Is there such a thing as an up wind turn

[plowboy]

My brother-in-law have argued about this a bit.[He drives a supercub]
If you are referencing the ground yes, if you are just in the moving airmass I say no. What do you all think?

[aero101]

The airplane only knows airspeed, upwind, downwind, xwind, etc, etc... BUT if wind is gusting or windshear conditions, the wind can change directions so fast that airspeed can drop off or increase to the point it affects airspeed and if you're low and slow, watch out below....

[Lowflybye]

If you are moving within an airmass there is no such thing as wind (other than the relative wind generated by our forward motion) as the aircraft also moves with the airmass. The only time we (the aircraft never knows) have any idea of any other wind is if there is a fixed reference point such as a ground point. With a fixed reference point wind can be determined but not without it. If you have a headwind (based on a ground reference) and you make a 180 turn to a tailwind your groundspeed may change dramatically, but your airspeed (relative wind) will remain the same because the aircraft is still moving at the same speed within the airmass. Your groundspeed is either helped or hindered by the speed of the airmass moving in relation to the fixed point on the ground.

Take a hot air balloon ride sometime...when you are on the ground you will feel the wind, but as soon as you launch airborne the wind goes away as you are now moving with the airmass. Close your eyes and you will not know you are moving at all as you lose the fixed reference point.

Another example is a kite...when you hold the string you become the ground reference point for the wind to act on the kite. If you let the string go the kite is free to move with the airmass and no longer has wind acting on it.

[flyer]

You are flying downwind, you turn base but decide because of someone on the runway not to land. You then turn UPWIND for another pattern.

[Hottshot]

No offence but go to supercub.org and look up the 20 page thread on this ....

[RanchPilot]

The lightbulb came on for me on this topic after reading the classic, Stick and Rudder, by William Langewiesche (a book I would highly recommend).

The example he gave was of a guy walking down the aisle of a train going 30 mph. When the guy turns around and walks the other direction in the aisle, he feels no adverse force despite the fact that, relative to the outside world (i.e., the ground reference), he is moving 30 mph in the other direction of the way he is now walking. This is because he is one with the moving mass around him (i.e., the plane relative to the air mass).

Those with better minds than me probably understand these principles intuitively, but I never really fully visualized it until I read this explanation in Stick and Rudder.

That said, I agree with the previous comments about gusty winds. When I'm flying on the deck in gusty conditions, I always cut my downwind turns a little fatter, even if it's only in my head!

[Duane]

Ranch, Yes that book brings back memories. when I first started flying (gliders), I had to read that book as the gospel it is. For probably 15 years or so I would read it every January. May be a little old and have some unfamiliar terminology (flippers?), but is so relevant even today in basic knowledge.

[Andy Young]

You are flying downwind, you turn base but decide because of someone on the runway not to land. You then turn UPWIND for another pattern.

This brings up an often incorrect use of the term, though it is a someone subtle point:

People often called "Upwind" if they have just departed the runway and are still flying runway heading, not yet to the crosswind leg. This is more correctly called the DEPARTURE leg.
The UPWIND leg is parallel to the departure leg, but is offset from the runway, on the opposite side from the downwind leg.

Hmmm....I wonder what sort of debate THIS might stir up;)

[Andy Young]

Woops: I meant someWHAT subtle point

[chris.johnson]

I only worry about upwind if something stinks!