How to do a Positive Control Check?

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

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.

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

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

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

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

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

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

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

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

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