Garmin 530 WAAS?

How are they going to provide outbound guidance in a hold, and make proper
allowance for wind, while allowing a standard rate turn to inbound?


"Sam Spade" wrote in message
...
scott moore wrote:
Al G wrote:

Thanks to the certification and AML STC approval, owners of Garmin's
popular GNS 400/500 series panel-mount avionics will be able to upgrade
their products to meet the FAA's WAAS standards* without a field
approval**. These upgrades include 5 Hz position updates, faster map
redraws, fully coupled and guided procedure turns and holding patterns,
and increased XM weather content. Pilots will also experience
significantly enhanced functionality because of the WAAS LPV, LNAV/VNAV,
LNAV+V, and LNAV approach capabilities.


Coupled procedure turns and holds? Why is WAAS an enabling factor for
that?

I don't read where he said WAAS is the enabling factor for track-guided
procedure turns or holding patterns.

How are they going to provide outbound guidance in a hold, and make proper
allowance for wind, while allowing a standard rate turn to inbound?

With ordinary approach certified GPS.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

"Jose" wrote in message
om...
How are they going to provide outbound guidance in a hold, and make
proper allowance for wind, while allowing a standard rate turn to
inbound?

With ordinary approach certified GPS.


So how does ordinary approach certified GPS do it? None of those I have
used do it.

"Stan Prevost" wrote:


"Jose" wrote in message
om...
How are they going to provide outbound guidance in a hold, and make
proper allowance for wind, while allowing a standard rate turn to
inbound?

With ordinary approach certified GPS.


So how does ordinary approach certified GPS do it? None of those I have
used do it.

The 430/530 didn't provide hold guidance prior to the upgrade. The point he was trying to make is that
this feature is part of the same upgrade package, but not specifically related to WAAS. As Sam said, the
big-boy FMSs have provided hold and procedure turn guidance for years, using just VOR/DME or
DME/DME position updating.

Mike

"Mike Adams" wrote in message
...
"Stan Prevost" wrote:


"Jose" wrote in message
om...
How are they going to provide outbound guidance in a hold, and make
proper allowance for wind, while allowing a standard rate turn to
inbound?

With ordinary approach certified GPS.


So how does ordinary approach certified GPS do it? None of those I have
used do it.

The 430/530 didn't provide hold guidance prior to the upgrade. The point
he was trying to make is that
this feature is part of the same upgrade package, but not specifically
related to WAAS. As Sam said, the
big-boy FMSs have provided hold and procedure turn guidance for years,
using just VOR/DME or
DME/DME position updating.

Mike

But my question is how do they do it? The desired track in a hold is not
the pretty little racetrack pattern with two parallel sides and two
semicircles at each end, except in a no-wind situation. The desired track
on the outbound leg is that which will put you in a position from which a
standard rate turn will roll you out on the inbound track That is why we
fly outbound with a multiple of the inbound wind correction.. The GPS box
cannot do that without knowledge of the wind. A fancy FMS which determines
the wind correction from the autopilot can do that, but how can a standalone
GPS box, WAAS or not, do that?

But my question is how do they do it?

I don't know how they do it. (and true, the 430 doesn't alter the hold
track for wind, though it does for airspeed). There's no reason it
couldn't though - WAAS has nothing to do with it. As long as you know
heading, airspeed, groundspeed, and track, the rest is just math.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

"Stan Prevost" wrote:

But my question is how do they do it? The desired track in a hold is
not the pretty little racetrack pattern with two parallel sides and
two semicircles at each end, except in a no-wind situation.

An FMS does fly all holding patterns with two parallel sides and two semicircles. It corrects for the wind
by commanding the bank angle required to track the semicircle. This may be more or less than a
standard rate turn, depending on the wind.

Mike

"Stan Prevost" wrote:
The GPS box cannot do that without knowledge of the wind. A fancy FMS
which determines the wind correction from the autopilot can do that, but
how can a standalone GPS box, WAAS or not, do that?

Stan,

According to a Garmin rep I spoke to at NBAA, it can compensate if it is
connected to an airdata computer. Even the current 430/530 models can be
connected to an ADC, which allows them to display TAS and winds.

-Mike

I can buy that, Mike. Given access to the air data, the machine can compute
an outbound track and turns to make it work out. But that was my point, the
box needs that data. Most of the GPS-equipped small airplanes have
standalone GPS boxes, no FMS, no ADC.

As Sam mentioned, increasing the bank angle to 30 degrees for the inbound
turn helps in some ways. For a small airplane holding at 90 kts, tracking
an outbound leg offset by 1 nm, and a 30 kt xwind, it just about works out,
IF the pilot knew he needed to use a 30 degree bank turn to inbound. I am a
bit reluctant to encourage pilots to use the higher roll rates associated
with those maneuvers in IMC, for physiological reasons.

I don't think my S-Tec 55 autopilot, without GPSS, could follow the
maneuver, anyway.

Stan


"Mike Murdock" wrote in message
...
"Stan Prevost" wrote:
The GPS box cannot do that without knowledge of the wind. A fancy FMS
which determines the wind correction from the autopilot can do that, but
how can a standalone GPS box, WAAS or not, do that?

Stan,

According to a Garmin rep I spoke to at NBAA, it can compensate if it is
connected to an airdata computer. Even the current 430/530 models can be
connected to an ADC, which allows them to display TAS and winds.

-Mike

Stan Prevost wrote:


Mike


But my question is how do they do it? The desired track in a hold is not
the pretty little racetrack pattern with two parallel sides and two
semicircles at each end, except in a no-wind situation. The desired track
on the outbound leg is that which will put you in a position from which a
standard rate turn will roll you out on the inbound track That is why we
fly outbound with a multiple of the inbound wind correction.. The GPS box
cannot do that without knowledge of the wind. A fancy FMS which determines
the wind correction from the autopilot can do that, but how can a standalone
GPS box, WAAS or not, do that?



Standard rate turns become irrelevant if they do it right. Keep in
mind, it is standard rate turn or 30 degrees of bank, whichever is less.

So long as Garmin observes the inbound limit (in the case of timing) or
the outbound distance limit in the case of distance, and a pattern is
computed to roll out on course, inbound, they would have a compliant
pattern.