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Eights on pylons

Old 07-28-2009, 12:10 PM
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Default Eights on pylons

I'm having trouble with my eights on pylons for single commercial. my problem is that i enter it right but I tend to get really far from the pylon coming around the turn back into the wind, every time i try a steeper entry angle by getting closer to the pylon I end up chasing the pylon with pitch like I'm supposed to but airspeed an altitude is getting really fast and I'm getting too low and its just all over the place. What are some things I can do? thanks
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Old 07-28-2009, 12:30 PM
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You could refer to this older thread on 8's on Pylons for one thing.

The distance you are from the pylon doesn't affect anything- it's all about your pivotal altitude. I know it's hard to take this on faith so go through the math on the above thread and see. Don't get caught up in theory, just accept that altitude above ground is the only thing that affects things very much in this maneuver. It's a simple maneuver in theory and a challenge to do.

Pylon moves ahead of the wingtip-> dip the nose to catch it.
Pylon moves behind the wingtip-> climb the airplane to catch it.


After setting the throttle for Va indicated by the airspeed dial in level flight, don't touch it again. Don't even put your hand on it. It's not about power, its about your ground speed. Pivotal altitude is proportional to the square of the GS. Go through in your mind what ground speed does on the various quadrants of the course. There will be a higher GS on the downwind legs and slower GS on the upwind legs. This is your clue that on downwinds you will need a higher altitude height and on the upwinds a lower one. How much is the skill part. If the winds are more than 25 knots I would suggest doing the manuever another day when things are calmer there, because to make it work out you would have to climb and dip too dramatically.
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Old 07-29-2009, 06:05 AM
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Cubdriver has it nailed. The other thing I really stress with students is that you should be anticipating what your pivotal altitude should be rather than just looking at the pylon and making the appropriate correction. The "follow the pylon with your yoke" is okay for small corrections, but you should not rely on that as your only cue to change your altitude. Downwind = higher GS = higher PA. Upwind = lower GS = lower PA.
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Old 07-29-2009, 07:40 AM
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I still have yet to figure out what purpose this manuever really has, I see purpose and actual use with the rest of them, but this one just boggles me. Cubdriver has it, it's all about the Pivitol Alt. A good set-up with trim, proper altitude, and where the winds are prior to entering the manuever will pay-off big during it.

These are also probably one of the hardest to perfect anyways, so I wouldn't get too tied up in knots about it, but keep practicing!!!
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Old 07-29-2009, 08:20 AM
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Originally Posted by Ewfflyer View Post
I still have yet to figure out what purpose this manuever really has, I see purpose and actual use with the rest of them, but this one just boggles me.
That was always my big problem with it.... No one has ever given me a good explanation for why you have to do it.

I cheat and always have a little chart taped to my kneeboard that has the GS and the pivotal altitude for that GS. I might have taken it from the Airplane Flying Handbook, but I can't really remember. Anyway, it definitely has helped me because when I enter the manuever I just look at my GS on the 430 and then look at the chart to determine my pivotal altitude to enter the manuever. Then I might glance at it during the manuever as my GS changes to see if my altitude is what it should be according to the chart. It has helped a lot.
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Old 07-29-2009, 09:11 AM
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Originally Posted by Ewfflyer View Post
I still have yet to figure out what purpose this manuever really has, I see purpose
It was an old maneuver flown by pilots so the gunners could have a steady visual target to shoot at. It is a great maneuver to teach the student to stay ahead of the aircraft.

Enter the maneuver on the down wind side, at the highest altitude because you are at the fastest ground speed. Math is unimportant here, you can see it in the other thread for proof, higher ground speed means a higher pivotal altitude and conversely for a lower ground speed.

The entire first 180 should be a slight descending turn, ignore the wing tip, look in front of you with periodic (10-15 seconds or more between) scans of the wing tip. Fly ahead of, not with the aircraft. The entire second 180 will be a slight climbing turn back to pivotal altitude, try it once and never look at the point and see how it goes. The climb and descent is roughly 100 feet for each 10 knots. Oh and for christ sakes enjoy the scenery and stop staring at your wing the point won't run away, you have my word.


Edit: For CFI's: I caution explaining this as pitching down to "increase" speed with rate/radius. If you have ever flown with a GPS and taken a look at an equal power setting descent, meaning just pitch the nose down, the airspeed may increase but the ground speed shows little change. In our Seminoles 145 pitched for 165, a 500 fpm descent with 146 GS. The pitching up and down without a change in power setting does very little to the ground speed.

In this maneuver you get blown further and closer to the point, if you hold constant bank +/-5 as you should, this requires a change in altitude to change the visual view of the point. Increasing speed to increase radius wouldn't work because aren't we diving when our ground speed is the fastest? This diving would increase our radius but we should have to be slowing down to decrease it since the wind is increasing right? Confused yet? Exactly. The maneuver is based on visual view point and has nothing to do with rate and radius.

PS: On an interesting note, I wonder how the bomber pilots did this since they didn't have a wing tip to stare at.

Last edited by shdw; 07-29-2009 at 09:26 AM.
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Old 07-29-2009, 10:56 AM
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Originally Posted by Ewfflyer View Post
I still have yet to figure out what purpose this manuever really has,
There are those who argue that about most ground reference maneuvers. In the case of the commercial ones, I think it's more about the fact that they are difficult and require lot of control while dividing attention in multiple ways than that they have any practical purpose.

I wouldn't spend too much time trying to find one.
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Old 07-29-2009, 12:10 PM
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Originally Posted by NoyGonnaDoIt View Post
I wouldn't spend too much time trying to find one.
Chandelles are a maximum performance climb/course reversal maneuver originally taught in air to air combat. If the stall horn isn't blaring redo the maneuver and don't be a panzy.

Lazy 8s were designed to demonstrate clean, smooth, aircraft control in a symmetrical, ever changing, maneuver.

Eights on pylons were used for circling a target, giving the gunners the most stable target to fire at. For a a non military pilot I haven't found a purpose, these are a waste IMO.

Emergency descents are for a loss in cabin pressurization systems needing a maximum performance descent.

Steep turns are to demonstrate precise control in a more sensitive maneuver than typical flight.

Ground reference is to improve situational awareness by understanding; how air flow effects your ground track and what things you can do to mitigate those effects.

Power off 180s, do I really have to mention, for engine out procedures, circle the field set up for an abeam point at an altitude you like and do your 180. The thinking that you have to start these at 1000' is a bit ludicrous, you should practice it from any altitude (the same one each time) that you can comfortably accomplish the maneuver at. If you like 500 feet with a tight pattern because you feel you can perceive it better, then why not? The examiners might not like this, so learn it the regular way, but in a real emergency I wouldn't think they would ask what altitude you started your abeam approach .

Steep spirals are for engine loss, you approach a field then circle over it. The whole point is to end this maneuver at the altitude you intend to start your power off 180 from, discussed above. This is why I say the altitude you start your 180 from should be your own determined altitude that you feel works for you with the most accurate result. If pattern altitude isn't your thing, in a real emergency use whatever you need, 1000' start isn't the be all end all.

I think I got them all? let me know.
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Old 07-29-2009, 08:14 PM
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As much as I hate turns-around-a-point, eights on pylons is the complementary maneuver. Remember that in a TAP, you must maintain a constant altitude and vary your bank to achieve a complete circle over the ground. In an eight on pylons, you maintain bank and vary your altitude to achieve a figure 8 over the ground. It helped me to tie the two maneuvers together. I used it to explain to students that struggled with the concept so that they would have something they were supposedly familiar with to start from. Of course, if they were terrible at PPL ground ref. maneuvers, you might have a bigger issue.
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Old 07-30-2009, 02:24 AM
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Originally Posted by shdw View Post
Steep spirals are for engine loss, you approach a field then circle over it. The whole point is to end this maneuver at the altitude you intend to start your power off 180 from, discussed above.
One version of the "reason" for steep spirals was to get through a hole in the overcast. I guess they came up with a new one, huh?
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