find
any details on how people do this.

I was trained by my CFIG, like most of you I hope, to do a positive
control check every day. Actually it was more like it was drilled
into me. This was even done on club ships that remain assembled for
the season.

As a beginning pilot I would sit in the cockpit and move the controls
as someone more experienced put their hands on the flight surfaces.
Later I found that anyone can handle the controls, it's the hands on
the surfaces that was much more telling if things were connected
properly or not. My ship does not have automatic hookups so this is
especially important to me.

I got into the habit of having my assistant move the control one way,
then the other, then back again with full deflection. All the while I
was putting pressure on the surface and, at the same time, wiggling
the surface to simulate take off vibration. So far, no incidents,
knock on wood.

So, the question is, how do *YOU* do your positive control check?

John "67" DeRosa

[[email protected]]

On Jun 3, 8:13*pm, ContestID67 > wrote:
> A recent accident (disconnected aileron) got me thinking about
> positive control checks. *I searched the RAS archives and didn't find
> any details on how people do this.
>
> I was trained by my CFIG, like most of you I hope, to do a positive
> control check every day. *Actually it was more like it was drilled
> into me. *This was even done on club ships that remain assembled for
> the season.
>
> As a beginning pilot I would sit in the cockpit and move the controls
> as someone more experienced put their hands on the flight surfaces.
> Later I found that anyone can handle the controls, it's the hands on
> the surfaces that was much more telling if things were connected
> properly or not. *My ship does not have automatic hookups so this is
> especially important to me.
>
> I got into the habit of having my assistant move the control one way,
> then the other, then back again with full deflection. *All the while I
> was putting pressure on the surface and, at the same time, wiggling
> the surface to simulate take off vibration. *So far, no incidents,
> knock on wood.
>
> So, the question is, how do *YOU* do your positive control check?
>
> John "67" DeRosa

John,

sounds like i do the same thing. I usually provide resistance to the
motion as the stick is moved to the stop in one direction, and then i
push it back to center. a little wiggle in there too.

[Nyal Williams]

What I prefer is not always what I do, but this is what I want.

I sit in the cockpit and have the assistant deflect the control completely
and I try to pull it away from the deflection (held fully deflected in both
directions one after the other. For the divebrakes I want the assistant to
hold them closed while I try to open, and then I want them to hold them
open while I try to close. For this latter test I want them to hold the
plate at the end and not ever hold by the cap.

I believe your notion is better -- being the outside person examining the
control and having the assistant work the stick and pedals, etc.

At 01:13 04 June 2008, ContestID67 wrote:
>A recent accident (disconnected aileron) got me thinking about
>positive control checks. I searched the RAS archives and didn't find
>any details on how people do this.
>
>I was trained by my CFIG, like most of you I hope, to do a positive
>control check every day. Actually it was more like it was drilled
>into me. This was even done on club ships that remain assembled for
>the season.
>
>As a beginning pilot I would sit in the cockpit and move the controls
>as someone more experienced put their hands on the flight surfaces.
>Later I found that anyone can handle the controls, it's the hands on
>the surfaces that was much more telling if things were connected
>properly or not. My ship does not have automatic hookups so this is
>especially important to me.
>
>I got into the habit of having my assistant move the control one way,
>then the other, then back again with full deflection. All the while I
>was putting pressure on the surface and, at the same time, wiggling
>the surface to simulate take off vibration. So far, no incidents,
>knock on wood.
>
>So, the question is, how do *YOU* do your positive control check?
>
>John "67" DeRosa
>

[noel.wade]

I (the pilot) always try to be the one on the control surfaces during
a PCC - because thin glass and foam (or fabric-covered controls) can
be dented & damaged MUCH more easily than a metal control-stick!

--Noel

[[email protected]]

For ships with *auto hookups* positive control checks are a waste of
time, and in fact do more harm then good. I have never heard of a
single case where a positive control check would have preveneted an
accident. I have seen ailerons fouled by clueless helpers who don't
know where the bloody bell crank is and what flat palm means.

On Jun 3, 9:13*pm, ContestID67 > wrote:
> A recent accident (disconnected aileron) got me thinking about
> positive control checks. *I searched the RAS archives and didn't find
> any details on how people do this.
>
> I was trained by my CFIG, like most of you I hope, to do a positive
> control check every day. *Actually it was more like it was drilled
> into me. *This was even done on club ships that remain assembled for
> the season.
>
> As a beginning pilot I would sit in the cockpit and move the controls
> as someone more experienced put their hands on the flight surfaces.
> Later I found that anyone can handle the controls, it's the hands on
> the surfaces that was much more telling if things were connected
> properly or not. *My ship does not have automatic hookups so this is
> especially important to me.
>
> I got into the habit of having my assistant move the control one way,
> then the other, then back again with full deflection. *All the while I
> was putting pressure on the surface and, at the same time, wiggling
> the surface to simulate take off vibration. *So far, no incidents,
> knock on wood.
>
> So, the question is, how do *YOU* do your positive control check?
>
> John "67" DeRosa

[noel.wade]

On Jun 3, 7:18*pm, wrote:
> For ships with *auto hookups* positive control checks are a waste of
> time, and in fact do more harm then good. I have never heard of a

I cannot believe this was posted. Its YOUR airplane. YOU are the
Pilot in Command. YOU have the responsibility to ensure that the
checks are done properly and by someone who can do it without damage
to the aircraft.

A "clueless" or "ham-handed" helper is no excuse - it just means you
were in a rush or trusted someone you should not have (or that you
didn't properly train them).

Even with auto-hookups, fittings can come loose, bearings can sieze,
and controls can fail.

Simply seeing the hookups slide together does NOT ensure that the
aircraft is functioning properly!

--Noel

[[email protected]]

Please name one accident of a glider with auto hookups that could have
been prevented by a positive control check. I sure don't know any. A
seized bearing will be detected by simply moving the stick. In all
gliders I know there is no scenario of control failure that would
necessitate a positive control check for detection.

You are making a slippery slope argument. Should we mandate annual
stress tests of wings in the name of safety? Overhaul all tost
releases every 100 cycles?

On Jun 3, 10:26*pm, "noel.wade" > wrote:
> On Jun 3, 7:18*pm, wrote:
>
> > For ships with *auto hookups* positive control checks are a waste of
> > time, and in fact do more harm then good. I have never heard of a
>
> I cannot believe this was posted. *Its YOUR airplane. *YOU are the
> Pilot in Command. *YOU have the responsibility to ensure that the
> checks are done properly and by someone who can do it without damage
> to the aircraft.
>
> A "clueless" or "ham-handed" helper is no excuse - it just means you
> were in a rush or trusted someone you should not have (or that you
> didn't properly train them).
>
> Even with auto-hookups, fittings can come loose, bearings can sieze,
> and controls can fail.
>
> Simply seeing the hookups slide together does NOT ensure that the
> aircraft is functioning properly!
>
> --Noel

[Marc Ramsey[_2_]]

wrote:
> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check. I sure don't know any. A
> seized bearing will be detected by simply moving the stick. In all
> gliders I know there is no scenario of control failure that would
> necessitate a positive control check for detection.

FWIW, I've owned 8 different gliders from 4 different manufacturers with
one or more automatic hookups, and every single one had at least one
failure mode where you could jam things together without properly
engaging the corresponding hookup. It was usually hard to get things
wrong, and the control stick would usually (but not always) bind when
something wasn't properly engaged, but it could be done, and I always do
PCCs as a result...

Marc

[Eric Greenwell]

Marc Ramsey wrote:
> wrote:
>> Please name one accident of a glider with auto hookups that could have
>> been prevented by a positive control check. I sure don't know any. A
>> seized bearing will be detected by simply moving the stick. In all
>> gliders I know there is no scenario of control failure that would
>> necessitate a positive control check for detection.
>
> FWIW, I've owned 8 different gliders from 4 different manufacturers with
> one or more automatic hookups, and every single one had at least one
> failure mode where you could jam things together without properly
> engaging the corresponding hookup. It was usually hard to get things
> wrong, and the control stick would usually (but not always) bind when
> something wasn't properly engaged, but it could be done, and I always do
> PCCs as a result...

If, after assembly on an auto hookup glider,

* you moved the stick and flap handle to their extremes, saw all the
surfaces deflect appropriately (direction and range of motion), felt the
controls moving just as freely as they should, and then
* moved each aileron and flap surface by hand (applying pressure at the
point the control horn is attached), and saw and felt it move
appropriately, and saw the other surfaces move appropriately, and
* opened the spoilers, saw they moved the same amount on each wing,
then closed and locked them, and saw the caps being pulled flush with
the surface on both wings,

would you be confident the controls were properly connected and
functioning correctly?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Richard[_1_]]

On Jun 3, 7:18*pm, wrote:
> For ships with *auto hookups* positive control checks are a waste of
> time, and in fact do more harm then good. I have never heard of a
> single case where a positive control check would have preveneted an
> accident. I have seen ailerons fouled by clueless helpers who don't
> know where the bloody bell crank is and what flat palm means.
>
> On Jun 3, 9:13*pm, ContestID67 > wrote:
>
>
>
> > A recent accident (disconnected aileron) got me thinking about
> > positive control checks. *I searched the RAS archives and didn't find
> > any details on how people do this.
>
> > I was trained by my CFIG, like most of you I hope, to do a positive
> > control check every day. *Actually it was more like it was drilled
> > into me. *This was even done on club ships that remain assembled for
> > the season.
>
> > As a beginning pilot I would sit in the cockpit and move the controls
> > as someone more experienced put their hands on the flight surfaces.
> > Later I found that anyone can handle the controls, it's the hands on
> > the surfaces that was much more telling if things were connected
> > properly or not. *My ship does not have automatic hookups so this is
> > especially important to me.
>
> > I got into the habit of having my assistant move the control one way,
> > then the other, then back again with full deflection. *All the while I
> > was putting pressure on the surface and, at the same time, wiggling
> > the surface to simulate take off vibration. *So far, no incidents,
> > knock on wood.
>
> > So, the question is, how do *YOU* do your positive control check?
>
> > John "67" DeRosa- Hide quoted text -
>
> - Show quoted text -

The AD on the ventus sailplanes for replacement of the elevator push
rod in the tail is an example of accidents avoided because of a
positive control check. A hole was missing in the push rod that
allowed water to collect and rust the rod. I for one am glad that the
pilot did an unnecessary waste of time control check. The rod broke
during the check.


Richard
www.craggyaero.com

[Andy[_1_]]

On Jun 3, 7:43*pm, wrote:
> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check. I sure don't know any. A
> seized bearing will be detected by simply moving the stick. In all
> gliders I know there is no scenario of control failure that would
> necessitate a positive control check for detection.

I know of one accident that was prevented by a positive control check
on a glider with automatic hookups. An Arizona pilot with a Ventus
experienced an elevator push rod failure during a positive control
check. Many will remember the hole drilling and push rod inspections
that happened around that time.

I also know it is possible to assemble some gliders with the automatic
wing hook ups not engaged. That should be detectbale by a free and
correct check though.

Automatic control hook ups are not the panacea that many think and I
never cease to be surprised that some people think that gliders with
manual hookups are inherently unsafe. They are not. It's the pilots
that don't do adequate preflight inspection that are unsafe.


Andy

[Marc Ramsey[_2_]]

Eric Greenwell wrote:
> If, after assembly on an auto hookup glider,
>
> * you moved the stick and flap handle to their extremes, saw all the
> surfaces deflect appropriately (direction and range of motion), felt the
> controls moving just as freely as they should, and then
> * moved each aileron and flap surface by hand (applying pressure at the
> point the control horn is attached), and saw and felt it move
> appropriately, and saw the other surfaces move appropriately, and
> * opened the spoilers, saw they moved the same amount on each wing, then
> closed and locked them, and saw the caps being pulled flush with the
> surface on both wings,
>
> would you be confident the controls were properly connected and
> functioning correctly?

Yes, but that's a bit too many ifs for me. I'd rather find someone to
do a PCC, but in those rare cases when I couldn't, that's pretty much
what I would do...

Marc

[Bill Daniels]

Lotsa good stuff in this thread

I have a Nimbus 2C which has eight manual connections - six in the fuselage
and two in the wings. There's also an incredible number of moving
mechanical components comprising an almost incomprehensible monkey motion in
the fuselage and wings. If you move any control, pretty much everything
moves. Although I don't have a lot of experience with the N3 and N4, it
appears they are even more complicated than the N2.

I do the control hookups in overlapping stages. First, I make the outer
wing connections and safety them - then I try to take them apart again by
pulling and twisting on the connection and by pushing on the release tab.
If they fail to come apart, I figure the connection is well made. I do the
same with the six fuselage connections.

But, of course, there's more ways for the control linkage to fail. I
regularly inspect and lubricate all the control system pivot points even if
it takes a flashlight and mirror

With the ship well assembled and lubed, I do the classic positive control
check with me at the control surfaces if the helper is inexperienced or I
may wiggle the stick if the helper knows his job.

I think that a takeoff with one outer aileron connection disconnected and
positive flap would be a certain disaster. Fortunately, negative flaps for
the takeoff roll up to picking up the tailwheel and neutral flap after that
works fine.

Bill D



"ContestID67" > wrote in message
...
>A recent accident (disconnected aileron) got me thinking about
> positive control checks. I searched the RAS archives and didn't find
> any details on how people do this.
>
> I was trained by my CFIG, like most of you I hope, to do a positive
> control check every day. Actually it was more like it was drilled
> into me. This was even done on club ships that remain assembled for
> the season.
>
> As a beginning pilot I would sit in the cockpit and move the controls
> as someone more experienced put their hands on the flight surfaces.
> Later I found that anyone can handle the controls, it's the hands on
> the surfaces that was much more telling if things were connected
> properly or not. My ship does not have automatic hookups so this is
> especially important to me.
>
> I got into the habit of having my assistant move the control one way,
> then the other, then back again with full deflection. All the while I
> was putting pressure on the surface and, at the same time, wiggling
> the surface to simulate take off vibration. So far, no incidents,
> knock on wood.
>
> So, the question is, how do *YOU* do your positive control check?
>
> John "67" DeRosa

[Philip Plane]

wrote:

> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check. I sure don't know any. A
> seized bearing will be detected by simply moving the stick. In all
> gliders I know there is no scenario of control failure that would
> necessitate a positive control check for detection.

Well, a few years ago I had an 'incident' with a glider with automatic
hookups that passed two positive control checks.

The elevator hookup on the DG1000 has a little label beside it that
says that the trim must be fully forward when the elevator is
attached to the tail. The hookup requires a small bearing to fit into
a channel.

On the first flight of the season the second season I had the glider
I rigged it without putting the trim full forward. I wasn't happy
with it, but couldn't see what was wrong. I got an experienced pilot
for was nearby to do a positive control check with me. We couldn't
see anything wrong.

I towed out and gridded. On the grid I still felt there was something
wrong, but couldn't put my finger on what was wrong. I asked another
experienced pilot to do a control check before I launched. We found
nothing wrong.

As soon as the tow commenced I could see what the problem was. I
only had approx half stick movement. The stick was hard against
the back stop on tow. I towed high, dumped my ballast and returned
to the field. With the stick full back I could get the speed back
to 60knots. I landed OK. We removed the tail, pushed the trim
forward, rerigged, and all was fine.

Lack of familiarity with the rigging bit me that time.

There is no silver bullet. You must always be aware of the
specific requirements and problems of whatever equipment
you are using.


--
Philip Plane _____
|
---------------( )---------------
Glider pilots have no visible means of support

[Ian]

On 4 Jun, 03:26, "noel.wade" > wrote:
> On Jun 3, 7:18*pm, wrote:
>
> > For ships with *auto hookups* positive control checks are a waste of
> > time, and in fact do more harm then good. I have never heard of a
>
> I cannot believe this was posted. *Its YOUR airplane. *YOU are the
> Pilot in Command. *YOU have the responsibility to ensure that the
> checks are done properly and by someone who can do it without damage
> to the aircraft.

It sounds to me as if that's what he's doing: taking responsibility
for the checks which are done. It's just that he doesn't believe some
checks need doing, or doing in a particular way.

After all, he's going to be the one in trouble if he's wrong. But it
would be interesting to hear of a real case where a glider with
automatic connections has had a problem discovered during the positive
control check. Anyone?

Ian

PS I do 'em myself. But then, my glider doesn't have automatic
connections. I think I'd still do them then, though.

[Ian]

On 4 Jun, 02:13, ContestID67 > wrote:

> So, the question is, how do *YOU* do your positive control check?

Get someone to hold the control surfaces in place. I push the stick, s/
he tells me which way the surface is trying to move.

And I do it after towing to the launch point, to give things a chance
to fall off. At Sutton Bank it used to be mandatory to to a positive
check at the launch point before the first flight of the day, with a
column in the launch log to record this.

Ian

[Andreas Maurer]

On Tue, 3 Jun 2008 19:43:51 -0700 (PDT), wrote:

>Please name one accident of a glider with auto hookups that could have
>been prevented by a positive control check. I sure don't know any. A
>seized bearing will be detected by simply moving the stick. In all
>gliders I know there is no scenario of control failure that would
>necessitate a positive control check for detection.

There have been SEVERAL incidents and accidents of DG gliders where
the automatic hookup of the elevator was not connected correctly.

Not to mention several (unfortunately usually fatal) crashes of
gliders where the auto hookups were connected correctly, but the
horizontal tail was not. Ernst-Gernot Peter and Clem Bowman come to my
mind...

>You are making a slippery slope argument. Should we mandate annual
>stress tests of wings in the name of safety? Overhaul all tost
>releases every 100 cycles?

Nope... but to do a simple 2 minute check before the flight...


Bye
Andreas

[JJ Sinclair]

On Jun 3, 7:43*pm, wrote:
> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check. I sure don't know any.

Clem Bowman, Genesis 2, Minden Nationals.................pilot didn't
fully seat the locking mechanism on the elevator because he had given
the little red tool to his wife so she could put water in the
wings..........................didn't do a critical assembly
check..................elevator fell off during take-
off.........................Clem is no longer with us!
JJ

[Marc Ramsey[_2_]]

Ian wrote:
> After all, he's going to be the one in trouble if he's wrong. But it
> would be interesting to hear of a real case where a glider with
> automatic connections has had a problem discovered during the positive
> control check. Anyone?

Just about any DG (already mentioned): possible to get horizontal stab
on and secured with elevator pushrod outside of receptacle, resulting in
reduced range of elevator movement and binding. Only managed to do this
once.

Duo Discus: possible to get horizontal stab on and secured with elevator
drive pins jammed in-between torque tube and upper elevator skin, rather
than in the receiving wholes on the torque tube, resulting in reduced
range of movement and funny stick feel.

LAK-17A: Possible to get wings and secured on with one control (I think
it was aileron) disconnected, resulting funny stick feel and no surface
movement. Never figured out how I managed to do that, and it never
happened again.

Ventus B: Possible to get wing on and secured with one control pushrod
end (aileron again?) outside of socket and jammed into fuselage opening,
resulting in no surface movement and binding. This area was apparently
changed at least once during the production run.

Marc

[Bob Kuykendall]

On Jun 3, 7:43*pm, wrote:
> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check.

Russia elevator. Air Sailing contest. Pilot Chad Moore. Broken
elevator pintle discovered. Accident averted.

Thanks, Bob K.

[SoaringXCellence]

On Jun 4, 8:48*am, Bob Kuykendall > wrote:
> On Jun 3, 7:43*pm, wrote:
>
> > Please name one accident of a glider with auto hookups that could have
> > been prevented by a positive control check.
>
> Russia elevator. Air Sailing contest. Pilot Chad Moore. Broken
> elevator pintle discovered. Accident averted.
>
> Thanks, Bob K.

Russia pilot, at North Plains Oregon discovered broken rudder
connection (I can't remember if it was a control horn problem or
cables) while doing a PCC. He was glad he did!

[Bob Whelan[_2_]]

wrote:
> Please name one accident of a glider with auto hookups that could have
> been prevented by a positive control check. I sure don't know any. A
> seized bearing will be detected by simply moving the stick. In all
> gliders I know there is no scenario of control failure that would
> necessitate a positive control check for detection.

Lots of food for serious thought in this thread.

Having flown/flying (since 1981) a ship with auto-connects everywhere,
but one loose pin (the main one) anywhere, locking mechanisms (for
all-flying stab/main pin) in open/plain sight, and (for all practical
purposes) impossible to safety the wings without
bending/crushing/breaking something in the auto-connect systems, the
only control failure I've (yet) had, occurred - progressively - in
flight...on the one control never routinely disconnected. (The weldment
in the rudder actuation system that converts rudder cable motion to
pushrod motion to the rudder began to fail; by the time I got it
diagnosed and [uneventfully] landed [after a pattern sized so the
absence of a rudder would not have been a problem], the weldment was
nearly in two pieces and the rudder [gently] fluttering with large
displacements at low-frequency.)

If I didn't previously believe Murphy was real (which I did!), this
incident would have removed all doubt. I guess my main point here is,
if it happens it must be possible...combine that reality with Murphy and
the certainties in life become fuzzier.

Methinks (annual/daily inspections notwithstanding) skepticism when it
comes to the structural integrity of one's sailplane is a likely a wiser
approach than blindly trusting certitude...


> You are making a slippery slope argument. Should we mandate annual
> stress tests of wings in the name of safety? Overhaul all tost
> releases every 100 cycles?

I don't argue the point(s) immeedjutly above. Life itself is a risk.
Certainty is not an option...although the belief in it, is.

Respectfully,
Bob W.

[Bob Kuykendall]

On Jun 3, 7:18*pm, wrote:
> For ships with *auto hookups* positive control checks are a waste of
> time, and in fact do more harm then good.

To expand a bit on my earlier response:

Having designed and flight tested sailplane control systems, I feel
compelled to take strong issue with that statement. I won't say it's
wrong, but I will say that I strongly disagree.

You state that it is a "fact" that PCCs do more harm than good. Please
educate us with cites to evidence that proves or demonstrates or at
least supports this fact.

To my way of thinking, sailplanes are designed, engineered, built, and
maintained by fallible beings. They are fallible machines. Their
mechanisms get mis-assembled. They break and they get broken. Lives
depend on their correct operation.

Their operation can be easily checked for serious faults. Admitted,
these checks can be done wrong and they can done ineffectively so as
to consume time better spent elsehow. However, the applicable solution
set also includes many ways of doing them quicky and safely.

In my history as a glider bum, I have seen:

* HP ruddervator, supposedly auto-connecting, failure to engage its
driver on assembly, allowing only up/left input. Condition discovered
in pre-flight. Dick Schreder not so lucky (but still pretty lucky!)
with the RS-15 prototype.

* Standard Cirrus tailplane, again supposedly auto-connecting,
possible to mis-engage at the drive pushrod, allowing down elevator
but not up. See the assembly-check drawing I did at the Standard
Cirrus Web site for details.

* Factory-new 304, trailing edge airbrake drive pushrod locking nut
not tightened, pushrod free to rotate and eventually disengage from
rod end. Condition discovered while wiggling random bits prior to
first flight.

* (Previously reported) Russa AC4, elevator center pintle broken loose
from stabilizer. Up stick moves the elevator root aft without pivoting
elevator up. Condition discovered in mandatory pre-launch PCC.

Thanks, Bob K.
http://www.hpaircraft.com/hp-24

[Wayne Paul]

As mentioned in another thread. I too had a disconnected HP ruddervator and
wrote an article about it for Soaring.
http://www.soaridaho.com/Schreder/Stories/Assembly_Check.pdf
This article contains a link to Dick Schreder's RS-14 adventure.

Back when I was in the Navy I served with Steward Tittle. We have kept in
touch through out the years. As many of you will remember he had an
accident in an LS-6 caused by a disconnected flaperon. Stew reviewed my
article prior to it being published and identified two things in common with
his accident. In both cases we assembled with the control surfaces locked.
(LS-6 wing cuffs in place and my ruddervator gustlocks in place.) We were
both in a hurry to launch and didn't do a PCC.

This sequence is becoming all too familiar.

Wayne
HP-14 "Six Foxtrot"
http://www.soaridaho.com/Schreder


"Bob Kuykendall" > wrote in message
...
On Jun 3, 7:18 pm, wrote:
> For ships with *auto hookups* positive control checks are a waste of
> time, and in fact do more harm then good.

.... Snip..

In my history as a glider bum, I have seen:

* HP ruddervator, supposedly auto-connecting, failure to engage its
driver on assembly, allowing only up/left input. Condition discovered
in pre-flight. Dick Schreder not so lucky (but still pretty lucky!)
with the RS-15 prototype.

....Snip....

Thanks, Bob K.
http://www.hpaircraft.com/hp-24

[sisu1a]

>I towed out and gridded. On the grid I still felt there was something
>wrong, but couldn't put my finger on what was wrong. I asked another
>experienced pilot to do a control check before I launched. We found
>nothing wrong.

In between this last paragraph and the text below, did you go through
a pre-flight checklist, that had a C for "CONTROLS, CLEAR AND FREE-
FULL MOVEMENT? Or did the problem not manifest itself until full
flight?

> As soon as the tow commenced I could see what the problem was. I
> only had approx half stick movement.

Umm, pop the cord? Did you not also have an E somewhere on your
preflight checklist, for EMERGENCY, which in theory should have left
you with clear options for aborting a takeoff at different phases? I
realize that the layout of the airport this happened at may not have
good emergency options and also that it may not have occurred until
already past the "point of no return" so these points may be moot and
your actions taken executed flawlessly (after all, you are here to
tell about it...), so I don't mean to harp. I'm just curious if this
particular frightening occurrence could have been avoided altogether
or at least handled at MUCH lower energies if a thorough preflight
checklist was actually performed. Thanks for sharing.

Paul Hanson

[kirk.stant]

On Jun 4, 12:54*pm, "Wayne Paul" > wrote:
> As mentioned in another thread. I too had a disconnected HP ruddervator and
> wrote an article about it for Soaring.http://www.soaridaho.com/Schreder/Stories/Assembly_Check.pdf
> This article contains a link to Dick Schreder's RS-14 adventure.
>
> Back when I was in the Navy I served with Steward Tittle. *We have kept in
> touch through out the years. *As many of you will remember he had an
> accident in an LS-6 caused by a disconnected flaperon. *Stew reviewed my
> article prior to it being published and identified two things in common with
> his accident. *In both cases we assembled with the control surfaces locked.
> (LS-6 wing cuffs in place and my ruddervator gustlocks in place.) *We were
> both in a hurry to launch and didn't do a PCC.
>
> This sequence is becoming all too familiar.
>
> Wayne

The LS6 configuration makes the critical PCC extremely easy to
accomplish solo. Just stand behind the wing at the fuselage, and
grasp both flaperons at the same time. They can then be checked for
symmetrical and assymetrical motion and resistance.

For those not familiar with them, the LS6 elevator is auto and can be
checked visually for engagement.

I assemble with the control surface lock in place as the flaperons can
foul the drive fairings if left to drop all the way. Since the only
real emergency in the LS6 flight manual is takeoff with a disconnected
flaperon, I am extremely conscious of the need to get it right - by
feel when hooking up the hotelliers and safeties, by sight using the
mirrors provided, and by PCC.

I have rigged an LS4 and misconnected a spoiler, so I know it can be
done. (Caught during a PCC on the grid at Parowan, thanks PT!).

Now if it would just stop raining, maybe we could get some gliding in!

Kirk
Soggy in St Louis (30+ inches of DiHydrogenMonoxide and counting...)

[[email protected]]

> For ships with *auto hookups* positive control checks are a waste of
> time, and in fact do more harm then good. I have never heard of a

PCC should also cover whether the stabilizer is actually bolted on and
bolted all the way. Good luck flying a glider with stabilizer
flapping up and down, regardless of whether it has auto hookup or
manual. Reminds me of the discussion about the wing pins being in
all the way.

[noel.wade]

> > On Jun 3, 7:18*pm, wrote:
>
> After all, he's going to be the one in trouble if he's wrong. But it

Let's tackle that statement once and for all, shall we?

Yes, there's usually only 1 guy in the cockpit of a sailplane; and if
he doesn't do a CAC and a PCC then his ass is the one most at risk.

BUT, let us not forget that there is a tow-plane on the other end of
the rope! And what about the other pilots and aircraft at the
airport? What about possible bystanders (demo ride people and their
families, for example)?

An out-of-control glider can be just as deadly to those people as it
can be to the person inside it.

And I think the lawyers would have a FIELD DAY with the issue of
responsibility, if someone on the ground got hurt as a result of an
improperly assembled glider.

I know this wasn't Ian's main point in his post - but its important to
mull this over before you think that "its OK becuase I'm the one who
will pay if I screw up". You can't be that certain.

--Noel
P.S. Contrary to popular belief, its possible to be safe AND still
have a ton of fun. Being safe doesn't mean being nasty or boring - it
just means taking 5 minutes to be responsible!

[Philip Plane]

sisu1a wrote:

> In between this last paragraph and the text below, did you go through
> a pre-flight checklist, that had a C for "CONTROLS, CLEAR AND FREE-
> FULL MOVEMENT? Or did the problem not manifest itself until full
> flight?

Normal control checks were done. Restricted range of movement should
have been noticed, but as I said, the glider was relatively new, and
it was the first flight of the season after maybe three months in the
trailer. You might notice a trend in start of season incidents.

Currency and familiarity with the equipment you're flying and the
environment you're flying in are important factors.


> Umm, pop the cord? Did you not also have an E somewhere on your
> preflight checklist, for EMERGENCY, which in theory should have left
> you with clear options for aborting a takeoff at different phases? I
> realize that the layout of the airport this happened at may not have
> good emergency options and also that it may not have occurred until
> already past the "point of no return" so these points may be moot and
> your actions taken executed flawlessly (after all, you are here to
> tell about it...), so I don't mean to harp. I'm just curious if this
> particular frightening occurrence could have been avoided altogether
> or at least handled at MUCH lower energies if a thorough preflight
> checklist was actually performed. Thanks for sharing.

As the glider was stable and there was nowhere good to go ahead I elected
to continue with the tow and try to sort it out with a little altitude.

I used the time on tow to think about what I was going to do.

--
Philip Plane _____
|
---------------( )---------------
Glider pilots have no visible means of support

[Jim Vincent]

One of my friends from RAS told me about this thread and asked that I put
the link in for my presentation on PCC.

http://www.mymedtrans.com/personal/

[ZL]

wrote:
>> For ships with *auto hookups* positive control checks are a waste of
>> time, and in fact do more harm then good. I have never heard of a
>
> PCC should also cover whether the stabilizer is actually bolted on and
> bolted all the way. Good luck flying a glider with stabilizer
> flapping up and down, regardless of whether it has auto hookup or
> manual. Reminds me of the discussion about the wing pins being in
> all the way.

Do you do a positive control check on the towplane? I mean the 2-man
yank on the controls from both ends check. Not the normal pre-flight
walk around, controls free and correct check.

Probably not.

The critical assembly check (everything critical installed, tightened,
saftied, etc. tailored to the specific glider) makes sense as does the
normal pre-flight. I'm not sure the positive control check does.

What's the fundamental difference between the towplane's controls and a
properly assembled glider's controls?

Do you really know how much load is safe to apply to a control surface?
Is it in your operators manual? Airloads on modern tiny control surfaces
can be quite small in comparison to what an enthusiastic human hand can
apply. Is your control system designed for airloads or positive control
check loads? Are you sure you can tell if you pushed too hard?

-Dave

[noel.wade]

On Jun 4, 5:23*pm, ZL > wrote:

> What's the fundamental difference between the towplane's controls and a
> properly assembled glider's controls?

The fundamental difference is that the tow-plane isn't being
disassembled and reassembled all the time. And the tow-planes control
systems aren't designed with disassembly in mind; whereas a glider's
are. It creates some fundamental differences in the engineering...

> Do you really know how much load is safe to apply to a control surface?

Ok, so let me get this straight - you'd rather risk your LIFE (and the
lives of those around you) instead of risking damage to your control
surface?

Common sense should work for figuring out how to do the PCC without
damage, just as common sense should encourage us to DO a PCC in the
first place.

--Noel

[Bob Kuykendall]

On Jun 4, 5:23*pm, ZL > wrote:

> Do you really know how much load is safe to apply to a control surface?
> Is it in your operators manual? Airloads on modern tiny control surfaces
> can be quite small in comparison to what an enthusiastic human hand can
> apply...

Actually, it's not that hard to reverse-engineer estimated maximum
hinge moments from (rho*v^2)/2 and the suggested loading schedules in
the old FAA pub "Basic Glider Criteria." The total forces can be
pretty great, especially the accumulated torsion for something like a
c*.17, 2-drive full-span flaperon like yours.

As you observe, the maximum hinge moment and normal loading on
something like your LS6 elevator is pretty small. However, JAR22 and
FAR23 both require a fair bit of margin over the flight loads. They
also specify some pretty hefty minimum input loads between the control
stick and the stops, though by the looks of the European marques they
tend to weasel out of the default input forces with the "unless lower
can be rationally justified" clause.

Thanks, Bob K.

[[email protected]]

Guys you are missing the point! There is a difference between a
Critical Assembly Check and a Positive Control Check. A PCC would NOT
have helped Clem. With the elevator connecting bolt taped over, the
glider would have most likely passed the PCC! I am all in favor of
doing the Critical Assembly Check. I always do mine twice, first after
rigging, second before launch. Of all of the accidents described, most
would have been avoided by doing a proper CAC, not PCC!

On Jun 4, 8:56*am, Andreas Maurer > wrote:
> On Tue, 3 Jun 2008 19:43:51 -0700 (PDT), wrote:
> >Please name one accident of a glider with auto hookups that could have
> >been prevented by a positive control check. I sure don't know any. A
> >seized bearing will be detected by simply moving the stick. In all
> >gliders I know there is no scenario of control failure that would
> >necessitate a positive control check for detection.
>
> There have been SEVERAL incidents and accidents of DG gliders where
> the automatic hookup of the elevator was not connected correctly.
>
> Not to mention several (unfortunately usually fatal) crashes of
> gliders where the auto hookups were connected correctly, but the
> horizontal tail was not. Ernst-Gernot Peter and Clem Bowman come to my
> mind...
>
> >You are making a slippery slope argument. Should we mandate annual
> >stress tests of wings in the name of safety? Overhaul all tost
> >releases every 100 cycles?
>
> Nope... but to do a simple 2 minute check before the flight...
>
> Bye
> Andreas

[Ian]

On 4 Jun, 20:27, "noel.wade" > wrote:
> > > On Jun 3, 7:18*pm, wrote:
>
> > After all, he's going to be the one in trouble if he's wrong. But it
>
> Let's tackle that statement once and for all, shall we?

> I know this wasn't Ian's main point in his post - but its important to
> mull this over before you think that "its OK becuase I'm the one who
> will pay if I screw up". *You can't be that certain.

OK, I will happily amend that to "He's the one person who will
certainly be in trouble if he screws up..."

> P.S. *Contrary to popular belief, its possible to be safe AND still
> have a ton of fun. *Being safe doesn't mean being nasty or boring - it
> just means taking 5 minutes to be responsible!

Of course. That's why I do positive control checks. But one of the
best ways to reduce safety is to make checks and routines /too/
automatic. I think it is much better to have people follow routines
they've thought about than follow a checklist blindly.

I think, for example, of all the pilots trained by BGA instructors in
K21s (or K13s or Bocians or ...) to say
"...strapstightinstrumentsoknoflapsfittedcanopyclos ed..." pre take-off
or
"windslightlycrossfromtherightundercarriagefixeddow nspeedappropriate ...."
while downwind.

Ian

[Herb]

On Jun 3, 8:13 pm, ContestID67 > wrote:
> A recent accident (disconnected aileron) got me thinking about
> positive control checks. I searched the RAS archives and didn't find
> any details on how people do this.
>
> I was trained by my CFIG, like most of you I hope, to do a positive
> control check every day. Actually it was more like it was drilled
> into me. This was even done on club ships that remain assembled for
> the season.
>
> As a beginning pilot I would sit in the cockpit and move the controls
> as someone more experienced put their hands on the flight surfaces.
> Later I found that anyone can handle the controls, it's the hands on
> the surfaces that was much more telling if things were connected
> properly or not. My ship does not have automatic hookups so this is
> especially important to me.
>
> I got into the habit of having my assistant move the control one way,
> then the other, then back again with full deflection. All the while I
> was putting pressure on the surface and, at the same time, wiggling
> the surface to simulate take off vibration. So far, no incidents,
> knock on wood.
>
> So, the question is, how do *YOU* do your positive control check?
>
> John "67" DeRosa

John,

Your topic is an old favorite of mine. When starting glider flying in
this country many years ago I was appalled by the way positive control
checks were done. The pilot was in the cockpit, in line for getting
towed and a more or less hapless assistant was asked to lock a
particular control surface or the airbrakes with their hands. The
pilot would then bang the stick around and declare the airplane safe
for flight (leaving the assistant with pinched and bruised fingers).
You already described well a better way to do this. Put the assistant
into the cockpit, yes, sitting in it, not just standing outside. Have
her move control surfaces on your command, slowly and deliberately.
The pilot will put pressure on those surfaces simulating in-flight
forces around the center position but also test full deflections.
Walking around the glider doing this also allows for a full assembly
check, looking for mylar seals, hinge conditions, gap tape, tire
inflation etc.
My wife and I have done this for many years with me calling out the
control movements (in German) and her repeating them and executing.
It's been a source for amusement for many bystanders but I believe it
kept me safe.
Now, I can teach you to do this in German (with a Colonel Klink voice)
but that's not really necessary...

Herb, J7

[BB]

> Now, I can teach you to do this in German (with a Colonel Klink voice)
> but that's not really necessary...
>
> Herb, J7-

Please, Herb! That would make it much more fun.

More seriously, missing in much of this discussion is the approach
that US contests have taken to this whole question. We don't call it a
"posiitve control" check, we call it a "critical assembly" check.
Whatever you think of the value of pushing around control surfaces on
gliders with automatic hookups, "critical assembly" includes making
sure the bolt is in the horizontal stab (Schleicher) or stub pushed in
(Schempp), the mylar isn't falling off the tail, the main pins are in
and locked.

John Cochrane

[JJ Sinclair]

> My wife and I have done this for many years with me calling out the
> control movements

Just had a terrible thought, check out this scenario.........

My whife doesn't come to the airport much anymore, so I ask the pretty
little thing who's been interrupting my assembly to help with a
control check. She says sure and jumps in the cockpit (like Herb
recommends). We go through the left aileron, left spoiler, elevator,
right spoiler, right aileron...................she hasn't missed a
beat. Then I say, Oh I forgot the flaps. Which one of these handles
does that, she asks sweetly? It's that little black one down on the
left side.................BAM the ships alams to the ramp as the
landing gear retracts!

Errrrrr, the OTHER little black handle down there on your left!!!!

Here's how I handle the control check (solo for above reasons) I have
automatic hook-ups.

I assemble with the aileron control locks in place. When she's
together, I attach a stiff bungee from the stick to the left rudder
pedal, which keeps the stick full forward and rudder full left. Then I
move out to the left aileron, remove the control lock and try to move
the aileron. If I can't move the aileron, it's connected. I then
replace the control lock and try the same thing with the right
aileron, If I can't move it, it's hooked up also. Next I pull full
spoilers and check to see they're both wide open and that the wheel
brake is locked. Then I close and lock the spoilers and check to see
that both spoiler caps are down and flush, indicating ther're hooked
up. Then I go to the rear and try to move the elevator and rudder. If
I can't move them, ther're hooked up also.
JJ
PS, I have seen a pilot retract the gear when asked to do a control
check.........it can happen!

[Sarah Anderson[_2_]]

JJ Sinclair wrote:
....
> PS, I have seen a pilot retract the gear when asked to do a control
> check.........it can happen!

Interesting, thanks for that detail. I've always wondered if it's possible to retract the gear
with weight on the wheel - that is, on the ground. One'd think it possible to design an over-center
mechanism that would make that impossible, or at least *really* hard to do.
But it is experiment I've never been willing to try.

Sarah

[[email protected]]

On Jun 5, 7:54*pm, Sarah Anderson > wrote:
> JJ Sinclair wrote:
>
> ...
>
> > PS, I have seen a pilot retract the gear when asked to do a control
> > check.........it can happen!
>
> Interesting, thanks for that detail. *I've always wondered if it's possible to retract the gear
> with weight on the wheel - that is, on the ground. * One'd think it possible to design an over-center
> mechanism that would make that impossible, or at least *really* hard to do..
> But it is experiment I've never been willing to try.
>
> Sarah

I have tried it. With the plane assembled, but still in the 'cradle',
extend the undercarriage, then lower the cradle until the weight is
all on the wheel, but it can only drop an inch (or less). Get in, and
try to retract the gear. In the Speed Astir, I can't do it with a
very firm pull on the gear handle.

[Bruce]

Distressingly easy on a Std Cirrus.

wrote:
> On Jun 5, 7:54 pm, Sarah Anderson > wrote:
>> JJ Sinclair wrote:
>>
>> ...
>>
>>> PS, I have seen a pilot retract the gear when asked to do a control
>>> check.........it can happen!
>> Interesting, thanks for that detail. I've always wondered if it's possible to retract the gear
>> with weight on the wheel - that is, on the ground. One'd think it possible to design an over-center
>> mechanism that would make that impossible, or at least *really* hard to do.
>> But it is experiment I've never been willing to try.
>>
>> Sarah
>
> I have tried it. With the plane assembled, but still in the 'cradle',
> extend the undercarriage, then lower the cradle until the weight is
> all on the wheel, but it can only drop an inch (or less). Get in, and
> try to retract the gear. In the Speed Astir, I can't do it with a
> very firm pull on the gear handle.

[Andreas Maurer[_1_]]

On Thu, 5 Jun 2008 14:39:47 -0700 (PDT), JJ Sinclair
> wrote:

>.BAM the ships alams to the ramp as the
>landing gear retracts!

I can assure you that an ASW-20 and a DG-300 retract their gear so
quick that even the gear doors are closed before the fuselage touches
the ground. If this happens on grass, there won't even be a damage.
I'd call this a fool-proof design...

Unfortunately the gear doors on the ASW-24 are crushed by the weight
of the fuselage.

Guess how we found out.

Since the last incident of this kind (yes... there were several) it's
mandatory that there needs to be a pilot in the cockpit who has
already flown the glider in question.


Bye
Andreas

[Michael Huber]

"BB" > wrote

> making sure the bolt is in the horizontal stab (Schleicher)

Just as a side note: in newer Schleicher designs the bolt is slightly
modified and cannot be removed from the tailplane. If you don´t fasten the
bolt its head protrudes which is easily detected during a check. Schleicher
published a TM allowing the modification of older designs in the same way.
Material and work required is negligible, it is convenient and a real
benefit in safety.

Just thought some owners might not know...

Michael

[J a c k]

ZL wrote:

> Do you do a positive control check on the towplane?



Absolutely! Every time I assemble one.


Jack

[[email protected]]

As long as JJ is confessing, I guess I can, too (especially since
there's already been at least one posting on this subject).

I've been doing solo positive control checks this season. I typically
camp at the airport for a contest and solo rig anyway, often before
anyone else arrives in the morning. I have a two-column printed
checklist. [41 assembly items, 20 cockpit equipment items, 7 task
items, 9 pre-launch items, and my old ABCCCD in-cockpit checklist just
to be sure. In addition to grouping, they're arranged so that I can do
a walkaround inspection in sequence. At the Std. Nats in Cordele this
year, Bif Huss and I compared checklists and I saw he had some
improvements based on his Navy-influenced training that I want to
incorporate.] I check everything off whether or not I have a helper. I
use a pencil so I can come back and pick up any items I skipped but
I'd just as soon not skip anything. Anyway, I lock the stick back and
centered, hard, with the lap belt, then yank/pull on the ailerons and
elevator. Then I release the stick and do several rapid full-
deflection cycles and watch the control surfaces and listen. Same
routine as JJ for the dive brakes. I think I'm safe doing it this way
with my ASW 24 with auto connections everywhere.

If I had an early ASW 20, I'd want to use a trained helper to move
each surface through its full deflection while putting a load on it,
plus some vibration testing. Plus a visual inspection to make certain
all the safety pins or sleeves were properly installed. Plus yanking
on the control rod going into the Hotelier connector itself.
Especially the elevator. Especially the elevator. Especially....

In aviation, as in life, we're all searching for absolute truths. In
the real world, a lot of things are situational or contextual. What's
safe on one glider or for one pilot or in one set of circumstances can
be dangerous when something is different. That's why we try to train
people to use judgment. Unfortunately, some pilots don't or can't seem
to exercise good judgment so we put these rules into place; e.g., the
critical assembly check at U.S. contests, which I voted for as an SSA
director but which I regularly violate by doing it myself (rather than
using a helper) because (1) I use a printed checklist (which has the
CAC items in bold) and (2) I reuse my wing tape multiple times so the
initials are on there every day regardless. :)

Now I'm really in trouble. But I'm a little frustrated with the
lengthy exchanges on RAS recently where various pilots argue adamantly
at length over their versions of the absolute truth: rules that should
NEVER be broken or that should ALWAYS be observed. Life isn't that
simple. If we were insistent on absolute safety, we'd never fly again.

Chip Bearden
ASW 24 "JB"
USA

[Ken Kochanski (KK)]

On Aug 4, 11:23*am, wrote:
> As long as JJ is confessing, I guess I can, too (especially since
> there's already been at least one posting on this subject).
>
> I've been doing solo positive control checks this season. I typically
> camp at the airport for a contest and solo rig anyway, often before
> anyone else arrives in the morning. I have a two-column printed
> checklist. [41 assembly items, 20 cockpit equipment items, 7 task
> items, 9 pre-launch items, and my old ABCCCD in-cockpit checklist just
> to be sure. In addition to grouping, they're arranged so that I can do
> a walkaround inspection in sequence. At the Std. Nats in Cordele this
> year, Bif Huss and I compared checklists and I saw he had some
> improvements based on his Navy-influenced training that I want to
> incorporate.] I check everything off whether or not I have a helper. I
> use a pencil so I can come back and pick up any items I skipped but
> I'd just as soon not skip anything. Anyway, I lock the stick back and
> centered, hard, with the lap belt, then yank/pull on the ailerons and
> elevator. Then I release the stick and do several rapid full-
> deflection cycles and watch the control surfaces and listen. Same
> routine as JJ for the dive brakes. I think I'm safe doing it this way
> with my ASW 24 with auto connections everywhere.
>
> If I had an early ASW 20, I'd want to use a trained helper to move
> each surface through its full deflection while putting a load on it,
> plus some vibration testing. Plus a visual inspection to make certain
> all the safety pins or sleeves were properly installed. Plus yanking
> on the control rod going into the Hotelier connector itself.
> Especially the elevator. Especially the elevator. Especially....
>
> In aviation, as in life, we're all searching for absolute truths. In
> the real world, a lot of things are situational or contextual. What's
> safe on one glider or for one pilot or in one set of circumstances can
> be dangerous when something is different. That's why we try to train
> people to use judgment. Unfortunately, some pilots don't or can't seem
> to exercise good judgment so we put these rules into place; e.g., the
> critical assembly check at U.S. contests, which I voted for as an SSA
> director but which I regularly violate by doing it myself (rather than
> using a helper) because (1) I use a printed checklist (which has the
> CAC items in bold) and (2) I reuse my wing tape multiple times so the
> initials are on there every day regardless. :)
>
> Now I'm really in trouble. But I'm a little frustrated with the
> lengthy exchanges on RAS recently where various pilots argue adamantly
> at length over their versions of the absolute truth: rules that should
> NEVER be broken or that should ALWAYS be observed. Life isn't that
> simple. If we were insistent on absolute safety, we'd never fly again.
>
> Chip Bearden
> ASW 24 "JB"
> USA

Agreed …

I had an asw20b (manual wing control hookups) and checked everything
three times because they were manual hookups, after all … and did a
pcc 99.999% of the time with a helper - never had a problem.

I then bought a ship with auto control hookups and thought I was safe
… and then discovered a problem one day as I cycled the controls on
the flight line before hookup. Root causes were a failure to position
the flap handle to the proper position for assembly - and a failure to
do a thorough control check. The latter caused in large part by a
belief that you could not assemble an auto-hookup ship
incorrectly.

Today, I do a CAC 100% of the time (admittedly only 99% with a helper)
- and I check/cycle everything three times - and I'm very attentive to
deflections/sounds/pressures that (even fractionally) differ from
'normal'.

BTW, having a helper does not insure you will find an assembly
problem ...

KK