The nice folks at Flight Safety seem to believe that PLM does not exist. I'm not sure why.

Or...

Left hand on the yoke, right on the throttles.
Rotate.
Positive rate - gear up!
The right hand leaves the throttles and moves towards the gear lever, but the rollback is quick with simultaneous yaw and the right hand never reaches the gear.

Sorry for your loss of a good friend.

What in particular did you see as being different or disqualifying as to not being within the profile of a typical PLM accident? I think it checked all of the boxes except maybe the pilot being thoroughly familiar with the potential hazard.[/quote]

Part of it is that Ron knew to check, especially coming out of maintenance. The main thing is the airplane pitched up and came back down, instead of turning left and rolling over.

I also have one bit of insight that I can not share publicly, I'll just say that I am not the only one that suspects it was something else.[/quote]

Here is the final report and some excerpts

It did turn left and eventually rolled over in a similar manner as other PLM suspected crashes. The potential health issue was covered in the report. I don’t think it was a factor.

I think that it supports a strong likelihood of a PLM occurrence. Like I have said before I would not put much merit on post crash trim tab and tab control positions. The cables get tugged differentially when an aircraft essentially cartwheels and breaks apart. I don’t buy the tab positions as evidence that he didn’t use a checklist.

https://asn.flightsafety.org/asndb/319129

Narrative:
A Beechcraft 200 Super King Air, was destroyed following a takeoff accident at Chicago/Rockford International Airport (KRFD), Chicago/Rockford, Illinois.

The purpose of the flight was to relocatr the airplane to the pilot's home base near Wayne, Illinois. The airplane was at a repair station at Rockford Airport for maintenance work. Shortly after liftoff from runway 19, the airplane started turning left, and the airplane developed a large left bank angle as it was turning. The airplane departed the runway to the left and impacted the ground. During the impact sequence, an explosion occurred, and there was a postimpact fire.
An NTSB airplane performance study showed that during the takeoff, a nose-left sideslip, a left side force, and a left roll occurred, consistent with the loss or reduction in thrust of the left engine.
The sideslip was reduced, likely due to inputting rudder to balance the side force, and the airplane briefly rolled right possibly due to an overcorrection in rudder. The airplane pitched up and was able to begin climbing again; however, it continued to lose speed. The sideslip then reversed, and the airplane rolled left again before impacting the ground. The study indicated
that before rotating and lifting off, the airplane accelerated to a groundspeed of 98 knots (kts) and an airspeed of 105 kts, which was about 19 kts above the published minimum control speed for the airplane. Therefore, the airplane had achieved sufficient airspeed for the pilot to maintain control despite a loss or reduction in left engine thrust provided he made the
appropriate control inputs. The sideslip force calculations indicated that there was a partially successful attempt to maneuver the airplane back to level flight when the airplane rolled back right, but it was not maintained.
Teardown examinations of the engines and propellers found no evidence of preimpact failure.

Analysis
The pilot departed on a positioning flight in the twin-engine airplane. Videos recorded by
multiple airport-based cameras showed the airplane take off from runway 19. Shortly after
liftoff, the airplane started turning left, and the airplane developed a large left bank angle as it
was turning. The airplane departed the runway to the left and impacted the ground. During the
impact sequence, an explosion occurred, and there was a postimpact fire.
An airplane performance study showed that during the takeoff, a nose-left sideslip, a left side
force, and a left roll occurred, consistent with the loss or reduction in thrust of the left engine.
The sideslip was reduced, likely due to inputting rudder to balance the side force, and the
airplane briefly rolled right possibly due to an overcorrection in rudder. The airplane pitched up
and was able to begin climbing again; however, it continued to lose speed. The sideslip then
reversed, and the airplane rolled left again before impacting the ground. The study indicated
that before rotating and lifting off, the airplane accelerated to a groundspeed of 98 knots (kts)
and an airspeed of 105 kts, which was about 19 kts above the published minimum control
speed for the airplane. Therefore, the airplane had achieved sufficient airspeed for the pilot to
maintain control despite a loss or reduction in left engine thrust provided he made the
appropriate control inputs. The sideslip force calculations indicated that there was a partially
successful attempt to maneuver the airplane back to level flight when the airplane rolled back
right, but it was not maintained. The right rudder input would need to be held until the thrust
asymmetry was corrected.
Teardown examinations of the engines and propellers found no evidence of preimpact failure.
Both engines exhibited evidence of operation at impact. Damage to the propeller blades and
hubs indicated that neither propeller was feathered at impact. The predominant left propeller
Page 1 of 11blade bending and twisting was aft and toward low pitch. The predominant right propeller
blade bending and twisting was forward in the thrust direction and toward high pitch. Analysis
of the propeller internal witness marks and the blade damage found that the right engine was
producing more power than the left engine at initial impact. Based on the available evidence, it
could not be determined why the left propeller was not feathered at impact, even though the
autofeather system was armed.
The rudder trim knob was found 4 units to the left; the aileron trim knob was found 6 units to
the right; and the rudder boost switch was found in the OFF position. The before engine
starting checklist in the pilot’s operating handbook for the airplane specified that the rudder
and aileron trim be set and that the rudder boost switch be on. Therefore, the postaccident
positions of the rudder trim knob, aileron trim knob, and rudder boost switch likely indicate the
pilot did not follow the before engine starting checklist. With the rudder boost switch not being
on, it could not be determined based on the available evidence, what role that system may
have had with the pilot attempting to maintain control of the airplane during the asymmetric
thrust sequence.
Although the pilot’s previous history of significant coronary artery disease and the scar in his
left ventricle placed him at increased risk of an acute cardiac event, whether such an event
occurred at the time of the accident could not be determined from the available information.
Absent evidence of an engine malfunction, the investigation considered whether the left
engine’s thrust reduction was the result of a malfunction in the throttle control system or an
uncommanded throttle movement due to an insufficient friction setting of the airplane’s power
lever friction locks. However, heavy fire and impact damage to the throttle control system
components, including the power quadrant and cockpit control lever friction components,
precluded determining the position of the throttle levers at the time of the loss of thrust or the
friction setting during the accident flight. Thus, the reason for the reduction in left engine
thrust could not be determined.
Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot’s failure to maintain airplane control following a reduction of thrust in the left engine
during takeoff. The reason for the reduction in thrust could not be determined based on the
available evidence.

Does any other turboprop have a rudder boost system that moves the rudder uncommanded?

It's not really a rudder boost because it does not magnify the pilots pedal input.

Dead foot dead engine is a bit different if the pedal you need to push is not there because the rudder already moved itself. But the opposite pedal you don't want is pushing up well above neutral and pushing your knee towards the yoke.

Do any of the current Kingair Sims simulate the rudder boost function by moving the pedals like the real airplane or have a way to pull the left power lever back to simulate PLM?

I think this is the problem. Things in real life not as we trained for normal engine failure or control reactions.

Don’t you love first world problems.

Will I buy a Citation or a King Air?

Isn’t that the truth!

One of the coolest things about representing buyers is the insight we gain into these decisions and why they choose what they choose.

Mike is like the vast majority of aircraft brokers, “you need to buy what I am selling” and because of that they never get the opportunity to see how the sausage is made.

If they’re selling Citations and a prospective purchaser goes off and buys a King Air, they just think he is stupid. It’s a combination of bias and ignorance, they think the buyer made a mistake because they aren’t privy to the “why”.

You also get a lot of half truths and misleading information as these folks are trying to steer someone in a certain direction. If I have a client who may purchase a King Air of a Citation, it literally matters not which one he chooses. I provide the pros and cons of each and allow them to make the decision.

I love the fact that Beechtalk is open to those who search, so they can find threads like this and gain insight to this complicated world… this world full of first world problems!

I've never flown a TP but this is interesting to me. In the single-pilot jet world, we keep a hand on throttles until V1, then we consciously move our hand from the throttles to the yoke to remove temptation to abort the take-off after V1. Corey's post above says that 350s are flown the same way but then in Norman's post it sounds like "rotating with both hands" is wrong in a King Air. Is this a 350 vs smaller King Air model difference?

Where should the second hand be other than the yoke?

Seems proper to be on the yoke in case after liftoff you need significant control input such as one wing heavy, or in a stiff crosswind, or trims are set badly.

Seems like King Air EFATO check list should have this as a first memory item:

- VERIFY BOTH POWER LEVERS AT FULL POWER

If every King Air pilot did that, then the PLM problem would not exist.

Mike C.

Ok so I have a grand total of 8.1 hours in a propeller twin. But between studying Martin and Doug's videos and my 5-day multi course in a Seminole, wouldn't you still do "The Drill" in a King Air? Lower the nose (pitch for Vyse/V2), throttles forward (at least in a turbine you don't have to worry about mixture), clean up, etc......

I can tell you that in an actual engine failure on take-off I will firewall both throttles until 400' and then sort it out. I might overtemp but who cares at that point? The engine can be inspected and repaired. I want every single foot-pound of thrust available to get me up and away, especially when I've got gear and flaps hanging out. The engine should sacrifice its life for me, not the other way around. Plus in a King Air you don't have to rush the feathering since if it's an actual engine failure (and not PLM) the autofeather will kick in and your only job is to maintain directional control and pitch for V2 until 400'. If it was PLM then yes you may have overtemped but you aren't a smoking hole in the ground....

My understanding of the theory: you have auto-feather because it is so unmanageable otherwise. In the power lever rollback case, you don't get auto-feather because the power is not forward. And (apparently) it goes into a VMC roll faster than a surprised pilot can get the power back up.

The KADS crash, from a point just after rotating where yaw is evident, to ground contact was 10 seconds.

So the pilot had about 6 seconds during which moving the PL forward would have saved the situation.

That seems long enough for the first step of a memory item to be done, but still very tight.

If PLM migration is the root cause (which NTSB doesn't seem to clearly agree), then why do we have the idle return spring at all? What problem is it solving? Is that problem really worse than the one it is creating?

Mike C.

Where should the second hand be other than the yoke?

Seems proper to be on the yoke in case after liftoff you need significant control input such as one wing heavy, or in a stiff crosswind, or trims are set badly.

Seems like King Air EFATO check list should have this as a first memory item:

- VERIFY BOTH POWER LEVERS AT FULL POWER

If every King Air pilot did that, then the PLM problem would not exist.

Mike C.

Flaps are not typically used for takeoffs in King Airs. There is only minimal benefits on short runways. They are also a little quirky in operation with presets as TC explained in this article.

https://kingairnation.com/blog/flaps-in ... 9Cppmb1la4

I think the majority of King Airs pilots have come up from pressurized turbo charged piston twins with engines that are much more likely to grenade under takeoff power and most will not fly away with one operable engine. The chance for an abort is one reason the power levers are guarded during the entire takeoff roll. That and the fact that maintaining max take off power without exceeding temp limits that can drift on the takeoff roll is another reason most keep their hand on the power levers until selecting gear up or using both hands to rotate. The likelihood of a failure on takeoff roll with PT6s or TPE331s is near zero. No other plane uses return springs so only those familiar with the PLM issue on King Airs tend to care much about friction lock settings and proper function. There are no cones except an insignificant drift in others.

Pilots that are used to flying jets typically set take off power earlier in the roll and due to neutral or negative angle of incidence frequently use both hands to rotate. A properly trimmed King Air will fly off by itself while many jets will just continue to accelerate until aggressively pulled off. King Airs are very light on the controls with balanced aileron and pitch harmony and are very easy to maneuver with one hand.

To address Mike Cs comment on the reason for the springs, Beech actually issued a communique to add as many as 2 more additional springs on the 350 to cure the hysteresis that apparently came about with the longer cables. (Don’t do that). I had a friend fly his 200 with the spring removed on one side and he reported that the difference was barely detectable.

Not a pilot, and certainly not a King Air pilot, but I thought approach flaps were normal for take-off?

So people are dead because Beech wants to impress people with low slop throttles?


I'd want just enough friction at the FCU so that any control disconnect (which is very rare) would leave the power right where it is at. No springs.

You obviously don't want the engine rolling back, that's lethal.

You obviously don't want the engine surging to max (or more) power if the control disconnects.

So just leave it where it is.

There is definite slop in my Citation throttles but not so much as to be really annoying. I have no idea if there is an idle return spring, I hope not, but even if there was, it would be safer than the King Air setup. Even with my friction lock all the way loose, the levers don't move.

Mike C.