It's long past the time when certificating authorities should do a proper evac test. By this I mean brief the test passengers, a mix of ages and mobility, and brief them with cash prizes for first ones off, factored for position on aircraft of course, but also brief ONLY a smaller percentage of a VERY healthy additional bounty if they get their bags off too. $$$ talks, and such a staged Evac would be absolutely fascinating to watch....

This video shows separated engine abeam first TDZ marking, so we are looking at minimum 500 m ground slide after the wing-engine separation has been achieved. I'd say that by the time engines decided they had enough on-wing time, main gear was either gone or retracted.

That's what I thought as well.

FlightGlobal reporting "engine failure at or around V1".

Almost litteral translation of the statement of the (non illiterate, surely wealthy) passenger inteviewed on video of post#17

"The AC was all OK for TO, run in conditions "with good wind for TO" but when a little aloft (apparently) a sudden gust of wind made it (the AC) to "go back down" and don't TO, then crossed the limits of the runway (supposedly a side of the RW) for ABOUT 2-3 kilometres [1&half miles] --*--
Me (the pax), this man (gesture signaling somebody out of sight in the video) and "la señora" (this meaning "my wife") were seated in BUSSINES (says clase PREMIER) so we could go out "that fast", but all the move (evac procedure) was made in 3-4 minutes until all the junk got fire ("comenzar a explotar").

--*-- Considering the lenght of Durango's RW (9200 ft/2800mt) this measurement is almost accurate taking in account the final position of the AC


Note: the pax (in the video) DOESN'T SAY ANYTHING about any storm, hail, rain or anything related to atmospheric bad conditions as a cause for the accident. Only says "strong wind".

Well having read the whole thread, I'm going to go ahead and add my speculation.

If everybody ends up walking away from that there will have been:

a lot of luck involved

and, any number of hero's.

Weather in Durango (at the moment of TO)

Until CCTV cameras from the airport (surely THERE ARE) show the exact moment of the TO, it's not sure to talk about "heavy rain, hail & etc".

In the video of post #17 can be seen a ditch with a generous (but not an ocean) amount of water at the back of the interview. Muddy water: this means +/- recent rain.

In the video of post #42 (the ride of an airport's car along the RW, no real date/time of recording) doesn't show traces of a BIG RAIN. Asphalt shows to be slightly WET in some areas, but no "pools" as sign of a recent shower

An "interesting" thought about tests, but how could that affect "real life"?
Would "automatic locking overheads" help, or would they cause more evac delays as pax struggled trying to get them open? :confused:

Not wanting to say that can't be a factor but it would require at least a bigger mistake in setting up the take-off in the MCDU as the E-Jets will not accept empty take-off settings (defaulting to max thrust) and warn if the flap setting is different from the one set on the take-off data pages.

Not familiar with characteristics of this type of engine and hot and high operations, though.

ALPINE FLYER........I suppose I was thinking about that four engined Airbus that left somewhere in Australia for the Middle East having set a too low assumed temperature - or what ever system they used for less than rated t/o thrust. They got airborne ok that time, but not without collecting a few twigs and airport souvenirs in the process. My last modern type was the 744 twenty years ago, so I'm not up to date with technology. When I began as junior trash, it was a case of working speedily through several fine printed pull-out graphs with added interpolations and corrections. Ironically it was probably simpler to avoid gross errors than reading off numbers from a table and twiddling knobs.

Old Fat: I retired from 25+ years as an accident investigator and have concluded, among other things, that--by far--most aviation luck is good. Unfortunately there are always exceptions.

Some pax reports from media articles:


https://www.nbcchicago.com/news/loca...489685751.html


https://www.cnn.com/2018/07/31/ameri...ngo/index.html

https://www.nbcnews.com/news/world/a...rvived-n896431

There is a video of the takeoff run on AvHerald.
Scary......

I am assuming the actual aircraft in question
 

The very approach, including the cash bonuses but also setting off smoke, that you mention was abandoned when it was found that about 1 in 10-20 of such evac test participants suffered a serious injury (which probably reflects reality itself, but whatever). On one of the last such tests done on a widebody in the US, a volunteer was paralysed for life.

http://articles.latimes.com/1991-11-...vacuation-test

Be careful what you wish for.

True... though most incidents I have seen over the last 42 years involved the pushing of that luck.... right up until it ran out. :sad:

Slightly OT, but no system is fool-proof obviously, and there are ways to mess up the Embraer's performance calcs for sure.

I'm with you on the speed advantage of the graphs, for a regional jet operating on non-limiting runways most calculations were as simple as checking that max. FLEX was possible and reading off three V speeds. Now we type lots of data into a computer to get much more accurate results in much more time. There are error messages to warn you of potentially inconsistent data but some of them (such as GW < MZFW) pop up for every calculation which results in them being clicked away as a matter of routine.

testing for a new member!

Yes, the comments on YouTube make it clear that it is.

Though the title, courtesy of Avherald, "Aeromexico Connect E190 at Durango on Jul 31st 2018, overran runway on rejected takeoff" doesn't seem to be supported by the content.

It is possible the gear had started to retract, the aircraft had definitely got airborne. Remember what happened in DXB with the EK 777. Potentially similar result despite that being lack of thrust and returning to earth, and this one being that or wind shear. Would explain the engines location.

I don't think so about the gear.

I tend to see lift but little rotation and no engine pops or spool downs

Lots of possibilities to be explored

Passengers and their phones can be a nuisance but in this case it gives a lot of detail. It certainly enters a heavy shower and is still on the runway when it passes over the upwind touchdown markers. It will be interesting to see if the windshear alert warning was activated during the takeoff run.

This is the reason why in many countries there is no more spin training or single-engine-out exercises during check rides on twin engine GA aircraft.
The number of accidents during such training intended to prevent future accidents made it questionable.

However, if we accept that it is too risky to test it, how can we rely on it to be a safe procedure in case of an emergency? Giving the message to all crews that an evacuation is too risky to test, how do we expect them to take the decission in a real emergency? Just compare with the discussion for the BA in Las Vegas.
Being able to safely evacuate an aircraft is one of the basics in aircraft design and certification. So we should make sure it really works.
It is quite encouraging to see, that in the last 20 years it did. It is the big question whether the situation has become worse since (more carry on, more uneducated passengers...).

All recent accidents showed that:
- there are high risks, passengers do not follow the instructions, crews do not always take the best decissions
- it works

Or engine failure/flameout due to heavy rain... Engines are tested to accept heavy rain in flight, we do not assume that pilots would take off in such situations, we do not design engines to accept any ammount of rain at take-off power, potentially also ingesting additional water from the nose wheel spray.

Some media are already calling the captain a hero. :}
https://www.forbes.com.mx/carlos-gal...-100-personas/ (Translation)
I don't like it when people jump to conclusions, blaming the crew, but calling him a hero so soon...?
Didn't he have enough clues that starting the take off roll was not a good idea? The investigation will tell if he's a reckless fool or a hero or a victim of circumstances...

Can you elaborate on this point? My type doesn't have any limitation for rain, nor advise me to delay takeoff with precipitation.

Pilots are not supposed to perform a take-off in a hailstorm.

Appendix (CS/FAR specific) gives a diagram which requires 20 g/m³ Water up to an altitude for 20.000ft, which is the value relevant for take-off.

Pilots are not supposed to perform a take-off in extreme rain exceeding 20 g/m³ (which is extreme, but happens). In most countries you only encounter such rain in heavy thunderstorms, pilots are not supposed to take off in that situation, especially as you typically just have to wait a few minutes before it has passed.

Aircraft are certified to flown reasonably by the pilot. Every pilot is trained to avoid severe weather.
Sometimes the job of a pilot is to just say no.

THere is ANOTHER video taken from a port window in which is clearly seen that the "storm" is INCREASING during the TO procedure.
When it begins, seems to be a "regular" rainy TO (nothing unusual in lots of places on Planet Earth) but increases once rotation begins.
Possibly metars weren't given correctly to the PIC for the TO calcs...
Just a guess.

Rather than redefining the parameters for an evacuation test, how about using real-life data from the last 10 years? There's been quite a few evacuations, following different kind of incidents and in wildly different settings. 'Real life' data will always give us a better picture of how passengers and crew will act than any simulation, regardless of how well thought out it may be, so why not use that data to see if there are any reasons for change? It should start with a couple of very simple questions: Was evacuation achieved within 90 seconds? If not, what caused the slow down?

we had a mileage restriction relative to thunderstorms which certainly precluded TO in one.

Video
 

Difficult to see on the video but I have the impression that no flaps were set.

The higher the power to more easier it is to ingest rain.

With today's engines the majority of the rain is centrifuged by the fan or diverged behind the fan to not pass through the engine innards. More fan RPM at slow speeds shields the compressor more. In flight low fan rpm and high air speed drives the rain droplets straight.

The cycle of the engines is also important as it affects air to water ratio and the energy needed to process the rain to a gas. Thus the higher the power is good.

Many other considerations enter into this in flight conditions

Looks like a very violent and brief squall with hail and windshear. The predictive windshear would have been inhibited just prior to the time they encountered it . Many warnings are inhibited during T/O until established in climb.
Note that the after crash videos don't show any rain.