How to do a Positive Control Check?

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!

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.

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

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/St...mbly_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

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

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/St...mbly_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...)

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.

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!

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

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/