Sport aviation is growing rapidly. But the new sport pilot / light-sport aircraft rules are still a mystery to many flight schools and instructors. To locate a flight school offering sport pilot training and/or light-sport aircraft rentals, click on the "Flight School And Rental Finder" tab above. This is a great place to share ideas on learning to fly, flight schools, costs and anything else related to training.
Still a good candidate, I think, because I'm virtually certain that the "wind indicator" he mentioned was not relative wind, nor was "primary wind force" referring to AOA.
I anxiously await the moment when the concept of relative wind dawns on him. He is on the path, he used swimming across a river and adjusting the heading to compensate for the current as an example in one of his recent posts.
He used to accuse me of bending airframes because I advocate 'full stall landing' technique instead of flying it on. At some point he changed but never acknowledged the change. There have been a number of changes without acknowledging. When he 'gets' relative wind I doubt there will be acknowledgment but I will be happy for the epiphany none the less.
FastEddieB wrote:As background, Stick and Rudder is a book written by Wolfgang Langewiesche in 1944. Though a little dated, it still makes good on what the subtitle promises: “An Explanation of the Art of Flying”.
I finished this book 2 weeks ago, full of great insight. Mr. Langewiesche has done a wonderful job, bless his soul.
FastEddieB wrote:
6) Someone suggested in a strong enough wind, a plane that was not tied down could eventually just hover.
Nice one. At first I didn't get it. The trick is that the moment the plane levitates, it's relative speed against the wing becomes 0. Right?
FastEddieB wrote:
7) Many have expressed that banking the airplane may cause fuel to flow unevenly from wing tanks. When queried, they were not referring to uncoordinated flight.
MovingOn wrote:If you have 1000 pounds of flys sitting in your plane while you are flying, what happens to your gross weight if the flys all start flying around inside your plane?
FastEddieB wrote:
7) Many have expressed that banking the airplane may cause fuel to flow unevenly from wing tanks. When queried, they were not referring to uncoordinated flight.
Can you explain what you mean by his example?
Taking thus one first...
In any coordinated turn, the total forces will still be acting "downward" relative to the pilot and the fuel will still flow evenly.
That's what the ball will tell us when it's in the center.
So coordinated, banked turning flight cannot cause uneven fuel flow. The fuel still "thinks" the plane is wings level, albeit heavier in a coordinated turn.
Of course, slipping or skidding changes everything, as CT pilots have found.
Last edited by FastEddieB on Sat Oct 04, 2014 7:24 am, edited 1 time in total.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME [email protected]
As soon as the plane's wheels leave the ground and inertia is overcome, it will simply move with the moving air mass it now finds itself in and it's flying days are over for the moment.
It would take a tether, anchoring it relative to the ground, to turn it into the levitating kite that's so easy to visualize.
Of course, if it was producing enough power to overcome the movement of the air mass - with a pilot at the controls - it could just hover. But since I was talking about a tied down plane, I assumed it was neither running nor piloted.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME [email protected]
Looks like it did levitate for a short time, but the "up" elevator caused the nose to come up exposing the large surface area of the belly to the wind, and away she went. I think the elevator position was due to the stick being tied back. Had it been neutral ... ?
dwayne wrote:Looks like it did levitate for a short time, but the "up" elevator caused the nose to come up exposing the large surface area of the belly to the wind, and away she went. I think the elevator position was due to the stick being tied back. Had it been neutral ... ?
It would gave been less dramatic, but it still would have been blown downwind.
A parked airplane can be thought of as a kite. Under the right conditions, I can imagine an airplane being able to lift up, as long as there is a force able to counteract the force of the wind. I used to 'launch' kites by laying the kite down, playing out a good bit of line, then wedging the spool/handle under a rock. Think of this as an airplane tied down, but with a lot of slack in the lines. Then I'd walk back to the kite, pull the line tight, then let the wind lift it out of my hands. This worked great in a steady wind and as long as I had wedged the line spool securely. If it yanked free, or the line broke, the kite was Gone with the Wind and would inevitably come down. A levitated airplane would come down, too.
As soon as the "levitated" plane was clear of the ground, it rapidly began moving with the moving air mass (wind). Without thrust there would almost immediately be no lift in very short order - again, unless tethered.
The second video of the Cubs was different in that these planes had power and pilots - at least the ones that became airborne and stayed there did. The power would be necessary to resist moving with the air mass and the resultant loss of lift.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME [email protected]
As soon as the "levitated" plane was clear of the ground, it rapidly began moving with the moving air mass (wind). Without thrust there would almost immediately be no lift in very short order - again, unless tethered.
The second video of the Cubs was different in that these planes had power and pilots - at least the ones that became airborne and stayed there did. The power would be necessary to resist moving with the air mass and the resultant loss of lift.
What about a glider flying in the wind? I see guys slope soaring models that appear to be stationary.
3Dreaming wrote:
What about a glider flying in the wind? I see guys slope soaring models that appear to be stationary.
Good question.
I'm not a glider pilot, but I'm pretty sure one way or another they are simply gliding - i.e. trading altitude for lift. They can only stay up like you're seeing if the air they find themselves in is itself rising - on one of the "thermals" they seek out.
Best not to think of it as "wind" - they are simply gliding as they normally would in an airmass which is itself moving. Again, your "hovering stationary" would only work with if tethered, or gliding against the movement of an airmass which is moving exactly the same speed they are gliding, but in the opposite direction.
Right?
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME [email protected]
3Dreaming wrote:
What about a glider flying in the wind? I see guys slope soaring models that appear to be stationary.
Good question.
I'm not a glider pilot, but I'm pretty sure one way or another they are simply gliding - i.e. trading altitude for lift. They can only stay up like you're seeing if the air they find themselves in is itself rising - on one of the "thermals" they seek out.
Best not to think of it as "wind" - they are simply gliding as they normally would in an airmass which is itself moving. Again, your "hovering stationary" would only work with if tethered, or gliding against the movement of an airmass which is moving exactly the same speed they are gliding, but in the opposite direction.
Right?
Birds can easily 'hover' in ridge lift because they can fly at slow speeds. In a glider, at higher speeds you will probably have positive ground speed.
CharlieTango wrote:
Birds can easily 'hover' in ridge lift because they can fly at slow speeds. In a glider, at higher speeds you will probably have positive ground speed.
Sure.
But a glider moving at 40k into a 40k "wind", and descending at 100 fpm in a 100 fpm updraft would appear to "hover".
Just an illusion caused by the air mass that it's in moving in two directions at once.
Fast Eddie B.
Sky Arrow 600 E-LSA • N467SA
CFI, CFII, CFIME [email protected]
