The RAT automatically deploys in case of an electrical emergency (losing both AC buses).

It has a generator that generates 15kva for the essential buses, one of them connected to an electric hydraulic pump for the 3rd hydraulic system, for primary flight control tasks. The RAT takes 8 seconds to start generating power, and in the meantime the 2 primary batteries supply electrical power.

If the RAT fails to deploy, the flight crew can manually deploy it.

If all of these fails, including your engine generators, you have a FBW backup battery, that the manufacturer states lasts at least 15 minutes for the elevator and rudder actuators. Note that the ailerons are not FBW, and use conventional cables to command the PCUs.

That's basically how it works.

Does the E-Series have a mechanical backup (stabilizer trim + rudder, like the A320 familiy) or is it a full FBW aircraft ? Or is it even fully mechanical, and no FBW at all ? Even the Embraer Homepage does not say anything...

Indeed it does have a backup battery for the FBW, but it does have a nasty habit of tripping to direct mode when surfaces are exerted to extreme forces.

and yes it does have two modes of operation: normal (FBW) and direct (conventional). Rather than get into an in depth discussion about the control system of the Ejet, I'll say again..mine is just a theory. I think we all really want to hear the preliminary report at the very least. If it's a technical problem, then perhaps it can be stopped from ocurring again.

As Pugachev Cobra said above, the Ailerons are conventional cable/PCU control. Rudder, Elevators and spoilers are FBW. Flaps/slats are electric.

The FBW computers can be deselected and the aircraft can still be flown with certain features disabled (tail strike protection stall protection etc)

If all three hydraulic systems are lost then control is reduced to stab trim and engine thrust.

I noticed in the plane had just been through a maintenance check the day before. No indications of what type check.


This adds another possibility.

Someone on avherald noted it was a simple night service check:

That is absolutely a fair question.
I am posting a screen grab of the face of one of the engines from the video taken at the site, for the purposes of discussion.
http://home.comcast.net/~shademaker/LAM-ENGINE.PNG


The engine clearly shows signs of rotation but the question is, what approximate power setting?

What appear to be the fan blades seem to have taken a lot of abuse, but what appears to be the core engine behind doesn't look as mangled as I would expect from a high power setting.

Maybe somewhere around idle but I don't have much experience in this area.

Any qualified volunteers?

Can anyone tell if that is an engine or the APU ?

Andrasz,

That's an Engine.

Engine is a GE CF34-10E, and the photo above shows the fan rotor disc (hub), with the spinner and most of the fan blades missing. (but why?)

The condition of the LE of the blades says they were abused perhaps by very heavy hail.

Barit1,

Just a question, obviously ice can be very hard especially if cold enough and could be the cause of the LE damage but would not an engine under power pick up debris, rocks etc during the crash sequence with possibly similar effects?

Yes it would. The damage suggests that the engine did produce power at impact.

On a Namibian pilot's forum quoted by AVH it has been reported that the weather was clear at the time of the accident, the line of T/S only moved in later in the afternoon hampering SAR. It appears that weather did not play into this, something seems to have gone fundamentally wrong mid-cruise.

Don't rule out Wx
 

Andrasz, post #32 indicates there was a very active CB in the same time and space that the 190 started descending. Confirmed by Simon on Avherald.
Seems it was CAVOK at the impact site which was approx 70 nm and 12 minutes from departure from FL380 to loss of radar contact which wilh Namibia's Wide Area Multilateration coverage is quite close to ground level.
Initial descent was reported at about 6000 ft/min, and the 12 min total would give an average of around 3000 ft/min. The final resting place was close to the airway and the impact scar in line with the airway heading.
Lomapaseo - Agree that engine photo indicates rotation at the time of impact and barit1- could be hail damage.
So a couple of questions for the 190 pilots.
How many minutes, and how far do you estimate a light 190 would glide with both engines out and RAT deployed - without any pilot input after the first 30 seconds or so. Also do engines remain at idle after FADEC induced relight without pilot intervention.
Maybe ice stopped the engines and broke a windscreen leaving just 30secs to get a lot of things done. Remember thats all you get at FL380 without O2
A possible explanation?

That damage does not look bad enough for an engine producing power, it was probably windmilling when it hit the ground.
Think about it - The pictures suggest that the aircraft was under control and slow when it met the ground. If the engines had been producing power they would not have needed to attempt what looks like a forced landing under control in the bush.

Ancient G,
If they were under control, why head straight on into the bush when Shakawi, 1400m tar runway, was within easy gliding distance from initial altitude departure point?

Sadly we will probably never know the causes.

The investigation will be carried out by Angola and Mozambique, neither of which has a good record for publishing the results of investigations.

Hypothetical Scenario
 

Suppose the E-190 commenced a descent from altitude by bringing the throttles to idle, and the guys flying it were then no longer able to do so (for whatever reason.)

What would the aircraft then do-assuming initially flying with AP engaged?

Best answered by those with experience in that type aircraft.

You might have to add initial conditions of various initial nose down pitch attitudes at the time the crew ceased to function.

The objective is to see if we can create a flight profile that then fits the observed data.:8

Mach,

If they had set alt sel to 0 and press LVL CHG they'd come all the way down. If they had pressed LVL CHG and a certain alt sel (above 3kft) the airplane would capture that selected alt.

The problem is that advertised 6kftpm ROD is an average. It varied much more than that (all I can say).

We have to wait fo the preliminary report to figure what happened. At least to have an hint about.

Yes, to know with some surety as to what happened. Any idea how long that might be? Are the recorders available? Why wait?

Consider this possibility:
Aircraft in level flight in A/P encounters a serous problem (eg Very Large Hail/ Fire in cockpit/ Depressurization).
Throttles pulled to idle and possibly the nose is dropped.
Crew becomes disabled
(Flight control system is C*, isn't it?) (Also works if C*U)
Aircraft slows.
AOA protection limits maximum AOA and aircraft commences a minimum safe speed descent on previous heading. (If C*U, it would be a phugoid descent)
Does this scenario permit the observed arrival conditions?
Can it match the ATC observed ROD?

If a viable scenario, then that might explain how engines could be at low power but still running (if true).

Toxic vapors, smoke, beginning of fire for instance ?

I think it has already been stated that the recorders have been recovered and will be read by the NTSB

Nowt to do with Namibia, if they were conducting the investigation we could be confident of seeing a final report and we would probably have had an interrim by now.

Embraer will be involved and maybe a year from now they will recieve a confidential draft report for comment. As is usual for Angola, the final report will be buried to avoid embarrasing anyone.

The Namibian - Nam radar captured plane fall (News | Namibia)


Officially naught to do with Angola, rather Moz (aircraft registered there) and Nam where it crashed


"He said the black boxes and voice recorders of the plane, which were retrieved from the scene of the crash on Saturday, will be sent to the United States for analysis as part of the investigations into the accident.

According to Nengola, a Namibian investigator will accompany the voice boxes and the voice recorders to the state-of-the-art National Transportation Safety Board (NTSB) laboratories in Washington DC for the analysis.

Although he could not say when exactly the black boxes and voice recorders will be sent to the USA, Nengola indicated that this could be as early as today.

He said some investigators from the NTSB arrived in Namibia yesterday while two more from Brazil also joined the investigation team"

Hmmmm - did it come down inside the namibian border ?, there seems to be some confusion about which side of the Namibia / Angola fence it landed.

Namibia is very good at publishing reports.

TAG,

You're wrong. Embraer is already there and will help in the investigation. The team is huge.

It came down in Namibia. When looking at a map this is a strange extension of Namibia running east between Angola and Botswana, only about 50 km wide. Guess this is lucky for the outcome of the investigation on the cause of the crash.

The "Caprivi Strip." a.k.a Okavango Panhandle, etc. Created to give Namibia (then German West Africa) access to the Zambezi River.

Anyway - I'm waiting for the data. I can imagine numerous scenarios that account for the rapid descent and lack of radio transmissions as reported so far. But without further detail they are just possibilities, not probabilities.

And I'm willing to wait. Absent an obviously identifiable and imminent threat to other aircraft and crews, I don't see a lot of value in handling investigations as "data dumps" into the social-mediasphere.

According some recent sources two very important informations were released some hours ago.

1) There was some luggage collected in Botswana Soil...!

2) Searching for 2 bodies still going...

If this 2 items are true, can we be in the presence of some fuselage ruptured, explosive decompression or even structural failure?

First of all:
Again, there are not too many proven ways to get a modern airliner crashing down from cruise altitude.
One of the few ways that will surely lead to this is any kind of explosive device. Be it from the outside (shot down - not so likely) or the inside.
And these two bits of information seems to fit quite well to this kind of incident.

The only mysterious bit in such an instance would be why there was no distress call received.

Structural failure would theoretically be another possibility but in a pretty new aircraft of a type with a (so far) impeccable record this doesn't seem terribly likely.
Occam's Razor says: Rather Not.

Here's waiting for more information.

Emphasis on IF. Investigation sources do confirm two bodies unaccounted for, but I have not seen any reliable source suggesting that they are being searched for anywhere other than the crash site.

Source ?

I have read an article in a newspaper stating two bodies are still missing.
Could have caused by aircraft disintegrate in midair.

However it is also possible the remains of the two bodies are at the crashsite. The police found only one body intact. he rest were either dismembered or strewn into pieces of flesh. The Villager-Flight TM470: Only one body intact

So DNA research has to be done on all remains of bodies to find out how many bodies are actually found at the crash site.

This is writen by Namibian newssite
The Namibian - Nam radar captured plane fall (News | Namibia)

THE Namibian Directorate of Aircraft Accidents yesterday said they now have radar footage showing how the Mozambican plane, which crashed in the Bwabwata National Park on Friday, fell.

Captain Ericsson Nengola told The Namibian that flight LM470 fell at a steep angle and high speed.

In most cases, Nengola explained, planes falling from a height of 38 000 feet at that speed would disintegrate in midair before crashing. He said the pilots did not send a mayday signa - See more at: The Namibian - Nam radar captured plane fall (News | Namibia)

Before talking about explosives lets first look at something much more likely that happened before - say like Air France flight 447 quite recently, a jetliner full of people plummets from high cruise alt. to sea. Or numerous business jets that fell from their cruising altitudes after penetrating a thunderstorm (a Westwind jet out of Dallas executive airport is a particularly nasty case), so yes, it had happened before that a jet aircraft fell from their cruising altitudes and there were no explosives involved. By the way a structural failure often happens during a way down when pilots try to recover and overstress the aircraft - this was the case for the Westwind scenario - overstress caused the gear door to separate which flew off and severed the horizontal stabilizer. Overstressing has little to do with old/new aircraft.

This is one post that makes a lot of sense. Overstressing (or even structural failure) has little to do with old/new aircraft

The NTSB incident summary on the crash of the Westwind mentioned two posts above can be read here. http://libraryonline.erau.edu/online.../AAR88-01S.pdf

It starts at page 9. Accident happend April 4, 1986. Aircraft had malfunction of radar. Flew into a level 6 thunderstorm and crashed.
No mayday call of the crew. Part of the report listed in this image.


http://oi39.tinypic.com/33jhixl.jpg

And no thunderstorm is even needed to fall from the skies.

China Airlines 747 flight 006 plummeted from FL410 to 11000 feet over Pacific, they barely recovered, at some point they were even upside down (!), they landed in SFO with parts of the aircraft missing. And the cause - pilots badly mishandled an engine failure.

The speculation is getting a bit wild here - it was clearly under control when it met the ground rather slowly. Looks like a forced landing to me.

I highly doubt it was under any 'control' and the 'speculation' was helpful in discounting assertions that only explosives could force such outcome.

olasek:


On autopilot at cruise. No one minding the store. The engine failed and the autopilot tired to compensate, until it couldn't.


As I recall one of the pilots was out of the cockpit and the events overwhelmed the other pilot and F/E.

Just to summarize what we know up till now:

• Aircraft suddenly descended from FL380 at around 6000 fpm with no communications until impact with ground.
• Continuous long straight ground track and relatively large pieces of wreckage remaining indicates low to medium energy impact with ground at a shallow angle (I recall the An12 that crashed on approach fully configured for landing somewhere in central Africa after descending into the ground in patchy fog left a very similar ground track and wreckage)
• At least one engine produced some power at impact.
• Two on board are still unaccounted for.
• Weather at accident site was clear at time of impact, some contradiction whether there may have been T/S cells along the original flight path.
• Pilots plenty of experience both in terms of hours and on type.

I find this the most puzzling accident since AF447, I'm sure Embraer will go to very great lengths to figure out what happened, if will not be obvious from FDR/CVR.

That's what I meant when I said : No proven ways. AF447 was almost a first in its kind. I didn't consider AF447 a proven way, rather (hopefully) an exception.

OK, flying directly into a TS is indeed a proven way but my understanding so far was that they flew along some TS but not straight into it.

But this requires complete LoC upfront which -except flying directly into a cell- is a very rare occurrence.