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-   -   Jet goes down on its way to Medellin, Colombia (https://www.pprune.org/rumours-news/587574-jet-goes-down-its-way-medellin-colombia.html)

Airbubba 3rd Dec 2016 16:39


Originally Posted by DaveReidUK (Post 9597412)
GE plot of the taxy out and take-off.

http://www.avgen.com/LMI2933%20taxy%20&%20takeoff.jpg

The ADS-B offset looks pretty close to a mile to me :O. It's highly likely that a similar offset applies to the published track of LM2933 in the hold, but I agree it's still not enough to put it over the VOR.

You are right (as usual, I'm afraid ;)). I was looking at the track in this link I posted earlier:

https://www.flightradar24.com/data/a...-2933/#bbef1b9

It doesn't show the taxi at Viru Viru and since most of the shift is aligned with the runway, the track starts near the pavement, perhaps at liftoff.

Flightradar24's blog has this comment on the transponder in the RJ85:


Positional Accuracy

CP-2933 was equipped with an older ADS-B transponder which may be subject to positional accuracy issues. The position of the aircraft is calibrated prior to take off and the on board computer calculates positions based on speed and direction of the aircraft. With certain types of flying (including holding patterns), the calculation can become inaccurate.
Also, FR24 has this playback of traffic in the Medellin area near the time of the mishap:

https://www.flightradar24.com/2016-1.../6.14,-75.5/10

Many of the other planes drop out of ADS-B receiver coverage from time to time and give jagged plots but it appears that they are holding at the VOR while LMI2933 is holding several miles south of the navaid.

Has anyone found other plots of the holding on other ADS-B trackers like RadarBox24 or FlightAware? Also, on the RJ85 are the nav instruments and computers updated with radio nav and maybe as Dave says, the transponder only sends inertial position? The holding pattern does look like it is nicely plotted, just not in the right place.


Originally Posted by PEI_3721 (Post 9597456)
Any 146/RJ operators prepared to admit one of those 'Doh' moments when using the GNS fuel planning page as an inflight guide - 'how goes it', forgetting that the system requires manual updating.
Memory fades, but only part of the system, fuel contents or fuel flow, was automated.
Well, yes; I managed at least one Ooops during in-flight planning. More seriously, witnessed at least two Doh moments, one involving a tech stop to refuel.

Recall the A300 at Vienna landing without fuel; as an industry we tend to forget safety lessons.

It was an A310 at VIE that ran out of gas, but as in this crash, they were very late in confessing the problem to ATC.

Years ago I flew a bizjet, perhaps a Lear, with partially automated fuel tracking and prediction supplied to the nav computers. It was as you described, helpful but a real gotcha if you forgot to initialize it each leg.

And, I've been sitting in a holding pattern in a Boeing, trying to figure when to go to plan B. Obviously, doing rough calculations in my jet-lagged head, and then looking at the FMS prediction. Whatever algorithm the box used made the landing fuel look great when on the inbound leg and then it dropped by several thousand pounds turning outbound.

Airbubba 3rd Dec 2016 17:02

I found this FlightAware plot of the holding:

https://flightaware.com/live/flight/LMI2933

It seems to agree with the Flightradar24 plot and it looks like the pattern is not as closely aligned with inbound course to the runway as I had first thought.

DaveReidUK 3rd Dec 2016 17:27

The FlightAware plot stops about 2 minutes earlier, so it doesn't add much to what we already knew from the FR24 data, except that it does usefully include groundspeed.

Looking at the GS inbound/outbound in the hold, there appears to be a slight headwind (northerly) component of about 15-20 kts (at FL210).

GS in the cruise was about 375 kts, again suggesting a similar headwind at FL300, which can't have helped under the circumstances.

Livesinafield 3rd Dec 2016 18:02

Really suspicious of this flight plan talk...I think it stinks of a hoax

Chronus 3rd Dec 2016 18:15


Originally Posted by Hippy (Post 9597865)
ATC don't see the endurance. That part of the plan is not transmitted when the plan is filed. That part of the plan is only disseminated when overdue/SAR action needs to be taken.

Not that I would claim any in depth knowledge as to the precise reasons and authority for refusing FP`s, but had such a FP been stuck under my nose, my inclination would have been to turn it down on the basis that it lacked AAR data.

YRP 3rd Dec 2016 19:27

The idea of the fuel stop in Bogata is curious. If the distance is 116nm as someone posted, that gives about 15 minutes less time. Bogata might have been possible to make, but certainly not legal -- no alternate/reserve fuel.

About ATC acceptance: ATC has no ability to confirm the actual legality of fuel for each flight. They'd need the fuel performance tables for the type, actual fuel and weight, plans for alternates, contingencies, etc. They don't have the knowledge to do that, not being flight dispatchers or ATPL, so can't reject flight plans for illegal reserves. Give them a flight plan legal and one just short, they wouldn't know.

The only reason "Celia" spotted it here was that it was egregiously obvious: only enough to make it with dry tanks.

YRP 3rd Dec 2016 19:28


Originally Posted by Livesinafield (Post 9597942)
Really suspicious of this flight plan talk...I think it stinks of a hoax

LivesinaField, I wonder about that myself. One thing that does give it credence: it matches where they ran dry...

Chronus 3rd Dec 2016 19:46


Originally Posted by YRP (Post 9597976)
The idea of the fuel stop in Bogata is curious. If the distance is 116nm as someone posted, that gives about 15 minutes less time. Bogata might have been possible to make, but certainly not legal -- no alternate/reserve fuel.

About ATC acceptance: ATC has no ability to confirm the actual legality of fuel for each flight. They'd need the fuel performance tables for the type, actual fuel and weight, plans for alternates, contingencies, etc. They don't have the knowledge to do that, not being flight dispatchers or ATPL, so can't reject flight plans for illegal reserves. Give them a flight plan legal and one just short, they wouldn't know.

The only reason "Celia" spotted it here was that it was egregiously obvious: only enough to make it with dry tanks.

It is not a matter of what is not known, but a matter of that which is known. Namely endurance and time en route. More to the point the obvious, which leaves only the incredulous. Hence the remarks by Livesinafield, "..... I think it stinks of a hoax ".

ATC Watcher 3rd Dec 2016 19:51

The PLN is not the key to this accident . whether it is a hoax or not does not change the subsequent facts since they were apparently from the beginning intending to stretch the flight beyond legal reserves.
They could have put 3 alternates and 5h endurance and sign it as Jan Smith and the PLN would have been "perfect" for the ARO and ATC. No one on the ground knows how many (extra) tanks any aircraft carries in reality ( I have seen PLNs with 10h endurance on cross Atlantic Ferry Cessna172s) , and nobody can force you to land at your alternates anyway. ALTN are just there for info and the Endurance / EET part is only for SAR not for ATC. ( as someone said earlier those boxes are not even transmitted/processed to ATC)

It is the attitude of the Dispatcher ( and possibly the Captain) which is interesting in Miss Celia memo , not the PLN itself.

TowerDog 3rd Dec 2016 20:08


. ATC don't see the endurance. That part of the plan is not transmitted when the plan is filed. That part of the plan is only disseminated when overdue/SAR action needs to be taken.
Hippy is offline Report Post
I did not know that, but it would explain why this flight plan was "accepted" by the various ATC agencies. Seems the local ATC in VVI did not raise an eyebrow as they saw the whole flight plan before they entered the info into the ATC system.
I sure had plenty FPs turned down or questioned if I made a small mistake or forgot to dot an I or cross a T in various third world countries where we filed manually and in person at the local office.

Chronus 3rd Dec 2016 20:17

ATC Watcher "The PLN is not the key to this accident . whether it is a hoax or not does not change the subsequent facts since they were apparently from the beginning intending to stretch the flight beyond legal reserves."
Does this not mean that the intention was to actually commit an illegal act.
But of course it would be expected for a C172 on a Atlantic ferry flight to "declare" a 10 hr endurance. What would anyone think if 2 hrs was declared on the FP of such a flight.

MungoP 3rd Dec 2016 20:25

I for one have never submitted a FP where I've calculated and then listed endurance down to a single minute.. Usually rounded to the nearest 15 min. Seems odd to me .. but then so do many things.

Livesinafield 3rd Dec 2016 20:35

I just think the 4hrs 22 Endurance and the 4hrs 22 EET looks too obvious, if you where on the jimmy riddle, why would you put that ? maybe put 5hrs 22 whether atc see it or not its just looks really dodgy.

I am really struggling to believe this FPL is genuine, as someone has already said it doesn't really matter, they clearly didn't have enough fuel for the trip.

Is anyone else finding it really hard to believe why a professional pilot with some degree of experience would be happy flying to an aerodrome and arriving with approx 7 minutes of fuel until engines stop working at night?? I was looking at the maps and if they had to make an approach via the North onto runway 19 they would have likely ran out of fuel on the approach....

They must have flown over the top of Bogota airport nearly into their Final reserve, it just doesn't make any sense

Lancelot de boyles 3rd Dec 2016 20:56


a professional pilot with some degree of experience
...does not necessarily infer a 'competent professional, with some degree of knowledge'

In a previous job, I was unfortunate enough to encounter an experienced co-pilot, with an ATP from the FAA along with another from his country of origin. His understanding of fuel capacity, management, reserves etc are eerily similar to many of the failings highlighted in this case. That attitude complemented an equally cavalier attitude by the management towards aircraft maintenance. Sadly, it matters little how much you pay for the aircraft (new and fairly prestigious in our case) and the staff, or the value of the contracts; if there are folk involved devoid of integrity or genuine knowledge, the tragic outcome is likely only a matter of time and luck.

one phrase that keeps coming to mind as I read this is 'normalisation of deviance'.

Toruk Macto 3rd Dec 2016 21:10

To put the same figure for EET and endurance is in my opinion an egotistical bost .

AndyJS 3rd Dec 2016 21:28

"Really suspicious of this flight plan talk...I think it stinks of a hoax"

I would agree with you if the pilot was attempting to hide something. But I don't think he was trying to hide anything.

fdr 3rd Dec 2016 21:40

The information on the FPL and the response by the ATC Officer is disturbing. Celia's email to her manager appears to pre date the crash, and it indicates that she did not accept the ATS FPL. If so, how did the aircraft end up 1600nm away following an IFR flight. When was the FPL accepted by ATS, and by who, and with what presumed intervention to Celia's legitimate complaints?

This aircraft was never legal to operate this flight under any ICAO Annex 6 Part 1 compliance. This particular part is not recommended practice it happens to be a minimum standard. Para 4.3.6.3 doesn't allow you to be so criminally cavalier as this operation has been, nor does it allow the state to waive the rules if they are ICAO signatories.

These unfortunate passengers and hapless crew have been killed by the actions of the PIC and the dispatcher, and those others that facilitated this dispatch, and the operation of such a reckless program operating outside of the law.

peekay4 3rd Dec 2016 22:04


Many of the other planes drop out of ADS-B receiver coverage from time to time and give jagged plots but it appears that they are holding at the VOR while LMI2933 is holding several miles south of the navaid.

Has anyone found other plots of the holding on other ADS-B trackers like RadarBox24 or FlightAware? Also, on the RJ85 are the nav instruments and computers updated with radio nav and maybe as Dave says, the transponder only sends inertial position? The holding pattern does look like it is nicely plotted, just not in the right place.
If these RJ85s are really transmitting at NUCp 0 data quality level as Dave says then forget about trying to match positions. NUCp 0 means the position error could be greater than 10 nm.

Garbage In, Garbage Out. All that can be determined from the data is that the aircraft was somewhere within the vicinity of the VOR.

archae86 3rd Dec 2016 22:08

Possible measurement error contribution?
 

Originally Posted by Livesinafield
Is anyone else finding it really hard to believe why a professional pilot with some degree of experience would be happy flying to an aerodrome and arriving with approx 7 minutes of fuel until engines stop working at night?

I'm not a pilot, but spent years in responsible positions in very high-value, high-technology factories. A lesson there is that maintenance of even the most critically important equipment was less likely to be successful for aspects of operation not having any impact in normal circumstances.

Obviously normal fleet operation does not involve frequent exploration of the zero-fuel end of fuel-state operations. I wonder whether there are plausible failure modes which might have introduced a modest zero-offset in the fuel readout of this aircraft, and whether (possibly slopply) maintenance and normal operational experience might have left that error in place for weeks.

If such an error was already in place on previous excessive range flights, all concerned might not have detected just how close those flights came to exhaustion. If the error was in place on this flight, alerts and indications may have come later than people posting on this thread are assuming.

Since normal operations seem unlikely to verify the zero-fuel readout point directly, what special procedure or maintenance is done which would catch such an error? How frequently?

None of which is in any way to suggest such an error as a primary cause here, but specifically a possible explanation to some of the late-stage lack of urgency.

dmba 3rd Dec 2016 22:08

Am I wrong to say that this could have all been avoided if Celia had not permitted the flight to take off without raising the issues further instead of backing down...where does the buck stop? Aren't these systems in place to avoid this kind of thing?


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