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Posted

Two aircraft accidents have claimed a total of 25 lives.

 

In Switzerland, a vintage Ju-52 tri-motor crashed into a mountain killing all 20 on board.

 

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In California, a Cessna 414 crashed into a shopping mall car park killing all 5 on board. No-one on the ground was injured.

 

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Posted

One can only wonder how this JU 52 came to dive vertically into the earth with 2 very experienced pilots aboard.

 

 

Posted
One can only wonder how this JU 52 came to dive vertically into the earth with 2 very experienced pilots aboard.

I can only think major control failure.....elevator?

 

 

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Posted
I can only think major control failure.....elevator?

So many accidents (per the NTSB Forum that I attended at Oshkosh) ... turn .. stall .. spin .. crash ... burn ... die ..

Might not be relevant to this accident, my comment is generic, I can wait for the final report ...

 

I wouldn't think a "major control failure" would result in: "A witness who was on the mountainside at the time of the crash told the 20 Minutes newspaper that "the plane turned 180 degrees to the south and fell to the ground like a stone"."

 

 

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Posted
In California, a Cessna 414 crashed into a shopping mall car park killing all 5 on board.

See the video and a witness statement: "It, like, lost control, and it was twirling, and the more twirl, the more lower it came down and then we heard the bang,"I can only recall that NTSB forum again per my prior post.

 

 

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Posted

That kind of result is becoming too common. We can't judge, as we don't have all the facts but as we should know an aeroplane is not very forgiving when things go out of shape. That Junkers operation had been going on for decades and should not be a dangerous flight even though it's an old aeroplane I would think if any of them are in good condition that one would be. They were a magnificent workhorse.. Bad end for a normally fantastic holiday flying experience that had I been there, would not have hesitated to be on . Nev

 

 

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Posted

FYI from my brother overnight in Luzern:

 

Well, over lunch & since my eml of Mon, Aug 6, 2018 at 8:36 PM [your time], I read the 20min.ch article, which had the "turned 180 degrees to the south and fell to the ground like a stone" = «Sie flogen [better = flog] eine 180-Grad-Kurve Richtung Süden, dann fiel sie wie ein Stein vom Himmel.»

 

A search shows this as published by 20min.ch on “05. August 2018 17:11; Akt: 05.08.2018 17:18” – and is described as «Ersten Erkenntnissen» = “1st reports,” so why didn’t the TV in general and SRF in particular report this ‘back then?’ Never mind.

 

Then, also in your citation:

 

{Der Absturz wurde von mehreren Augenzeugen beobachtet, darunter auch ein Militärpilot aus der Region. Er geht davon aus, dass die Piloten ein ernsthaftes Problem mit der Steuerung hatten. Der Pilot konnte aus seinem Garten beobachten, wie das Flugzeug über das Tal flog, zu einer Linkskurve ansetzte – und dann plötzlich abrupt nach links vorne wegkippte. «Solche Manöver machte man früher, um den Ausfall eines Motors zu simulieren. Aber mit Passagieren macht das niemand», sagt der Mann dem «Tages-Anzeiger».

 

Daraufhin habe ein Motor laut aufgeheult, Sekunden später sei das Flugzeug dann wieder ausbalanciert gewesen und habe den Flug normal fortgesetzt.}

 

You may translate that with google-translate, but the sense is ‘turn, stall, recover’ with power added somewhere in that sequence.

 

And so the ‘struggling’ idea.

 

Now, reports say ‘no pieces lost, no visible [pre-]damage observed.’

 

IF the pilots were ‘struggling’ THEN I would think they would head for the next known landing-place - like Mollis, say [~30km, one valley all the way], but if I understand correctly, they continued and some time later initiated the fatal 180 to face south, exactly the ‘wrong’ direction for Mollis or home-base Dübendorf.

 

So now if report-snips here are correct, we have two turns, two stalls but only one recovery.

 

"Your guess is as good as mine?"

 

Don

 

 

Posted

Translation of the passage by Google:

 

The crash was observed by several eyewitnesses, including a military pilot from the region. He assumes that the pilots had a serious control problem. The pilot could watch from his garden as the plane flew over the valley, made a left turn - and then suddenly abruptly tipped to the left front. "Such maneuvers were done earlier to simulate the failure of an engine. But nobody does that with passengers, "says the man to the Tages-Anzeiger.

 

 

 

 

 

Thereupon an engine had howled loudly, seconds later the airplane had been balanced again and continued the flight normally

 

 

Posted
Just another two stall spin crashes, airspeed airspeed airspeed at all times.

Angle of attack, angle of attack, angle of attack

 

 

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Posted

Some good advice by Jim at http://www.dylanaviation.com/dont-stall/

 

Despite my briefing to wait until established on final before reducing airspeed, pretty much all of my tailwheel students lose airspeed during the base to final turn so they purposely pull back and increase the angle of attack - definitely not a good habit.

 

The turn method of "bank ... balance ... back pressure" used in initial training has its place but not in this situation.

 

 

Posted

Well you don't usually have an angle of attack (reserve lift) reference. (You do in a jet) and they are useful. Plenty of times you will be adding flap and changing power in a tight turn as well. This is all a part of being able to fly a plane, but you don't achieve it before doing your first solo.. Nev

 

 

Posted
Angle of attack, angle of attack, angle of attack

Very true, AoA AND load factor, AS is only part of it!

 

 

Posted

Like facthunter said most of us don't have an angle of attack indicator we only have airspeed, but we should all know what a 60 degree bank turn feels like (2g) and that our stall speed will be 1.4 x normal.

 

The vane type stall warning systems do work regardless of airspeed, 80kts 2g the beech23 will sound.

 

 

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Posted

djpacro: That article is nicely confused. Stick PRESSURE has nothing to do with it. That is a result of what you did with the elevator trim.

 

Stick POSITION is what counts. Stick position controls elevator deflection (it is rigidly connected) which controls ANGLE OF ATTACK due to the stability of the aircraft.(depends on C of G position, flap position also)

 

Demand an angle of attack greater than the angle at which the wing stalls and it WILL stall.

 

The stick controls angle of attack, the pilot controls the stick.

 

We really should have a stick position indicator. Something as simple as a red pole which starts to protrude above the glareshield at elevator deflections which cause angles of attack approaching the stall.

 

 

Posted

The stick position indicator is the stick itself. Stick position for stall is dependent on trim, configuration (Gear, wheels, flap) and CofG. For any given flight situation there is a stick stall position. On a moving horizontal stabiliser trim the stick position means little as you could trim to a stall and still have the stick mid position. Nevertheless the concept is a good one. Remember.. The plane won't stall itself. The pilot determines the angle of attack of the wing with the elevators. If you push the stick forward you unload the wing but the nose keeps dropping. IF you hold the stick back the nose will drop then also because you are stalled and have a problem if you are low. Nev

 

 

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Posted

The actual stick position in your hand is pretty subtle and not necessarily obvious while occupied. Vision is better. AoA indicators get confused in turbulence. If you damp them to give useable indications the AoA may exceed stalling angle before the thing indicates so.

 

A gust (entering thermal) can stall the wing momentarily (aircraft tries to line up with new relative airflow direction). The aircraft will begin to pitch down (aircraft tries to line up with new relative airflow direction) and the danger is that you try to maintain the same attitude by pulling the stick back which maintains or deepens the stall. I believe this caught somebody out at Waikerie a couple of years ago in a spin in on turning final in a glider.

 

The only small aircraft I know that trims the entire tail is Mooney. Even there the way stick position varies with trim will depend on the details of the linkage. I sure wouldn't design it so the stick could stay in the middle with the aircraft at the stall.

 

This only applies to simple aircraft. Aircraft with fly by wire can do just about anything and then there are aeronautical abortions like Airbus aircraft with their appalling un-ergonomic cockpit philosophy.

 

The bloke who used to be the RAAF chief test pilot during the 50's and 60's once told me that if the aircraft is trying to go in a different direction from what you are trying to command, it is trying to tell you something. Go with it.

 

 

Posted

People instinctively pull back on the stick when the nose drops. This instinct must be overcome or what is happening will keep on doing so. Not much different from picking up a dropped wing with aileron when you stall. You JUST shouldn't do it.

 

Once you are slow the whole thing changes. A lot of people are absolutely scared of flying slow. That's a good thing in a way, but you still need to be trained how to handle things when you do get slow due to unintended circumstances like encountering a rotor downwind of a ridge. or getting caught in clous and mucking it up. You can pretend the problem is not there if you fly carefully but that's not always going to be the case. Once you are in a spin there's going to be a substantial height loss even if you know what to do and in the circuit you just don't have that height to play with .

 

Few know how to recover from a spin so in that case, release the controls and some planes will come out by themselves, but you can't count on it and you still might muck it up recovering from the dive resulting. Airlines teach their pilots how to recover from upsets and deep stall/ spins if they are doing it properly.. but it takes 1000's of feet. Sometimes 12,000+. You need to know the difference between a spin and a spiral also Spirals kill people and the plane is not stalled in a spiral .. Nev

 

 

Posted

Stall stick position also depends on power setting and loading on the controls. I have previously posted data on stick position vs AoA for specific aircraft - one in which stick position would be particularly useless in indicating an approach to a stall - regardless, it is a sensible cue. Unless one has one of these new-fangled AoA indicators fitted but many don’t. Unfortunately many people don’t sense stick position, instead they are generally aware of stick force hence the choice of that link I recently posted.

 

 

Posted

'someone' noticed I was not co-ordinating my turns correctly - he showed me what happens (in a Drifter) when you wash off speed in an un-coordinated climbing turn (as you could do climbing away after a take-off)

 

the Drifter virtually flicked inverted and it took 700 feet for a full recovery - and then he said "now imagine what would happen if you did that at 500 feet in the circuit, David"

 

as an instructor he is a demon on airspeed and co-ordination in turns, which may be something to do with the fact that I'm still here.....which brings me to this:

 

did anyone else notice the article in the latest Sport Pilot magazine, where it was stated in an aircraft flight review: "The instrument panel is missing a balance ball so you can never be flying out of balance, or indeed in balance".

 

this is obviously a flippant comment, but I do wonder about the lack of balance information being communicated to the pilot

 

This was in relation to a pusher prop aircraft, so (as per on Drifters) the little piece of red wool taped to the bottom of the 'screen gives you all the info you need as far as 'balance' is concerned...

 

 

Posted
'someone' noticed I was not co-ordinating my turns correctly - he showed me what happens (in a Drifter) when you wash off speed in an un-coordinated climbing turn (as you could do climbing away after a take-off)the Drifter virtually flicked inverted and it took 700 feet for a full recovery - and then he said "now imagine what would happen if you did that at 500 feet in the circuit, David"

as an instructor he is a demon on airspeed and co-ordination in turns, which may be something to do with the fact that I'm still here.....which brings me to this:

 

did anyone else notice the article in the latest Sport Pilot magazine, where it was stated in an aircraft flight review: "The instrument panel is missing a balance ball so you can never be flying out of balance, or indeed in balance".

 

this is obviously a flippant comment, but I do wonder about the lack of balance information being communicated to the pilot

 

This was in relation to a pusher prop aircraft, so (as per on Drifters) the little piece of red wool taped to the bottom of the 'screen gives you all the info you need as far as 'balance' is concerned...

How do we ride bikes, fly no ball thruster's or ski without the aid of the ball ?

 

 

Posted

"............there are aeronautical abortions like Airbus aircraft with their appalling un-ergonomic cockpit philosophy.

 

Interesting analogy there seeing as Airbus are now the most popular Airframe especially in the single isle twin jet!

 

 

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