Procedure turn in Strong X-wind

(smackey) wrote:
OK, I'm flying my local VOR-A which calls for an outbound heading of
252, then I'm suppoosed to turn 45 deg to 207 to begin the PT. But
there is a STRONG x-wind and I am already crabbed to about 215 to hold
the 252 outbound course.

That's a heck of a cross-wind correction: 37 degrees. Are you really
sure it took that much? If you're doing 90 KTAS, 37 degrees would imply
a 54 kt crosswind component, which seems unlikely.

I assume I turn to something not quite
approaching 170 (45 deg from 215), just something inbetween in order
to sort of track 45 deg off the outbound course and fly a bit longer
than 1 min so I don't get blown back through the inbound course when I
do the turn back toward the inbound course. It just seems weird to be
flying at almost 90 deg from the outbound course. Any opinions on
this?

In a really strong crosswind, a lot of the geometry of the PT gets blown
out of whack. For example, with the 37 degree WCA above, your outbound
speed is only 72 kts, so your 1-minute outbound leg doesn't get you as
far out as you normally would be. If you added in another 45 degrees,
you'd be heading 82 degrees away from the FAC and only making 12 kts
outbound (assuming a direct crosswind). Clearly this makes no sense.

What I would do in a situation like that is go for positive course
guidance on the outbound leg. Assuming the IAF/FAF is the VOR (like the
POU VOR-A,
http://www.myairplane.com/databases/...s/00286VGA.PDF), instead
of dead-reckoning your way through the PT, reset the OBS and track a
course 30 degrees from the FAC on the protected side. Essentially
you're flying the PT as a teardrop hold entry. I would track outbound
for 3-4 minutes; this is longer than your usual PT, but you want to give
yourself a bit of extra time to get setup on the inbound course. If
you've got any way of measuring your distance from the VOR (DME, or even
a VFR GPS), use it.

On the inbound turn, don't be a slave to making standard-rate turns. If
the CDI is coming in way faster than you expected, speed up the turn.
The alternative is blowing through the FAC and if you do that in a
strong crosswind, you may never manage to claw your way back in time.

A moving map GPS makes this soooo much easier :-)

On Tue, 23 Nov 2004 08:14:50 -0500, Roy Smith wrote:

On the inbound turn, don't be a slave to making standard-rate turns. If
the CDI is coming in way faster than you expected, speed up the turn.
The alternative is blowing through the FAC and if you do that in a
strong crosswind, you may never manage to claw your way back in time.


Yeah. Steep turns in the clouds is just what an inexperienced IFR
pilot needs.

I'll take going across the course anytime. There's no way a wind is
going to blow an aircraft so far across course that it will be a
serious problem.

In article ,
wrote:

On Tue, 23 Nov 2004 08:14:50 -0500, Roy Smith wrote:

On the inbound turn, don't be a slave to making standard-rate turns. If
the CDI is coming in way faster than you expected, speed up the turn.
The alternative is blowing through the FAC and if you do that in a
strong crosswind, you may never manage to claw your way back in time.


Yeah. Steep turns in the clouds is just what an inexperienced IFR
pilot needs.

I'll take going across the course anytime. There's no way a wind is
going to blow an aircraft so far across course that it will be a
serious problem.

I wasn't suggesting 45 degree bank angles, but going to 1.5 standard
rate isn't going to hurt anybody.

Keep in mind that if your outbound heading is 60 degrees off the FAC to
the left and your inbound heading needs to be 30 degrees off in the
other direction, you're making 270 degrees of heading change, which
takes a minute and a half at standard rate.

On Tue, 23 Nov 2004 08:28:11 -0500, Roy Smith wrote:

I wasn't suggesting 45 degree bank angles, but going to 1.5 standard
rate isn't going to hurt anybody.

Keep in mind that if your outbound heading is 60 degrees off the FAC to
the left and your inbound heading needs to be 30 degrees off in the
other direction, you're making 270 degrees of heading change, which
takes a minute and a half at standard rate.


Well, you didn't mention limits. But maybe 1.5 standard rate won't do
it either. Then what? Twice standard rate?

In my opinion, going across the course is vastly preferable to
steepening up a turn in the clouds, especially when you don't practice
it a lot, and most pilots don't.

wrote:

On Tue, 23 Nov 2004 08:28:11 -0500, Roy Smith wrote:


I wasn't suggesting 45 degree bank angles, but going to 1.5 standard
rate isn't going to hurt anybody.

Keep in mind that if your outbound heading is 60 degrees off the FAC to
the left and your inbound heading needs to be 30 degrees off in the
other direction, you're making 270 degrees of heading change, which
takes a minute and a half at standard rate.



Well, you didn't mention limits. But maybe 1.5 standard rate won't do
it either. Then what? Twice standard rate?

Whatever you are comfortable with. I have no problem going to 40
degrees in the clouds and routinely practice steep turns under the hood
every few months. I actually fly better steep turns under the hood than
I do visually. Go figure...


In my opinion, going across the course is vastly preferable to
steepening up a turn in the clouds, especially when you don't practice
it a lot, and most pilots don't.

It depends on how steep. To me, it is very sloppy instrument flying to
blow across a course by half a mile because I'm afraid to increase bank
from 15 degrees to 30.


Matt

wrote:

On Tue, 23 Nov 2004 08:14:50 -0500, Roy Smith wrote:


On the inbound turn, don't be a slave to making standard-rate turns. If
the CDI is coming in way faster than you expected, speed up the turn.
The alternative is blowing through the FAC and if you do that in a
strong crosswind, you may never manage to claw your way back in time.



Yeah. Steep turns in the clouds is just what an inexperienced IFR
pilot needs.

At most light plane speeds, a standard rate turn requires a bank of a
fair bit less than 30 degrees. So even increasing bank to 30 degrees
makes a lot of difference and this is hardly a steep turn. Roy's advice
is sound and I often increase or decrease from standard rate as
required. Any pilot who can't fly a 30 degree bank in the clouds, has
no business being in the clouds without an instructor.


Matt