Let's refine the straight-in debate with an example & poll

[rhkennerly]

(I created a poll above, but there are limitations on length. Here is the information: )

Given: a. "Cessna 340 on a 5-mile straight-in final for 36"
Given: b. Cessna 150 pilot on base for 36

What should the Cessna 150 pilot do?

1. cut the corner to final and get on the runway pronto?

2. abort at low altitude flying straight ahead and across the flight path of the straight-in flight?

3. Yield the to the aircraft on his right by adjusting his flight path to the right and turning into the approaching straight-in aircraft and circling back to

• a. re-enter base or
• b. leave the pattern and fly back to the 45 degree downwind entry?

4. turn left with his back to the highspeed straight-in traffic and fly parallel along the left side of the runway and be in the turning path of any aircraft taking off below them?

5. or should he turn his back to the straight-in traffic by turning left to parallel the runway, but cross over the runway to the right side so that he'll be in the proper position for aircraft on missed approach and not in the path of departing aircraft?​

(Extra credit: rework the problem so that if the pattern is Right-Handed, then the C-150 on base is the aircraft on the right.)

The whole purpose of a pattern at airports is just that: a pattern.

• Repeatable.
• Predictable.
• Self-regulating.
• available to NORAD pilots

VFR traffic separation depends on shared knowledge, shared situational awareness, and cooperation. It works even with NORAD aircraft.

When the pattern is full with 3 or 4 aircraft in the circuit, distances, speeds, and size of the pattern is constantly adjusting to fit the situation where everyone is working with the same set of information.

Straight-in aircraft, provide little observable information to pilots in the pattern and straight-in pilots possess none of the situational awareness pilots in the pattern have.

 

[Lowflynjack]

Seems like we're starting off with bad data. I just listened to the audio again. It wasn't a 5 mile final when the 150 turned base.

340: "Watsonville area traffic, Twin Cessna 740WJ, 3 miles, straight-in , 20, full stop."
150 4 seconds later: "Watsonville traffic, Cessna 931, left base 20, Watsonville."

Everyone will debate whether or not it was okay for the 150 to turn in front of the 340, but once he did and wanted out of the situation, I'm not sure what I would do. Immediate 360? Go straight and climb? I guess it would depend on where the 340 was. He clearly saw him and stated as much.

 

[rhkennerly]

I'm not sure what I would do. Immediate 360? Go straight and climb? I guess it would depend on where the 340 was. He clearly saw him and stated as much.

and it's not clear to me he saw the actual aircraft or he saw (or the passenger saw) the aircraft on ads-b closing fast behind him. In any event, judging an aircraft's speed on a straight-in is clearly a problem for pilots turning base to final. And not just when the straight-in aircraft is flying at 3 miles a minute.

Even if the twin had flown a pattern wide of the slower aircraft on final (as I've observed many times), then everyone in the pattern can adjust to make a hole because everyone is working with a complete set of knowledge. that's the beauty of patterns, they adjust--expand and contract--almost automatically, dynamically.

 

[eman1200]

another thread on the same thing? not enough pages in the last one?

 

[Lowflynjack]

another thread on the same thing? not enough pages in the last one?

It got you to chime in!

 

[dmspilot]

An important piece of information needed to make decisions on collision avoidance and right-of-way is the airspeed of other aircraft. Even if the Twin pilot was flying a normal 1.3 Vso approach (which he should have been), the closure rate would have been tight...but the average Cessna 152 may have not familiarity with a C340 or ability to conceptualize the airspeed differential between itself and the twin. The C152's pilot decision to turn base and final would have allowed for completely adequate separation if the other aircraft had been another C152.

 

[William Pete Hodges]

Ordinarily I would say the 340 on 5 mi final should yield right of way to the aircraft already in the pattern on base. That aircraft is likely below 700 feet and close to landing anyway. If I were on 5 mi final at 1000 feet and was aware of another aircraft on base, I would proceed upwind and enter the traffic pattern on crosswind. Unfortunately we already know the 340 pilot did not do that.

The problem is if both airplanes abort at the same time, both heading for the upwind leg then a midair collision could still occur. The airplane on base should not go straight across and enter the upwind leg without confirmation that the straight in pilot will not abort. Not a great scenario even if it works, but it could work if both pilots are talking, which may not be the case.

The pilot on left base should execute a level left 270 degree turn, and declare intentions to re enter and extend downwind. (This would be a level right 270 if on right base) This airplane is now below any normal downwind traffic behind him in the pattern, and has a view of that traffic in the 270 degree turn. He can then decide to lead the traffic remaining if room is available, or follow the downwind traffic as it passes, or pull out of the pattern altogether near the end of the downwind leg. To me it all depends on where the airplanes are when it's time to abort the landing.

So I choose item 6. Perform a level left 270 and re enter an extended downwind leg.

 

[eman1200]

It got you to chime in!

yeah, uh, congratulations?

 

[Tantalum]

Maybe better asked - what would a controller do? And let's mimic that...

How often has a controlled airport tower put a small slow plane right in front of a faster one?

Had this been controlled
(A) tower likely would have asked 340 to slow to final approach speed somewhere in the 3-5 mile zone
(B) tower likely would not have turned the 152 in.. "extend downwind I'll call your base"

We have a motley cru of planes at MYF here. They split tower frequency between 28L and 28R and you've got students, solo students, King Airs, Jets, Cirrus, helicopters, Cubs, and everything you can imagine in between

Sometimes they'll clear someone for a no-delay with aircraft on close final "no delay, aircraft on x mile final" but in 12 years of flying around MYF I've never heard them turn an aircraft in front of oncoming traffic. When on an IFR approach you'll be "straight in" and they seem to give a very wide margin there.. and in my experience will send the slower plane around. I kept the Aztec power in a few months ago (showing 180 over the ground) and they still gave me a huge box delay vector (in IMC) to let a King Air pass me

 

[luvflyin]

another thread on the same thing? not enough pages in the last one?

Last ‘one’? Aren’t there about 3 or four? We need a new Forum called Traffic Patterns.

 

[Tantalum]

..I also took the bait - even though I didn't participate in the poll


Sad part is, Paul already addressed this. With his takeaway, again, being "don't be a dick"

 

[MauleSkinner]

“Not fly bomber patterns” isn’t in the poll.

 

[pburger]

...

• available to NORAD pilots

VFR traffic separation depends on shared knowledge, shared situational awareness, and cooperation. It works even with NORAD aircraft.

NORAD pilots? Are these the guys flying the "bomber" patterns?

Or perhaps did you mean NORDO??

 

[Salty]

No interest in the poll, but

Had this been controlled
(A) tower likely would have asked 340 to slow to final approach speed somewhere in the 3-5 mile zone
(B) tower likely would not have turned the 152 in.. "extend downwind I'll call your base"

is interesting to me. I'd like to hear from a controller without radar how they would have dealt with this.

 

[steingar]

One of the participants in the first thread said that there was nearby terrain that limited the options of the aircraft in the pattern.

 

[rhkennerly]

Seems like we're starting off with bad data. I just listened to the audio again. It wasn't a 5 mile final when the 150 turned base.

340: "Watsonville area traffic, Twin Cessna 740WJ, 3 miles, straight-in , 20, full stop."
150 4 seconds later: "Watsonville traffic, Cessna 931, left base 20, Watsonville."

Everyone will debate whether or not it was okay for the 150 to turn in front of the 340, but once he did and wanted out of the situation, I'm not sure what I would do. Immediate 360? Go straight and climb? I guess it would depend on where the 340 was. He clearly saw him and stated as much.

In truth, I wasn’t thinking about a specific accident. I’m just trying to get people to focus on the dilemma of a pilot on base with straight in traffic.

 

[rhkennerly]

another thread on the same thing? not enough pages in the last one?

trying to refine the question to focus on issues without the "turbine" & "jet" distractors. Or the "at a controlled airport" comments. Or the "guidance" vs "reg" questions. If you're at 300 ft on a left base headed to the final turn & there is traffic closing "straight-in" on your right, what are the options?

all the rest is smoke & mirrors.

 

[jbarrass]

In truth, I wasn’t thinking about a specific accident. I’m just trying to get people to focus on the dilemma of a pilot on base with straight in traffic.

...or the pilot on final with a plane reporting in on base. Perspective is everyhting.

 

[rhkennerly]

No interest in the poll, but
is interesting to me. I'd like to hear from a controller without radar how they would have dealt with this.

At a tower, spacing & sequencing is not done by the pilots themselves. But ithis is an uncontrolled field reliant on a self-regulating traffic system based on everyone working with the same set of information. That's the point of the dilemma here.

 

[rhkennerly]

NORAD pilots? Are these the guys flying the "bomber" patterns?

Or perhaps did you mean NORDO??

sorry, Cold warrior. I was thinking of all those pilots coming over the poles.

 

[rhkennerly]

“Not fly bomber patterns” isn’t in the poll.

And it doesn't have to be a "bomber pattern" for there to be a conflict on base to final with incoming straight-in traffic. Or at least confusion in the base to final plane about the speed & location of straight-in traffic and whether to turn in or not.

 

[Salty]

At a tower, spacing & sequencing is not done by the pilots themselves. But ithis is an uncontrolled field reliant on a self-regulating traffic system based on everyone working with the same set of information. That's the point of the dilemma here.

The point of my query is that controllers may have guidance that would help us, or at least be interesting to hear. A controller without radar is in no better position to make the call whether or not to turn base than the guy in the 152 was.

 

[MauleSkinner]

And it doesn't have to be a "bomber pattern" for there to be a conflict on base to final with incoming straight-in traffic. Or at least confusion in the base to final plane about the speed & location of straight-in traffic and whether to turn in or not.

If a Cessna 150 is on a normal base, he’s less than a minute from the runway. Even at 180 knots, the traffic on 5-mile final is almost two minutes from the runway. Where’s the conflict?

 

[Mxfarm]

Sounds like a 340 should have just flown a overhead break.

 

[Tantalum]

No interest in the poll, but



is interesting to me. I'd like to hear from a controller without radar how they would have dealt with this.

I don't believe most controllers have radar, at best ADSB, otherwise they're using mark II eyeball. In my post I can only speak from my experience at MYF, which handles a lot of volume, english as second language, and a whole array of craft. They're making these judgment calls throughout the day, should I turn the plane now, should I extend, do I close the pattern to more traffic, etc. I agree, hearing their perspective would be insightful

 

[pburger]

If a Cessna 150 is on a normal base, he’s less than a minute from the runway. Even at 180 knots, the traffic on 5-mile final is almost two minutes from the runway. Where’s the conflict?

^^^^^^^^
THIS

The option I was looking for in the poll was: -Continue

 

[luvflyin]

No interest in the poll, but



is interesting to me. I'd like to hear from a controller without radar how they would have dealt with this.

At a tower, spacing & sequencing is not done by the pilots themselves. But ithis is an uncontrolled field reliant on a self-regulating traffic system based on everyone working with the same set of information. That's the point of the dilemma here.

Spacing is done by pilots. They tell you to follow another plane, they’ve done the sequence. You make sure you have enough space to follow and land behind. EXCEPT, yeah, sometimes they do the I’ll call your base thing.

 

[rhkennerly]

...or the pilot on final with a plane reporting in on base. Perspective is everyhting.

that’s true. Flip the pattern to RP & what does the pilot on straight in do is even more pertinent, since then the base to fina” traffic is on his right and likely lower.

 

[MauleSkinner]

that’s true. Flip the pattern to RP & what does the pilot on straight in do is even more pertinent, since then the base to fina” traffic is on his right and likely lower.

Why would the base to final traffic be lower?

 

[rhkennerly]

If a Cessna 150 is on a normal base, he’s less than a minute from the runway. Even at 180 knots, the traffic on 5-mile final is almost two minutes from the runway. Where’s the conflict?

pilots don't fly painted lines on the ground. Inbound pilots don't always estimate their position accurately. The size of patterns expand & contract dynamically, depending on any number of factors. At 300 ft & looking to your right, trying to gauge the distance & speed of a straight-in is difficult.

 

[rhkennerly]

Why would the base to final traffic be lower?

if you're on a straight-in, don't you suspect you'll likely be above the spot where the base to final is making his turn? Or are is that pilot dragging it in from a mile or two?

 

[Silvaire]

31 responses (10 from the OP) and only six votes. This one's a dud.

 

[Salty]

31 responses (10 from the OP) and only six votes. This one's a dud.

Hey, at least nobody posted “yawn”

 

[Hang 4]

 

[MauleSkinner]

if you're on a straight-in, don't you suspect you'll likely be above the spot where the base to final is making his turn? Or are is that pilot dragging it in from a mile or two?

If I’m in conflict with someone, I wouldn’t assume that they’re at a different altitude. In your scenario, it would be more likely that the aircraft on base would be higher, in my experience, because they’re trying to do that “gliding distance to the runway” thing.

 

[MauleSkinner]

pilots don't fly painted lines on the ground. Inbound pilots don't always estimate their position accurately. The size of patterns expand & contract dynamically, depending on any number of factors. At 300 ft & looking to your right, trying to gauge the distance & speed of a straight-in is difficult.

So your poll is based on parameters that aren’t correct. Kind of a waste of a poll, IMO.

 

[Velocity173]

No interest in the poll, but



is interesting to me. I'd like to hear from a controller without radar how they would have dealt with this.

Technically there’s no hard and fast rule here. There’s nothing that states any sort of speed calculation on the part of the controller to achieve “proper spacing” on final. It’s all eye balling it.

Lots of variables involved here, radar or no radar. Some controllers don’t know performance of a C340 from a C152. You could have radar up but if the aircraft isn’t tagged, there’s no ground speed. You could have no radar and an inaccurate report from the C340 complicating matters. How wide is the C152 on downwind? If you tell the C152 to “make short approach” how short will that really be? It’s debatable whether or not a speed restriction can be give to the C340 (on final and less than 5 miles is a no go) but I wouldn’t do that.

Personally, if the C152 is abeam the numbers and the C340 just reported 5 miles, I’d tuck him in front of him. If it didn’t look like I’d have runway sep (4500 ft) then send the C152 around.

 

[Palmpilot]

In truth, I wasn’t thinking about a specific accident. I’m just trying to get people to focus on the dilemma of a pilot on base with straight in traffic.

Having to find a solution to the conflict when you're already on base is a tough spot to be in, so it's best to err on the side of caution be not turning base until you're sure there's enough room to get down and off the runway in time.

 

[Palmpilot]

if you're on a straight-in, don't you suspect you'll likely be above the spot where the base to final is making his turn? Or are is that pilot dragging it in from a mile or two?

A fair point, but not relevant, because of the part of the reg that prevents us from using the "lower" rule to cut in front of the plane on final.

 

[danhagan]

We have right traffic to RWY 28 at our field with sky divers south (straight ahead not an option). Initially option 4 sounds bad, but if you side step large to the right in right traffic and the goof on the straight in doesn't abort with you, things should work out ... he'd have to aim at you to hit you as you are no longer on the runway center line ...