Issues around de-ice on a 182

"Richard Kaplan" wrote
Does it mean you can fly if you are willing to deviate by 50 miles? 100
miles? 200 miles?

I would say that 90% of the time, I deviate less than 50 miles (20
minutes or less as my plane flies) total. I have had to deviate over
100 miles. I've never had to deviate 200.

Does it mean you can fly if you are willing to adjust your departure time by
an hour? 4 hours? 8 hours?

I think the longest I've ever had to adjust was close to two hours (I
won't launch into conditions I think nothing of flying through because
options are so limited on takeoff) but adjustmentst of up to 30
minutes are common.

As a general rule I find I can make most summer trips if I am willing to
adjust my flight plan either by 200 miles or by 8 hours.

And that was more or less where I was when I started using spherics.
It's just that by sheer experience, I've learned to judge the weather
and the capability of the equipment more accurately than that.

Michael

"Michael" wrote in message
om...


"Richard Kaplan" wrote

I think the longest I've ever had to adjust was close to two hours (I
won't launch into conditions I think nothing of flying through because
options are so limited on takeoff) but adjustmentst of up to 30
minutes are common.

OK so suppose you are traveling due West on a 160 nm trip from Pittsburgh PA
to Columbus OH and in between there is an occluded cold front with a 250
mile vertical line of thunderstorms associated with the front. The line of
storms includes level 3 through 5 cells and the largest break in precip
would be a circuitous path at times only 15 miles wide.

I presume you are saying you would penetrate this line based on the areas
where spherics show the least activity. Yet not all storm areas with hail
or severe turbulence will show up on spherics, not to mention that the holes
between the storms could easily close. I am not sure how I could
comfortably do this trip even with multiple sources of information, i.e.
spherics plus radar plus datalink, plus the ability to fly in the lower
flight levels up to FL230.


--------------------
Richard Kaplan, CFII

www.flyimc.com

"Richard Kaplan" wrote
OK so suppose you are traveling due West on a 160 nm trip from Pittsburgh PA
to Columbus OH and in between there is an occluded cold front with a 250
mile vertical line of thunderstorms associated with the front. The line of
storms includes level 3 through 5 cells and the largest break in precip
would be a circuitous path at times only 15 miles wide.

Well, that would be the day I would need up to a 125 nm deviation, now
wouldn't it? How often does this actually happen?

And no, spherics alone would not cut it for that kind of penetration.
In fact, in my entire flying career, I've only encountered similar
situations three times. Twice I followed another (RADAR equipped)
aircraft while also getting RADAR assistance from approach control.
In both cases, I had been maintaining a steady watch on what the
weather was doing and was confident that it wasn't going to get much
worse in the few minutes the penetration would require. The other
time this wasn't an option. Remember the one time I needed a
deviation in excess of 100 nm? Well, that was it. To be honest, I
don't even think of it as a deviation if it only adds 30 minutes to my
trip. After all, car trips and airline flights are routinely delayed
that much.

Usually, my trips are significantly longer than 160 nm (if that was
typical for me, my airplane would be overkill) and so the deviations
are less significant. Also, having my course line directly
perpendicular to the front, while not particularly rare, is still a
minority of cases.

Michael

"Michael" wrote in message
om...

Well, that would be the day I would need up to a 125 nm deviation, now
wouldn't it? How often does this actually happen?

I would say this happens about weekly in the spring or summer, sometimes
twice weekly. It is not rare at all.

Your comments about rarely flying 160nm trips are quite relevant and may
explain a difference in our perceptions -- in the Northeast it is not at all
uncommon for a 160nm trip to be 1 hour flying in a 160 knot airplane or 5
hours driving in a car due to traffic issues... granted that is not the case
for the trip from Pittsburgh to Columbus but in the NYC-Boston-DC corridor
this is quite possible. While such short trips can be extremely
convenient uses of an airplane when weather cooperates, you are correct that
there are lots fewer practical deviation options on such a short trip. This
may well be a big difference between general aviation in the Northeast vs.
in Texas.

--------------------
Richard Kaplan, CFII

www.flyimc.com

"Richard Kaplan" wrote
While such short trips can be extremely
convenient uses of an airplane when weather cooperates, you are correct that
there are lots fewer practical deviation options on such a short trip. This
may well be a big difference between general aviation in the Northeast vs.
in Texas.

I suspect you are right. There are few meaningful destinations within
160 nm of Houston - even Dallas, which is right next door by Texas
standards, is significantly farther away. My only recurring trip of
under 160 nm is Austin - it is also the trip that, proportionately,
gets the most delay time. It's a 45 minute trip for me in good
weather; in bad weather it's not particularly rare for it to take
twice that due to deviations/delays. On the other hand, it's still
over two hours by car, and that's if I'm willing to speed a lot.

Certainly deviations/delays for weather have a proportionally bigger
impact on short trips - to the point where it may not be worth it. Of
course as a result, you get less experience optimizing your deviation,
and that makes the deviation even bigger.

Michael

Cessna 182s vary in their susceptibility to carb ice.
A friend of mine didn't have much trouble until he
had a carb float AD complied with. Since then he has
had a number of character building experiences.

My 182 is the previous model year (64) and I have not
had an obvious in flight carb ice encounter. N2469R
has a carb temp meter so it's possible I've headed off
a few encounters by timely application of heat.

The meter shows an increase in carb temp when approaching
landing with the cowl flaps closed.

As for airframe ice, an ex-Cirrus salesman thinks the
Cirrus with TKS is worse for ice than a stock Skylane.
Apparently it takes much more ice to bring down a Skylane
than a Cirrus.


--
Chuck Forsberg www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665

Chuck Forsberg WA7KGX N2469R wrote:

As for airframe ice, an ex-Cirrus salesman thinks the
Cirrus with TKS is worse for ice than a stock Skylane.
Apparently it takes much more ice to bring down a Skylane
than a Cirrus.

This is a great thread and I'm glad it came back up as it will be that
time of year soon.

The central issue is that ice distorts the shape of airfoils causing
them to behave in unpleasant ways. The more critical an airfoil is, the
less ice it takes to hurt its performance. This was illustrated most
dramatically by the recent string of accidents with the
Challenger-series jets which have power-to-weight ratios far in excess
of any GA plane. These appear to have involved amounts of ice that
would have simply made a 182 act piggy with their fat old non-laminar
wings. FWIW, the same comparison could be made between a 182 and a
Mooney.

Another thing I wonder about with the newer planes is their use of
cuffs and other sharp breaks on leading edges. It's known that ice
accumulation starts on smaller-radious objects and I can't help but
wonder whether these otherwise-useful features make the planes even
more susceptible to ice.

-cwk.

Chuck Forsberg WA7KGX N2469R wrote:

Cessna 182s vary in their susceptibility to carb ice.
A friend of mine didn't have much trouble until he
had a carb float AD complied with. Since then he has
had a number of character building experiences.

My 182 is the previous model year (64) and I have not
had an obvious in flight carb ice encounter. N2469R
has a carb temp meter so it's possible I've headed off
a few encounters by timely application of heat.

The meter shows an increase in carb temp when approaching
landing with the cowl flaps closed.

As for airframe ice, an ex-Cirrus salesman thinks the
Cirrus with TKS is worse for ice than a stock Skylane.
Apparently it takes much more ice to bring down a Skylane
than a Cirrus.

I don't know how much airframe ice it takes to bring down a Skylane, but
I had the unfortunate experience of finding out that a Skylane will
carry 2" of ice on the leading edge and pitot tube and who knows how
much on the windshield and still fly just fine. It flew a little slowly
as I had to use 24 square to maintain level flight at 9,000 feet and top
of the white arc (110 MPH on my '67 if memory serves), but it handled
just fine. Sure made a racket when I descended into warm air on the
approach. Fortunately, no damage to the tail.


Matt