Because each separate "L" has since the beginning shown both departure and landing turns, not just landing. Pairs of them show the big picture--all turns on one side of the runway. No paradox. No plan for dual right-hand patterns to one runway.
Well this certainly proves your point about drawings being a more effective way to communicate about this stuff!
All indicators should be in pairs, according to the AC. The purpose is to show right traffic is using the same space as left traffic.
Read it and weep, I guess. They say it: https://www.faa.gov/documentlibrary/media/advisory_circular/150_5340_5d.pdf
Runways that use right traffic on one end and left traffic on the other are runways that use right-hand traffic patterns. Notice that it doesn't say "USED ONLY ON RUNWAYS THAT ONLY USE RIGHT-HAND TRAFFIC PATTERNS."
Btw, the same C.A.R. book has a diagram that lays to rest the question of whether the pattern indicators are only for landing or can include takeoff turns too. I also found the same diagram reproduced in Charles Zweng's "New Private Pilot" below. It was bigger and made a better copy. Note the arrow directions are for departing traffic:
dtuuri
Yes and since the single right pattern requires a "pair" of traffic indicators it follows that dual right-hand patterns would require TWO pairs, i.e., four traffic indicators! They would not indicate clockwise vs. counter-clockwise flow, though, hence the need for a new symbol for Friday Harbor or they should make one of the two patterns left-hand. Swastika symbols are too out of step with a 50+ year long training tradition, imo.
TPA is not regulatory, and Class E usually stops at 700 AGL. This means you can see legal VFR traffic below that.
The sentence in the AC is ambiguous which was my point from the beginning.
All correct. Advisory Circulars aren't regulatory and the small leg of the "L" points toward the side the pattern is on whether landing or taking off. No dispute with any of it. My dispute is with those who stretch the standard to accomplish something it isn't meant for and in so doing trash the way we all were supposed to have learned in interpreting the symbols for the past fifty-odd years. Under the "stretched" application (Friday Harbor, AFH, PHAK) only those who stopped reading the explanation of the pointers halfway through the AIM paragraph will get by. The rest of us have to re-learn something that's opposite of our lifetime flying experience. It isn't necessary and shows bad planning. A new symbol like this is one way to avoid confusion at Friday Harbor for everybody not just the lazy readers:
The way you have drawn that conveys to me that departure turns should be to the right, but it's clear from the Friday Harbor Airport pamphlet (attached), that they want approach turns to be to the right, and they don't care which direction departure turns are made as long as they occur at or above 1100 MSL.
Where's the problem? Departure turns to the right are always followed by landing turns to the right. Been doing it that way forever.
Sure, for aircraft remaining in the pattern. I think that pilots arriving from elsewhere would find the intent of your diagram non-obvious regarding direction of arrival turns. Furthermore, it does not convey the fact that the airport operator doesn't care whether departure turns are made to the right or left (which is a problem it shares with the existing pattern indicator).
It's more intuitive than having a backwards indication like they have now that doesn't work in the same way it always has.
The airport operator is already trying to cram more into the pointer than ever intended by attempting to depict both traffic patterns as non-standard with one ambiguous indicator for each. You can't tell from either "L" whether to associate it with landing or takeoff, which for the other 99.99% in the country both ways work. Maybe the manager can get some inspiration here:
I had an aunt like you who could walk across the lawn, look down and find a four leaf clover with uncanny frequency. Which reminds me, I need to go spray some weed killer. Bye-bye.
dtuuri
Hopefully it's been instructive for those who make willy-nilly changes to long-established procedures based on nothing more than their own personal preferences. When somebody gets violated for going the wrong way at one of these airports (or worse) maybe they (or their survivors) can find this thread and beat the rap (or divert the lawsuit). Nothing to apologize for at all, imo, I enjoyed it.
Hopefully it's been instructive for those who make willy-nilly changes to long-established procedures based on nothing more than their own personal preferences. When somebody gets violated for going the wrong way at one of these airports (or worse) maybe they (or their survivors) can find this thread and beat the rap (or divert the lawsuit). Nothing to apologize for at all, imo, I enjoyed it.
dtuuri
Several folks have quoted the reg 14 CFR 91.126(b), but seem to have missed the first phrase:
Who said there was? You know there's plenty of discussion in the AIM about the rectangular nature of traffic patterns including giving names for each of the separate legs. The segmented circle and traffic pattern pointers dovetail with those words not Part 91. Each "L" of the pair point in the direction of the rectangular pattern not in the direction of the base leg of the pattern. Though you can choose to imagine it that way, I think the pair working together is easier to interpret and historically correct.
Hold on there pardner. These words from the regulation create an explicit connection between Part 91 and the visual traffic pattern indicators:
"Approved" light signals. "Approved" markings. Too bad the "approvers" didn't know, way back when, that there would be a need to have clockwise traffic around both sides of a runway instead of, on occasion, just one side. Then they wouldn't have made drawings and instructions associating departure turns with the pattern pointers. With a little clairvoyance, they could have designed more robust pointers. Maybe like this (if you didn't like the last one):
Did you post a reference that says the markers indicate the direction of crosswind turns? I might have missed it. But why would they? The segmented circle is meant to be read by planes in the air, so there's no need for it to indicate the crosswind direction. It will be the same as base turn. And pilots on the ground usually can't see the segmented circle anyway, so it would be useless.
See posts 243 & 249. FAR 60.18-2 said "...the entire L will indicate the course of the turn..." and "...the short member of the L will show the direction of traffic in the air..."
Nothing in your references says what you are saying. I think you're relying on confirmation bias to back up faulty assumptions. Only one indicator is necessary per each runway direction because all turns in a pattern go the same way. Since all the documentation says the indicators are for pilots landing at the field, it makes the most sense that you'd look at the arrival end. There's no need for an indicator at the departure end, because there are no runways with figure-eight patterns like you drew earlier. All of the diagrams, including the ones you don't like, are totally consistent with the indicator showing the directions of turns for traffic landing on the indicated runway. They're not consistent with your explanation.
Sayin' it's so don't make it so. The pattern indicators point to the side of the airport on which both patterns lie. How do you explain the AIM statement re: the departure end? And the arrows in post 249, how do you explain that? Clearly there was no problem using the departure end to show how pilots can visualize the traffic pattern.
Indeed.