ANOTHER PATTERN COLLISION - NOT M20

[Marauder]

With full blown TCAS installed, it is interesting how often the pilots' instincts are exactly opposite what the boxes are telling the pilots to do.  Simple things like relative altitude and closure rate can be very deciptive.  The first rule of TCAS is "Do what TCAS says".  the pilot is to ignore ATC instructions and his own instncts.
TCAS does not give lateral guidance, merely vertical guidance.  Keeping the problem two dimensional seems to have merits.

I would love to have full TCAS capability in my plane. The proximity warning zones (PAZ & CAZ) for the Lynx system is about 8 to 12 seconds before potential impact. Just enough time to hear the proximity alert, say “Holy Crap!” and begin a turn hopefully away from the conflict. It would be a lot easier if it said to me “Hey stupid, turn left and dive!” I tend to understand those pretty well.

When ADS-B was initially proposed, I thought this was going to be another Mode S exercise. Once I became equipped, it really enlightened me to how much traffic I never saw before. If this was the World War II era, I’m afraid I’d end up as a victory symbol on the side of someone’s plane.


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[GeeBee]

Remember there is a latency in ADSB traffic. It is not perfect.

 

[chriscalandro]

50 minutes ago, GeeBee said:

Remember there is a latency in ADSB traffic. It is not perfect.

 

The latency in ADSB traffic is minimal. The weather component has a latency that requires planning. 

[Pinecone]

2 hours ago, DCarlton said:

If you know someone is right in front of you and you are talking to them and you don't see them, I'm not sure how much ADSB can help.  

And I don't know why would continue at well above pattern speed and descending into unseen traffic

 

[aviatoreb]

8 hours ago, GeeBee said:

In addition, experienced and professional pilots have a duty to watch out for students. When I hear inexperience or I see it is a trainer, I assume they are inexperienced and I give them all the courtesy I can as they are struggling to control the airplane let alone watch out for me. Their field of view and SA is narrow. You cannot expect them to view the pattern as easily as you.  

That was my thought.  I listened to the audio.  My feeling is it was not an especially experienced 152 pilot, and for the fact he was in a 152 in the pattern, likely a student.  So if the Cessna 340 or any experienced pilot's plan is the student will do all the work to make the situation right, it might not turn out well.  Whether or not the 340 had the right away, that's not the point in the end since crashed is crashed and the 340 might have anticipated this is a problem.  

Maybe 5 years ago - I know I have aborted my final in a comparable situation - when a 172 I knew was a student pulled in front of me as I was on practice approach - I was maybe 8 miles out and he pulled in front of me maybe 1 mile ahead of me - despite I was making regular position calls.  But I wasn't doing 180.  I was doing maybe 110 and the Cessna was doing maybe 90.  Rather than try to slow up and ride up even closer I just broke right joined the pattern upwind and did the full square pattern.  Landed and later talked to the student to describe where we all were.  he heard me but wasn't yet up to the point of making position maps in his head as traffic patterns are being made.  It was a good talking experience.

[whiskytango]

1 hour ago, GeeBee said:

Remember there is a latency in ADSB traffic. It is not perfect.

 

I have wondered if there would be a benefit to having a HUD with just ADSB traffic, to minimize the time you are looking at a display inside the cockpit (particularly when in the pattern!).  The HUD would be less beneficial, and could provide misleading information in the pattern environment if there is latency in the depiction of ADSB traffic. 

[kortopates]

Remember there is a latency in ADSB traffic. It is not perfect.
 

You have me wondering where that would be a factor. Not with air to air targets, but i imagine so with ADS-R targets but haven’t really noticed. I mostly operate under the class B veil where we are all required to be equipped and i don’t see any latency with close by targets that would allow discerning any latency such as in the pattern and on parallel runways.


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[Mooney in Oz]

4 hours ago, Marauder said:

I found the ATAS feature of my Lynx 9000 does a really good job of tracking these potential conflicts….
 

I find the Trend Vector feature with the traffic system on the Garmin G3X display to be similarly useful.

[carusoam]

Started the day with Juan Brown/blanco lerio…

 

heard…

Plane A: 180 kts straight in…

Plane B:  in the traffic pattern… and seeing everything going on…

 

knowing…

There is no training for handling other planes going 180 in or near the traffic pattern..

There is no experience, for most people, doing 180 into a traffic pattern…

There is no way C152 driver is going to be able to adjust…  if he did something different, he would have surprised the incoming speed demon one way or the other…

he did an amazing job announcing…

 

Unless you are alone…

Try to be at TPA going traffic pattern speeds when you get there…

 

This was just dumb.

let me know when it is OK for a Mooney to approach straight in to an uncontrolled field doing 180 with C152s in the pattern…

 

Keep in mind… very few people have experience going 3 miles per minute any where near the ground… this is a blistering speed!

expect the 340 driver had no idea what was going on, while it was happening.

Similar to…

going down and slowing down…

or…

Being 1k’ high entering the traffic pattern…

 

Expect to go out, get things sorted, then come back in… it only takes an additional two minutes… (?)

 

I’m pretty sure we are all on the same page… unless I didn’t write things correctly.  

Self defense… Don’t turn in front of a speed demon and lose sight of him…

 

Dad advice…

Know that somebody was dead right going into this situation… ending up dead isn’t very right.

prayers for the lost airmen…

Best regards,

-a-

[Bolter]

2 hours ago, kortopates said:

You have me wondering where that would be a factor. Not with air to air targets, but i imagine so with ADS-R targets but haven’t really noticed. I mostly operate under the class B veil where we are all required to be equipped and i don’t see any latency with close by targets that would allow discerning any latency such as in the pattern and on parallel runways.


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I have noticed latency in the form of "jumps" in traffic that is displayed.  A few seconds of not moving, and then it is someplace else.  This seems to happen more in rural areas where the ADS-B is possibly the radar's feed of direct reflection and not the target using ADS-B. 

[Jcmtl]

In canada it’s common to mention your position relative to everyone in a pattern at an uncontrolled field (maybe it’s the same in the states?).  
 

if i was the 152 i would have said i was turning base/final, and that i was number 1 and possibly would have told/ suggested to the guy on the long straight in to join the pattern the correct way ie 45 degree downwind or overhead the field and joining downwind that way. 
 

The fast guy wouldn’t have risked his life mowing down a slower guy on short final.  
 

Nobody should be going straight in at an uncontrolled field unless theyre sure nobody else is in the pattern.

[Pinecone]

8 hours ago, carusoam said:

Started the day with Juan Brown/blanco lerio…

 

heard…

Plane A: 180 kts straight in…

Plane B:  in the traffic pattern… and seeing everything going on…

 

knowing…

There is no training for handling other planes going 180 in or near the traffic pattern..

There is no experience, for most people, doing 180 into a traffic pattern…

There is no way C152 driver is going to be able to adjust…  if he did something different, he would have surprised the incoming speed demon one way or the other…

he did an amazing job announcing…

 

Unless you are alone…

Try to be at TPA going traffic pattern speeds when you get there…

 

This was just dumb.

let me know when it is OK for a Mooney to approach straight in to an uncontrolled field doing 180 with C152s in the pattern…

 

Keep in mind… very few people have experience going 3 miles per minute any where near the ground… this is a blistering speed!

expect the 340 driver had no idea what was going on, while it was happening.

Similar to…

going down and slowing down…

or…

Being 1k’ high entering the traffic pattern…

 

Expect to go out, get things sorted, then come back in… it only takes an additional two minutes… (?)

 

I’m pretty sure we are all on the same page… unless I didn’t write things correctly.  

Self defense… Don’t turn in front of a speed demon and lose sight of him…

 

Dad advice…

Know that somebody was dead right going into this situation… ending up dead isn’t very right.

prayers for the lost airmen…

Best regards,

-a-

 

Agree with most of what you say.

But a good number of people have experience with 3 miles per minute, or faster, low to the ground.  Heck, the A-10 easily does that, and it is slow.

[GeeBee]

The latency may be "minimal" compared to weather, but what is if you have two aircraft closing at 4 miles a minute? Remember, those electrons have to go, from the airplane, to antenna, through a data network, to the ATC facility, through their data network, then........back through all that again. TCAS....well that's plane to plane with their own processors which is why it works so good. 

A while back I was near Asheville, NC. I was IFR at 10K with a VFR Piagglo Avanti coming at me VFR at 9,500 (why he was VFR, go figure). So we had a smoking closure rate. I had my finger on the A/P disconnect just in case. I had my traffic display down to 6 miles. The ADSB was a good two miles behind the real situation, when I acquired a visual. Hey its good, better than nothing but it is not perfect.

[M20F]

The take away should be.  You should not assume right of way, you should not assume people are on frequency, and you should assume everyone is trying to kill you. 
 
There is being right and there is being dead.  I know my preference. 

[rpcc]

Terrible.   Was there an instructor onboard the 152 too?  I see some mention of that on bt.

[ilovecornfields]

I was talking to one of my CFI friends about this crash on Friday. We were talking about how learners often can’t see the situation that is developing as well as more experienced people and as you progress further along the accident trajectory (to borrow from Mr. Reasons’s Swiss cheese model) your options become more limited. Even worse, the rate at which your options become more limited accelerates as you get closer to the accident.

In retrospect, the accident was waiting to happen when the 340 announced he was on a 10 mile straight-in and the 152 was on crosswind. The available options rapidly narrowed as soon as the 152 turned base and essentially went away completely once he was on final.

I’m not going to assign blame or comment on right-of-way rules, but it seems like this was avoidable with better situational awareness.

Both myself and my CFI friend did our primary training before the days of GPS and ADS-B and it seemed a lot more emphasis was placed on situational awareness and knowing where you were relative to other planes, navaids and terrain. He said they don’t really teach the “I’m lost” three C’s anymore (climb, conserve, confess), DF steers or how to buzz a water tower to find out where you are. That’s fine. I don’t miss NDB approaches and I love my moving maps. Technology is good, but not when it is used as a substitute for situational awareness.

Edit: I also wanted to agree with the practice of coordinating what order planes are going to land in. I don’t mean you should try to play air traffic controller, but I think if there is any doubt about the order it is best to work that out explicitly “Twin Cessna on final, I’m going to turn base behind you,” for example. 

[ilovecornfields]

7 minutes ago, rpcc said:

Terrible.   Was there an instructor onboard the 152 too?  I see some mention of that on bt.

Juan Brown said a single occupant in the 152, two in the 340.

[GeeBee]

Your CFI is correct. Fear or stress restrict perception. Lack of perception due to fear is why pilots often come to grief and why good dogs bite. A student and in particular a solo student can never be made so comfortable that his perception is unrestricted which is why when you are in the pattern with them, you give them some "slack". 

[Marauder]

The latency may be "minimal" compared to weather, but what is if you have two aircraft closing at 4 miles a minute? Remember, those electrons have to go, from the airplane, to antenna, through a data network, to the ATC facility, through their data network, then........back through all that again. TCAS....well that's plane to plane with their own processors which is why it works so good. 
A while back I was near Asheville, NC. I was IFR at 10K with a VFR Piagglo Avanti coming at me VFR at 9,500 (why he was VFR, go figure). So we had a smoking closure rate. I had my finger on the A/P disconnect just in case. I had my traffic display down to 6 miles. The ADSB was a good two miles behind the real situation, when I acquired a visual. Hey its good, better than nothing but it is not perfect.

Your post has me wondering how my TAS plays with TIS-B in my Lynx 9000. I’m going to read up on it.

Also, I agree that in ADS-R situations where 1090 or 978 are retransmitted to the opposite receiver through a ground station, there would be some sort of latency potential. I thought that one selling point of ADS-B was the direct plane to plane was also occurring. In other words, if a 1090ES plane is broadcasting out, a plane able to receive 1090ES, doesn’t require a ground station. It’s supposed to be truly plane to plane. I get that right?

I remember my primary reason for getting TAS was to locate non ADS-B compliant planes (i.e. Mode C guys) and give me coverage when I am too low to receive an ADS-B ground (in my area, I usually don’t receive FIS-B in until I am around 800 AGL).

I guess I need to freshen up my understanding of the technology and the limitations.


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[M20F]

3 minutes ago, Marauder said:

I guess I need to freshen up my understanding of the technology and the limitations.


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Technology often has a way of stop working or working incorrectly.  This is not to imply you fall into this category but far too many folks these days get reliant on it.  The amount of junk people hang of the yoke, windscreen, etc. it creates a hazard just being there and people tend to forget about their eyeballs. 
 
The technology can also be confusing.  ADSB is great at giving me a traffic alert in the pattern for a plane on the ground.  It distracts at time and to me causes a momentary loss of awareness while I try to process what it is telling me. 
 
Technology is great but the basics are the basics for a reason. 

[EricJ]

10 hours ago, Bolter said:

I have noticed latency in the form of "jumps" in traffic that is displayed.  A few seconds of not moving, and then it is someplace else.  This seems to happen more in rural areas where the ADS-B is possibly the radar's feed of direct reflection and not the target using ADS-B. 

That's not latency, that's outages.   In other words, you get some updates that display, then for whatever reason (terrain gets in the way, interference, whatever, there are lots of possibilities), your receiver isn't able to process subsequent updates for a while (because it doesn't receive them, they contain errors, etc., etc.), and then finally when it gets a reliable update it has to jump the displayed position from where it was at the last known position.

The actual latency, i.e., the time from when an aircraft calculates its position to when it is transmitted, received, and displayed on another airplanes display, is very, very short for the direct airplane-to-airplane case.   The amount of time between updates can be random, though, due to outages, terrain, interference, or other reasons, or if you're getting updates only from the ATC broadcast towers.   For the case of getting updates from the broadcast towers, the latency is still pretty small, essentially still real-time in most cases, but will naturally be a little longer than the direct airplane-to-airplane case.   

[Sue Bon]

40 minutes ago, ilovecornfields said:

In retrospect, the accident was waiting to happen when the 340 announced he was on a 10 mile straight-in and the 152 was on crosswind. The available options rapidly narrowed as soon as the 152 turned base and essentially went away completely once he was on final.

Yes, but the 340 was twice as fast as he should have been. There was no way for the 152 to know that. It took the 340 two minutes to go from 10-mile final to 3-mile final. That is over 200 knots... I deleted my comment earlier, but I still don't understand how the 340 planned to land when he had the accident at 1-mile final, 182 knots, and flaps one speed is 160 knots and gear extension is 140 knots.

I don't have much experience at all (especially compared to you guys), but I don't know how concerned I would have been with a 10-mile final call. However, after the three mile final call two minutes later, I would have searched for any escape route I could find.

[Marauder]

Technology often has a way of stop working or working incorrectly.  This is not to imply you fall into this category but far too many folks these days get reliant on it.  The amount of junk people hang of the yoke, windscreen, etc. it creates a hazard just being there and people tend to forget about their eyeballs. 
 
The technology can also be confusing.  ADSB is great at giving me a traffic alert in the pattern for a plane on the ground.  It distracts at time and to me causes a momentary loss of awareness while I try to process what it is telling me. 
 
Technology is great but the basics are the basics for a reason. 

I think that is where this technology has some shortcomings for GA. For those of you flying heavy iron, does TCAS ever provide false alerts? When I was looking at ADS-B options, I learned that TAS could fill an important role where ADS-B might have shortcomings. As well, as I mentioned earlier, the Lynx ATAS has been 100% accurate in the 5 years I have had it. It has never given me a false alert. That said, this technology, if it has done anything for me, it has heightened how much traffic I never saw before.

Just to be clear, I don’t depend exclusively on the technology but I certainly didn’t install it to be the equivalent boat anchor of my old LORAN-C. Understanding how it can fail and the shortcomings is an important part of using it.

I still remember a VFR departure out of Ocean City Maryland before the mandate. I was climbing and my wife who was sitting in the right rear seat came on the intercom and said “is there supposed to be a plane above us?” I think if I can ADS-B back then, it wouldn’t have happened.


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[ilovecornfields]

20 minutes ago, Sue Bon said:

Yes, but the 340 was twice as fast as he should have been. There was no way for the 152 to know that. It took the 340 two minutes to go from 10-mile final to 3-mile final. That is over 200 knots... I deleted my comment earlier, but I still don't understand how the 340 planned to land when he had the accident at 1-mile final, 182 knots, and flaps one speed is 160 knots and gear extension is 140 knots.

I don't have much experience at all (especially compared to you guys), but I don't know how concerned I would have been with a 10-mile final call. However, after the three mile final call two minutes later, I would have searched for any escape route I could find.

Ideally, at the 10 mile final call you would think “Oh, there’s someone else coming in on a straight in. Better keep and eye out for them.” You have a lot of options at this point - slow down, do a 360, extend downwind, leave the pattern, clarify who is going first, etc.

I would not turn base knowing there is someone on final unless I was clear about our relative positions, closure rate and who was landing first. As soon as you turn base your options are narrowed and even less options on final. Maybe he thought “I can always go around.” Apparently, he couldn’t.

Again, I’m not trying to place blame on anyone and I definitely won’t try to defend (or even pretend to understand) what the 340 was doing, but if you “think you might make it” then you probably shouldn’t be doing it. I’ve scrubbed plenty of flights that I “probably could have made” because you only need to be wrong once to have a fatal outcome.

[OR75]

 

AC 90-66B encourages standard pattern at uncontrolled airports. Straight in landings are authorized but it seems that the burden of not disrupting traffic is on the pilot executing a straight in