How Low to Spin??

This is one of the strangest threads I've ever read on this group.
It's a bit like arguing about how many aliens it takes to screw in
a light bulb.

You definitely should use a pre-takeoff check list. I can't imagine
anyone arguing about this.
The only relevant pre-landing item is "Gear down and locked".
Everything else should flow from a normal landing.
Use whatever spoilers you need. Keep the airspeed at or above
the yellow triangle. If you have flaps, use whatever you need.
How can you land without looking out? You don't need a
checklist for that. If you don't know what the wind is, you
ought not to be landing there. The landing pattern is no place to
be dumping ballast.

No stalling on turn to final allowed.

Good luck,

Allan

"Bill Daniels" wrote in message
news:45%_c.386696$%_6.208174@attbi_s01...

...SNIP...

For example: BUFSTALL (In downwind)

Ballast: Dump started 7 minutes ago, valve in open position, water should
be
gone by now.
Undercarriage: Visually check handle is securely in the down position
where
I put it a minute ago.
Flaps: Visually check, securely in landing position where they have been
since pattern entry.
Speed: Still correct for wind and turbulence.
Trim: Still set.
Airbrakes: Visually check, left hand still on correct handle since
testing.
Look: Surrounding airspace and landing area are still clear of conflicting
traffic - select aim point.
Landing: Mentally review, touchdown attitude, flaps to negative after
touchdown, stick back to make tailwheel heavy, brake smoothly.

Used in this manner, the BUFSTALL checklist can be done in just a few
seconds.

Bill Daniels

Ian Johnston wrote:

circuit extras are Undercarriage (check only, should be down
already), Speed, Airbrakes (in case frozen).

USA! I love it. U (because I've seen several gear-ups).

S (because it reminds one to turn early or late on
downwind, and compensate for headwind/look at the sock),
also, many landing accidents are undershoots.

A (less important, but worthy of a check to ensure you
don't have a flap handle (L-13), and that they actually
unlock)

Everything else should
have been done before or is plain bleeding obvious.

Yep, the rest could be further down the list...

I had one instructor who
used the F for "Fag (extinguish and chuck out of DV panel)"...

LOL! I had to read this one twice...


--

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

Chris Reed wrote:
Frank,

Not a troll. There's no BGA-mandated checklist for pre-landing checks, as
far as I know (this kind of thing changes regularly), and in any event as a
basic instructor I'm not permitted to let the student fly below 500 feet or
to teach this stuff, so what I wrote was about my own flying practices.
Certainly, in my pre-solo training (following the then BGA manual) in 1996/7
I wan't taught pre-landing checks.

I love the BGA instructor levels. Good for you being a basic instructor!

landing checklists are potentially
problematic because on training aircraft some parts don't apply - thus, e.g.
learning to say "Undercarriage - fixed" can cement the idea in a student's
mind that there is no need for action, so when moving to retractable
undercarriage they don't lower it.

We call this in the USA "negative transfer." And yep, having a bunch
of items ignored on a checklist is a bad way to introduce checklists.

(For what it's worth, I understand my wheels-up landing met all the common
criteria - 10th flight on retractable, so I'm just becoming comfortable with
it and not consciously thinking about the differences from previous
aircraft; high workload (trying to scratch away from a winch launch); and
distractions (other aircraft in the circuit and the launch point in an
unfamiliar place). Result - reversion to primary training which, of course,
was on fixed wheel aircraft).

I flew a power plane yesterday where a yoke clip was blocking BOTH
pilot views of the gear indicator. Took that bugger off...

In gliders I use my wife's hair clip: to retract the gear, first take
the clip off the gear handle and put it on the spoiler handle.
Then raise gear. When pulling spoilers for landing, if the clip is
in the way, put the gear down and put it on the gear handle, then use
spoilers.

Not perfect (what if I'm getting sucked into a cloud?) but it's worked
so far...


But how many people have accidentally landed with ballast? And is
it common in gliders to have a limitation that one can only land without
ballast? Kinda makes a rope break interesting...
--

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

You definitely should use a pre-takeoff check list. I can't imagine
anyone arguing about this.

Pre-takeoff is with a glider stopped, on the ground. Yep, a great
place to do a good thorough checklist. I think we all agree,
it's just I'm advocating a prioritized list...

The only relevant pre-landing item is "Gear down and locked".
Everything else should flow from a normal landing.
Use whatever spoilers you need. Keep the airspeed at or above
the yellow triangle. If you have flaps, use whatever you need.
How can you land without looking out? You don't need a
checklist for that. If you don't know what the wind is, you
ought not to be landing there. The landing pattern is no place to
be dumping ballast.

Allan

I'm thinking US is ok. Undercarriage seems primo, beyond that I really
do consciously think about airspeed because of the wind, and there
really are ballast issues (two people or one in a two seater?).

The rest does seem very subconscious, but I'd guess there are
differing thoughts. If I was flying something that I had
a subtle ballast imbalance in previously, I might add that
next. If it was an L-13 and I was prone to mixing up flaps and
spoilers, I'd add it. But you're right, from what I've seen,
I think U should be number one for many people...
--

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

Ian Johnston wrote:

Personally, I think the best idea is to work out a personal check
list, where each item appears as a result of thought and decision.
And, of course, discussion with other pilots and instructors,
intelligent reading of accident reports and so on.

!!!!

Absolutely. I'm a big fan of teaching pilots to evaluate their own
weaknesses too. They make checklists which focus on the things
they are likely to do wrong. I have three pilots who fly one
partnership aircraft, and they all use their own custom checklist.
Two are long and pedantic, one is shorter and much more focussed,
but each works well for the personality of the pilot.

And from this thread, there have been some excellent points, but
it seems clear we all use different checklists based on our
varying needs and aircraft...

--

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

Eric Greenwell wrote:

Unfortunately, +5 knots is not very good insurance against gusts and
turbulence, which typically increase with wind speed. Or was this
supposed to be added on top of the "1/2 the wind speed"? If so, I
suggest the +5 knots is redundant in general (specific sites [hill
sites, for example] may require much higher speeds, of course).

US flying handbooks seem to suggest 1.3 times stall speed for
approach. Perhaps the aircraft POH differ (so I won't address that,
as there are too many reasons for that and too many POHs to
speak clearly to). But at 1.3 times Vso, for the gliders I know
of that stall at 30kts+, this means 40kts, which is 10 kts over
stall speed, and seems pretty good. With a 20 knot headwind,
now one would be on final at (1.3 x 30) + (1/2 x 20) = 50kts.

That seems pretty good for a glider that stalls at 30 kts.

So yep, it's a SWAG (scientific wild arse guess), but it seems
ok. Now a thermal right at flare and touchdown is a much
more interesting problem, but hey, ya gotta land SOMETIME!

I believe, but have no direct evidence for it, that it was chosen
empirically: over many years, people that used that value had it work
out well, so it became the recommendation. I suspect the origin is now
shrouded in the fog of history.

Yeah, trying to figure out the polar during landing was probably just
too complicated. The GFH tries to simplify things to 7th grade math.
Yep, so a 14 year old can do it
--

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

Mark James Boyd wrote:

But how many people have accidentally landed with ballast?

Thousands, I'm sure, over the years. I've done it. If you do it
intentionally so you can adjust your landing, it's not a problem, but if
it's unintentional, you can find yourself wondering why you aren't
stopping...

And is
it common in gliders to have a limitation that one can only land without
ballast?

Yes, it is. They can do it, of course, but on some gliders it can raise
the weight 40%, and the landing speed 20%, so it's going to be lot
harder to stop! Another potential problem is a leak on one side means
one wing can be a lot heavier than the other, so it goes down first and
early, often leading to a ground loop.

The structural margins are reduced, but still well within the G loadings
of the usual landing.

Kinda makes a rope break interesting...

Yes, as the turn radius is increased and turn rate lowered, in addition
to the weight and landing speed issues.



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

Eric Greenwell
Washington State
USA

In gliders I use my wife's hair clip: to retract the gear, first take
the clip off the gear handle and put it on the spoiler handle.
Then raise gear. When pulling spoilers for landing, if the clip is
in the way, put the gear down and put it on the gear handle, then use
spoilers.

Not perfect (what if I'm getting sucked into a cloud?) but it's worked
so far...

In my club's B4, we used a short length of a heavy duty cardboard roll
the same way. One day, a bunch of years ago, the Kinsman ridge was
cooking and the clouds were just above ridge top and I had to run the
ridge at 100 knots and/or spoilers to keep out of the clouds. I kept the
gear up due to the high speeds. I got used to using the spoilers with
the cardboard tube still on it. You know what happened but because the
landing was on grass, only the paint was slightly scuffed (a B4 is
metal, BTW).

The fault was clearly my failure to use a proper landing checklist. I'm
MUCH better at using a landing check list now :-). Still, when I bought
the LS6, the first thing I did was to install a gear warning.

Tony V.

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.

Close to it but, yes - as you can see in the lines drawn on the L23
polar of the article
http://home.comcast.net/~verhulst/GB.../headwind.html

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.

I suspect that you may be confusing the "best speed to cover the most
ground in a headwind" with "the best speed to make a safe approach to
landing".

Tony V.

At 15:42 07 September 2004, Tony Verhulst wrote:

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.

Close to it but, yes - as you can see in the lines
drawn on the L23
polar of the article
http://home.comcast.net/~verhulst/GB.../headwind.html

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.

I suspect that you may be confusing the 'best speed
to cover the most
ground in a headwind' with 'the best speed to make
a safe approach to
landing'.

Tony,

As I read his question it, he was asking for 'best
speed to cover the most ground in a headwind. Actually,
he seemed to confuse the two in the question.