Netto

On 8/2/2011 11:56 AM, kirk.stant wrote:

Major snip...

Slightly OT, but do you fly without an audio?

Probably more than 50% of the time. Learned that way, have had ships with and
without audio, and find it useful and a convenience, but far from
'life-or-death crucial.' For that matter, having: 1) flown (including
thermal-XC) without functioning vario (several times...usually from water in
the plumbing); 2) flown (thermal XC again) without functioning ASI
(intermittent 'T/U' on a series of XC flights before 'indubitable death'); and
3) flown (once, thermal XC again) w/o vario *and* ASI (water, again), I've
found the first two conditions are pretty much non-events, while the last
combination took maybe 15 minutes or so to get accustomed to, but one's butt
and ears are actually quite sensitive if you pay attention to 'em. The butt in
particular is really good at detecting vertical acceleration *changes* which -
if Joe Glider Pilot learns to pay effective attention to it/'em - is far
quicker than any vario, which displays motion only after it has occurred, no
matter how short the vario's time constant.


THAT is scary!

Why?

Especially, if you are staring at a stopwatch and
altimeter, trying to figure out what your climb rate is, and watch the
vario needle to center the thermal. Doesn't leave much time for
looking out the window...

Ah! Who said anything about 'staring'? Peripheral vision works quite well for
noting (say) vertical passage of a sweep second hand and progression of an
altimeter hand on routine panel scans. (Anyone who thinks measuring a climb
rate over less than 30 seconds is 'XC valid' is indulging in self-deception; I
happen to prefer 60 seconds as 'more honest.' In any event, it's probably the
rare glider pilot who doesn't scan SOMEthing on the panel once or twice a
minute. Time yourself some time!)

Furthermore, my instructor pithily noted, "Staring at the instruments doesn't
make you climb any faster." He further noted, "Besides, climbing after a
mid-air collision is generally impossible." Both droll understatements made
perfectly good sense to me, even if I had NOT paid very close attention to
listening to and learning from what he sought to convey to me.


The beauty of modern gizmos is that they do all that "stuff" for you,
and let you concentrate on what is going on outside the cockpit, where
there be dragons!

Agreed on both counts, but especially the 'dragons' bit. Situational awareness
is the key.

That's true not 'merely' in sailplanes. Consider the drive to and from the
gliderport...I don't - in the absence of a functioning speedometer - have any
trouble driving a vehicle with which I'm 'a few drives worth' familiar and
remaining speeding-ticket-free. BTDT in lots of vehicles, from cars to big
rigs to buses over the years. 'Ear calibration' is real. Situational awareness
is real. Practice ought not to be only a sometime event.

Of course, I'm not about to claim ear/butt calibration is as precise/effective
as 'the latest-n-greatest instrumentation,' but I hope the point that - at
least in the intermountain west on any averagely decent day for a 'moderately
experienced' sailplane pilot - 'modern gizmos' while usefully enabling, are
far from absolutely necessary. Cat-skinning remains a multi-method activity.

As far as Relative (or Super) Netto, it just takes one more bit of
math out of the cockpit - just like regular netto takes some math out
compared to plain old TE.

Granted, but you don't get it 'for free.' The instrument designer is making an
educated guess as to your ship's 'circling sink rate increment.' Presuming
curiosity, Joe Pilot's own tests may disagree with the designer's guess. But
more to the point, is it *really* so difficult to always subtract 2 knots from
a glanced-at instrument reading? As non-mathematical a mind as is mine, that
subtraction quickly became second nature for me. This is one case where I find
the raw data more rapidly comprehensible/useful than massaged data.
Cat-skinning, again...

So, I'm cruising along, waiting for a 5 knot thermal to climb in.
With a regular Netto, I've got to wait for a 7 knotter. With
relative, I just wait until I see 5 knots, and up we go!

Truthfully, I've tried both, and kinda prefer plain old netto,
especially when running under cloud streets...

Cheers!

Kirk
66

Regards,
Bob - no harm, no foul? - W