Commercial maneuvers.

[Ryan F.]

​

According to the AFH (my emphasis):

"The altitude at which the visual reference line ceases to
move across the ground is the pivotal altitude. If the airplane
descends below the pivotal altitude, the pilot should increase
power to maintain airspeed while regaining altitude to the
point at which the projected reference line moves neither
backward nor forward but actually pivots on the pylon. In this
way, the pilot can determine the pivotal altitude of the airplane."​

If you're saying there is no longer a one-lap limit then I would say the applicant can orbit around as long as he likes. No tables required.

I'm not clear what you mean by a one-lap limit so I'm certainly not commenting on them or making any kind of statement regarding them... if I'm misunderstanding you please explain.

 

[midlifeflyer]

Also, the AFH doesn't support the "on the fly" method of pylon selection.

Airplane Flying Handbook (FAA-H-8083-3B) Chapter 6, page 6-16"

"Selecting proper pylon is an important factor of successfully performing eights-on-pylons. They should be sufficiently prominent so the pilot can view them when completing the turn around one pylon and heading for the next. They should also be adequately spaced to provide time for planning the turns but not spaced so far apart that they cause unnecessary straight-and-level flight between the pylons. The selected pylons should also be at the same elevation, since differences of over few feet necessitate climbing or descending between each turn. The pilot should select two pylons along a line that lies perpendicular to the direction of the wind. The distance between the pylons should allow for the straight-and-level flight segment to last from 3 to 5 seconds."

"The pilot should estimate the pivotal altitude during preflight planning."

That's pretty strong support for selecting pylons prior to starting the maneuver. An evaluator who requires selection in this manner has a lot of guidance in his back pocket supporting his request.

Literally everything you describe in red is done when starting with one and selecting the second in Flight. They are adequately spaced. They lie on a perpendicular path to the wind. They are prominent enough to allow repetition of the maneuver, even multiple times. Approximately the same elevation is accomplished by the site selection, not the pylon selection. of course you cneed to estimate pivotal altitude, even if the task was "turns on a single pylon" 90 KTS and 5,000 AGL isn't going to work too well.

You've decided one way is right and are interpreting neutral language in a way which supports the bias.

Of course an Examiner who insists in advance selection has language to support it. Thats the nature of neutral language. It's subject to personal interpretation. Good reason to know with whom one is dealing with in advance. Not unlike most checkride tasks.

Sorry about the "purist" monicker. I admit to being a purist about certain things, so I don't think of it as always connoting a negative.

 

[brcase]

1/2 mile is usually about a close as I can make the work in something like a 172. With significant wind I might be closer to 3/4 mile. 1/4 miles sounds about right for the radius, again might need to be bigger with significant wind.

Brian

 

[Ryan F.]

Literally everything you describe in red is done when starting with one and selecting the second in Flight. They are adequately spaced. They lie on a perpendicular path to the wind. They are prominent enough to allow repetition of the maneuver, even multiple times. Approximately the same elevation is accomplished by the site selection, not the pylon selection. of course you cneed to estimate pivotal altitude, even if the task was "turns on a single pylon" 90 KTS and 5,000 AGL isn't going to work too well.

You've decided one way is right and are interpreting neutral language in a way which supports the bias.

Of course an Examiner who insists in advance selection has language to support it. Thats the nature of neutral language. It's subject to personal interpretation. Good reason to know with whom one is dealing with in advance. Not unlike most checkride tasks.

Sorry about the "purist" monicker. I admit to being a purist about certain things, so I don't think of it as always connoting a negative.

OK, I'm simply pointing out ways the task can be evaluated in a supportable way. I'm not injecting any bias. I suppose that is about as far as we can take it. Thanks for the conversation.

 

[dtuuri]

I'm not clear what you mean by a one-lap limit so I'm certainly not commenting on them or making any kind of statement regarding them... if I'm misunderstanding you please explain.

I tested for my commercial license in the 1960s under the Flight Test Guides. There was a specific allowance for applicants to make a single lap around a pylon to establish the pivotal altitude. I became a DPE at the very same time as the PTS came into being. Examiners were learning how to conduct flight tests i/a/w the PTS the same as they are today learning the ACS. Although the one lap was not mentioned in the PTS it made sense considering the history of the maneuver. You can't accurately calculate a pivotal altitude before takeoff, it needs to be done "on the fly".

 

[midlifeflyer]

I tested for my commercial license in the 1960s under the Flight Test Guides. There was a specific allowance for applicants to make a single lap around a pylon to establish the pivotal altitude. I became a DPE at the very same time as the PTS came into being. Examiners were learning how to conduct flight tests i/a/w the PTS the same as they are today learning the ACS. Although the one lap was not mentioned in the PTS it made sense considering the history of the maneuver. You can't accurately calculate a pivotal altitude before takeoff, it needs to be done "on the fly".

I think I understand. Its true in the real world anyway. The best we can do is guesstimate pivotal altitude before flight. Actual pivotal altitude is whatever keeps the pylon in position.

 

[Ryan F.]

I tested for my commercial license in the 1960s under the Flight Test Guides. There was a specific allowance for applicants to make a single lap around a pylon to establish the pivotal altitude. I became a DPE at the very same time as the PTS came into being. Examiners were learning how to conduct flight tests i/a/w the PTS the same as they are today learning the ACS. Although the one lap was not mentioned in the PTS it made sense considering the history of the maneuver. You can't accurately calculate a pivotal altitude before takeoff, it needs to be done "on the fly".

I see. Thanks for the explanation (and you probably have some pretty cool stories to share from your days as an examiner.) I do agree that the pivotal altitude needs to be "determined" during the maneuver itself -- of course! That is the point of Eights-on-Pylons. Still, an applicant should employ a method for determining pivotal altitude prior to attempting the maneuver.

In any case, now that you've clarified your comments, my original statement stands. There is no specific provision for this "one lap" to be flown to "determine pivotal altitude" in the ACS. I've never seen or heard of it in my time flying, and I've never had an applicant ask for the opportunity to use such a "tool" (so to speak) to determine pivotal altitude -- so whatever the genesis for what you've described is probably lost to time at this point.

There's a lot of splitting hairs here about the language in the ACS here but really, it's whatever a plain language reading can support. These are message board arguments in my experience and don't really happen in the real world. Mark Kolber's CFI checkride example is more apt simply because the ability to properly teach maneuvers is being evaluated through the Flight Instructor XX practical test. In that case the technical subtleties might come to bear, but usually these discrepancies are handled in an amiable way and are shaken out prior to the flight portion.

 

[dtuuri]

...so whatever the genesis for what you've described is probably lost to time at this point.

You didn't read my earlier post then. The ACS requires determining pivotal altitude and the AFH explains how to do it (I emphasized it in bold text). They just dropped the one-lap limit from the PTS/ACS.

 

[Ryan F.]

You didn't read my earlier post then. The ACS requires determining pivotal altitude and the AFH explains how to do it (I emphasized it in bold text). They just dropped the one-lap limit from the PTS/ACS.

Although I now understand your argument, I don't come to the same conclusion you do. But that doesn't mean to me that either view is categorically right or wrong.

 

[texasclouds]

I suggest a new CFI...

 

[dmspilot]

OP asked about my two least favorite commercial maneuvers. They're an extra pain now that people are using slower non-complex aircraft. Seems odd the FAA would condone maneuvers that require flying below 500 feet.

 

[MauleSkinner]

OP asked about my two least favorite commercial maneuvers. They're an extra pain now that people are using slower non-complex aircraft. Seems odd the FAA would condone maneuvers that require flying below 500 feet.

Wasn’t it previously possible to show up with a slow, non-complex aircraft and a complex for different parts of the checkride? It’s not the maneuvers that seem odd to me, it’s the fact that the FAA seemingly waives the distance from persons, vehicles, or structures for the commercial maneuvers.

 

[Ryan F.]

Wasn’t it previously possible to show up with a slow, non-complex aircraft and a complex for different parts of the checkride?

Yes, it has always been possible to use more than one aircraft to meet the requirements of the practical test for the certificate or rating sought, if needed.

It’s not the maneuvers that seem odd to me, it’s the fact that the FAA seemingly waives the distance from persons, vehicles, or structures for the commercial maneuvers.

Those requirements are not waived. The lowest published altitude for ground reference maneuvers in the ACS is 600 feet AGL. The applicant is still required to adhere to 14 CFR §91.119.

 

[RussR]

Those requirements are not waived. The lowest published altitude for ground reference maneuvers in the ACS is 600 feet AGL. The applicant is still required to adhere to 14 CFR §91.119.

I don’t see the 600 ft restriction in the Commercial ACS.

Also, with anything less than a 75 kt ground speed, the pivotal altitude is below 500 ft AGL. This would easily happen if flying at 90 knots with a wind speed of 20. Imagine doing it in a Cub or Champ, you’d be even lower. And even if the definition of “sparsely populated” wasn't vague and flexible, you still have to stay 500 feet away from “structures”. I don’t see “structure” defined in the FARs, but I’d say a fence is a “structure”.

I don’t like the 8s on pylons maneuver. I don’t see the practical application, it seems like a dangerous low altitude maneuver with the proliferation of cell towers and other pointy objects, and it seems to be almost requiring violations of 91.119 to perform.

 

[dmspilot]

Those requirements are not waived. The lowest published altitude for ground reference maneuvers in the ACS is 600 feet AGL. The applicant is still required to adhere to 14 CFR §91.119.

Then there are many aircraft/wind combinations for which the maneuver cannot be performed.

 

[dtuuri]

I don’t like the 8s on pylons maneuver. I don’t see the practical application...

Came in handy one day when I circled over my parents' house in my Cessna 140. I made the chimney my pylon, throttled back and opened the window when I saw my dad out in the driveway, "How do you like my airplane?" I yelled out. A neighbor a few houses down, out working in his yard, looked skyward and shouted back, "I like it just fine!"

 

[midlifeflyer]

Old photo but a propos, although it was actually "turns about a battleship."

 

[MauleSkinner]

I don’t like the 8s on pylons maneuver. I don’t see the practical application.

It’s actually been one of the more useful commercial maneuvers for me...seems Like there’s always something I want to take a better look at as I’m flying by, and maneuvering so that it’s in view all the way around is preferable to blocking my view with the wing half the time and being too far away the other half.