Have another read of what I wrote, junior, and maybe look at the context in which it was written.

Is checking flight controls for 'full and free movement' not a legal pilot pre-flight responsibility? Buried somewhere in the CAR or CAO or Act of every jurisdiction I ever flew in, this one is up there with ensuring instruments work etc.
Are trims not 'flight controls' , albeit classified as secondary on some types?
In any case every checklist ever written says to check them. Where the FCOM is not specific, 'check' may be open to interpretation, but the word check implies more than a cursory glance. Depends on how one was trained in these matters, I suppose.
Of course it is impractical to check every single item, so much of our trust is with the maintenance people. But flight controls are in the 'easily checked' category, so why wouldn't you?. A whole lot more useful than flicking on landing lights to 'check' them, only to bring them one cycle closer to failure. Yet some pilots are absolutely diligent about this exercise in irrelevance, but can't take a minute to run the trims once a day?
But we are digressing from what we believe could have caused this crash. I certainly subscribe to the mis-set rudder trim theory. Whether or not it was properly checked pre-flight can never be known. Because of its mechanical design the trim wheel is highly unlikely to have moved full scale during the crash, so someone put it there. But all this has already been said.

As drivers you place faith in the system, and that it works as it should.

Had to winch a pilot and his pax out of the water after a ditching because of vibrations (helo). Turned out a component in the rotor head, which had been installed as a new item, obtained from the manufactures distribution centre, was actually time expired and should have been scrapped, but somehow made its way back into the supply chain.

Called early one morning to do a medevac in a helo. The routine was that the aircraft had been pre flighted, prepped etc the previous day, so all the responding crew had to do was pull the bungs, a quick walk around, and get the show on the road. In flight the aircraft had a bit of a vibe and was written up on return. Engineering inspection found that bearings had not been installed on any of the rotor blades. The only way that that was evident was a black powder emanating from where the bearings should have been, the black powder being the result of flying/operating. Without the black powder as a clue you would have had no idea the bearings were missing. So many questions to be asked, duplicate inspections on build up of the rotor head, vibrations during the blade tracking and test flight, pre flight during the prep for the medevac duty - was powder evident? Don't know any of the answers found. And it was not a shoddy organisation when it came to maintenance, quite the reverse in fact, but it highlights how fallible we humans are, or can be.

"Full free and correct" while helpful is not a guarantee of a controllable aircraft. Same with the external pre-flight inspection.

For the most part, the only time trims are moved all the way to the stops are for such checks.

If, a slipping grub screw or broken cable prevents the return of said tab to the desired setting the crew is unlikely to be any the wiser, given the control position in the cockpit will appear normal.

The only time the trims are moved all the way to the stops in any aeroplane I fly is every first flight of the day. By doing that, one gets a feel for the system and hopefully would notice a change of friction associated with slipping grub screws, broken cables etc. On the walkaround I grab hold of the tabs that I can reach and give them a bit of a waggle to feel for too much play in the actuaters while noting their position relative to the controls in the cockpit. Am I so diligent on every flight? Yep, but I make no claim to being perfect. Other stuff I do gloss over if I perceive it as not likely to kill me..
But, that's just one old man's opinion and practice.

Agreed and perfectly reasonable.

Megan,

What does the B200 AFM say regarding preflight checks/inspection of trim tabs?

Edited to add:

We know what the checklists say. Just interested in what it says for the "walkaround" phase.

As follows FGD

Cockpit/Cabin check - Trim Tabs SET TO "0" UNITS - Caution - The elevator trim system must not be forced past the limits which are indicated on the elevator trim indicator scale, either manually, electrically, or by action of the autopilot.

Left Wing & Nacelle - Aileron and Tab - CHECK

Right Wing & Nacelle - Aileron and Bendable Tab - CHECK

Tail - Rudder, Rudder Tab, Stinger and Static Wicks (4) CHECK

Tail - Elevator, Tab, and Static Wicks (3 each side) CHECK, Verify Tabs are in "0" (Neutral) Position. NOTE - The elevator trim tab "0" (neutral) position is determined by observing that the trailing edge of the elevator trim tab aligns with the trailing edge of the elevator when the elevator is resting against the down stops.

Thanks, Megan.

And does it say the cockpit/cabin check must be done before the external walk-around?

Yes, the list above is in order of execution.

So apparently the PIC did neither the cockpit/cabin check nor the external walk around check, at least not in relation to the rudder trim.

Still no explanation as to how the rudder trim apparently came to be set full NL before the flight. And the performance airborne with two engines producing full power was really poor - puzzling so - even assuming the rudder was trimmed full NL.

Incredible. Really incredible.

A little bit of context. It's a very large trim. You'd think it would be hard to miss it. I also note what may be a slight off-set of the rudder to the right, despite the controls appearing to be in a neutral position.


https://cimg6.ibsrv.net/gimg/pprune....798bdda263.jpg
https://cimg0.ibsrv.net/gimg/pprune....1ffdb5fbc9.jpg
Sincerest apologies if I have the wrong model.

The report notes that the pilot is seen doing a walk around on CCTV.

The big unanswered question is, assuming the trim was left full left for the take-off, could the pilot counteract it?

The report has not tested this.

They put a guy in a SIM, but he did not fly the accident profile. The SIM flew up to (or slightly over) 140 knots, but the accident aircraft did not get above about 112 knots airspeed (report lists groundspeed).. If the trim condition was the cause of the accident and the SIM flew the accident profile, then the SIM should have a) not got above 112 knots and b) crashed.

The other alternative would be to do what the ATSB did in the last trim related fatal accident at Essendon - the Partenavia. in 1978. In this instance the ATSB flew a real aeroplane in a disciplined test manner and recorded the force required to counteract the elevator trim at different trim settings and airspeed. The results table was part of the report. I would think that a diligent report would have followed the same methodology the ATSB used in the past.

As a result of the Partenavia accident an AD was issued soon after that changed the elevator trim limits. If the out of position rudder trim is so catastrophic and there is a history of other incidents, you would think that some review of the B200 rudder trim might be warranted and mooted in the report.

Old Akro, you are making the assumption that the sim is a 100% faithful replication of the real aircraft. Myself and several other posters have already pointed out to you that no simulator, of any aircraft, is that accurate - especially when flight "outside the envelope" is involved.

I suspect that, due to the large sideslip angle, the fin would have been fully stalled - thus putting the aircraft outside the envelope.

And you're also not allowing for possible differences in the physical performance of the sim pilot vs the real pilot. This has also been pointed out to you.

I suspect that ATSB policy may not permit them to take a real aircraft outside the envelope. To have done testing with less than full NL trim may not have had sufficient validity - particularly whilst the fin remained unstalled.

Firstly, FGD. I disagree strongly with you, but do respect that you apply intellect & logic.

But, a) simulators are commonly used to reconstruct accident scenarios. Its clear that the ATSB didn't do this. and b) we don't know what they did because they haven't provided any details in the report (unlike for example the Partenavia report). But the SIM flying they did and the conclusions they reached are from airspeeds outside that flown by the accident aircraft and therefore, invalid.

You don't need to fly "outside the envelope" to test a hypothesis and I think the 1978 Partenavia report demonstrates this nicely. in this instance, the ATSB took a real aeroplane that was identical to the crashed one and had a pilot experienced on type fly it. The pilot flew a predetermined flight test that consisted of flying a range of different airspeeds at each of the marked trim settings. The control forces were measured at each airspeed / trim combination. When the pilot approached the limit of comfort of control-ability of the aircraft, he stopped and didn't proceed to the next trim setting / airspeed.

If this testing was possible and warranted for the last trim related fatality, why wouldn't it be now?

A 1 hour flight, 2 brake pedal force transducers, a motec logger and this topic would have been nailed and if it was the smoking gun would have obviated the need for the whole sideslip calculation mess.

The ATSB has not provided any firm evidence either in terms of statements from the manufacturer, interviews with other B200 pilots or flight test data to support its assertion that the aircraft was not controllable with full left rudder trim. If full left rudder trim can be counteracted by foot application of right rudder, then there is another factor at play (which may better fit the long take-off run which the ATSB has conveniently glossed over).

The B200 aircraft certification requires that the pilot is able to counteract full elevator trim. There is no similar requirement for rudder trim, although someone pointed to another requirement that infers this. I would question whether full rudder trim leading to loss of control of the aircraft was diligent "fail safe" deign.

The whole premise of the report is therefore based upon speculation.

From a 2002 edition of Design Standards for Licensed Aerodromes. Who knows what the standards were when Essendon was built. Standards current at the time of construction are grandfathered into the MOS (subject to some conditions)
No need for a safety case, just provide what you can to at least the minimum standard, and adjust your landing minimums.
CASA threw all the safety case stuff in later when they hardened up the language to "must" and "shall". The interesting part is why CASA said to put 300m in the docs, when it probably never had been.

As someone who works in this field (in another country), I find this truly incredible. Words fail me.....

Does anyone else hear what appears to be the sound of Lawyers sharpening their knives?:eek::uhoh:

Pinky asked does anyone else hear what appears to be the sound of lawyers sharpening their knives?

There's absolutely no 'appears' about it at all Pinky :ooh:

See:

https://www.theage.com.au/national/v...23-p50t3z.html

which refers back to:

https://www.theage.com.au/national/v...24-p505n0.html

It's going to get VERY VERY ugly (and VERY VERY expensive) I think.

Never really occurred to me that these shops thrived to the point of making more room for them. Actually I would have been tempted to ask: just who wants to do their shopping there anyway?

Problem is, there are medium sized business jets operating in and out of there every day. Eventually there will just be a 25 metre diameter helipad, the way they are going.

Remember the lessors of YMEN are in it for money, not cause they love planes! There's money in everything bar aviation! The only thing that's stopping YMEN from closing as a drome completely is the EMS facility. take that away & you can kiss YMEN goodbye!

machtuk,
Not so, there would need to be a very major, indeed fundamental change to the terms and conditions of the head lease. That change would also fly in the face of the current Commonwealth Government airport policy. And, for that matter Cth Labor policy.

More importantly, given the relative political weights of Lindsay Fox, versus those whose aircraft (the bigger ones, not flying schools etc.) use YMEN, the political likelihood of that lease amendment happening is remote ---- and the newspaper talk about how the airport was expected to be closed to aviation once it was leased is plain nonsense. An additional factor is that the Commonwealth Government will not do anything that assist the ambitions of the ratbag left, both within and surrounding the Andrews state government, to close YMEN.

Whether some like it or not, YMEN is quite an important cog in the Victorian industrial and business machine.
Tootle pip!!

King Air Down At Essendon
 

Leadsled,
A timely reminder of Essendon's status. From memory the lease was signed in 2001 for 99 years with a condition that it continue as an operational airport for a minimum of 45 years with no reduction in capability.
That takes it through until 2046 or thereabouts - allowing for Government changes.
The place houses about a third of the corporate jets in Australia with at least half a dozen Global Express, a G450, a gaggle of CL604 and various other medium cabin jets.

https://cimg1.ibsrv.net/gimg/pprune....ea6fa5063f.gif

What exactly does this have to do with the tread topic? Surely a new thread would have been much more appropriate. I saw there was a new post and clicked to read about the King Air accident. I didn't come back in here to read about the politics of an airport.

Why would that be? Is there no checklist item calling up "Trims - Set for Takeoff" or something similar?

How do you know that accident was caused by the trim, Lead Balloon?

It may have been one of the other King Air vices (e.g "power lever migration").