How do you leave this airport IMC?

Matt Whiting wrote:

Bob Gardner wrote:

You may be remembering some Canadian regs. The MSA is irrelevant. It has no
operational significance and is not part of an instrument approach
procedure. Under Part 91, you don't have any takeoff minimums.

I thought published takeoff minimums applied to Part 91 operations. No??

Matt

No.

Paul Lynch wrote:

Under 91 there are no takeoff minimums (unless specifically stated in a
departure procedure) for any size aircraft, including a 747.

Or, contained on a SID, in which case they become part of your ATC clearance.

"Paul Lynch" wrote in message
news:GnPle.4510$%Z2.1986@lakeread08...
Unless there are specified takeoff minimums, a flight conducted under Part
91 does not have any departure weather requirements, only
destination/alternate requirements. That is where judgement comes into
play. You can legally takeoff with only enough viz to see the centerline.

Actually, there isn't even any requirement to be able to see the centerline.
My instructor once had me take off under the hood, to show that a
zero-visibility departure is possible. (He didn't recommend doing it for
real, of course.)

--Gary

In a previous article, "Gary Drescher" said:
Actually, there isn't even any requirement to be able to see the centerline.
My instructor once had me take off under the hood, to show that a
zero-visibility departure is possible. (He didn't recommend doing it for
real, of course.)

I had three different instrument instructors, and they all had me do that,
and then said "but you'd never do it for real, of course". Then why make
me do it?

The closest I had was leaving Muskegeon after being weathered in there
leaving Oshkosh. Off the approach end of the runway there was a wall of
fog and low visibility weather, but I could see both ends of the runway
and scattered clouds at a few thousand feet. The ATIS was reporting RVR
instead of visibility, and when I called for my clearance the controller
asked if I was sure I wanted to depart in this. I told him the visibility
situation, and he explained that the tower and the RVR sensors were in
that wall of fog.

If I'd had problems I could have landed downwind through VFR conditions,
or done a tricky approach to the upwind runway. I know which one I would
have taken.

--
Paul Tomblin http://xcski.com/blogs/pt/
I assume HR did send out the ad I wanted, not "apply for a cool job if
you're a clueless ****".
-- The Flying Hamster, on the receiving end of too many CVs

"Steven P. McNicoll" wrote in message
ink.net...

"Journeyman" wrote in message
. ..

On the way to Pinckneyville last weekend, I stopped at Jimmy Stewart
Field, Indiana, PA. KIDI. I had to shoot the GPS 28 approach with
a cirle to land 10. There's a nice transition off the Revloc VOR.

Since we had a late start, we had planned to stop there for the night,
but by the time we left for the hotel, the overcast had broken up and
it was clear. Next morning, we left VFR.

Looking at the plates, 10/28 has minima 300-1 and 600-1 respectively.
The procedure for runwya 10 is to climb runway heading to 2300 before
proceeding on course. The MSA for the area is 4200. How do you get
from the DP to the nearest Victor airway safely when it's 300 and 1?


Departing runway 28 I'd make sure I crossed the departure end of the
runway at least 35 feet above the departure end of runway elevation, that
should be easy as the runway slopes downward to the west some 45 feet.
I'd climb to 400 feet above the departure end of runway elevation before
making my initial turn and I'd maintain a minimum climb gradient of 200
feet per nautical mile until above the minimum IFR altitude.


If there are no specific instructions on the DP it is considered a "diverse
departure". Like Steven says, you only have to cross the departure end of
the runway at 35' (or greater) and climb 200'/nm to 400' at which point you
can turn any direction and continue to climb 200'/nm to a published altitude
(MEA, MOCA, OROCA). The actual obstacle plane is 152'/nm so you are gaining
48' of additional clearance each mile if you are climbing the minimium
(200'/nm).

In the IDI case there are obstacles that penatrate the obstacle plane, that
is the reason for listing TO minimiums. Once you are above the 300' or 600'
you won't hit anything if you climb 200'/nm. Below those altitudes you must
avoid obstacles visually

The "gotyas" on a departure of this kind are cross winds and tail winds.
Crosswinds can put you off centerline and into the obstacles, You really
should be flying a runway track as opposed to a heading. A tail wind will
reduce your climb gradient because of your increased groundspeed. In really
strong winds you might want to climb higher than 400' before turning and
make your turns into the wind even if it means turing 300 deg instead of 60
deg.

There was an article in IFR about diverse departures recently.

Mike
MU-2

"Paul Tomblin" wrote in message
...
In a previous article, "Gary Drescher" said:
Actually, there isn't even any requirement to be able to see the
centerline.
My instructor once had me take off under the hood, to show that a
zero-visibility departure is possible. (He didn't recommend doing it for
real, of course.)

I had three different instrument instructors, and they all had me do that,
and then said "but you'd never do it for real, of course". Then why make
me do it?

Possibly just because it's fun and harmless (under the hood with an
instructor, that is).

Or if you really stretch your imagination, you might come up with a rare
scenario in which a zero-visibility departure is warranted (say you're in a
remote area with someone who's having a medical emergency). In that case,
you're probably better off having at least tried it once before.

--Gary

Gary Drescher wrote:

"Paul Tomblin" wrote in message
...

In a previous article, "Gary Drescher" said:

Actually, there isn't even any requirement to be able to see the
centerline.
My instructor once had me take off under the hood, to show that a
zero-visibility departure is possible. (He didn't recommend doing it for
real, of course.)

I had three different instrument instructors, and they all had me do that,
and then said "but you'd never do it for real, of course". Then why make
me do it?


Possibly just because it's fun and harmless (under the hood with an
instructor, that is).

Or if you really stretch your imagination, you might come up with a rare
scenario in which a zero-visibility departure is warranted (say you're in a
remote area with someone who's having a medical emergency). In that case,
you're probably better off having at least tried it once before.

That is one of the few situations where I would consider a zero-zero
takeoff. I agree that it is good practice and good to know that it can
be done in an extreme situation.

Matt

That is one of the few situations where I would consider a zero-zero takeoff. I agree that it is good practice and good to know that it can be done in an extreme situation.

Did one at IAD. Could barely see the jets in front of me while
taxiiing. Fifty feet up, blue sky.

Jose
--
The price of freedom is... well... freedom.
for Email, make the obvious change in the address.

Jose wrote:

That is one of the few situations where I would consider a zero-zero
takeoff. I agree that it is good practice and good to know that it
can be done in an extreme situation.


Did one at IAD. Could barely see the jets in front of me while
taxiiing. Fifty feet up, blue sky.

Would have been dicey had your engine failed at sixty feet...


Matt

Would have been dicey had your engine failed at sixty feet...

So is VFR on top of fog. Nothing is risk free, and the runway is very
long and very wide.

Jose
--
The price of freedom is... well... freedom.
for Email, make the obvious change in the address.