SF Bay Area to San Diego

Just completed the trip last night. The Gorman pass is actually pretty
short, about 5 mins of flight to the LA basin, or looks like just a
minute or two if I'm going to Palmsdale. A very easy pass at least for
day time VFR.

Now, the wind was really strong this Saturday. It's over 40kts at 9K.
There is a Sigmet (is that Sigmet T?) for strong and severe
turbulence at or below 17k. I got a lot of pilot reports of strong
turbulence near my route and down draft over 1500fpm and these were
from twins and commuters. Somehow I decided to go forward. I figure
I'll reduce the speed to 100mph and climb to 11.5k and prepare to ride
it out, not really sure a good decision or not. But by the time I
reached the pass from the north, the air was very smooth. But I was
still very nervous and figured the turbulence must be ahead at the
leer side. But it never happened. It was very smooth all along. Not
sure if this experience, which might make me bolder, is good or bad
to me for the future. Can anyone share your experience with turbulence
in mountain flying? What is really happening in a severe turbulence?

Jizhong

On Fri, 21 Nov 2003 20:38:07 -0800, wrote:

Jim,

Thanks. I like simple rules. It's comfortable to hear about your rule.
So I should not do a night mountaineous flight with a single engine.
But I'm nore sure about the other two combination: SE at night or SE
over mountains. I'm also a little more reserved to do a night
mountaneously than yesterday. That's why I'm here hitting the
keyboard. Now, by the way, my proposed route is only a 10min flight
over a pass. Flat land both sides.

Jizhong
On Fri, 21 Nov 2003 11:43:03 -0800, Jim Weir wrote:

Single Engine
Night
Mountains


Pick any two.

Jim
(CFI from the mountains)



shared these priceless pearls of wisdom:

I'm thinking of a night flight. Will this be a
-foolish choice to cross the Gorman pass in the dark?
-
-Jizhong


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

Jim, now I have (assuming that's what I call Gorman Pass). :-) Do you
really think it's that hard?

Jizhong
On Sat, 22 Nov 2003 09:45:08 -0800, Jim Weir wrote:

Obviously you've never been over the Grapevine before.

Jim



shared these priceless pearls of wisdom:

Now, by the way, my proposed route is only a 10min flight
-over a pass. Flat land both sides.



Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

Greg,

Very nice post. Thanks. I just posted my shrot "pass" report. I said 5
min of passage. After reading your post, I realize that I could be
wrong. But that's certainly my honest impression. I was too concered
with the coming turbulence.

I'm still not sure if I want to do a night pass on the Grapevine. At
daytime, there looks like quite a few places at the foothills or near
the shore of the lakes that make good emergency landing spot. But it
would be impossible to tell at night. I feel like I will never land
at/on a highway. I hate eletricution when I'm dying. But I figure if I
ever fly at night through the Grapevine, I-5 would be a nice to follow
and avoid the moutains nearby.

Jizhong
On Sat, 22 Nov 2003 22:00:57 GMT, "Greg Goodknight"
wrote:

Jim, I've been over the Grapevine at night multiple times. In VMC, the area
is such that it is rare to not be within gliding distance of some lit chunk
of pavement that is more hospitable than the usual invisible night granite.
It is certainly more than a 10 minute passage, though; I'm not sure where he
got that number.

Many twins have such poor single engine performance that the extra engine
does little besides give a false sense of security; it will indeed allow you
to fly to the accident site. Having a well maintained single with a low Vs
and better glide ratio can be as safe. Safe is a very relative term here.
The "pick any two" from "Single Engine, Night, Mountains" guide is a good
starting point to evaluate a plan and to give folks pause, but as a real
go/nogo rule I think it is too simplistic.

To the unitiated, Tejon Pass (also known as Gorman or the Grapevine) is
between the California Central valley and the San Fernando Valley of Los
Angeles. There is an 8040' peak just 8 miles to the west of the airway and a
few others that are nearly as tall; to the east, the hills are nearly to
6000'. And a four lane (each way) freeway known as Interstate 5 cuts through
it, the main artery between northern and southern California. The actual
pass is marked as being at 4239'. The MEA on the V 23 airway is 9500', a
good bet for a night VMC flight and it has radar coverage by Bakersfield
Approach and LA Center.

In my Cherokee, at night in VMC, IFR or VFR Flight Following, I'd not
hesitate to fly the Grapevine (and *some* other mountainous routes) with a
flight plan filed and both eyes open. *Might* be doing it again on Wednesday
eve, although I-5 will be bumper to bumper and not a good emergency landing
choice (it really never is, anyway). If VFR I make the occasional call to
FSS (if a long flight) to update position just like my primary instructor
had me do in 1974 when flying the Grapevine on my long solo XC on my way to
Bakersfield, Santa Barbara and back to Brackett/Pomona.

-Greg

"Jim Weir" wrote in message
.. .
Obviously you've never been over the Grapevine before.

Jim



shared these priceless pearls of wisdom:

Now, by the way, my proposed route is only a 10min flight
-over a pass. Flat land both sides.



Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

Jumped into this late as I just saw it...but
did you do the flight?

If so I bet it was alot less eventful than you guessed it'd be. Is this an
owned or rented C182? Rented I'd have a few more reservations, owned and
well known - not that many.

This night/single engine/mountain flight stuff is always a hot topic amongst
a couple pilot friends of mine. Perhaps history and training has something
to do with it (they were trained where mountains are no higher than 2k, I
was trained from the Continental Divide and west). As far as the 2 out of 3
rule, if those 2 are single engine and mountains, is that a no-go factor? I
guess I'd never fly then. This IS a C182 you're talking about, right? They
go considerably higher than 4k or even 8 or 10k feet.

What is the comfort level then? Gliding distance to an airport? 3-4k above
terrain? Does that number change based on winds or cloud coverage? I'll
take clear night VFR over Gorman than solid IMC down there in the day.
Personally I'd take the Gorman routing over the coast (IMC) or Tehachapi
Pass (strong winds), but have done each several times. Now I have to deal
with passes no lower than 10k if I want to go west, they arent to be feared,
just respected.

Just for grins I fired up Anywhere Map Flight Planner, it's the one with the
"Cones of Safety" that put circles around airports. It is based on your
altitude and the glide performance you plug in. It doesn't account for
winds. Over GMN at 8,500 you'd be still within glide range of CL96, and
over GRAPE intersection within gliding distance of 7CA2. There is a gap in
between though. Bump that up to 10,500 and that gap is gone. Use those
numbers as you will, no guarantees you'd make those airfields, may have to
do everything RIGHT to make it, but it's not like flying through the Andes.

I guess what I'm trying to say is, personally, I don't make my go no-go
decisions based on personal opinions to the extent I sit and not go at all.
Typical scenario for me is to get in the air, climb up, and make my decision
before the point of no return. Often times that's at 12,500 approaching the
Continental Divide westbound. The decision has to be made to climb,
continue forward, take notice of up/downdrafts and turbulence, visibility on
both sides of the pass, etc. This is without the benefit of a international
airport width continuous runway (I-5) below. Foolish to make this flight?
I think not. The fact you ask it though... if you're not confident in your
decision making skills or the airplane, then you should have doubts.

Go get a mountain checkout, and read the book "Mountain Flying Bible" by
Sparky Imeson. Just for fun fly it with FS2004, it'll give you some idea
what it'd look like with varying altitudes, weather, and darkness. Cut the
engine while you're at it. Simple rules don't apply to all decisions. As
far as IFR or VFR - fly VFR with flight following, that way you can pick
your route and fly directly over airports as you see fit. The airways don't
always do this for you.
And Greg, that "Bakersfield, Santa Barbara and back to Brackett/Pomona"
mustve been popular with instructors, mine assigned that one to me, too.
In a Traumahawk no less.
Chris