This was sent to Hubby by his CFI. Can someone here decode this and explain in terms I can understand?
http://www.auf.asn.au/magazine/pivotal_altitude.html
http://www.auf.asn.au/magazine/pivotal_altitude.html
This was sent to Hubby by his CFI. Can someone here decode this and explain in terms I can understand?
http://www.auf.asn.au/magazine/pivotal_altitude.html
I'm pretty good at doing math in my head, but I still do Pylon-8's strictly by moving the stick as cued by movement of the point fore/aft of the wingtip.Maybe some folks can sense all the parameters and calculate the proper aircraft control inputs. I think most of us just make the aircraft go where we want in order to pass the check ride.
I'm pretty good at doing math in my head, but I still do Pylon-8's strictly by moving the stick as cued by movement of the point fore/aft of the wingtip.
I'm pretty good at doing math in my head, but I still do Pylon-8's strictly by moving the stick as cued by movement of the point fore/aft of the wingtip.
+1. I did the math before the flight so I had a rough idea where to start, but there's ALWAYS some wind, so the actual manuever was always done by "freezing" the pylon.
I suspect that the important thing is that it looks right to the person in the right seat - not for it to be actually, mathmatically, correct.
The math explains why the pivotal altitude is constant for a given groundspeed and independent of bank angle. To fly pylon 8's all you need to know about the math is:
"The pivotal height in nil wind conditions is readily calculated by squaring the TAS in knots and dividing by 11.3"
This formula gives you a place to start altitude wise and the relationship between groundspeed and altitude provides the clue for the following procedure:
When the groundspeed increases you will need more altitude and since pulling up will usually provide both a reduction in GS and an increase in altitude you can maintain the varying pivotal altitude when wind is present by climbing (and increasing bank) whenever you are too fast/low (pylon has moved to the rear) and vice versa.
With practice you find the ideal airspeed range for each airplane that meet the following requirements:
If you know the local winds, you will have a pretty good idea when to climb and when to descend, and the "pylon on the wingtip" task will be a simple matter of push forward when moving forward, pull back when moving back.
- < 30 degrees of bank
- < Va
- Maintains altitude with little trim or power adjustment
The "< 30 degrees of bank" is not fixed by the airspeed and associated altitude selected. You are correct that it's a good idea to fly pylon eights with 30 degrees of bank or less since greater angles will increase the g loading and stall speeds enough to matter. But you can adjust the required bank angle by adjusting the radius of the turn and that's mostly a function of the distance between the pylons.
YEEGADS!
I find the pylon 8 to be the easiest comm maneuver. If the idea of the comm maneuvers is to fly the plane, look outside, and learn the feel instead of flying the instruments, well, I still struggle with that on Lazy 8s and Chandelles. But the pylon 8? I don't even worry about #'s. Get down kinda low, and let the wingtip tell me what to do. Piece of cake.
Eights on pylons are easy so long as there's no wind.
Lazy 8s and chandelles are fun.
Just following along. Don't have IFR yet.Are you working on your commercial, or just following along?
We heard you went to lunch with Julia. You could have invited us for a ride, too.By the way, I was at BDR the other day and taxiied by your plane.
I assume pivotal altitude has an effect on turns about a point, and I should be concerned about the altitude chosen for those, too?