Bad: Downwind departure at non-towered airport?

Robert Ryan

Robert Ryan

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Robert R
I’m hoping somebody can enlighten me. I’ve read from AOPA that a downwind departure is bad, and it’s not listed in the AIM as a departure technique. But I don’t understand why. Let’s say 18 is active and you want to head North. It seems like a downwind departure would keep you in a place where you’re expected - and it’s like doing pattern work. Departing on the 45 from the upwind, then turning North after a couple miles seems to send you right through that nebulous space outside the pattern where people are setting up to come in on the 45. Plus I’d be nose-high and crossing the inbound 45 somewhere about 1500’.

(Making a right crosswind departure is technically not legal and violates the noise abatement rules at my airport)
 
It seems the standard traffic pattern has been disregarded for so long that it has become OK to make blatantly unsafe maneuvers.

The downwind departure is completely normal and expected. Just stay in the pattern until abeam the approach end of the landing runway and avoid the final approach by turning away a few degrees. If you are above the pattern altitude, you are not really in the pattern anyway.
 
Seems safe to me and it’s a common departure route at my airport. I could imagine the guy behind me on downwind might be confused to see me veer right out of the pattern, or worse if I just stayed in the downwind heading the #2 guy might hold off turning base.
 
Perhaps you can cite the AOPA article that says it's bad. I've never heard of it being discouraged before.
 
Robert Ryan said:
Seems safe to me and it’s a common departure route at my airport. I could imagine the guy behind me on downwind might be confused to see me veer right out of the pattern, or worse if I just stayed in the downwind heading the #2 guy might hold off turning base.
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Yeah, well it's inconsiderate to fly in a way others can't tell what you plan to do simply by observing you. Sometimes while doing pattern work it might be necessary to break out of the pattern due to spacing/congestion, etc., but to plan on a downwind departure in lieu of the prescribed AIM recommendation is a bridge too far, IMO. Once you are above pattern altitude, according to the AIM, making a turn back to the airport and using it as your first enroute checkpoint gives you a better chance of nailing down a compass heading if you're dead reckoning. I looked at your airport in the other thread you have and see where straight-outs off RWY 13 are restricted due to noise. That leaves a right left? [EDIT: can't remember if it's right traffic] 45, southbound eastbound?, after reaching pattern altitude. By the time you make a 180 and get back to the airport you'll be above 1500' so I don't share your concerns. Just because you have a radio doesn't mean everybody else hears you and sees you. You're a student. Learn the right way now. Later on, you'll develop a sense for when bending the rules a bit would be appropriate like, say, a low overcast keeping you at pattern altitude, a mountain or a Class B surface area off the departure end for instance.
 
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It's a common departure which has been done at literally every nontowered airport I've seen other traffic at since I was a student pilot.

And notice the article is almost 15 years old. Back then the now-officially-OK crosswind-to-downwind entry was also a huge no-no. You'd probably also get heated discussions about how terrible a long straight-in is.
 
A good general rule of thumb is "if you don't need to be in the pattern, don't be there". That's where everyone else is and you're just occupying valuable airspace that you don't need. That's especially true in a busy pattern, although at some quiet airports a downwind departure has almost zero impact.
 
Helpful? Obfuscating? ‘Annoying but Correct’, lol?

https://www.faa.gov/regulations_pol...iation/airplane_handbook/media/09_afh_ch7.pdf


“If departing the traffic pattern, the pilot should continue straight out or exit with a 45° turn (to the left when in a left-hand traffic pattern; to the right when in a right-hand traffic pattern) beyond the departure end of the runway after reaching the traffic pattern altitude.”
 
dbahn said:
A good general rule of thumb is "if you don't need to be in the pattern, don't be there". That's where everyone else is and you're just occupying valuable airspace that you don't need. That's especially true in a busy pattern, although at some quiet airports a downwind departure has almost zero impact.
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Perhaps related, the FAA and NTSB consider the AIM-standard pattern to be preferential. The regulatory required turn direction aside, most anything reasonable you do is ok, so long as we don't interfere with aircraft flying the normal pattern.
 
Unless you're at a really high altitude or in a dog of a plane, usually you can exit the pattern by climbing out of it.
 
midlifeflyer said:
Perhaps related, the FAA and NTSB consider the AIM-standard pattern to be preferential. The regulatory required turn direction aside, most anything reasonable you do is ok, so long as we don't interfere with aircraft flying the normal pattern.
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I wish you'd think more like a good pilot and less like a good lawyer. Looking at your signature line, it seems like you speak with forked tongue:

Aviation Regulation Fallacies and Half-Truths
  • The AIM is not regulatory.
 
Robert Ryan said:
Really?
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Mark is so fond of the importance of following the AIM he put it in his signature, i.e, it's a fallacy that the AIM is NOT regulatory. But he's arguing for disregarding its advice (because he thinks anything that came before he did is "too old", I think).
 
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I did this yesterday, (but at a towered facility). Rwy 7L/R was in use, and I wanted to depart VFR to the West.

I departed on 7R, tower had me extend my upwind a little due to traffic, then I did a RH turn to crosswind/downwind, keeping a modest climb in the whole time.

As soon as I was pointed West, I just kept on going. I was already 2,000' above the airport elevation when I was abeam the numbers on 7R.

Wasn't a big deal. Is it supposed to be?
 
dtuuri said:
Mark is so fond of the importance of following the AIM he put it in his signature, i.e, it's a fallacy that the AIM is NOT regulatory. But he's arguing for disregarding its advice (because he thinks anything that came before he did is "too old", I think).
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I think you misread my signature block. The AIM is not regulatory is not a fallacy. It's a half-truth. Some things in it parrot regulations. Those are regulatory. Other things are recommendations for good operating procedures - those can be a problem if you do something different and cause a problem as a result. Pilot judgment and risk management involve understanding the difference.
 
Downwind departure shouldn't be a problem, as long as you continue to climb and stay aware of instrument traffic that may be learning the wonders of the localizer. Its those early crosswind turn departures that I get a little miffed about. Its freak'n great that your high-wing wonder can climb out at 1,500fpm and 60kts. But, you're now head on with traffic arriving on the 45.
 
midlifeflyer said:
The AIM is not regulatory is not a fallacy. It's a half-truth.
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Careless and reckless is a regulation. A prudent pilot will exit as the AIM recommends not whatever he feels like doing for the sake of his selfish convenience.
 
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Rgbeard said:
I did this yesterday, (but at a towered facility)...
...tower had me extend my upwind a little due to traffic...
Wasn't a big deal. Is it supposed to be?
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Not a big deal at a controlled field because the controller directs the traffic, as you were instructed. Left to your own devices there may have been a dangerous conflict.
 
You know, in almost 2000 hours of flying I really hadn't contemplated the hazards of a downwind departure, or how annoying/disruptive it could potentially be to others in the pattern who don't have radios. OTOH, I've almost always been based at a Midwest/Plains sleepy airport or one that is towered and directs you.
dbahn said:
A good general rule of thumb is "if you don't need to be in the pattern, don't be there". That's where everyone else is and you're just occupying valuable airspace that you don't need.
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^^^that post^^^ really rings true. I think I'll completely exit the airport environment either straight out or at a 45 in the future...get well outside the pattern and then turn in course. What's it gonna cost me...2 freakin' minutes?!?! That's a cheap price to pay.

...thank you for getting me to consider something I hadn't...
 
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Tim, that is a really admirable attitude.
I am going to reconsider what I sometimes do too.
 
Considering the number of people that don't enter downwind correctly (and who can blame them, the diagram in the AIM is even drawn incorrectly), departing straight out or making a left 45° turn during departure do not seem tied for first place as the two safest options IMO.
 
Thanks for the helpful info. My home airport can get busy at times. Here’s what I saw this morning. Unusual Vref speed. Radio was interesting too.
 

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timwinters said:
You know, in almost 2000 hours of flying I really hadn't contemplated the hazards of a downwind departure, or how annoying/disruptive it could potentially be to others in the pattern who don't have radios. OTOH, I've almost always been based at a Midwest/Plains sleepy airport or one that is towered and directs you.

^^^that post^^^ really rings true. I think I'll completely exit the airport environment either straight out or at a 45 in the future...get well outside the pattern and then turn in course. What's it gonna cost me...2 freakin' minutes?!?! That's a cheap price to pay.

...thank you for getting me to consider something I hadn't...
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Quite possibly the first time in the history of POA that someone’s mind was changed. :)
 
dmspilot said:
Considering the number of people that don't enter downwind correctly (and who can blame them, the diagram in the AIM is even drawn incorrectly), departing straight out or making a left 45° turn during departure do not seem tied for first place as the two safest options IMO.
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I don't understand why not. I would think the main increase in safety would result from simply climbing THRU traffic pattern altitude and immediately getting above the fray instead of remaining in it for a 1/2 circuit or more and significantly extending your exposure to the goat rodeo.

also, I'm curious about an AIM pattern diagram being drawn incorrectly. I'm not familiar with that one. Please do expound.
 
timwinters said:
I don't understand why not. I would think the main increase in safety would result from simply climbing THRU traffic pattern altitude and immediately getting above the fray instead of remaining in it for a 1/2 circuit or more and significantly extending your exposure to the goat rodeo.
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I'm still trying to figure out why closed traffic is ok but doing the same thing to leave is reckless.
 
The "average" GA airplane may spend two minutes climbing to pattern altitude (at a 500 fpm climb rate). That's a long time to occupy the departure path if every departing aircraft is doing the same thing as recommended in the AIM. That plane is "in the way" of the next departing aircraft, and the departing pilot on the ground has to decide if he can safely out climb you in the distance between him and you, and that distance is short if the departing aircraft is slow.

Personally, if I'm headed to a destination behind my take-off direction, I'll often turn opposite the pattern as soon as I'm past the departure end and do my climbing and on-course heading on the non-pattern side. Since 91.126 specifically says "while approaching to land" you are not violating that regulation by departing with a turn opposite of the direction of the pattern, and although the AIM may not like it I feel it's a much safer option, particularly in a slow airplane with a low rate of climb and without a radio (like my 65 hp Cub on a hot day).

I haven't done the math, but imagine a Cub climbing at 500 fpm at 50 mph ground speed. Thirty seconds later a C172 departs with a higher ground speed and a slightly higher rate of climb. Both aircraft follow the AIM religiously. Even if the C172 doesn't actually collide with the Cub that he can't see below his cowling, he may pass dangerously close to it. So the only prudent way for the C172 to depart per the AIM is to wait until he is certain that the Cub will have turned away from the runway heading. That works for the aircraft waiting to depart, but what about all of the other planes that are already in the pattern to land? Some might need to go around and some may be doing touch and goes, effectively creating the same hazard as if the C172 on the ground had departed too soon.
 
I was taught, and do, and teach the downwind departure as a regular procedure. You keep climbing, but follow the ground track. I do feel this is safe.

For those that follow the exact AIM method, let me ask you this - WHEN do you turn towards your destination? The main problem with the AIM method is that the wording is awful, incomplete, and unable to be followed as written.

"If departing the traffic pattern, continue straight out, or
exit with a 45 degree turn (to the left when in a left−hand
traffic pattern; to the right when in a right−hand traffic
pattern) beyond the departure end of the runway, after
reaching pattern altitude."

To break it down and remove extraneous words:

If departing the traffic pattern:
1. continue straight out, or
2. make a 45 degree turn once past the departure end of the runway and after reaching pattern altitude.

Note it doesn't say "after reaching pattern altitude, proceed on course", or "when you're 5 miles away from the airport, proceed on course", or anything about when to actually turn on course.

As it is, we're given two options - straight out or turn 45 degrees. But until when? No guidance. I hope your takeoff runway always points directly at your destination (or, I suppose, 45 degrees to the correct side dependent on the traffic pattern direction). Obviously this is silly.

So at some point, even the people who want to comply with the AIM need to make up their own method, one that they think is safe. So at that point, it just becomes an argument over whose attempted-AIM-compliant method is safer, which is exactly the same discussion as with the downwind departure.
 
Worse than a downwind departure is a light winds departure at a non-towered airport. People use whatever runway they want but hopefully they announce what they're doing.

Downwind takeoff issue is purely mechanical. You have a tailwind, so you must accelerate more and it takes more runway length.
 
bflynn said:
Worse than a downwind departure is a light winds departure at a non-towered airport. People use whatever runway they want but hopefully they announce what they're doing.

Downwind takeoff issue is purely mechanical. You have a tailwind, so you must accelerate more and it takes more runway length.
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We are talking departure (leaving the area) not takeoff. Also, I'm with Russ on this one.
 
bflynn said:
People use whatever runway they want but hopefully they announce what they're doing.
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That's if they even have a radio and more importantly if they're using it correctly and not announcing false and misleading information, which can be worse than no information at all.
 
RussR said:
As it is, we're given two options - straight out or turn 45 degrees. But until when? No guidance.
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The guidance says "beyond the departure end of the runway."

The problem with many of these discussion is that we get so caught up in the minutiae of the trees, we lose sight of the forest of the goal. What the departure guidance is concerned about is a turn head-on into the path of the pilot arriving on a correctly-performed standard 45 degree entry. If you wait until after the departure end, you won't conflict.
 
Seems to me that much of the safety of whatever you choose depends largely on the amount and composition of traffic at your airport. If there is significant traffic in the pattern, I would exit straight or 45 and stay well clear of the traffic. If it's a quiet day and there's little to no chance of you being a part of the spacing in the pattern, why not depart on the downwind.

Planes have pilots for a reason and our best tool is between our ears. (usually)
 
midlifeflyer said:
I'm still trying to figure out why closed traffic is ok but doing the same thing to leave is reckless.
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Read post number 3...just one example of why...

...that was the first post to nudge me towards rethinking my attitude towards this...and #8 made me think more...

...but it's a free country (at least in theory), so do what you want!
 
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midlifeflyer said:
The guidance says "beyond the departure end of the runway."

The problem with many of these discussion is that we get so caught up in the minutiae of the trees, we lose sight of the forest of the goal. What the departure guidance is concerned about is a turn head-on into the path of the pilot arriving on a correctly-performed standard 45 degree entry. If you wait until after the departure end, you won't conflict.
Click to expand...

Lots don't "correctly" perform it, and fewer make them exactly 45°.
 
timwinters said:
I don't understand why not. I would think the main increase in safety would result from simply climbing THRU traffic pattern altitude and immediately getting above the fray instead of remaining in it for a 1/2 circuit or more and significantly extending your exposure to the goat rodeo.

also, I'm curious about an AIM pattern diagram being drawn incorrectly. I'm not familiar with that one. Please do expound.
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"Enter the pattern in level flight, abeam the midpoint of the runway" -- lot of people do neither. Here is the diagram, "1" is not "the midpoint".

Screen Shot 2019-11-25 at 9.32.09 AM.png

Given a long runway and angles that aren't exacty 45°, "6" could be very close to "1".
 
midlifeflyer said:
The guidance says "beyond the departure end of the runway."
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It says to make the 45 deg turn past the departure end of the runway. No mention of when you can proceed on course. So if my runway is 36, left traffic, I can either keep heading 360, or turn to 315 when past the departure end of the runway. It says nothing about when I can turn on course.

Which is silly.
 
Likely they assume that pilots are smart enough to understand that once you're outside "the airport environment" then you do what you want to.

but, hey, that's just my assumption of their assumption!
 
dmspilot said:
"Enter the pattern in level flight, abeam the midpoint of the runway" -- lot of people do neither. Here is the diagram, "1" is not "the midpoint".

View attachment 80197

Given a long runway and angles that aren't exacty 45°, "6" could be very close to "1".
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incorrect? Yeah.

substantial enough to make a chit? No.

they must have outsourced the proofreading to AOPA Pilot's editors.:rolleyes:
 
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