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-   -   N72EX (Kobe Bryant) Crash Update- (https://www.pprune.org/rotorheads/638330-n72ex-kobe-bryant-crash-update.html)

377 Pete 28th Jan 2021 02:53

N72EX (Kobe Bryant) Crash Update-
 
Final NTSB report due on 2/9/21
Finding well probably be spatial disorientation in IMC conditions.

Here's a rendering of the final minute of flight based on the granular ADSB data-

https://i.imgur.com/YsiA23k.png

And an update from Blancolirio-


gulliBell 28th Jan 2021 06:21

I'm not expecting any surprises in the final report.

airplanecrazy 28th Jan 2021 12:12

I think there may be one surprise. In December, the NTSB posted to the docket the data extracted from the Flight Management System (I only noticed it yesterday). I am not a pilot or aviation professional, but I noted some anomalies:

1) When the FMS was powered on at LGB the day of the crash, its last known position was at the IEX helipad on Catalina Island. Can someone more knowledgeable about FMS operations explain to me how that is possible? Do you have to turn on the FMS separately, or is it normally powered on by switching on the avionics power bus?
2) The NTSB notes: "When the FMS is initialized, it will default to the position stored when power was previously removed or the GPS position, if it is available. This position is presented to the crew on the FMS initialization page, where the crew can accept it, or manually change it before accepting it. Should the crew accept a Reference Position that is significantly different from the actual aircraft position, the FMS will annunciate position uncertain and post difference warning messages after GPS position becomes available. Over time, the Reference Position would converge to true position by using DME and GPS.
3) There are unseen (by the pilot) warning messages in the FMS: "GPS 1 DIFFERENCE 6 NM" "REFPOS and GPSPOS > 6.0 NM". "DEAD RECKONING MODE"
4) When the pilot selects DTO (Direct To) KCMA, the FMS records a present position (PPOS) not on the flight path (this is recorded in the NAV Leg Editing Buffer). I am wondering if the FMS has not yet converged to true position.
5) The CDU at the time of the crash appears to me to be showing errant data (Figure 4-1 in the report). I think it is saying the distance to the destination is closer that it actually is and that the bearing between the displayed PPOS and Destination is incorrect. It would be fantastic if someone with more experience with the UNS FMS can confirm.

If I am interpreting the information correctly, it seems that the above would have added to the pilot confusion and workload. Here is a link to the docket entry: https://data.ntsb.gov/Docket/Documen...edRev2-Rel.pdf

Gordy 28th Jan 2021 18:09

Blancolirio clearly caters to the masses and not aviation experts. He could not even pronounce Ara's name correctly.

malabo 28th Jan 2021 20:55

FMS especially an old one in the 76B is insignificant for low level VFR operations. Usually the pilot just has an iPad balanced on his lap - though EASA and USCG pilots are known to have them on knee boards. The EGPWS recommendation is just a tired old NTSB hobby horse that they trot out on every investigation, again, of no consequence in this situation.

Torquetalk 28th Jan 2021 22:23


Originally Posted by airplanecrazy (Post 10977989)
I think there may be one surprise. In December, the NTSB posted to the docket the data extracted from the Flight Management System (I only noticed it yesterday). I am not a pilot or aviation professional, but I noted some anomalies:

1) When the FMS was powered on at LGB the day of the crash, its last known position was at the IEX helipad on Catalina Island. Can someone more knowledgeable about FMS operations explain to me how that is possible? Do you have to turn on the FMS separately, or is it normally powered on by switching on the avionics power bus?
2) The NTSB notes: "When the FMS is initialized, it will default to the position stored when power was previously removed or the GPS position, if it is available. This position is presented to the crew on the FMS initialization page, where the crew can accept it, or manually change it before accepting it. Should the crew accept a Reference Position that is significantly different from the actual aircraft position, the FMS will annunciate position uncertain and post difference warning messages after GPS position becomes available. Over time, the Reference Position would converge to true position by using DME and GPS.
3) There are unseen (by the pilot) warning messages in the FMS: "GPS 1 DIFFERENCE 6 NM" "REFPOS and GPSPOS > 6.0 NM". "DEAD RECKONING MODE"
4) When the pilot selects DTO (Direct To) KCMA, the FMS records a present position (PPOS) not on the flight path (this is recorded in the NAV Leg Editing Buffer). I am wondering if the FMS has not yet converged to true position.
5) The CDU at the time of the crash appears to me to be showing errant data (Figure 4-1 in the report). I think it is saying the distance to the destination is closer that it actually is and that the bearing between the displayed PPOS and Destination is incorrect. It would be fantastic if someone with more experience with the UNS FMS can confirm.

If I am interpreting the information correctly, it seems that the above would have added to the pilot confusion and workload. Here is a link to the docket entry: https://data.ntsb.gov/Docket/Documen...edRev2-Rel.pdf


The FMS (inc this UNS model) will update its position very quickly once it has sight of satellites (out of the hangar) and in receipt of signals from VORs and DME equipment (the aircraft was flying in well-served airspace). It is very unlikely that the UNS did not know exactly where it was. That is usually a pilot problem.

airplanecrazy 29th Jan 2021 00:47


Originally Posted by Torquetalk (Post 10978349)
The FMS (inc this UNS model) will update its position very quickly once it has sight of satellites (out of the hangar) and in receipt of signals from VORs and DME equipment (the aircraft was flying in well-served airspace). It is very unlikely that the UNS did not know exactly where it was. That is usually a pilot problem.

Let me first say that I acknowledge that I am out of my area of expertise, and so this is my amateur speculation. I believe the Reference Position in the NTSB report (l34.25080n 118.76038w) recorded at 17:37:43 does not accurately reflect the actual position of the aircraft at that time. I am wondering if the UNS incorrectly determines position in the following scenario:

1) UNS Powered off in Santa Catalina
2) UNS Powered on at LGB
3) UNS Never receives DME.
From the report:
  • "DME Stations for shortrange navigation: No DMEs Received"
  • "Scanned DME Stations: Fifteen DMEs being scanned. None responded."
4) UNS records Reference Position (according to the report "Reference Position is Blended GPS/DME position propagated with GPS velocities")

This is last reported position information as detailed in the report:
  • System Position (GPS position propagated by heading and true air speed) N 34:08.17861 W118:41.55108 (34.1363101n 118.692518w)
  • Reference Position (Blended GPS/DME position propagated with GPS velocities) N 34:08.17861 W118:50.54967 (34.1363101n 118.8424945w)
  • DME Position (Position computed from DME range measurements) N 34:23.21876 W119:13.96316 (34.38697938n 119.2327194w)

As you suspected, the GPS position information is correct (very close to the crash location). However, the Reference and DME Positions are not. I wonder if this corner case is rare because most of the time UNS systems receive DME. I do not have a hypothesis as to why the FMS was not receiving DME data.

gulliBell 29th Jan 2021 02:22


Originally Posted by airplanecrazy (Post 10977989)
...In December, the NTSB posted to the docket the data extracted from the Flight Management System (I only noticed it yesterday)...

Red Herring. Furphy. Whatever you care to call it. The pilot was navigating visually in sight of the ground in an area well known to him. He knew exactly where he was until he lost sight of the ground, lost control, and crashed. The FMS had nothing to do with it.

Torquetalk 29th Jan 2021 07:00

Airplanecrazy,

Gullibell is sure to be right.

As a point of interest, the FMS sums all available sources to determine ppps, and tells you when it doesn‘t have a reliable determination. No or poor DME signal or a discrepancy means the FMS will disregard the unreliable source. No issue.

What might have helped him was regular real IR training and a greater willingness to use the automatics to get him out of trouble once he lost reference. Not pressing on and chomping it whilst scud running, with limited visibility, in a rising ground environment, would have avoided the accident altogether.

Sikpilot 29th Jan 2021 14:00

The S76 is not a great machine for scud running, ESPECIALLY single pilot. Sitting in the right seat, you cant look over your left shoulder and see out behind you if your trying to turn left. The high Sikorsky console doesn't can also block the horizon. While I never had a problem flying the 76 single pilot, I NEVER did it with VIP passengers. Kobe could afford to put a second pilot up front and as PIC I would have expressed to the customer that a second pilot is mandatory for safety reasons. I can't say I would or would not have taken off that day since I have never flown that route but if I did it would have been with 2 pilots and EVERY helipad between my takeoff point and destination punched in to the GPS ready to be pulled up for an emergency landing due to weather. The PNF would make sure we always had a pad to land at. No one would complain if we dropped on in when they saw Kobe get out, not even the sheriffs helipads. This was a completely avoidable tragedy.

airplanecrazy 29th Jan 2021 17:07


Originally Posted by Torquetalk (Post 10978515)
Airplanecrazy,

Gullibell is sure to be right.

As a point of interest, the FMS sums all available sources to determine ppps, and tells you when it doesn‘t have a reliable determination. No or poor DME signal or a discrepancy means the FMS will disregard the unreliable source. No issue.

What might have helped him was regular real IR training and a greater willingness to use the automatics to get him out of trouble once he lost reference. Not pressing on and chomping it whilst scud running, with limited visibility, in a rising ground environment, would have avoided the accident altogether.

Thanks for your reply. I have reviewed the FMS extraction report again and I still suspect that the FMS is using the wrong position. Either the authors of the report incorrectly decoded the position information, the FMS is confused, or I am confused. The "Active From Waypoint" recorded at 17:37:43 is 34.25080271n 118.7603827w, and that is over 15nm from the actual position at that time of 34.250610n 118.450834w. Furthermore, the aircraft never comes closer than 7nm to that waypoint.

I certainly defer to your experience on whether that possible discrepancy could have had any influence on the outcome. I was hypothesizing that when the pilot entered the steep left turn about 30 seconds before the crash, that something distracted him from watching the primary flight instruments. I was wondering if problems with the NAV radios could have been that distraction, but it sounds like you think that is unlikely. I guess we will see what the NTSB thinks in a couple of weeks. I really appreciate your time!

gulliBell 29th Jan 2021 18:42

The left turn didn't happen because the FMS was doing something it shouldn't. The left turn happened due to spatial disorientation of a pilot who had never flown in cloud before.

airplanecrazy 29th Jan 2021 19:55


Originally Posted by gulliBell (Post 10978996)
The left turn didn't happen because the FMS was doing something it shouldn't. The left turn happened due to spatial disorientation of a pilot who had never flown in cloud before.

Thank you for your reply!

[email protected] 30th Jan 2021 07:44

Add in some potential complacency because he had flown the route before (possibly in similar conditions) and got through OK - plus the commercial pressure to get the job done and personal pressure since he seems to have had a good relationship with his pax.

All adds up to an accident waiting to happen that wouldn't have been prevented by TAWS which would have been constantly alerting at low level anyway.

Plan properly and know when to say no.

TowerDog 31st Jan 2021 04:05

Interesting article on the final flight and crash in the March 2021 Vanity Fair Magazine.
(Yes, I know it is not March yet and I know V.F. Is not an aviation magazine, but sometimes they shine with well researched articles, this one seems to fall in that category)

gulliBell 31st Jan 2021 12:10

Yes, the Vanity Fair Magazine story was well written. I found this comment compelling "If he handled it right, no one would ever know what he’d done." But, handle it wrong he did, and everybody found out. As an aside, $1800/hr for an S76B sounds on the cheap side to me.

MikeNYC 31st Jan 2021 14:10


As an aside, $1800/hr for an S76B sounds on the cheap side to me.
Possible that Bryant purchased block time of 50-100h/year for that rate?

gulliBell 31st Jan 2021 14:51

That's a 204L4 or AS350 charter rate. They would be lucky to break even at that rate for a 76B. $5000/hr would be a more realistic number. Give clients a 10% discount for block hours. Obviously having a prang really screws up the economics.

Arnie Madsen 31st Jan 2021 15:51

I think Kobe owned the S76 and then the charter service took it over .... maybe he got a special hourly rate within the deal.

albatross 31st Jan 2021 19:41

I guess nobody uses the old “Climb, Confess,Comply” rule anymore.


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