M61A1 Posted September 24, 2018 Posted September 24, 2018 Anyone want to speculate why you would have a slipping turn to the left with an excess of left rudder?
old man emu Posted September 24, 2018 Posted September 24, 2018 Dumb question perhaps but why do you need rudder trim in a twin engine aircraft? Not a dumb question. Apart from the same reason that there is a rudder trim on any aircraft to deal with rigging problems that could induce a yaw in cruise configuration, multi-engined aircraft have to deal with the problem of unequal power from engines to the left and right of the Centre of Mass. It is simply explained by considering the principle of levers - which you know from Weight & Balance calculations. If each engine is located 'r' metres from the Centre of Mass, and each engine produces 'F' Newton-metres of force, then the torque, 't' of each engine is: t = r x F as shown in this diagram: (ignore the L = r x p) If an aircraft has an engine on each side of the Centre of Mass, then, at equal power output, the torque on the left side equals the torque on the right side, and there is no force to produce a yaw in either direction. Rudder trim is set at "Centre". If one engine is a bit more worn than the other, it might produce a tad less power that the other. The two forces would be unbalanced, setting up a yaw about the Centre of Mass towards the lower powered engine. The rudder trim would be used to counter the yaw by setting the rudder to turn the aircraft towards the more powerful engine. This relieves the need for the pilot to hold in the rudder pedal, which is fatiguing for the pilot while cruising.The greater the difference in power output of the engines, one side or the other, the greater this torque effect. That is why a big part of converting from a single-engined aircraft to a multi-engined one is learning to respond to an engine loss of power on take-off. At this time, the engines are producing lots of power and there's not much airspeed or altitude. If an engine goes out, then the aircraft will quickly begin to yaw. If the yaw is not controlled, the wing on the side with the working engine will develop more lift, because the air flow is faster. This can induce a roll and put the aircraft on its back. Recovery from that attitude at low altitude would not be possible.
facthunter Posted September 24, 2018 Posted September 24, 2018 It's not only a multi engine aircraft. with engines offset. Single engined fighters (Piston) preset a lot of trim prior to commencing the take-off roll. If you set it the wrong way you may, (probably will) crash. as you will lose directional control.. Nev
turboplanner Posted September 24, 2018 Posted September 24, 2018 It's not only a multi engine aircraft. with engines offset. Single engined fighters (Piston) preset a lot of trim prior to commencing the take-off roll. If you set it the wrong way you may, (probably will) crash. as you will lose directional control.. Nev As a rich NZ gentleman did when he stepped out of one of his Spitfires with left prop rotation to the other which had right prop rotation; wrecked it!
old man emu Posted September 24, 2018 Posted September 24, 2018 It's not only a multi engine aircraft. with engines offset. Single engined fighters (Piston) preset a lot of trim prior to commencing the take-off roll. If you set it the wrong way you may, (probably will) crash. as you will lose directional control.. Nev I didn't mention high powered War Birds because not many of us get to fulfill our dreams.
turboplanner Posted September 24, 2018 Posted September 24, 2018 I didn't mention high powered War Birds because not many of us get to fulfill our dreams. Yet only yesterday someone wanted to lump all non-commercial aircraft in one basket - Corporate Jets to powered parachutes. What could possibly go wrong?
M61A1 Posted September 25, 2018 Posted September 25, 2018 Yet only yesterday someone wanted to lump all non-commercial aircraft in one basket - Corporate Jets to powered parachutes.What could possibly go wrong? The real question is “How good could this be?” Corporate jets aren’t recreational in any case.
turboplanner Posted September 25, 2018 Posted September 25, 2018 The real question is “How good could this be?”Corporate jets aren’t recreational in any case. Mine is. 1
turboplanner Posted September 25, 2018 Posted September 25, 2018 Yep, I don’t own a corporate jet. This thread really is about a fatality which ATSB has judged to be human factors. The consequences look as if they are going to be huge. How do we avoid missing pre-takeoff checks, removing gust locks, neutralising trim?
M61A1 Posted September 25, 2018 Posted September 25, 2018 Agreed...over 80% of all crashes in the western world are HF related, I don't know what the answer is, but tighter regulation and safety management systems don't seem to have changed outcomes much. Corporate jet is for business...Private jet maybe for recreation?
pmccarthy Posted September 27, 2018 Posted September 27, 2018 Who hasnt tried to start with the mixture pulled? And that is after saying the checklist out loud and even touching each control as you did it. The engine starts on primer, then stops. You sit there dumbfounded. I still don’t know what the human mind is doing when that happens.
Yenn Posted September 27, 2018 Posted September 27, 2018 I know, just gone to sleep. I am guilty and it took a long while to wake up.
JerzyGeorge Posted September 27, 2018 Posted September 27, 2018 It is hard to accept that very experienced pilot could not quickly identify problem with wrong trim and correct it in split second, Also trim could not be strong enough when adrenaline is pumping to negate rudder control ( in my opinion) But I do not know all the facts. Did he indicate over the radio the nature of the problem?
turboplanner Posted September 27, 2018 Posted September 27, 2018 Who hasnt tried to start with the mixture pulled? And that is after saying the checklist out loud and even touching each control as you did it. The engine starts on primer, then stops. You sit there dumbfounded. I still don’t know what the human mind is doing when that happens. In terms of hitting the target to prevent HF deaths the people who wrote the training hit outer space It is hard to accept that very experienced pilot could not quickly identify problem with wrong trim and correct it in split second,Also trim could not be strong enough when adrenaline is pumping to negate rudder control ( in my opinion) But I do not know all the facts. Did he indicate over the radio the nature of the problem? No, just several Maydays in a row.
facthunter Posted September 27, 2018 Posted September 27, 2018 I can't see they have much real evidence. the plane was extensively destroyed due the intense post impact fire. There's no CVR or other flight data. available. No witnesses with precise confirmation of many allegations of neglect.. The pilot cannot defend himself, being deceased and no images of the plane flying showing control surfaces positioning in flight etc Things are alleged in the absence of any other explanation as being likely but much of it's not what one would expect of a pilot who must have passed many checks involving engine out situations which are pretty extreme in nature and would show if the person being tested was not managing such situations well or competently on any of what must have been many occasions. Even though this wasn't an engine out situation the actions required and assessment of the physical forces acting on the plane are similar. We as pilots are often judgemental as a first assessment of other pilots when a catastrophe happens,. It happens time and time again. Why is this? Is it a defence of the concept that WE would not do such "wrong " actions, (in our own mind) to put blame so easily on others. Nev 3
pmccarthy Posted September 27, 2018 Posted September 27, 2018 There is no mention in the report of who flew the previous flight or whether they interviewed the passengers of that flight. Someone turned the trim knob.
Birdseye Posted September 27, 2018 Posted September 27, 2018 There is no mention in the report of who flew the previous flight or whether they interviewed the passengers of that flight. Someone turned the trim knob. Doesn't matter, somebody should have set it before take-off. 2
old man emu Posted September 27, 2018 Posted September 27, 2018 I still go back to my thought in Post #24 - Non-pilot smart-arse playing with the knobs and switches after pre-takeoff checks completed.
Birdseye Posted September 27, 2018 Posted September 27, 2018 A "thought", that is fanciful, unlikely and not based on any fact.
pmccarthy Posted September 28, 2018 Posted September 28, 2018 I have rudder trim in my aircraft and to be honest I never check it because I am the only pilot and I know where I left it set. I check the elevator trim of course. I will try to add the rudder trim to my pre takeoff checks but it will be hard to break old habits.
onetrack Posted September 28, 2018 Posted September 28, 2018 I find it rather abhorrent, and even borderline defamation, that anyone would suggest that any of the vital controls of this King Air, had been interfered with by a passenger. The simple reason being, the pax were of mature-age, and were highly responsible people, held in high regard over a long period of time in important commerce, legal, and law-enforcement positions. If the pax had been a bunch of football hooligans, or 16 yr old bogans who specialised in regular practical jokes, or juvenile pushing and shoving - perhaps a case could be made, for unauthorised aircraft control interference. But the pax weren't 16 yr olds, and they weren't drunken hooligans - they were people who were 100% responsible, and fully aware of the dangers of unauthorised skylarking with aircraft controls. The bottom line is, the facts speak for themselves. 90% of aircraft crashes are simply caused by serious pilot error. So there's a 9 out of 10 chance this crash was pilot error. The investigators are experienced, and there are numbers of them. The final report is a collection of pre-crash and post-crash information, gathered by numerous people, and distilled. The pilot took off overloaded. He failed to switch on the CVR. He did not have appropriate flight checks in place. He made a major error in setting trim. He had 5 chances to correct it, and failed to do so. The aircraft was seen to yaw noticeably left with substantial sideslip, and failed to gain rapid height, with an adequate climb rate. Each one of these events viewed in isolation, is not necessarily a reason to crash - but combined they did - and more importantly, the combined events show a pilot with serious deficiencies in his aircraft-handling ability. The pilot was 67 yrs old, and operating a high performance twin turboprop as a single-pilot operation, as well as running an air charter business. Regardless of how good you think you are - serious, but transient memory failure with advancing age, is a common event, starting in your early 60's for many people. Failure to assess ones deteriorating skills with advancing age, and failing to ensure you have important check lists at hand, to counter your declining memory skills, is something that a high-performance twin will not easily forgive. 5
turboplanner Posted September 28, 2018 Posted September 28, 2018 I don’t think anyone is doing that. For ATSB to have said what they said there will be evidence. I had a ute which burnt I have rudder trim in my aircraft and to be honest I never check it because I am the only pilot and I know where I left it set. I check the elevator trim of course. I will try to add the rudder trim to my pre takeoff checks but it will be hard to break old habits. potentially fatal action. A farmer jumped in his Cessna which rolled over after take off, killing him. A bull had scratched an itch during the lunch break. You just never know whether the aircraft has been bumped, a kid has climbed in etc. 2
facthunter Posted September 28, 2018 Posted September 28, 2018 That's why a walk around is so universally required. Controls must be free and operate in the correct sense. TRIM is 3rd on my generic checklist and I NEVER take of without some form of check that's adequate for the circumstances and the aircraft. A lot of people have commented on the things I find wrong with a plane on preflight . I don't make the faults. I find them. Best place for that is on the ground. That plane could have suffered some unknown damage/ to that trim system and so many assumptions are being made to arrive at the conclusion which is FAR from being an absolute finding with a high degree of verifiability. Easy to blame a dead pilot. Nev. 1
old man emu Posted September 28, 2018 Posted September 28, 2018 A "thought", that is fanciful, unlikely and not based on any fact. Of course, a simple way to dismiss that idea would be to indicate passenger seating positions. If no passengers was seated in the right hand seat, then I accept that the thought can be shown to be incorrect. onetrack, It's not OK to defame a passenger, but without undeniable proof it is OK to defame the pilot? You have to agree that the investigation of the pre-impact behaviour of the aircraft, and the post-impact inspection of its systems leads to a high possibility of pilot error, but is not absolutely conclusive. 1
GraemeK Posted September 28, 2018 Posted September 28, 2018 RH seat was unoccupied: The occupant seating positions were established from information provided by Victoria Police. This information indicated the front right or co-pilot seating position was unoccupied.
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