PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rumours & News (https://www.pprune.org/rumours-news-13/)
-   -   Jet goes down on its way to Medellin, Colombia (https://www.pprune.org/rumours-news/587574-jet-goes-down-its-way-medellin-colombia.html)

throwaway85 29th Nov 2016 14:05

The CityJet RJ's have wing and a center tank, max total fuel of around 9000kg, but not the aux tanks.

Fuel burn of a conservative 2T/hr, giving you 3.5h-4h + reserves. Cruises at 0.68-0.70. You would be able to lift 81 males + 9T fuel provided you had over about 1500-1800m runway at those temperatures.

So, if they filled it up to the gills they may have been approaching diversion fuel after 1600NM, but not running out. But then who knows how much they brought with them, or whether they's been able to get to panned cruise level, etc etc etc.

Anyhow, very sad.

M68 29th Nov 2016 14:15

Sky News: Brazilian football team's plane crashes in Colombia killing 76

"The head of Colombia's civil aviation agency, Alfredo Bocanegra, said reported comments from a female flight attendant that the plane had run out of fuel were being evaluated."

T28B 29th Nov 2016 14:28

Source = JACDEC:

The en-route altitude changed to 30,000 ft. before the pilots began their descent to Medellin at around 21:30L. The landing runway in use at the time was runway 36, meaning an approach from the south. It was dark at the time ... For reasons unknown the aircraft began to fly a holding pattern at 21.000 ft (FL210) near the Rio Negro VOR, about 17 miles southeast of their destination.
According to Colombia media, the pilots requested a holding because the flight experienced some kind of electrical problems. A minute later the pilots requested priority handling.
After one circle, the aircraft cancelled the holding and proceeded northbound its altitude gradually decreasing to 15,000 ft. before contact was lost.
The aircraft was found to have crashed against hillside in wooded, upsloping terrain ... Medellin is surrounded by mountains.
This report does not indicate that an emergency fuel state was declared. Whether or not fuel was related to the crew requesting priority handling is unclear.

The Ancient Geek 29th Nov 2016 14:35

The RJ85 can be fitted with 3 extra fuel options:- Panier tanks, a Rear Bay tank and a Front Bay Tank. Each option increases range at the expence of payload.
There is a graph here, 2016-11-28 LAMIA Avro RJ-85 crashed near Medellin with 81 on board » JACDEC scroll down about 1/3 of the document.

We do not know which tank options, it any, were fitted or how much fuel was actually loaded. It is also unclear whether the quoted ranges are with or without reserves but no sane pilot would have departed without reserves for a diversion plus 60 minutes so we must assume that some extra tanks were fitted.

The fuel theory is most likely a total red herring, expecially in view of the reported electrical problems.

All speculation is futile until we have more facts.

birmingham 29th Nov 2016 14:35


Originally Posted by The Ancient Geek (Post 9593131)
Yea right - the usual idiot speculation.
All will become clearer when we have some real facts. There are always a chain of contributing causes and the full story will not be known until the official report is published.

I think speculation that fuel management played some (though not maybe the primary causal role) her is inevitable rather than idiotic here and given the surviving wreckage should be a relatively straightforward task for the investigation. As usual FOD to the fans will indicate if the engines were running and the recorders will indicate the status of the fuel system,

But the speculation (and I agree it is that) is justified to a certain extent ...

If you know the 85 this 1600 nm mission is right at the end of the envelope so even with the correct calcs/weight/speed management they would have been under some time pressure if something went wrong on approach. Further those of you who know the A/C will be aware that the outboard (1 & 4) engines (fed from the outer wing tanks) are responsible for power generation while the APU is fed if I remember correctly from the inboard wing tanks. In normal circumstances the fuel system is very straightforward - set and go with the centre tank emptied first as usual. However in the event of fuel starvation anyone getting creative with the valves could also inadvertently create a situation where electrical power is lost as was initially reported (though not verified yet). Even if fuel starvation was not the cause of the reported malfunction Medellin is not the approach where I would want to deal with an electrical failure with limited hold/diversion options.

As people have correctly pointed out there are always multiple causes in incidents such as this and I would be very surprised if fuel management wasn't at least part of the problem.

2Donkeys 29th Nov 2016 14:39

The source of fuel starvation rumours, quite apart from any speculation here or elsewhere, appears to be a comment made by the surviving Flight Attendant, and reported by Sky News.

eagleflyer 29th Nov 2016 14:41

No CFIT without fuel, I guess.

If I understand right what I´ve found electrics on the RJ come from two generators (gone) plus the APU (gone) and a battery. No ram air turbine if I´m informed correctly. The hydraulics would have had to be provided by electrical power. I doubt battery alone would provide enough power for very long enough to provide hydraulics as well as keeping basic instrumentation going.
Flying only privately I would not consider planning to the absolute edge of my theoretical max performance or maybe beyond at night into a demanding airfield.

Martin_123 29th Nov 2016 14:43


Originally Posted by The Ancient Geek (Post 9593301)
The RJ85 can be fitted with 3 extra fuel options:- Panier tanks, a Rear Bay tank and a Front Bay Tank. Each option increases range at the expence of payload.
There is a graph here, 2016-11-28 LAMIA Avro RJ-85 crashed near Medellin with 81 on board » JACDEC scroll down about 1/3 of the document.

We do not know which tank options, it any, were fitted or how much fuel was actually loaded. It is also unclear whether the quoted ranges are with or without reserves but no sane pilot would have departed without reserves for a diversion plus 60 minutes so we must assume that some extra tanks were fitted.

The fuel theory is most likely a total red herring, expecially in view of the reported electrical problems.

All speculation is futile until we have more facts.

thanks for this.

According to avherald -
In the early morning hours of Nov 29th 2016 the CCAA reported, that an investigation has been opened into the crash, data and information are being collected. The head of investigation stated: "No existe evidencia de combustible en la aeronave" (there is no evidence of fuel in the aircraft).

A0283 29th Nov 2016 15:11


.The fuel theory is most likely a total red herring, expecially in view of the reported electrical problems.
Too early to say of course.

But there have been a number of high profile accidents in the past where the crew focussed on a (minor) technical issue and forgot properly monitoring fuel or speed.

Next to that accidents happen when multiple things go wrong. It is a series of events and not (as far as i have seen - never) a single cause.

IHF 29th Nov 2016 15:27


Originally Posted by FrontSeatPhil (Post 9593270)
As a frequent SLF on a chartered luxury RJ85, nine seems steep but not impossible. I usually see 5 or 6 for a passenger count of maybe 20 people.

Thanks FSP, good point (my SLF experience is on just regular scheduled ops, not charters)

dmba 29th Nov 2016 15:33

It's being reported here in Brazil that José Maria Córdova airport has stated that there was an electrical failure, notified by the aircraft.

dmba 29th Nov 2016 15:37

Of the six survivors, three are Chapecoense players. One of these has had a leg amputated in hospital and remains in a critical condition, with head trauma and injuries to his abdomen and thorax. Two other survivors, who were crew, are considered to have non-critical injuries. The other survivor is a journalist who is said be in a stable condition.

A fourth player who survived the crash has since died in hospital.

eagleflyer 29th Nov 2016 15:37

I saw a picture in some British paper that suggests the flight carried a second flightdeck crew. Might be an explanation.

PEI_3721 29th Nov 2016 16:06

eagle #49, incorrect.
The RJ has 2 engine driven generators (engs 1 and 4), and 1 (non essential) on the APU; this is the Normal power level.
AC and DC power can be supplied from a hydraulically powered generator (green system) from either of the 2 hydraulic systems (engs 2 and 3) via a power transfer system. This is the Essential level of power.
There is also a Std By static inverter from the battery (second optional) supplying the Emergency level flight instruments.

Thus the aircraft is exceptionally well supported electrically, enabling flight without any power generating systems.
All other airframe systems have sufficient redundancy to enable an emergency landing without any generated electrical power.

dmba 29th Nov 2016 16:18

Now saying that there were 77 people on board. 4 people on the list did not board the plane.
Crew: 9
Passengers: 68
Survivors: 6

Super VC-10 29th Nov 2016 16:29

Apparently the airline's owner was flying the aircraft and is one of the fatalities.

Accidente avión Chapecoense: El piloto del avión siniestrado también era el dueño de la aerolínea LaMia | Marca.com

ULMFlyer 29th Nov 2016 16:39

FWIW, on the Brazilian aviation forum Contato Radar, someone posted a picture of one of the engines showing little to no damage to the fan blades that are visible

swiftyb 29th Nov 2016 16:47

Football
 

Originally Posted by dmba (Post 9593394)
Now saying that there were 77 people on board. 4 people on the list did not board the plane.
Crew: 9
Passengers: 68
Survivors: 6

I would hazard a guess at the possibility of a few "extra crew" hopping on board to get to watch the football match.

eagleflyer 29th Nov 2016 16:47

PEI, but where does hydraulic power come from when all engines have failed and the APU doesn´t run due to lack of fuel? I understand it would come from an electrical pump that would run on battery power (the only energy source left). How long would that battery last?

dmba 29th Nov 2016 16:51

This was not a charter flight. It was a commercial flight. ANAC, the Brazilian aviation authority, did not auhtorise the team to take charter flight from Sao Paulo to Medellin. This decision caused the team to be delayed 2 hours before leaving Sao Paulo and resulted in the connection in Bolivia. The decision was not the responsibility of LaMia.


All times are GMT. The time now is 00:23.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.