It was moved there by some sort of force. Check your killer items.

B200 is certified under FAR23 in the normal category. It doesn’t require all the bells and whistles that a FAR 25 aircraft does.
Killer items check-great idea. Dassault have a FATS check in all their aircraft. Done in the line ups- Correct Flaps selected and set, Air brakes retracted, Trims set, Speeds set

Unless there is a cockpit video recorder on board you will never be able to determine the how. All you have available to you is the reasonable assumption.

Out of curiosity, have any Kingairs had an accident with full right trim? Could it be trim position markings as mentioned by Al Fentanyl? Can any other contributors say they have taxied out with full trim only to pick it up at tcasblue’s “killer items” check?
Plenty of aircraft including multi-crew RPT have crashed from incorrectly set items.

There was a fatal C310 accident out of Tamworth in 2005 due to a rudder trim misset. Aircraft had come out of the hangar and the pilot was in a hurry.

Familiar with an A36 that attempted take off with trim set full nose down, managed to rotate with an immediate return to earth resulting in mucho damage. Came out of maintenance and individual in a rush to get home before last light.

How did it get to full right trim in the first place?

... and that is the multi-million dollar question.

As noted above, some kind of force moved it... presumably of the human kind.

Does not matter at all how in the first place the trim was placed in this position.
At the end of the day the PIC has to take full responsibility. The end.
The evidence clearly shows that the trim jacks position. It should be noted that in this this position it can not be put in this position due the accident.

Conned.

Can you post a copy of or link to the IPB/maintenance manual pages that show all of the components and physical layout of the rudder trim system?

Quote:

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Could it be trim position markings as mentioned by Al Fentanyl?

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A strong possibility indeed. Back in 1985, the RAAF had an incident in a Viscount of No 34 (Special Transport) Squadron during a training touch and go at Canberra. The pilot undergoing a type rating was making a practice three engine landing with the "dead" engine set at zero thrust. The rudder trim knob on the Viscount was (I think) similar to the King Air. That is, a round knob with the number of units of trim displayed up to the maximum of eleven units either side

In the Viscount, each rudder trim number had a a vertical indice of the same size next to it. For example, the trim reading could show number 9 but the small indice immediately adjacent to that number could make it look like 19.
Before final approach, the PF was briefed for an intended all engines touch and go. This included the PF would not select ground fine but keep all four throttles against the idle stops like any other landing until the instructor had centralised the rudder trim, reset the elevator trim for takeoff and retracted the flaps to the takeoff position. Those actions completed (about ten seconds max), the instructor would tell the PF to apply takeoff power on all engines and complete the takeoff normally.

Initially, everything went as briefed - or so the instructor thought; including the rudder trim being wound rapidly back to neutral. Shortly after liftoff on all engines, the PF muttered something about the rudder trim. The instructor looked down at the pedestal where the rudder trim in the Viscount was situated, and was startled to see he had inadvertently wound the knob to ten units instead of zero units. The problem being the indice and the number zero looked like zero units. However, because the instructor was looking down and to his left at a slight angle to see the rudder trim knob which he had intended to be neutral rudder trim, it had been inadvertently set to 10 units. This may sound confusing to the reader and perhaps a photo of the Viscount rudder trim knob should have been included. The whole point of this post was to show how markings of the various units of rudder trim on the Viscount and possibly the Kingair, could easily cause momentary confusion.

The lesson learned from that incident was it was not good airmanship to complicate things by turning a practice asymmetric landing (albeit using zero thrust on the "dead" engine) into an all engines touch and go. Put bluntly, the instructor was over-confident in his own ability to handle a busy situation. The instructor is busy enough as it is. He is not only watching the landing but has the extra work involved in looking down at the pedestal in order to reset flaps, plus re-setting rudder and elevator trims while at the same time relying on the PF to keep straight down the runway centre-line and lift off at the correct speed.

One can readily understand how a quick downward glance at the rudder trim setting in a King Air may not be enough to ensure it is in the correct position for the task at hand. In the case of the Viscount incident, the writer pleads guilty as charged Your Honour..

Has it been discounted that the trim was moved to that position during the flight? With a disking prop on one side that could have easily been the case. Its the most common killer in the King Air.

We had an LAME who would move ALL the trims to full deflection.
Asked about it one day after I found all the trims at full deflection following maintenance, his reply was that it was my job as a pilot to check the trims.
Stupid.

It used to be a common defect in the Duchess. The pilot would check full and free movement and in correct sense of rudder, ailerons and elevator as part of the pretakeoff check. As full aileron was being applied the aileron (?) trim would move in sympathy and stay in its last position when the control wheel was centralised. As one LAME told me when I wrote it up in the MR "Don't worry about it, it happems all the time and not worth writing it up in the MR".

. There are cowboy LAME's in the game as well as cowboy pilots.

Regards the Tamworth C310R I think you will find it was elevator trim and there was a screwdriver found in the wreckage located in the tail section.
Groggy

I will repeat my prior assertion that the rudder trim was displaced during the accident breakup sequence. Let me ask you all to consider the significant climb rate of a King Air with two engines operating and the gear remaining down. Now you have that picture in your head consider the photographic evidence showing the actual, much reduced, climb rate of the accident aircraft. There is no doubt in my mind that this was power lever migration and unfortunately it wasn't recognised by the pilot flying. It is a travesty that the ATSB have missed a golden opportunity to educate the King Air pilot community to a latent killer.

Groggy

please tell me how the trim was extended during the accident ?

the rudder trim control surface was still attached to the Trim actulator.

trim required rotary motion to turn into linear. Linear cannot be turned into rotational see above statement.

accident site shows zero reason that any other force can move the trim position

im lead to believe that the forward trim position wheel was in the position of the trim surface position.

there is no electrical motors attached to this trim system so no way for any trim runaway.

any break in the trim cable renders the system inoperative

hence at the accident site the rudder trim was in this position.

so please explain again how it is possible that the trim was in the position and cause by the accident.

most likely he hasn’t set the power lever friction was not set and it experienced roll back he thought he lost an engine place the trim into this position. Also I dare say he had the rudder boost selection to the off position.
if you could hold the rudder without rudder boost it would not be installed in the aircraft.

The trim assembly is of the jack-screw type. It can’t skip 43mm to full nose deflection to the left during an accident, as it has to be screwed over to that point. The take-off sequence indicated a condition that could have been a result of significant trim input and the post crash evidence found full deflection commensurate with this.

Ok I will bite. The trim system is cable operated. During the breakup the right trim cable is severed. The left trim cable remains attached but stretched tight by the breakup sequence imitating that there is left trim required thus rotating the left trim actuator to its maximum before it to severs. This action would have turned the cockpit knob full left and caused full left rudder in an instant. Much like when a marlin hits the bait on a fishing rod and you see the reel spinning at great speed against the clutch brake. Another way to visualise this is to imagine you could insert your hand into the aircraft fuselage at mid point and grab the left trim cable at mid point between the cockpit and the tail and give it a massive tug. The result would be the same.

I have personally experienced PLM in a King Air and I have seen it happen to other pilots. I have also simulated the Essendon scenario in the simulator and even though I knew what was coming ended up over the top of the same building. The ATSB have made a massive mistake which in their defence I can understand because they don't have experience on the type. I stick to my comments in my previous post.

Groggy

Conned.

Can you post a copy of or link to the IPB/maintenance manual pages that show all of the components and physical layout of the rudder trim system?

Look for the most simple possibility. Say for some reason the Kingair rudder trim was offset before the pilot entered the aircraft. Accept that why it was offset is not determined. I haven't flown a King Air but would an offset rudder trim show up while taxiing? In other words is there a nose wheel steering connection like a 737?

A 737-400 crashed during a botched abort in USA and the rudder trim (electrically operated from the cockpit) was found to be full scale one side. The captain was taxiing but the F/O was doing the takeoff and soon discovered the aircraft was pulling to one side during the early part of the takeoff roll so he applied corrective rudder but to no effect. The captain took over and delayed aborting initially. When he finally aborted his procedure was incorrect and the aircraft went off the end into a river.

The point here was with the 737 the fully offset rudder trim causes the rudder pedal to move by about three inches. This because there is limited nosewheel steering availibility with the rudders. The pull to one side taxiing is immediately noticeable. To correct for this, the captain uses his nosewheel steering wheel to keep the aircraft straight while taxiing. In other words similar to crossed controls.

In the case of the 737 accident there was CVR evidence the captain did not mention to the F/O there was something strange happening that required the captain to use excessive nose wheel steering to keep the aircraft tracking straight while taxiing.

Unless the F/O just happened to be keeping his own feet on the rudder pedals while the captain was taxiing (very unlikely) he would not have seen the split rudder pedal position on his side since it would have been only a couple of inches difference.
Once lined up for takeoff and when the captain handed over control to the F/O for take off, the aircraft would have tended initially to pull to one side which the F/O would have corrected for by rudder.

As the aircraft picked up speed during the takeoff roll it gets more difficult to keep straight. When the captain in the 737 realised the F/O was having a problem with directional control and took over control the aircraft was well off the centreline.

So that was what happened to the 737 according to the NTSB accident report. We replicated that in the simulator. As mentioned earlier I have not flown a Kingair so know nothing about its taxiing characteristics with its rudder trim fully offset. But if its rudder pedal steering system is tied into the rudder trim system, then this would have been obvious when taxiing as it was in the 737. That being so it would have been unwise to takeoff.

Centaurus,

There is no interconnection between rudder trim setting and nose wheel on a King Air. There is a connection between rudder pedal and nose wheel which you would expect. It is my belief that you could input sufficient force to overcome fully deflected rudder trim during the take-off roll and the initial climb long enough to recognise and correct. That is if there was no other contributing factor like an engine failure. The point I have been trying to make all along is that regardless of the trim setting the aircraft would have climbed like a homesick angel, even with the gear still extended, while both engines operated normally. The accident aircraft didn't perform just as it does not when one engine rolls back with PLM. The other point I should make is when the power lever migrates rearward it doesn't go back to flight idle but to a point where its still producing about 600 ft lbs of torque however the prop will disc up and cause significant drag along with associated performance reduction normally resulting in about a 300-500 ft/min descent rate with gear extended.

Groggy

B200 MM Trim schematic
 

For the people who requested a drawing here it is.

Thanks grogmonster.

Pending ‘approval’ of your attachment, I anticipate that it will show that the breakage of one cable in the rudder trim system with simultaneous tension put on another in that system will drive the rudder trim in one direction. I wish others luck in telling us what actually happens to those cables during a crash event.

Even so....

It remains odd that PLM would account for all of the ‘veer left then prang’ incidents, unless:

(1) it’s just the product of random chance (eventually there’ll be a bunch of ‘veer right then prang’ incidents due PLM (or the rudder trim being inadvertently being set, unnoticed, at full right); or

(2) there’s a design characteristic that means PLM usually only results in the left power lever migrating.

Any thoughts on #2?

shorter cable run run to the left engine, less internal friction on the cable, than compared to right.
thats was a lot of people in the king air community believe.

While I would not totally discount the power lever migration theory, I find it hard to believe experienced pilots would get sucked in by it. Most light aircraft drivers keep one hand on the throttles during takeoff and initial climb, only momentarily removing the hand long enough to retract the gear. The hand goes back on the levers until flap retraction and other non essential activities such as switching off lights. Initiating gear retraction would take 3 seconds at the most - hardly enough time for the power to go right back to negative thrust, and even if it did it would be naturally corrected.
A pilot with an airline background could be in the habit of removing hand from levers at V1, but a pilot with that discipline would probably retract the gear then go back immediately to the power levers if something did not feel right. I don’t think this pilot had any airline training, so would expect he would have kept his hand on the throttles throughout takeoff and rotation.
Either way, I would think it instinctive to push both levers forward if performance was being degraded. Auto feather would take care of a major power loss, but only if the system was armed. If the system was not armed, control with total loss of power close to V1 is very difficult, in fact probably beyond the capability of pilots who have not practiced it in the simulator. We do know that this pilot was not a believer in regular simulator.
The pilot was in a state of panic - that’s really as much as we know. But whether brought on by a medical episode or not is unlikely to ever be discoverable, due to the fireball.

As Centauras says, look for something simple.

Somehow before the flight the trim was moved to full deflection, during maintenance or preflight or kids in the cockpit or otherwise.

Pilot misses this due to interrupted pre-flight (as per video evidence) or lack of checklist (anecdotal evidence of this) or otherwise.

Power is applied, takeoff roll, control problems start, boost is off, pilot has never seen this before and the rest is history.

It’s a simple scenario that doesn’t require a complex sequence of events to transpire in order to explain, such as one specific trim cable breaking in the crash and then another being stretched or pulled straight after and the rudder trim being moved.

I can’t help but feel that a cable with a jack screw would need a firm and consistent pull to rotate the thread, possibly requiring both cables to activate, rather than a short sharp pull on a single cable, as the impact forces pulled on it abruptly. (Awaiting attachment approval above).

For a rollback scenario or friction issue, you’ve got too many things that add up to get to that end result, such as an engine failure / power loss AND the trim cable scenario has occurred? Plausible maybe, but unlikely... yes.
In option 1 above, only one thing has happened to cause the end result, not multiple things, working backwards from the end result.

Imagine the friction is not set properly before takeoff..

roll down the runway, airborne, hand off lever to raise the gear... and this happens.

hardly enough time for the lever to go back?



now imagine that you grab the control wheel with that hand you took off the power lever to raise the gear, rather than putting it back on the power levers... because all of a sudden you have a large yaw that requires control input to help manage...
and some panic thinking “engine failure”...

not such an implausible theory as S7700 might imply.


once again, I’m not saying this was the cause of this accident.
its hard to investigate and prove as being the cause; look up the report for VP-BBK, that’s got a good write up on this scenario.

It’s plausible, but doesn’t explain why the trim was all the way to the left. Sometimes the most obvious answer is staring you in the face.

Once the diagram is available, you’ll likely see that both cables are required to turn the jack-screw and will be able to discount that happening afterwards. It must require two cables as Conned has suggested, as otherwise if a cable broke in flight and you were turning the trim, you wouldn’t be able to turn it back again.

Out of those posting, who's actually flown the scenarios in the Sim? So far as I can tell, grogmonster is the only one.

The report states that the trim was to the left at initial impact due to witness marks on the trim tab. That sounds quite definitive and goes to the extent of discussing the abrasive surface that it came in contact with.

It feels like a long bow to draw to suggest that the cable pulled full left trim during the impact sequence as you’d have to think that it would be tearing out of the trim actuator so damn fast it would likely jam up or go past the stop or at least bend something in the process.

Remember that the report says that they started looking at the trim mechanism because a witness saw the aircraft yawing significantly to the left.

I'll take that as a 'no' from you, S7700.

Im only talking about the power lever moving, in generic terms, not in any specific relation to this event and the trim position.

however, if we want to get into combinations, another plausible scenario is, IF he did have the power lever drop back, did he incorrectly wind the rudder trim the wrong way in the heat of the moment?
We will never know. But it’s not an impossible scenario that the trim gets wound the wrong way.

i would have liked the power lever issue to be investigated/reported more, but without a working CVR from the accident flight a spectral analysis cannot be done to find out (unlike the VP-BBK crash).


LB, unfortunately I don’t get to have fun in the king air any more, so I’ve not been able to access a sim or aircraft to look at things.
however, I have personally experienced the left power come back whilst sitting in both seats.
As Mach has mentioned, shouldn’t be an issue (and it wasn’t) because if you put your hand straight back into the power levers, you’ll sort it out quick smart.

Clearly you know or are fairly sure I haven’t and I’m presuming you haven’t either, but that doesn’t mean I can’t engage in the conversation by analysing the information available, particularly around human behaviour.

Aircraft haven’t changed much in many years. They still have 3 axis, two or four wings generally, including a rudder, elevator, ailerons and an engine or two, three or four.

Human behaviour on the other hand does change, through training, procedures, SOP’s, competency, awareness, tiredness, health and other factors, which are never consistent.

Start looking at the end result here and regardless of what caused it, what would have been done to avoid it. If it was a rollback, what can be learnt from it? If it was engine related, it doesn’t change the outcome other than a witch-hunt to the manufacturer or maintenance organisation, but what does matter is how the event is handled.

The friction would have to be very loose for the lever to run back as quickly as it did in the video. Also the horn would be hard to ignore. Not saying impossible, merely improbable given the crash evidence of the mis set trim. In the very short time he was airborne it is doubtful that full rudder trim could have been wound on - it is fairly slow. Again, not impossible but I believe improbable given that he was yelling out "Mayday" repeatedly at the same time.
I have flown several scenarios in the King Air sim on more than one occasion, including power lever cut back at rotate, engine failure with no auto-feather, FCU over-torque, rudder boost switched off with engine failure, and spurious rudder boost. Knowing what was coming, all were flyable, though the engine failure with no auto-feather took some practice to make it climb. None of the events caused loss of directional control and none required both hands on the control wheel.
I don't recall trying the full rudder trim scenario (but may have; simply don't remember?), but those who have report it gets very ugly as speed increases toward 'blue line'.
However, the old King Air simulator in Melbourne is only a level B, so the fidelity may not be a true reflection of how the real aeroplane would handle in those various situations.
Those who have flown the level D simulator may be able to offer more comment.

Believe it or not, but the difference between the lever staying put, and the lever dropping back, can be about as much as half a turn. It is a little “aircraft dependant” depending on age, wear and tear (some people damage them by cranking them on way too tight for example) etc- having flown several they are all a little different, in my experience.


as for the gear horn, you won’t get it with one lever back and the gear still down, as in the accident case gear was down, the video I posted gear was up.

speed of trim? I could spin it to one side pretty quick, probably from neutral to full one side in 1-2 seconds without difficulty, but that’s me. Not a normal rate of using it though, mind you, but if I had to I could that quick.

I genuinely don't want to offend or get personal, S7700, but do really mean what you said?How do you come up with sensible ideas to avoid an end result, if you don't know the cause/s of the end result? It seems to me that that which should be done to avoid the risks arising from e.g. an unnoticed rudder trimmed to FSD is not the same as that which should be done to avoid the risks arising from e.g. unnoticed power level migration. And if there was a failure which no competent pilot could adequately overcome to save the aircraft, what then?

I'd suggest something different than if it was unnoticed rudder trim at FSD on take off. The first question that would arise is: What causes PLM in this type of aircraft? Should it happen in the first place?

There's a difference between a system design flaw or defect and the proper avoidance response to that problem, on the one hand, and a pilot's failure to use the system properly to prevent or reverse the migration, and the proper avoidance response to that problem, on the other.

On my interpretation of what grogmonster has posted, unnoticed PLM on this aircraft type is a far more dangerous situation than unnoticed rudder trim at FSD, with the former rather than the latter more likely to have resulted in the aircraft ending up where it did.Goodo, then. ATSB, CASA and us 'Monday morning quarterbacks' can confine our witch-hunts to pilots.

One wonders why they bothered grounding the Max 8s. Any competent pilot should easily be able to handle the consequences of MCAS activation on erroneous input from an AOA sensor.

I would have said spot on, however the Max8 contained software driven systems that Boeing themselves didn’t fully understand. They were coded by a guy in a Delhi software development company.

To answer your question above.. practice, but without significant investment, how does a one-man operation achieve task?

It’s not much different to someone that learns to fly in a C150, then flys a 172 for years, then his business does well and he buys a turbine Mirage to fly his staff around.

Good point. But if the gear was not selected up, it is even less likely that his hand would have been off the power levers, no? Of all the speculative causes, only one thing is certain - rudder trim was found fully displaced to the left and the aircraft went left as soon as it lifted off. So, it's also unlikely the pilot was busy winding trim on while barrelling down the runway. But possible...I suppose.

the theory behind when the migration occurs is just after liftoff, positive rate, gear up... when the hand comes off to grab the gear, the migration occurs.

Hand comes off to grab the gear, migration occurs, yaw happens, possibly think “holy **** engine failure” and grab the control column with that hand. Gear hasn’t actually been selected up because you got distracted by the yaw and grabbed the column.
Now, the proper response is to get your hands back to the power levers and realise that one has migrated. but if you don’t, your now left in a potentially ugly situation.


some places still try to tell king air drivers at what is effectively V1 to take their hand off the levers.
there is NO need for that.