Wind limits - small single engine aircraft

WestCDA wrote

I don't see that anyone has mentioned the demonstrated
crosswind component, which is in the P.O.H. for certified aircraft.
You may do better, but that's the best number the manufacturer
achieved with a new aircraft and a very good pilot.

I would suggest that it might be the highest number that the lawyers
would permit to be included in the flight manual.

Bob Moore

I don't see that anyone has mentioned the demonstrated
crosswind component, which is in the P.O.H. for certified aircraft.
You may do better, but that's the best number the manufacturer
achieved with a new aircraft and a very good pilot.

I would suggest that it might be the highest number that the lawyers
would permit to be included in the flight manual.

I have never looked it up, but my first instructor asserted that it was the
amount of crosswind in which it was demonstrated that the (tricycle gear)
aircraft would safely complete a landing without any crosswind correction
being applied.

Again, I have not verified the assertion; but it is certainly not the worst
case condition under which the aircraft can be landed safely by a highly
proficient pilot...

Peter

"Peter Dohm" wrote in message
...
I don't see that anyone has mentioned the demonstrated
crosswind component, which is in the P.O.H. for certified aircraft.
You may do better, but that's the best number the manufacturer
achieved with a new aircraft and a very good pilot.

I would suggest that it might be the highest number that the lawyers
would permit to be included in the flight manual.

I have never looked it up, but my first instructor asserted that it was
the
amount of crosswind in which it was demonstrated that the (tricycle gear)
aircraft would safely complete a landing without any crosswind correction
being applied.

Again, I have not verified the assertion; but it is certainly not the
worst
case condition under which the aircraft can be landed safely by a highly
proficient pilot...

Peter


Just the highest crosswind experienced and 'safely handled' during the
certification process, it appears. Here's a link to an article on the
subject, and it seems to agree with other references I found regarding the
DCC.

http://www.swaviator.com/html/issueMA05/Basics3405.html

"The 15-knot Demonstrated Crosswind Component is not a limitation, per se;
it's just a simple statement that sometime during certification the airplane
was landed successfully, without using any unusual skills, in a 15-knot
crosswind. But, remember the pilot who demonstrated the crosswind landing
was a very experienced test pilot. Are you as competent as he or she was?"

On 19 Jan 2007 22:53:33 -0800, wrote:

I was wondering what people view as their limitations in terms of wind.
I'm talking 172 / Warrior territory here.

Clearly this is a personal decision, based on your perceptions of your
own skills, the aircraft you are flying, the specific conditions on the
day (E.g. how gusty, reports of LLWS & turbulence), your risk
tolerance, etc.

But I'm interested in what the various opinions are. How much wind is
too much to fly, for you? And how much crosswind component? Does your

Too much cross wind is when I run out of rudder authority. On the Deb
that is about 25 MPH. I've taken off in 30G50 when it was down the
runway. After that trip my wife commented: "That Dramamine is
wonderful stuff!"

max crosswind component vary with windspeed? And how about how gusty it

Wind speed? No. Gusty? to some extent.
Both the Deb and I have the same limit of 25 MPH for cross wind
component.

is? Clearly if it's more gusty that's a bad thing, but how gusty is too
gusty?

It depends on the angle. Gusty means wind shear. Really gusty means a
lot of wind shear. I don't have any set figure. If I go out and don't
like the feel, I don't go.


Of course I have my own views on this but I'm wondering what others
think. And by the way the context is that I have decided to cancel my
flight tomorrow (Boston area) due to winds, but I'm still hoping to fly
on Sunday.

I guess as an aside, what are the scariest windy conditions you've ever
flown in? Would you do it again?

I don't think I've flown in any windy conditions I'd call scary. OTOH
the time airspeed in the Cherokee 180 dropped off scale when I was
only about 300 feet up on final was certainly attention getting.
However it was a freak gust and those can happen most any time the
wind is blowing.



Thanks

Tom
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Even a steady 25 knot wind directly down the runway _can_ catch the
unwary off guard (windshear).

I'll never forget that lesson... OAK was calling a 15 knot wind, no
gusts, coming right down the nines... I had my instructor with me at
the time. I noticed during the crosswind that my correction seemed
rather extreme (over 30 degrees) to stay on course, turned final, and
maintained a book 75mph IAS down final.

All of a sudden I hit the windshear layer, 35 knot wind above, 15 knot
wind below- and suddenly I had no where NEAR the kinetic energy I was
expecting, still 100 feet above the ground and well short of the
threshold.

My instructor saved that one, and Iearned a valuable lesson. One of
two times in my flying life I've made the 'Your Plane!' call.





On Jan 20, 9:01 am, "Vaughn Simon"
wrote:
wrote in ooglegroups.com...

Clearly this is a personal decision, based on your perceptions of your
own skills, the aircraft you are flying, the specific conditions on the
day (E.g. how gusty, reports of LLWS & turbulence), your risk
tolerance, etc. The title of this thread may be a little misleading to a newbie. Wind down
the runway is a GOOD thing that actually makes landings and takeoffs easier and
safer. Ground speed is less on landing, ground roll is less on takeoff and the
takeoff angle over the runway is far improved. In the pattern, winds can make
the downwind portion go so fast that a new pilot might get behind the airplane,
but if you are flying a slow plane and doing a crab for a proper base leg track,
you have a wonderful view of the runway while on your base leg, and your turn
onto final can actually be far less than 90 degrees. Short field landings into
a headwind are far easier, and can actually fool you into believing you have
skills that you don't.

Crosswinds and gusty conditions are a 'nuther whole matter. If you go out
to the airport and find those conditions, rather than canceling, it might be a
good time to seek an idle CFI and use the opportunity to work on skills and
self-confidence.

Vaughn CFIG

On Sat, 20 Jan 2007 22:39:03 GMT, "WestCDA" wrote:

I don't see that anyone has mentioned the demonstrated
crosswind component, which is in the P.O.H. for certified aircraft. You
may do better, but that's the best number the manufacturer achieved with a
new aircraft and a very good pilot. If the calculated crosswind based on
the wind speed, direction, and available runway exceeds the DCC for your
aircraft, it's cause for at least caution if not an outright scrub of the
flight.

That statement, for small Part 91 aircraft, is not the case.

The demonstrated crosswind component is merely what the wind happened to be
on some day when the crosswind was blowing at least strongly enough to meet
certification requirements. The 14 CFR 23 requirements are that this value
be at least 0.2 Vso.

========================================
§ 23.233 Directional stability and control.

(a) A 90 degree cross-component of wind velocity, demonstrated to be safe
for taxiing, takeoff, and landing must be established and must be not less
than 0.2 VSO.
======================================

It is not even close to being a limitation.


--ron

EridanMan wrote:

Even a steady 25 knot wind directly down the runway _can_ catch the
unwary off guard (windshear).

I'll never forget that lesson... OAK was calling a 15 knot wind, no
gusts, coming right down the nines... I had my instructor with me at
the time. I noticed during the crosswind that my correction seemed
rather extreme (over 30 degrees) to stay on course, turned final, and
maintained a book 75mph IAS down final.

All of a sudden I hit the windshear layer, 35 knot wind above, 15 knot
wind below- and suddenly I had no where NEAR the kinetic energy I was
expecting, still 100 feet above the ground and well short of the
threshold.

My instructor saved that one, and Iearned a valuable lesson. One of
two times in my flying life I've made the 'Your Plane!' call.

Were you a new student at the time?

Matt

On Sat, 20 Jan 2007 10:31:32 -0500, Jake Brodsky
wrote:


Bottom line: A good pilot uses experience to know when to stay on the
ground and training to deal with the unexpected. I have experience in
turbulence, LLWS, and gusty winds, but I won't launch in to it
deliberately. That's one of the nice things about flying for fun. If
it doesn't look like fun, don't do it.

Jake Brodsky

that is it in a nutshell.

one should always use the superior management skills to ensure that
the superior flying skills are not called for. :-)

in you example that I snipped you demonstrated a very good flying
skill. you kept thinking and flying right to the end and took
advantage of every opportunity that presented itself.
that will turn dangerous situations into stories on usnet :-)

if the weather is bad, the winds deplorable, or the forecast involved
and difficult my sincere advise is to find the window seat of the
closest airport bar and study the weather over a beer.
it all becomes much more obvious over a beer!

(for the humour impaired I will explain.
if it is marginal dont go.
the last beer you drink will see you avoiding the weather for another
8 hours :-) )

Stealth Pilot

On Sat, 20 Jan 2007 22:39:03 GMT, "WestCDA"
wrote:

"Stealth Pilot" wrote in message
.. .

you should be able to fly in conditions where the windsock is
horizontal from any direction.

I can't say I agree with this. I think it's worth pointing out that a
windsock is horizontal at 150 kts, just the same as it is at 15 kts. We had
conditions here a couple weeks ago (Rocky Mountain foothills)where the
windspeed at field elevation was gusting to 80 and 90 miles and hour.

do you know how to guess at the wind speed from the windsock angle?
its a useful skill.

Yes, up to the point the windsock is horizontal, after which you need a
better tool. I don't see that anyone has mentioned the demonstrated
crosswind component, which is in the P.O.H. for certified aircraft.

wrong wrong wrong!
if the certification test flight is done in nil wind and there isnt a
windy day available for ages then the design may have a low or no
demonstrated crosswind component ....for the simple fact that there
wasnt a crosswind available.
you are reading far too much into this figure.
it is really just the crosswind component that a demonstration landing
was made in for the purposes of certification.


You
may do better, but that's the best number the manufacturer achieved with a
new aircraft and a very good pilot.

wrong wrong wrong! that is not what the figure is about at all.

If the calculated crosswind based on
the wind speed, direction, and available runway exceeds the DCC for your
aircraft, it's cause for at least caution if not an outright scrub of the
flight.

yes caution in that you will need to work hard for the landing.


If you're landing at an airport with an overly strong crosswind, and fuel or
other concerns don't allow finding another airport with a more favorable
runway, lack of control authority may make landing on and maintaining the
runway extremely difficult if not impossible.

then dont maintain the runway. land diagonally across it.
if the wind is so strong that you can only find a taxiway into wind
then land on the taxiway.(advise people of what you are doing of
course)
locally here Bunbury is often unlandable in my aircraft because of
strong rotors off the adjacent row of pine trees but 20 miles away
there sits Busselton airstrip which is in the open and better oriented
to the predominant winds.
.....you've got the idea though.
Stealth Pilot

Your instructor was wrong. Seriously wrong, at that.

mike

"Peter Dohm" wrote in message
...

I have never looked it up, but my first instructor asserted that it was
the
amount of crosswind in which it was demonstrated that the (tricycle gear)
aircraft would safely complete a landing without any crosswind correction
being applied.

Peter