How Low to Spin??

On Wed, 1 Sep 2004 17:35:06 UTC, (Tom Seim)
wrote:

: "Ian Johnston" wrote in message news:cCUlhtvFIYkV-pn2-uRi7CmzCveOr@localhost...
: On Tue, 31 Aug 2004 18:19:55 UTC, (Tom Seim)
: wrote:
:
: : 2. An immediate check of each control linkage after hookup.
:
: Which I always get someone else to do.
:
: I have mixed feelings about this. Nobody knows your glider as well as
: you do (save, perhaps, by someone flying-or flown-the identical
: model).

That's a good point. But all I ask them to do is check the six control
connections, and I tell them exactly what to look for: can you feel
the pin sticking out there? can you see that the clip is on there? and
so on. Sure, if I don't say it won't be checked, but I find it helps
concentrate my mind on what needs done. And, on the topic of this
thread, I do have a printed checklist, but only for other people. I
reckon that if I don't know what needs done to rig such a simple
glider I shouldn't be flying it. I expect opinions will vary on that
...

Ian

Robert Ehrlich wrote:

BTW, as I noted in another thread, spins are not caused by lack of
airspeed, but uncoordinated use of the controls -- at least in modern

Well, you have to precise what you are calling "uncoordinated use". I
remember an incipient spin in an ASH25 (can be considered as a modern
sailplane, although it existed well before I started gliding 9 years ago).

Of course the controls
were badly crossed, but some amount of cross control is normal in order
to counter induced roll and induced yaw, this is not an uncoordinated
flight, the yaw string is is the middle.

As I mentioned earlier, as the bank angle increases, and the
wingspan increases, the AOA of the inner and outer wing
can differ by several degrees with the yawstring centered.

I think we calculated for 18m wingspan and 30 deg bank, something
like 3 degrees, and 6 degrees for 50 deg bank. But hey, this
is just a newsgroup, please do the math yourself and tell us what
you get.

It was a bit complex to calculate. Radius of circle for inner vs.
outer wingtip, stall speed and sink rate and... I don't remember
all the details, but it seemed painful...

Eric and Marc (?) I think made good points that at steeper
banks stalls are hard to muster. So perhaps the 10-30 deg banks
are really what we are discussing...
--

------------+
Mark Boyd
Avenal, California, USA

Tom Seim wrote:

I recently read the accident report of the ASW20 crash (fatal) at
Williams, CA. Per the check list, they did a positive control check of
the elevator by having the assistant (co-owner) hold the elevator
while the pilot applied force on the stick. Resistance was felt, check
list passed. Only problem was the elevator was not hooked up and what
the pilot felt was the push rod hitting the bottom of the elevator.
Now, if the guy just LOOKED at the connection it would have been
obvious that it was not hooked up (it is in plain site).

Following a list may give you tunnel
vision. A DC-9 was landed gear up by two experienced pilots following
a check list (they missed one step). They were so certain that they
had done everything right that they ignored the lack of the sound and
thump of the gear lowering (common sense, again).

I took my CFIG checkride with the FAA. On it, I told him
"there is no PCC in the schweizer manual for any checklist. The
checklist requires inspection during preflight of the connections.
I find the (over)use of the PCC distracts the pilot from the
more important action: checking the connection itself."

He nodded, and we moved on to other things.

My understanding of contests is that an "assisted PCC" is
required by many CDs. I wonder if an "assisted connection inspection"
wouldn't be a better, higher, priority...

As far as the DC-9, I'd guess this is another example of
information which is lost in the noise.

I remember asking a car dealer about his warranty. He had a
super long list of covered items. He said just about everything was
covered. I asked him to make a nice short list of what WASN'T
covered. He couldn't, and we parted.

Useful information is prioritized. When I write professionally,
I do a 200 word abstract, then a 1000 word introduction/summary,
then a 5000 word detail. And yes, the 200 word abstract is first.
I'd like to see all writing (including the checklists) follow this
idea. A few important points at the front, the nit details at the back.
--

------------+
Mark Boyd
Avenal, California, USA

In article ,
Kirk Stant wrote:
(Mark James Boyd) wrote in message news:412fa9ba$1@darkstar...
Kirk Stant wrote:

1) If they ain't locked for takeoff, a gnarly pio

1. Use a checklist. Oh, and why is the tow pilot fanning his rudder
at me?

LOL! "use a checklist."
Kind of covers everything, huh?

"Oh yeah? He had an accident? I bet he
didn't use the checklist!"

So Mark, you don't use any checklist before taking off? Yeah right,
bull****. What is it, not macho enough for you?

Kirk. I am very sorry that this appeared to be a condemnation of
checklists. It was not, and in fact my intetion was to strongly
support the significance of what you and others have stated. The
elevator connection on preflight, and the dive brakes closed, as you
mention, are very important.

I was simply pointing out that the bland assertion that one should
"use a checklist" can actually cause an accident. If the pilot
now uses that to (wrongly) make a checklist which is very long and
does not prioritize the importance of the items, it can cause
fatigue and inattention.

So yes, I certainly use a checklist, but I ALWAYS use a
prioritized checklist. And I teach students how to make a custom
prioritized checklist for a new aircraft by looking at the
accident reports and starting with that.

Again, Kirk, I apologise if this seemed offensive. I was
only wanting to gently steer us into a more detailed discussion.

I use CBSIFTCBE (instead of the useless SSA ABCCCDDEEEEFGHHHwhatever)
RELIGIOUSLY before every takeoff. It's as sacred as the old GUMP
checklist. No paper required, only need one brain cell awake to run
it. And even with that, I've managed to get airborne twice with my
spoilers unlocked - in an LS4 and my current LS6. Both due to
interrupted/rushed launches. No big deal, the tow didn't even notice
(because LS brakes don't suck open, they just stay cracked) the
decreased climb rate. I caught them both below 100', closed the
boards, swore a bunch, then went on to convincingly blow the task of
the day.

So CBSIFTCBE. Ok, what are the top 3? Is spoilers locked one
of the top 3 for you? I'm just saying put that one as the FIRST
item, instead of elsewhere if a) it is the number one checklist item
cause of fatal accidents in the type of glider you fly where you fly it
and b) if it is something that you tend to miss more often than other
items. At Truckee, maybe the low rope break briefing is more
important than the trim set. In the PW-5 at Avenal, maybe the
spoilers locked is more important than the emerg. brief. If
the student often reaches out to close the vent on takeoff and this
makes a PIO, then for him, maybe the vent closed for takeoff is the
number one item.

I simply do not believe that there is a correct ordering, or a
correct checklist that can work for all gliderports and all pilots
and all aircraft. I strongly believe in prioritized, personal
checklists. The checklist, and the process to make it, are
really important.

Seriously, if your students aren't going through a "last chance" check
before commiting to takeoff, they have really bad instructors, to say
the least. And that is "using a checklist". And it will usually
prevent brainfade idiotic accidents from happening. Usually.

I agree with you Kirk, just in a little more detail...ok?
Thanks for the responses...and again sorry if it looked like
I was pickin' on you...
--

------------+
Mark Boyd
Avenal, California, USA

In article ,
Finbar wrote:
The discussion of a) overly-long checklists that don't get used and,
on the other hand, b) the need for checklists reminds me of a
discussion with a power instructor (instrument), who made a
distinction I hadn't encountered before, but it made sense. He
distinguished between a written procedure, a written checklist and an
oral checklist. Here's the idea:

Written procedu a written sequence of steps to take.
Written checklist: a written list of things to check.
Oral checklist: a memorized checklist. Should be very short, and
memorable, used only for a few last-minute and "death/destruction"
items.

A written procedure may be quite long and can be detailed. It may
contain some lower-importance items. It is used for setting up the
aircraft and should be used when there is time for it. Sitting next
in line for takeoff on the runway, barreling down final approach, or
right after a rope break - not good times for a written procedure.

One other item. I've found that numbering the written checklist
helps. Then, even solo, I read it aloud. I read "1", and aloud
then I do "2". I've found that if I skip a step, my brain goes
instantly "3 isn't after 1!" and I'm saved.

Again, I also prioritize it. This makes for an awkward flow
in some aircraft, but I can repeat items to get a good flow.

Anyway, all good stuff...
--

------------+
Mark Boyd
Avenal, California, USA

In article ,
Chris OCallaghan wrote:
I'd always assumed there were two factors in choosing a pattern speed.
First, safety, thus the +5 for turbulence. The other was to place the
glider at best speed to fly. That way if you have to put the spoilers
away, you are guaranteed to cover the maximum distance. If I recall,
the simple formula for best speed was best l/d speed plus 1/2 the
headwind. Don't recall the second ever being explained though. Just
seemed to fit.

http://www.stolaf.edu/people/hansonr/soaring/spd2fly/

was really useful for me. It sort of drove home the
1/2 headwind idea as being close enough, and was useful for
deciding 30-45 deg of bank was fine for rope breaks.
But look at it yourself. Of course the 2-33 data is in
there, provided by yours truly

--

------------+
Mark Boyd
Avenal, California, USA

At 18:24 01 September 2004, Chris Ocallaghan wrote:
I'd always assumed there were two factors in choosing
a pattern speed.
First, safety, thus the +5 for turbulence. The other
was to place the
glider at best speed to fly. That way if you have to
put the spoilers
away, you are guaranteed to cover the maximum distance.
If I recall,
the simple formula for best speed was best l/d speed
plus 1/2 the
headwind. Don't recall the second ever being explained
though. Just
seemed to fit.

It appears that if you draw a tangent to your glider's
polar beginning, not at zero, but at any given headwind
speed, the line will touch the polar at a point that
is best L/D plus half that headwind.

Nyal Williams wrote:
At 18:24 01 September 2004, Chris Ocallaghan wrote:

I'd always assumed there were two factors in choosing
a pattern speed.
First, safety, thus the +5 for turbulence. The other
was to place the
glider at best speed to fly. That way if you have to
put the spoilers
away, you are guaranteed to cover the maximum distance.
If I recall,
the simple formula for best speed was best l/d speed
plus 1/2 the
headwind. Don't recall the second ever being explained
though. Just
seemed to fit.


It appears that if you draw a tangent to your glider's
polar beginning, not at zero, but at any given headwind
speed, the line will touch the polar at a point that
is best L/D plus half that headwind.

I was under the impression it was added to give you a margin for gusts
and turbulence, which are usually less than the average wind speed. The
"half" was likely chosen empirically, as something that was adequate
almost all the time.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

On Fri, 3 Sep 2004 20:51:22 UTC, (Mark James
Boyd) wrote:

: And yes, the 200 word abstract is first.
: I'd like to see all writing (including the checklists) follow this
: idea. A few important points at the front, the nit details at the back.

You should see some of the downwind checklists/mnemonics in use in the
UK. They include things like "trim" - for people who wouldn't normally
think of using the trimmer, I presume - and, most bizarrely of all,
"lookout". I'm not sure that I want to share the sky with people who
need a mnemonic to remind them to look out...

Which is not to say that a /short/ list isn't useful, but sticking
more and more things on is just silly. Check lists are not operating
manuals.

Ian

--

I quite like the "lookout" element of USTALL (though I don't actually chant
the checklist to myself on circuit). What I use it for is a reminder that,
in addition to my normal lookout, I also need to pay attention to the other
side of the circuit, look for aircraft on long, straight in approaches, and
look at what's happening on the ground. This is a different mode of lookout
to XC or local soaring, and I usually find myself muttering "lookout" at
some point to remind me of the change of mode.

But I take the point - if the pilot doesn't lookout except in response to a
checklist, I'd like to be in a different part of the sky.

S (straps or speed?) is pretty useless on downwind, T (trim) ditto, and A
(airbrakes I think) is wierd - if you can't find them you're in trouble,
though if I flew a flapped glider or had the UC lever on the same side as
the airbrake (LS4s excepted) I'd add a mental note to check which lever I
intended to use for approach control.

U is quite clear in my mind, having landed wheels up once already, and
hoping not to do it again.

"Ian Johnston" wrote in message
news:cCUlhtvFIYkV-pn2-zikdWvOGpoiF@localhost...
You should see some of the downwind checklists/mnemonics in use in the
UK. They include things like "trim" - for people who wouldn't normally
think of using the trimmer, I presume - and, most bizarrely of all,
"lookout". I'm not sure that I want to share the sky with people who
need a mnemonic to remind them to look out...