Can all HSI's be slaved -- should they be?

Hello,

I'm just reading up on HSI's and I notice some planes have HSI's that
are not slaved. I know this means i'm supposed to check it every 15
minutes or so to make sure the HSI and the compass jive. I guess I
should still do that even if it was slaved... but what I am wondering
is if you can make a non-slaved HSI slaved by buying the additional
equipment. Or are certain HSIs not slaveable and thus would i need to
get a new HSI if I want a slaved one?

Thanks,

-dr

Moving map GPS is making the HSI the buggy whip of the 21st century...
Having noted that I am old school who enjoys using an RMI / HSI and vor
navigating to an ILS approach... Like the dodo I will be gone soon,
also...
Whether an HSI head can be slaved depends on the exact model... Check
with the radio shop on a given airplane...

denny

Denny wrote:
: Moving map GPS is making the HSI the buggy whip of the 21st century...
: Having noted that I am old school who enjoys using an RMI / HSI and vor
: navigating to an ILS approach... Like the dodo I will be gone soon,
: also...
: Whether an HSI head can be slaved depends on the exact model... Check
: with the radio shop on a given airplane...

When the installed price of a moving map IFR GPS is a large fraction of the
value of the plane, going old-school still makes a lot of sense. I'm a big believer
in bang/buck, and blowing $10K for a GPS on a $35K airplane does NOT make sense.

-Cory (PA-28-140/180 driver)

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

wrote:
Denny wrote:
: Moving map GPS is making the HSI the buggy whip of the 21st century...
: Having noted that I am old school who enjoys using an RMI / HSI and vor
: navigating to an ILS approach... Like the dodo I will be gone soon,
: also...
: Whether an HSI head can be slaved depends on the exact model... Check
: with the radio shop on a given airplane...

When the installed price of a moving map IFR GPS is a large fraction of the
value of the plane, going old-school still makes a lot of sense. I'm a big believer
in bang/buck, and blowing $10K for a GPS on a $35K airplane does NOT make sense.


How do you feel about blowing $10K, $2K at a time as you repeatedly repair your
electromechanical moving map (HSI)? Well, OK, maybe a slight exaggeration, and
of course there's no subscription cost for the HSI.

Anyway, the HSI presentation is compelling. I like the HSI-style presentation on
my GNS480. Sometimes it's more informative than looking at the map page.

In the larger view, electromechanical HSIs are the equivalent of buggy-whips.

Dave

Not all HS's are slaved. Slaving the DG portion of an HSI is not
necessary for an HSI to function. Having said that, MOST HSI's ARE
slaved. Slaving is a major expense on an HSI. There used to be slaved
DG's around, dont see them anymore.

: How do you feel about blowing $10K, $2K at a time as you repeatedly repair your
: electromechanical moving map (HSI)? Well, OK, maybe a slight exaggeration, and
: of course there's no subscription cost for the HSI.

: Anyway, the HSI presentation is compelling. I like the HSI-style presentation on
: my GNS480. Sometimes it's more informative than looking at the map page.

: In the larger view, electromechanical HSIs are the equivalent of buggy-whips.

I'll agree with that. I was referring more generally to normal old-school
(VOR-indicator, DME, etc).. not the fancier old-school like remote slaved compasses,
HSI's, etc. Those *are* electromechanical nightmares to keep running. Something like
a VOR/GS indicator isn't that complicated. It also doesn't have a subscription....

Just as an aside, many of the moving maps that I've seen are much more
difficult to follow accurately than old-school methods. I'm sure it can be done well
(I just haven't seen it). As a quick, "reset-your-situational-awareness," or to
visually see things like airspace boundaries, moving-maps are wonderful. To keep the
needle centered on an airway or LOC, they're useless without augmentation.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

wrote:
I'll agree with that. I was referring more generally to normal old-school
(VOR-indicator, DME, etc).. not the fancier old-school like remote slaved compasses,
HSI's, etc. Those *are* electromechanical nightmares to keep running. Something like
a VOR/GS indicator isn't that complicated. It also doesn't have a subscription....

I have to agree. Like cable TV rates, I believe that eventually
the subscription fees will be the means by which Garmin will pay its
salaries in the coming years (once they have you hooked). Paying for
udates every 56 days just to be legal is an expensive way to fly IFR.
Plus if you are a safe pilot you're gonna by the paper charts also).

You get a lot more "bang" (and the best of both worlds) with the
venerable King KX-155 LOC/GS equipment and a handheld GPS for backup
and situational awareness at fraction of the cost. These radios are
repairable and have the potential to last the average Joe IFR pilot
for a lifetime of flying.... or until the GPS units become more
affordable to people besides John Travolta. :^)

On 3-Feb-2006, ktbr wrote:

You get a lot more "bang" (and the best of both worlds) with the
venerable King KX-155 LOC/GS equipment and a handheld GPS for backup
and situational awareness at fraction of the cost. These radios are
repairable and have the potential to last the average Joe IFR pilot
for a lifetime of flying.... or until the GPS units become more
affordable to people besides John Travolta. :^)


Or until the FAA, in a cost-saving move, starts decommissioning VORs.
Actually, I'm about as "old school:" as they come, having earned my IR more
than 30 years ago, but I have to say that I can hold a better course using a
GPS moving map display than an HSI display. But using the map you do lose a
sense of wind correction.
--
-Elliott Drucker

wrote in message ...
(I just haven't seen it). As a quick, "reset-your-situational-awareness," or to
visually see things like airspace boundaries, moving-maps are wonderful. To keep the
needle centered on an airway or LOC, they're useless without augmentation.

Useless?

Intercept the purple line, keep it vertical. Zoom in if you want to be EXACT.

I'm sorry, I guess I miss your point!

Cheers,
John Clonts
Temple, Texas
N7NZ

Zoom in if you want to be EXACT.

No... you got it right there. Moving map helps you visualize on the *big*
scale... at least the way I've seen it. If you zoom in to where it's accurate enough
to nail a hold/airway/loc, it's not a moving map anymore. It's now an indicator. You
can also put additional indications on as an indicator and have both. In any event,
that's what I initially meant by "augmentation."

: I'm sorry, I guess I miss your point!

Don't get me wrong. A properly done moving map+indicator display can be
much more intuitive and have lots more information than a simple VOR needle. If done
improperly (like the way I've seen lots of my VFR friends with handheld spiffy-do
moving map GPSs), it leads to sloppy, lazy, and overconfident navigating.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************