Watsonville midair

[bobbytables]

https://archive.liveatc.net/kwvi/KWVI2-Aug-18-2022-2130Z.mp3 @ 24:40

Seems a Cessna twin ran into the back of a 152, both on approach to WVI.

https://www.cbsnews.com/sanfrancisco/video/raw-video-aerial-view-of-plane-crashes-at-watsonville-airport/

[rfc143]

3 people are killed after 2 planes collide over California airport, authorities say.

Reported by CNN.

[Si Guy]

Good Live ATC find, and interesting listen. You can hear the twin Cessna calling straight in approach several times, beginning 10 miles out. And you can hear what I assume to be the C150, calling out his position several times, including crosswind, downwind, and left base. He even calls that he sees the twin "behind him" when it seems he turns final. Then he calls that the twin is coming faster than he expected, and he is going around. Sure sounds like the C150 turned base and final too soon, thinking he could get in before the twin. Also watched the replay on Flight Radar 24, can see the twin coming in, but do not see the C150 on there at all.

[BFSGrad]

Is it possible to land a C340 on a 4500 ft runway with a groundspeed of 180 kts at the runway threshold?

[Pilot DAR]

And you can hear what I assume to be the C150, calling out his position several times, including crosswind, downwind, and left base. He even calls that he sees the twin "behind him" when it seems he turns final.

Then it sounds like the 150 was established in the circuit, reporting his position (perhaps not using a transponder - perhaps not required), and the 340 flew a straight in. VFR landing traffic at an uncontrolled airport has to give way to airplanes established in the circuit.

Is it possible to land a C340 on a 4500 ft runway with a groundspeed of 180 kts at the runway threshold?

With great skill, somewhat abusive engine handling, and lots of braking, maybe. Normally, no.

[treadigraph]

Why the 340 would be doing more than twice its stall speed on short final unless the pilot was in some way not entirely with it...? Or the ADSB reported figures are incorrect.

Only types I've seen crossing the fence at that sort of speed have been Concorde, SR-71, F-104 and maybe a few other military jets...

[lederhosen]

I have observed a similar accident with two cessnas with one taking off and one going around. In that case the aircraft taking off climbed into the one overshooting.

One scenario is that in this case the 340 realised that he was catching up the 152 and went around. The Cessna also decided to go around and climbed back to circuit height. In such a scenario neither aircraft can easily see the other.

The important point is that if you need to go around with an aircraft climbing out it is important to offset to the right so he doesn’t climb into you.

[Maoraigh1]

"The important point is that if you need to go around with an aircraft climbing out it is important to offset to the right so he doesn’t climb into you."
BUT: Both were possibly going around. Both .move to right..

[lederhosen]

Fairly obviously the aircraft below is not advised to offset to the right in this situation. Situational awareness appears to have been lacking in both cockpits.

[biscuit74]

From the limited information available so far, the 152 pilot was a student pilot on an early solo. He was flying a circuit and almost certainly had no idea that the 340 was closing at such speed. The impression I have is that he continued onto finals, to follow his normal taught practice until it became obvious the other aircraft was closing rapidly. The 340 had announced its intention of doing a straight in when it was some distance away - 10 miles out - and appears to have held its speed right up to the accident point, which was just shy of the approach end of the runway.
If those figures are correct the 340 was still well above normal approach speed at impact point- around twice normal, so I'm not sure how its pilot intended to land off such an arrival.

This rather sounds as though the 340 driver completely lost situational awareness and had fixated on his approach path, even forgetting his need to slow down. The inexperienced student pilot did decide to go around, regrettably too late, but just in time to collect the overtaking 340.

Perhaps US rules are different. Straight in approaches put the onus for good clearance on the pilot doing the straight in - he/she needs to be sure the circuit and approach is clear. If in doubt, convert to a normal field arrival on the dead side and enter a circuit. (After all, there may be nonradio traffic around - or failed radio traffic)

Student pilots are on high workload just flying safely at first, so while I'd have hoped to see a low time pilot in this circumstance take positive action earlier, say orbit on base to remain clear of the potential conflict, what he did made sense within his likely awareness. (Who expects an aircraft rushing in at twice normal approach speed ?)

Horrible accident, with some sadly familiar old lessons.

[421dog]

From the limited information available so far, the 152 pilot was a student pilot on an early solo. He was flying a circuit and almost certainly had no idea that the 340 was closing at such speed. The impression I have is that he continued onto finals, to follow his normal taught practice until it became obvious the other aircraft was closing rapidly. The 340 had announced its intention of doing a straight in when it was some distance away - 10 miles out - and appears to have held its speed right up to the accident point, which was just shy of the approach end of the runway.
If those figures are correct the 340 was still well above normal approach speed at impact point- around twice normal, so I'm not sure how its pilot intended to land off such an arrival.

This rather sounds as though the 340 driver completely lost situational awareness and had fixated on his approach path, even forgetting his need to slow down. The inexperienced student pilot did decide to go around, regrettably too late, but just in time to collect the overtaking 340.

Perhaps US rules are different. Straight in approaches put the onus for good clearance on the pilot doing the straight in - he/she needs to be sure the circuit and approach is clear. If in doubt, convert to a normal field arrival on the dead side and enter a circuit. (After all, there may be nonradio traffic around - or failed radio traffic)

Student pilots are on high workload just flying safely at first, so while I'd have hoped to see a low time pilot in this circumstance take positive action earlier, say orbit on base to remain clear of the potential conflict, what he did made sense within his likely awareness. (Who expects an aircraft rushing in at twice normal approach speed ?)

Horrible accident, with some sadly familiar old lessons.



this…
it’s on the guy not entering in a standard manner.

[India Four Two]

Straight in approaches put the onus for good clearance on the pilot doing the straight in - he/she needs to be sure the circuit and approach is clear. If in doubt, convert to a normal field arrival on the dead side and enter a circuit.

biscuit74, US rules ARE different. Nobody would know what a “dead side join” is. Standard procedure is to join the downwind leg at a 45° angle from outside the circuit/pattern.

[fdr]

Fairly obviously the aircraft below is not advised to offset to the right in this situation. Situational awareness appears to have been lacking in both cockpits.

The 152 N449931 was well within its normal rights. He was also entitled to do a G/A when he considered the aircraft from behind posed a threat. The 340A was observed to be at high speed according to the local rags, but was in all cases the overtaking aircraft, and was required to give way. Being right doesn't give much consolation when you are still timex. The 152 did everything right, he did an avoidance manoeuvre and if the plane behind ran into him... Did the 152 start an offset to the right? It appears that there was little time between the decision to Go around and the impact, so at 152 speeds, he isn't going to be far off the centreline, and he was apparently looking over his shoulder at least for part of the time. At 65-70kt, the 152 isn't going to go far compared with a 179kt 340A running into him.

[biscuit74]

Thanks India Four Two, of course ! It's a long time since I last flew in the USA, too long evidently. Doing that downwind 45 degree standard join you describe would have allowed the 340 to see the circuit traffic, and them to see him.

It;s hard to see what the 152 pilot could have done safely, other than an orbit on base, which is not normal practice for students as far as I know. Doing a go around from base leg meant crossing the path of a fast moving machine - far from ideal., and would likely have led to the same outcome, without good luck. Not nice.

[ShyTorque]

The RAF used to teach (hopefully still do) a dead side join for light aircraft at training airfields, in order to avoid exactly this situation from occurring. The pilot of a joining aircraft must give way to those already in the circuit and joins parallel to the runway in use, in the circuit direction, but offset to the dead side. The joining pilot only crosses to the live side when safe to do so without getting in the way of others, even if this means flying well upwind.

Orbitting anywhere in the circuit, or extending down wind were both a big “no-no” and would result in a visit to the tower for a dressing down by the duty instructor.

[lederhosen]

I had a bad experience myself (air miss) with a light twin pilot attempting an unauthorized straight in approach to the opposite runway from which I was departing in a 737. So I will admit to potentially being a bit biased about light twins. In this case if the reports are true that the twin was doing 180 knots inside 3 miles then there is no excuse for such poor airmanship. As has been pointed out by others it is hard to know what the 152 pilot could have done differently if this is true.

[magyarflyer]

biscuit74, US rules ARE different. Nobody would know what a “dead side join” is. Standard procedure is to join the downwind leg at a 45° angle from outside the circuit/pattern.

in USA rules are definite different. A similar accident happened at HQZ a few years ago, father and son in a 150 doing a base to final turn when the big twin came behind doing a "straight in " approach to final that he called 15 miles out. Believe it or not the NTSB gave the right of way to the pilot calling for a straight in approach all 3 died in the accident. In 45 years of flying here i have seen the straight in approach being abused. No one respects the correct entry which is to listen for traffic or see traffic in the pattern. Almost impossible to do on a 15 mile final. Assuming no control tower is present no excuses, NORDO airplanes cannot transmit traffic so the onus should be on the pilot doing the straight in and see or hear traffic then if so give right of way. Almost all straight in approaches fail to correct that issue. Insanity at the best.

[172_driver]

Was the C340 overtaking the C152 or did the C152 cut in front of the C340 on final... depending on how you see it one or the other was right, the other was wrong. Doesn't matter now when the collision is a fact. Some active coordination, instead of just position reports, would have been appropriate. Especially if you're intending to approach a GA field at 180 kts. Personally I think the C340 approach was madness...

[Pilot DAR]

Referring only to what has been posted here, and with reference to the Canadian rules; The overtaking airplane must give way, and move to the right to accomplish this. The airplane which is lower on the approach has the right of way. And, the airplane approaching the airport must give way to the airplane which is landing (established in the circuit/has turned final).

While training a pilot in his new 182 amphibian years ago, we were flying established circuits, and I was making all the calls, at the airport. This airport was monitored, with a mandatory frequency, by a flight service station at another airport ('could hear but not see traffic). On the downwind to base turn, I started hearing radio calls for straight in approaches to the airport from four 172s (All from a flying school I knew). What was happening was that an instructor dual cross country flight was "leading" three other solo cross country flights to a mid trip stop and go at the airport. I was losing track of which was where, and none were appearing to consider a circuit, nor acknowledging that we were established in the circuit already. I remember writing down registrations on the palm of my hand to try to keep track, but I was not sure who was where. I saw two of the 172's, but couldn't figure where the other two were relative to the ones I could see. I decided to give up, and climb out of the base leg, to let them all go under me. At about the same time, a Learjet was inbound IFR, and on the frequency. As I climbed out of the base leg, I called that "I could not safely land at the airport at this time, and was climbing to exit the circuit vertically on the dead side. I don't think any of the 172 pilots cared, but the Lear pilot sure took notice of what I said.

We went and did some water training for an hour, and by then, everything was calm at the airport. We landed, and I phoned FSS. I asked that the tapes be held, and that the FSS Specialist have a listen right around when I said "I could not land safely...". I called the flight school, and asked for a review of circuit entry procedures among their instructors. Turns out, the daughter of a friend of mine was one of the solo students, and had more or less told her dad what had happened on that flight. When I described my flight, he joined the dots. He was very disappointed that not only was his daughter being "lead" on a solo cross country, but also being lured into really poor circuit entry procedures! I do fly straight in approaches to this airport, but I always establish with FSS that there is no other aircraft in the airport vicinity when I do. Otherwise, I join and fly a correct circuit.

I opine that the C340 pilot "missed" the position calls from the 152 pilot. If the speeds suggested were correct, he probably had the nose coming up to slow it down, and lost the 152 under the nose - if he ever saw it!

[FullMetalJackass]

The 152 N449931 was well within its normal rights. He was also entitled to do a G/A when he considered the aircraft from behind posed a threat. The 340A was observed to be at high speed according to the local rags, but was in all cases the overtaking aircraft, and was required to give way. Being right doesn't give much consolation when you are still timex. The 152 did everything right, he did an avoidance manoeuvre and if the plane behind ran into him... Did the 152 start an offset to the right? It appears that there was little time between the decision to Go around and the impact, so at 152 speeds, he isn't going to be far off the centreline, and he was apparently looking over his shoulder at least for part of the time. At 65-70kt, the 152 isn't going to go far compared with a 179kt 340A running into him.

I doubt the C152 pilot was looking over his shoulder, especially if he was a student pilot on final, he'd be focussed on what's in front of him. To ascertain a plane is closing from behind fast he would have had to turn his head, capture the intruding aircraft, judge it's distance and closing speed - all whilst coming in to land. I'm pretty sure he had ADS-B in and was watching the aircraft closing on that screen..... looking at Flight Aware / Flight Radar, the C152 isn't visible, therefore had the 340A also had ADS-B in, he still would not have been aware of the C152.

What I do note is the calls of the C152 pilot - downwind, base but no call on final? Maybe this would have alerted the twin pilot as he was still looking for traffic on base....

[fdr]

I doubt the C152 pilot was looking over his shoulder, especially if he was a student pilot on final, he'd be focussed on what's in front of him. To ascertain a plane is closing from behind fast he would have had to turn his head, capture the intruding aircraft, judge it's distance and closing speed - all whilst coming in to land. I'm pretty sure he had ADS-B in and was watching the aircraft closing on that screen..... looking at Flight Aware / Flight Radar, the C152 isn't visible, therefore had the 340A also had ADS-B in, he still would not have been aware of the C152.

What I do note is the calls of the C152 pilot - downwind, base but no call on final? Maybe this would have alerted the twin pilot as he was still looking for traffic on base....

Heres the thing, the time between the comment, "you're coming at me pretty fast I am going around..." and the call from the 3rd aircraft that 2 planes had crashed was not long. The last time I saw a 150 it didnt strike me as either fast or fast climbing... it crashed having lost one wing airborne by the looks of it around 50 yards short of the runway underrun and about 250 yards from the displaced threshold. It was also around 60 yards to the right of the C/L, without the left wing. With a pretty energetic impact stuff could have gone in all directions, but the loss of the left wing is going to make the plane roll left, pitch will depend on the wing tail geometry, in this case I would be expecting a slight pitch down from the reduction in downwash that the aircraft would have on the LHS to the lower stab. Either way, the 150 wasn't going to go far, it didn't make the runway end. The 340 got around 2800' down the runway going into the last of a series of T-hangers, with a final trajectory that was at a large angle to the runway direction. The position of the 150 suggests it was in front and therefore below the 340 and under FAR 91.113(g) the 150 would probably have ROW. It is common to shoot straight-in approaches, at controlled airports that not a problem, which makes the occasional uncontrolled airport arrival problematic; the guy who does a lot of IFR and only occasional uncontrolled airport VFR arrivals will have a natural bias towards straight in vs doing a std join. There is no evidence that the 340 did anything other than a straight in, at an uncontrolled airport. FAA-H-8083-3B Chapter 7 gives a bit of guidance for patterns, and reiterates the standard join of 45 to downind in level flight, and gives ROW to the lower aircraft. Its likely that the guys in the 340 confused the other aircraft in the circuit at the time for the one that was on finals, but there is no doubt that the 150 was on very short finals, and may well have been to the right of the C/L IAW with the G/A manoeuver. Given the time between call for the G/A and the alert of a crash, the 150 pilot is almost certainly had a look over his shoulder, so I would suspect that he was not showing poor SA, other than not continuing to manoeuver when he knew the 340 was a threat to him, and as a new pilot, hard to call his actions inappropriate, just unfortunately not achieving a clearance from the other aircraft.

FAA rules are slightly different to other countries, but only in detail, they all follow ICAO Annex 2, kind of.

[punkalouver]

It;s hard to see what the 152 pilot could have done safely, other than an orbit on base, which is not normal practice for students as far as I know. Doing a go around from base leg meant crossing the path of a fast moving machine - far from ideal., and would likely have led to the same outcome, without good luck. Not nice.

Best thing for the 150 would have been to extend the downwind leg. If already on base leg, one could decide to fly through final approach and get out of the way(especially if there is another aircraft behind you in the pattern/circuit), even if they have the right of way. Sometimes it is safer to just get out of the way. The 150 did try that but at a point that was too late to avoid a collision.

[olster]

Whatever is right or wrong in terms of rules and regulations it is very difficult to diverge from the fact that you have a solo inexperienced student being rammed by a Cessna twin. If the twin pilot had a reasonable level of SA then he / she should have listened out and / or slowed down. Or flown a standard join as per FAA rules for joining a circuit pattern. They obviously all paid the ultimate price and RIP for that but I am sure the relatives / friends of the solo student will not take much comfort in that their son / daughter etc always had the right of way.

[MechEngr]

Just a reminder that the electronics to make a warning system are about $100. A software defined radio to accept the ADSB transmission and a Raspberry Pi to interpret and some display and a warning buzzer are cheap.

But the FAA refuses to mandate ADSB-OUT on all manned aircraft and mandate ADSB receivers that can provide a warning on all manned aircraft. It's not just day-one pilots getting their solo time in and being mowed down by careless twin pilots. This has happened over and over and over and the FAA sits on its hands. Except for unmanned R/C hobbyists, whom the FAA are regulating out of existence in spite of no fatalities in the last 50 years.

[RatherBeFlying]

Unfortunately the FAA mandated a gold plated standard for ADSB Out on 1080 MHz that's far too expensive for most spamcan owners.

The gold plated standard does provide for deconflicting wingtips on adjacent taxiways at the big airports, but folks, centimeter positional accuracy is gross overkill in the air as well as for GA aircraft with wingspans below that of a 737.

Some bright spark at the FAA cooked up UAT as an affordable system, but the 1080 ADSB Out folk are dependent on retransmission to see the little guys on their screens.
​

[biscuit74]

Best thing for the 150 would have been to extend the downwind leg. If already on base leg, one could decide to fly through final approach(especially if there is another aircraft in the pattern/circuit) and get out of the way, even if they have the right of way. Sometimes it is safer to just get out of the way. The 150 did try that but at a point that was too late to avoid a collision.

Very true. Had he realised the potential for conflict then, that would have solved the problem the easy way. I rather had the feeling that the potential for conflict wasn't obvious until the 152 was on base leg. It's that astonishingly high closing sped, which would catch most of us out, I'm sure

[biscuit74]

'Mech Engr' - what are the FAA doing which is impacting up radio control flying in the USA, please ? Hand't heard of that.

I do a little r/c building & flying occasionally. Things have got awkward enough here in the UK !

[Maoraigh1]

Would it help if student pilots included "student" in their solo callsign?

[Pilot DAR]

Would it help if student pilots included "student" in their solo callsign?

Nope. Any pilot is entitled to caution, courtesy, and the right of way from every other pilot. If a "student" is flying solo, they are a pilot.

We don't all bow our heads and break off our established approach to get out of the way, when we hear the 20,000 hour old timer approaching from 25 miles out, nor do we needlessly coddle a student. If a student, or any other pilot, needs assistance, extra room, or is experiencing an emergency, they are most welcome to broadcast their need, otherwise, everyone follows the rules fairly. The rules for right of way work really well - if obeyed!

[RatherBeFlying]

I had ATC dump me in front of a twin turboprop airliner, likely at 250 kt. From a mile or so away I just barely had time to bank away.

[Pilot DAR]

I have had ATC caution me that for placement on very long straight in, I would have to maintain 160 knots to short final to fit in with other larger traffic, would I accept? I was flying a Caravan in one memorable case, which was capable, so I accepted, and no problem. I was informed, and given the choice in a controlled environment. In an uncontrolled environment, pilots have to increase their awareness, particularly pilots of aircraft which are obviously much faster than the types commonly known to use that airport. When I have flown faster types into smaller airports, I have been extra vigilant, and been certain to actually fly a larger circuit, so I was on the outside, looking in, with more space, a place to go to safely overtake if needed, and a good view of any slower traffic which could be ahead of me. Straight in affords none of these safety elements.

[Denflnt]

Would it help if student pilots included "student" in their solo callsign?

I have read that the pilot of the 152 had his license for Single Engine Land for about 2 years.

Known to friends as "Possum Stu," Camenson was a Santa Cruz resident who graduated from UCSC with degrees in chemistry and earth sciences. He went on to work at the university's IT division.

He earned his pilot's license in June 2020. His family said he was practicing "loops, touchdowns and takeoffs," last Thursday for additional certification.

[Pilot DAR]

His family said he was practicing "loops, touchdowns and takeoffs," last Thursday for additional certification.

I would easily believe that family could interpret the term "circuit" as "loop", and not read anything more into it than that. I'm sure that they are all very upset, and perhaps slightly imprecise in recalling exact terms. In any case, the 152 pilot was reported as established in the circuit, making position calls - that's the important part.

[BFSGrad]

Watsonville Midair Crash ExplainedVideo provides a good composite track of the accident aircraft (track presentation starts at 7:20). Unclear if aircraft tracks and audio are accurately synchronized. Several items of note from the video and associated comments:

1. V/LO and V/LE for the C340 are 140 kts.

2. One commenter claiming to be an eye witness states that neither the gear nor flaps on the C340 were extended immediately prior to the collision. Same eyewitness states there was no change in engine sound of the C340 prior to the collision. At least one eyewitness in media reports states the C340 maneuvered to the right immediately prior to the collision.

3. Another commenter notes the difficulty of spotting aircraft approach from the east due to the rising terrain as a backdrop.

[fdr]

Watsonville Midair Crash Explained (https://youtu.be/Hcnc5GcgRoc)Video provides a good composite track of the accident aircraft (track presentation starts at 7:20). Unclear if aircraft tracks and audio are accurately synchronized. Several items of note from the video and associated comments:

1. V/LO and V/LE for the C340 are 140 kts.

2. One commenter claiming to be an eye witness states that neither the gear nor flaps on the C340 were extended immediately prior to the collision. Same eyewitness states there was no change in engine sound of the C340 prior to the collision. At least one eyewitness in media reports states the C340 maneuvered to the right immediately prior to the collision.

3. Another commenter notes the difficulty of spotting aircraft approach from the east due to the rising terrain as a backdrop.


The accident sequence then saved the C340 pilot from a gear-up landing???? or rolling off the end at high speed... Was there another issue going on here that has not been considered, was the C340 pilot incapacitated? He doesn't sound so, but that is some time before the collision.

On the Student C/S, we used to do that in the military, and it always seemed like a good idea, mixing fast jet and student jets could lead to some hilarity, after some 20 or 30 years of time dilation.

[jimjim1]

NTSB preliminary report. NOT from NTSB website. I often find it very difficult to operate and I have this link handy.

https://htv-prod-media.s3.amazonaws.com/files/report-wpr22fa309-105763-9-15-2022-3-57-41-pm-1-1663273167.pdf

Here it is on NTSB website - does a download, may not work forever.
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105763/pdf

https://webtrak.emsbk.com/sjc3
Has playback of both aircrafts' ADSB. Can have long, short or no trails.

[BFSGrad]

Note the still photo from the NTSB prelim report appears to confirm that the C-340 was gear up and in a hard right bank at the time of collision.

[Si Guy]

Thanks jimjim1. I am curious how the NTSB got ADSB-out data for the C152, when we could not see it on any of the flight tracking aps. Also, your link for the ADSB out data just takes us to a site giving current conditions. Are you expecting us to use that site to go back and replay from the accident date, or were you expecting your link to already take us back to that date?

BFSGrad, That is some timing on the taking of that photo. Almost seems that if the C340 had not banked hard right, his left wing would not come up and struck the C150.

[DaveReidUK]

Thanks jimjim1. I am curious how the NTSB got ADSB-out data for the C152, when we could not see it on any of the flight tracking aps.

That's because it's radar data, not from ADS-B.

Also, your link for the ADSB out data just takes us to a site giving current conditions. Are you expecting us to use that site to go back and replay from the accident date, or were you expecting your link to already take us back to that date?

You need to use the replay function (works in a very similar way to that on FR24).

[jimjim1]

Thanks jimjim1. I am curious how the NTSB got ADSB-out data for the C152,.... Also, your link for the ADSB out data just takes us to a site giving current conditions. Are you expecting us to use that site to go back and replay from the accident date, or were you expecting your link to already take us back to that date?
.

I can find no way to do a link that incorporates a start time. Choose "Historical" and put in the LOCAL time of the incident.
This accident's collision is at 2:55:10 PM local time 18 August.
NE side of Watsonville Airport.

I have no idea where they get the data. I notice that Dave mentions Radar, however other discussion groups mention a different adsb radio frequency than used by "airline" grade (let me call it:-) adsb. There is certainly accurate looking height data. I think you can get that from a radar transponder.

Someone said:- "The C152 was pinging on 978mhz. A number of the services we commonly use like FlightAware can't see 978 signals unless the plane is closer to 1800' in the Watsonville area"

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/1264x1022/watsonville_crash_b800a36b8918979d6e35c57d877c5a816ff41a90.p ng

[DaveReidUK]

I have no idea where they get the data. I notice that Dave mentions Radar, however other discussion groups mention a different adsb radio frequency than used by "airline" grade (let me call it:-) adsb. There is certainly accurate looking height data. I think you can get that from a radar transponder.

Someone said:- "The C152 was pinging on 978mhz.

978 MHz is a reference to UAT (Universal Access Tranceiver (https://en.wikipedia.org/wiki/Automatic_Dependent_Surveillance%E2%80%93Broadcast#Universal _Access_Transceiver_(UAT))) - an alternative (in the USA) to the more common 1090 MHz Extended Squitter. For either to be used for ADS-B (i.e. tracking) requires the aircraft to be equipped (usually) with a GPS source. Whether or not fitted with GPS, the aircraft will still send altitude data via Mode C or Mode S.

A number of the services we commonly use like FlightAware can't see 978 signals unless the plane is closer to 1800' in the Watsonville area"

Don't confuse what's available to crowd-sourced tracking sites like FlightAware or FR24 with what ATC (and hence the NTSB) has access to.

[Si Guy]

Thanks for your replies. I did some Googling from your comments, and I see that there are indeed two ADSB-out frequencies in use, 978 and 1090. Well, that’s certainly interesting. And maybe the C150 was too low to be received by the open-source receivers in the area. I was not aware there were multiple frequencies.

The Webtrak site is interesting, seems to be able to track both frequencies, but that site is not available over the whole country.

Thanks!

[DaveReidUK]

The Webtrak site is interesting, seems to be able to track both frequencies, but that site is not available over the whole country.

SJC WebTrak is driven principally by radar data.

[Si Guy]

DaveReidUK - Ok, thanks. Been reading about it some more, seems it was primarily designed to allow for filing of noise complaints around major and medium size airports. But I can see it's useful for historical flight tracking as well.

[BFSGrad]

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The failure of the pilot of the multi-engine airplane to see and avoid the single-engine airplane while performing a straight-in approach for landing.

NTSB Aviation Investigation Final Report - N49931, N740WJ (https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105763/pdf)

[Andrewgr2]

I guess we’ll never know why the twin was doing 180 kts at 150’ on short final with gear and flaps up. If it hadn’t hit the light single it would have had an interesting landing.

[Maoraigh1]

"I guess we’ll never know why the twin was doing 180 kts at 150’ on short final with gear and flaps up."
Going Around?

[KRviator]

"I guess we’ll never know why the twin was doing 180 kts at 150’ on short final with gear and flaps up."
Going Around?That implies he intended to land. Something I'd suggest wasn't going to happen while maintaining 180 knots all the way down final without ever putting the gear or flaps out in the first place.

[BFSGrad]

That implies he intended to land.
Given that 740WJ called “straight in, 20, full stop” at 3 miles and one mile with no subsequent calls changing this plan, seems reasonable for others in the traffic pattern to conclude that he intended to land.