737-8 max plane goes down (2018) - new not Max crash Indonesia

[west didsblue]

I have been repeplatedly subjected to +6.5g for a little over 10s at a time and it is quite 'taxing' to say the least.

What g were you being subject to when you were typing “repeatedly”?

 

[Indaparkside]

If you had a “loss of the ‘tail plane’” (if I understand what you mean by that), the least of your problems would be any minor shift in CG!!!

Think of an aircraft as a seesaw, where the wings are the fulcrum.
If the side where the tail is suddenly departs the seesaw, what happens to the side where the pilots sit?

The “tail plane” has a far greater impact on the aircraft than any weight shift (which is what creates a change in CG). It makes it flyable…or not.

Your the only man people should listen to on this thread Hail Chicago blue

 

[Toney’s bookie]

If you had a “loss of the ‘tail plane’” (if I understand what you mean by that), the least of your problems would be any minor shift in CG!!!

Think of an aircraft as a seesaw, where the wings are the fulcrum.
If the side where the tail is suddenly departs the seesaw, what happens to the side where the pilots sit?

The “tail plane” has a far greater impact on the aircraft than any weight shift (which is what creates a change in CG). It makes it flyable…or not.

Aye I get the whole centre of pressure stuff vs the loss of tailplane pitch moment if you lost it vs CofG (I’ve flown Bombardier, Embraer, Boeing and currently Airbus fyi).

But there’s a lot of speculation on the usual sites about the aircraft being filmed flying vertically with no tailplane and bits being strewn away from the crash site but none of it really seems to make much sense. I just don’t see someone nosediving it like that intentionally and the other guy not doing anything. It was at the top of descent too I believe which would seem an odd time for that scenario (eurowings was cruise). This all seemed to happen very quickly and fall rather than be pointed down. I may be wrong of course.

Planes don’t really just fall vertically down and the 737-800 is pretty robust as you know - it just doesn’t make sense but usually in these accidents eyewitness accounts and online data turns out to be red herrings so we shall see. I seem to remember a flydubai 737-800 messing up a go around and being lost with a super high rate of descent but that’s a different scenario totally.

 

[PannickAtTheDisco]

If you are pinned by G forces, what about the other guy?

And when you’re going down like a bat out of hell, those G forces are working AGAINST you push the aircraft down, no?

Once again, unless there is definitive proof this is a murder-suicide, I’d start looking at CAUSE & EFFECT.

What can cause an airplane flying along at 29,000 feet to create the effect of it hitting the ground almost vertically, and seemingly without all its control surfaces intact?

I’d suggest upset of some kind, as either the initial cause or initial effect of something else, leading to a loss of control. During such an event, pilots and the airplane itself can exert forces on the aircraft outside its design envelope.

During my own “upset training” we do multiple scenarios to help pilots understand where that control envelope is and just how easy, given a wrong input at the wrong time, one can exert forces beyond design limits upon control surfaces, such as wings, elevator, rudder/tail.

It would be almost impossible to create an airplane that couldn’t experience such a thing, even though modern FBW automation attempts to do that.

Indeed, the 787 pilot inputs are normally REQUESTS! The pilot tells the aircraft to do something (turn right, for instance, by turning the yoke to the right. The aircraft then takes that electronic input and first checks it, then agreed it’s within limits, and then sends signals to the control surfaces to make the aircraft turn. That happens in a split second, and the pilot doesn’t control which control surfaces the aircraft uses! It decides which control surfaces and how far to make it the most efficient right turn possible.

The 737-800 is NOT FBW, so direct pilot inputs are sent to control surfaces. In extremis, these can be an over control.

Conversely, in a loss of control effectiveness (due to failure or having the surface depart the aircraft), the pilot may not be able to do anything to save the aircraft regardless of skill or competency.

Cause & effect.

I'm just curious and shooting the breeze, I'm not saying it was the case here at all.

 

[BlueHammer85]

from someone I know who did some brief flight training

As much as I know about planes there is nothing that can make a plane drop like that so long as the wings and fuselage (body) is in tact, any plane is designed to the highest degree of precision to glide even if all engines have failed, the wings are designed that way…..so I can only conclude that the plane is not in a natural aerodynamic state, I.e the wings/body are damaged, but to go down at that rate the damage must be drastic
Even if it’s a pilot controlled dive, that descent and angle is incredibly difficult to perform, the plane would fight against you, in a commercial plane he would have to cut all power (commercial planes would lock you from doing that) and then dive at that angle, just don’t see how that’s possible

 

[Millwallawayveteran1988]

Don’t planes normally break up mid air with those sort of forces?

 

[Indaparkside]

from someone I know who did some brief flight training

As much as I know about planes

Would that be your air fix glue in your bedroom and your raf stickers as you try to assemble it:)

 

[ChicagoBlue]

Aye I get the whole centre of pressure stuff vs the loss of tailplane pitch moment if you lost it vs CofG (I’ve flown Bombardier, Embraer, Boeing and currently Airbus fyi).

But there’s a lot of speculation on the usual sites about the aircraft being filmed flying vertically with no tailplane and bits being strewn away from the crash site but none of it really seems to make much sense. I just don’t see someone nosediving it like that intentionally and the other guy not doing anything. It was at the top of descent too I believe which would seem an odd time for that scenario (eurowings was cruise). This all seemed to happen very quickly and fall rather than be pointed down. I may be wrong of course.

Planes don’t really just fall vertically down and the 737-800 is pretty robust as you know - it just doesn’t make sense but usually in these accidents eyewitness accounts and online data turns out to be red herrings so we shall see. I seem to remember a flydubai 737-800 messing up a go around and being lost with a super high rate of descent but that’s a different scenario totally.

I won’t believe either pilot chose to fly into the ground until someone shows me proof.

Aircraft break up in flight because of forces outside their design limits. This is common on aircraft that fall uncontrollably out of the sky, because certain control surfaces are not designed for excessive side loads (see American A300 over Jamaica Bay, NY, departing JFK and encountering a low level wake turbulence event).

I don’t know what happened. Let me clearly state that. I also believe certain things did not happen, which (for me) narrows it down.

From there, the cause and effect become very important. Did a pilot cause a problem resulting in uncontrollability or did the aircraft cause an uncontrollability problem the pilots could not recover from OR did the aircraft cause a problem and the pilot response caused an uncontrollability issue?

For me, those are the three key questions, because an aircraft diving to earth while shedding parts is MOST PROBABLY a result of one of those scenarios.

As you can see, I don’t know enough. I don’t think anyone does yet.

 

[Toney’s bookie]

As you can see, I don’t know enough. I don’t think anyone does yet.

Amen to that

 

[ChicagoBlue]

Don’t planes normally break up mid air with those sort of forces?

In straight and level unaccelerated flight - no.

Remove those conditions at speed, and you may be looking at control forces from directions for which the surface(s) was (were) not designed, or are simply beyond design limits.

The 777 wing test to destruction at 154% of expected load…