Mid-air collision. Chandler, AZ

Rgbeard

Rgbeard

En-Route
Joined
Aug 26, 2017
Messages
4,343
Location
Phoenix, AZ and Ensenada, Mexico
Display Name
Display name:
rgbeard
Airplane vs Rorotcraft. Just before 8am, 1-Oct-2021.

According to a witness/pilot just interviewed on local TV, the rotorcraft was immediately disabled, falling from approximately 500’, bursting into flames on impact. Two confirmed deceased.

The PA-28 was now missing its LH main gear but landed successfully.
 
Last edited:
Wonder if both aircraft had adsb working
 
That's a pretty busy towered field, at least when I was there. They have parallel runways and had a busy pattern going on both runways
 
I had just pre-flighted the plan when I turned on the handheld to check the ATIS. First thing I hear was, "Chandler airport is closed". Such a tragedy. Two dead.
 
Flightaware track indicates the Archer was on downwind for 4R, on its tenth circuit around the pattern. Looks like he was making a short approach (simulated engine failure?); don't know if the collision occurred during that descending turn, or if the short approach was a result of the collision.
 
Airplane was a Piper. N number confirmed from the news.

https://flightaware.com/live/flight/N2868H

I'm fairly certain this was the Helicopter. N412TL. The ground tracks converge at the same point, at the same time, at the same altitude, when the crash occurred.

https://flightaware.com/live/flight/N412TL

It's common for the helicopters at KCHD to fly the "Charlie pattern". The fly right traffic at a lower altitude and tighter pattern than the fixed wing airplanes. They line up for T&G's on taxi way Charlie which is South of, and parallel to 4R.

If you look at the ground track for N2868H, it looks like they were flying a short approach for 4R and turned right over the top of N412TL.

The Piper had been doing T&G and was on landing number 10. The Helicopter had just taken off and appears to have been lining up for their first T&G.

RIP
 
Last edited:
From those flightaware links and the airport chart, it looks like both were flying the pattern at the correct altitude. The Archer short approach looks right to me for a simulated engine out. I hope he got approval for that. Maybe the controller didn't know how short he meant? If those tracks are right, it looks like the Archer could have been turning inside and above the R22...they might not have been able to see each other at all. This one is tragic and a bit spooky to me.
 
Hopefully they will determine the errors that lead to this. It does not make sense to do a simulated engine out in a busy pattern with 2 runways being used and helicopters in the mix...but how else to explain the short base turn of the PA28 after 10s of good pattern turns. Tower communication will be interesting to hear as well.
 
Even the normal pattern turns look too close to me. Or at least way too close to fly without being sure of visual separation. There was that mid-air recently with parallel runways, towered field, I believe one straight in and the smaller plane right base. That was one crossing over the invisible divide between the two runways. With this, and the helicopter taking an inside track, their tracks appear to be less than 1000' at times coming around the base/final turn, and within 200' vertical. On the good passes. Maybe this was routine, and everyone was used to it, but still seems too close for me. I know, armchair quarterback and all. Maybe I'm missing something.
 
Flying Doc said:
Hopefully they will determine the errors that lead to this. It does not make sense to do a simulated engine out in a busy pattern with 2 runways being used and helicopters in the mix...but how else to explain the short base turn of the PA28 after 10s of good pattern turns. Tower communication will be interesting to hear as well.
Click to expand...
I don't know about other locations, but our local tower would deny request for short approaches if there was much traffic.
 
Lindberg said:
What approval would he need other than a landing clearance?
Click to expand...

If youre going to make nonstandard turns in the pattern you need to let ATC know..and get approval...I am feeling too lazy to open the rule bible...but its got to be in there....or at least out of abundance of safety. Anyhow...who knows what was said and done. Who got approval to land first etc. I wonder if they cleared the helo 1st but didnt expect the PA28 to make the short turn... All guess work of course. RIP to the 2 guys. So sad to leave young family behind. Maybe POA should have a link to their GoFund Me page
 
Lindberg said:
What approval would he need other than a landing clearance?
Click to expand...
Has anyone pulled the LiveATC recording yet? I would have expected tower to say something like "#3 behind the helicopter" or something along those lines. At that point, it becomes an issue of see&avoid.
 
Flying Doc said:
If youre going to make nonstandard turns in the pattern you need to let ATC know..and get approval...I am feeling too lazy to open the rule bible...but its got to be in there....or at least out of abundance of safety. Anyhow...who knows what was said and done. Who got approval to land first etc. I wonder if they cleared the helo 1st but didnt expect the PA28 to make the short turn... All guess work of course. RIP to the 2 guys. So sad to leave young family behind. Maybe POA should have a link to their GoFund Me page
Click to expand...
Other than direction of turn, what is a standard turn in a traffic pattern?
 
asicer said:
Has anyone pulled the LiveATC recording yet? I would have expected tower to say something like "#3 behind the helicopter" or something along those lines. At that point, it becomes an issue of see&avoid.
Click to expand...
Its always an issue of see and avoid. Far, far, far, far too many pilots expect ATC to separate them in the pattern at tower-controlled fields.

And how do we know there wasn't an actual engine failure, other emergency, bird strike, or aliens?
 
:) It's a valid question, but from experience, if you're cleared for landing at a towered airport, and ask for a "short approach", the controller may STILL be surprised if you make a left turn abeam of the numbers. Even if that is the appropriate response in an aircraft with the glide angle of a sewing machine.

From the info above, there seemed to be 2 different runways in use, helicopter and airplane, running traffic in the same direction, with a 400' vertical separation between the two, and maybe 600' (guessing) horizontally on final - and with the base turn completely dependent on the judgement and/or preference of the two pilots, or a local understanding of how they were supposed to be flown. Without maintaining visual separation, that seems too close. Again, might be missing something here, it just doesn't sound like a good plan to me.
 
Lindberg said:
Its always an issue of see and avoid. Far, far, far, far too many pilots expect ATC to separate them in the pattern at tower-controlled fields.
Click to expand...
Especially at a Class D like this one, which may or may not have radar, I dunno.
 
Around 4 or 5 years ago we were flying into CHD 2-3 times a month for about 6 months. It was usually busy but I remember one day landing on 4R. On final we passed a SE trainer on our left and then a helicopter on our right. I got some comments from the passengers about how close the other aircraft were.
 
RyanB said:
Especially at a Class D like this one, which may or may not have radar, I dunno.
Click to expand...

I do not believe CHD tower had radar when we were going there, last trip maybe 18 months ago.
 
Plano Pilot said:
I do not believe CHD tower had radar when we were going there, last trip maybe 18 months ago.
Click to expand...
On the other hand, CHD Tower is the only facility I can remember ever asking me to ident, and they seemed to do so every time I arrived back from aerobatic lessons in the Great Lakes. That was December 2017. So they must have some kind of a feed in the cab.
 
I’ve spent some time in the Charlie pattern. That’s definitely a busy airport. Hopefully they are able to determine a cause that can be mitigated somehow for future operations. It’s always frustrating when the answer is don’t screw up…
 
iamtheari said:
On the other hand, CHD Tower is the only facility I can remember ever asking me to ident, and they seemed to do so every time I arrived back from aerobatic lessons in the Great Lakes. That was December 2017. So they must have some kind of a feed in the cab.
Click to expand...

They do, I've been up there. But since they're not a radar facility they don't use the radar for separation or in lieu of having aircraft in sight. It's more of a situational awareness tool, like ADSB is to us flying VFR.

I am just gutted for the controllers. Those guys (and girl) are fantastic and handle so much so gracefully day in and day out.
 
If they don't have radar, from the diagram of the tower position and where they were in their turns, I don't think they could have seen the separation even if they were right on it with glasses. The plane turn would be behind the aircraft turn, normally, at the closest position. Even if they were on final I don't think they'd be able to judge distance well from that angle, to the far runway.
 
I fly frequently fly in and out of KCHD. Other than 45 degree entry legs and pattern altitude, a standard pattern doesn’t exist. Some schools teach 747 patterns to their 172 students. Uggggghhh. Tower always seem to appreciate expedited landings at busy airports like KCHD so your out of their hair. Once tower states “clear to land runway—-“ without any other modifying statements the runway is yours. Fly to abeam the numbers, chop the throttle and dead stick it in if you like. I’m trying figure out how the pilot of the fixed wing aircraft got that low on downwind/base to hit the helicopter. The helicopter crashed either off the extended taxiway center line or just south of it. Aircraft lined up on the taxiway on short final?
 
Albany Tom said:
From the info above, there seemed to be 2 different runways in use, helicopter and airplane, running traffic in the same direction, with a 400' vertical separation between the two, and maybe 600' (guessing) horizontally on final - and with the base turn completely dependent on the judgement and/or preference of the two pilots, or a local understanding of how they were supposed to be flown. Without maintaining visual separation, that seems too close. Again, might be missing something here, it just doesn't sound like a good plan to me.
Click to expand...

The helicopter would have been flying the "Charlie pattern". They line up for T&G's on taxiway Charlie. It has 400' lateral separation from 4R.

upload_2021-10-3_12-1-31.png
 
There's no promise of that separation in the turn, though. If the helicopter goes out farther out than the aircraft, the tracks can collide. I think that's what might have happened here. The only way to keep the separation is to make sure the aircraft always has a longer downwind than the helicopter...at least from my understanding of the pattern. It's vertical separation on downwind, horizontal on final...but base is turn position dependent. And given the geometry from the tower, I don't think they had any chance to see. So up to the aircraft to maintain visual separation. Being that close and parallel, that's difficult and maybe not possible...certainly not always possible if they're directly above/below each other on downwind.
 
Flying Doc said:
It does not make sense to do a simulated engine out in a busy pattern with 2 runways being used
Click to expand...
Not super uncommon at SEE or MYF here.. both have parallel runways. Pilot has to ask first "request short approach" and the tower may say no.. may have you do a 360, or may grant it.. heck sometimes it will help them out if there's someone sorta-far-ish on a practice ILS final if you can squeeze in before them.. "you are now #1, cleared to land 28R"

The helicopter thing always freaks me out. You'll hear them at MYF and SEE get cleared with bonkers arrival and departure trajectories, ATC always give a disclaimer "at own risk" to them, but that's also at my risk, etc. Kind of annoying when you're short final and there's a chopper doddling around the pattern

Lindberg said:
Far, far, far, far too many pilots expect ATC to separate them in the pattern at tower-controlled fields
Click to expand...
Agree. People generally aren't situationally aware enough. It's easy to trust the tower blindly, but it always pays to know where you are, where the other traffic is, etc. In general I think people follow ATC a bit too blindly, but that's for another thread

Kritchlow said:
ther than direction of turn, what is a standard turn in a traffic pattern?
Click to expand...
..the student pilot answer is when the numbers are about 45* behind you.. but, of course, how wide or tight your pattern is, whether it's at 80 knots or 110 knots, etc. all factor in. Why you really have to be vigilant of the flow and where you are in it and fly the plane as such.. don't start turning that base leg if the dude in front of you hasn't turned yet, or isn't already making their turn to final, etc.

Albany Tom said:
the controller may STILL be surprised if you make a left turn abeam of the numbers
Click to expand...
yeah.. you sort of have to exercise the "does this feel right?" judgment. A brisk acceleration isn't illegal, but how rapidly are you really going to speed away from a green light if there's a cop next to you? I generally try and avoid short approaches and tight engine our practice patterns at towered airports
 
Tantalum said:
ATC always give a disclaimer "at own risk" to them, but that's also at my risk, etc.
Click to expand...

That’s standard ATC phraseology for allowing an aircraft to land or depart from an uncontrolled surface. We can only say “cleared” in reference to a controlled surface such as a runway or helipad.
 
Albany Tom said:
If the helicopter goes out farther out than the aircraft, the tracks can collide. I think that's what might have happened here.
Click to expand...

The ground tracks show that the Piper flew a short approach. He cut it much tighter than his previous landings. So I guess you're right, the helicopter and plane did turn base at basically the same point. But it does look like the Piper was flying the atypical pattern. We'll have to hear what the tapes say to understand who was cleared to do what, and who was informed about relative positions of other aircraft...
 
Tarheelpilot said:
With both aircraft in a visual pattern I doubt it would have been beneficial. Probably more of a distraction.
Just my opinion. Worth what it cost you.
Click to expand...


Chandler is under the Phoenix Bravo, so ADS-B out is a requirement. Most people I know fly with some form of ADS-B in now, but as you said, being that close in the pattern, it would probably be more of a distraction than anything. Speaking only for myself, once I am in the pattern, I rarely look at the I-Pad.
 
You must log in or register to reply here.
Back
Top