I hope most of the readers of King Air magazine are familiar with the BeechTalk internet forum (www.beechtalk.com). The site is very well-run and controlled by its moderators, members must use their real names, and it is visited regularly by a wide variety of people from novices just entering aviation to old timers like me and many others. The common bond we share is an interest in and love for Beechcraft airplanes, both old and new. Since the Beechcraft airplane model line involves such a mix of planes spanning over 85(!) years of production, the site is logically divided into sections that apply to certain parts of this spectrum: Singles, Twins, Turbines, Classics, etc. I encourage my readers who have not yet discovered this forum to log on and take a look at the Turbines section. There is a lot of great information there. A search button allows you to quickly find past threads of interest. However, I should give you a warning: When you start to explore, don’t have any important plans for the next few hours! You will quickly become enthralled by what you find.
One of the topics that recently received attention on the forum involved an aborted takeoff in a B200 King Air. The abort was initiated at about 60 knots while attempting to depart from an 8,000-foot-long runway. An outboard tire was blown during the abort that was initiated due to the illumination of the “Hydraulic Fluid Low” caution annunciator … yellow in color. The originator of the thread wanted input from the forum members to help answer two questions he had: (1) Was the abort justified? Should they have stopped due to that caution light? (2) Would blowing a tire be expected under these conditions? You can find and read that thread on BeechTalk and find a lot of good thoughts in the replies presented.
I, too, responded to the questions and it gave me the idea for this month’s article. I’d like to share with you my thoughts on this situation, in particular, and aborted takeoffs in general.
My discussion will begin with the acknowledgement that an aborted takeoff can and should be an absolute non-event, regardless of the speed – within reason – at which the abort is initiated, if the runway is long enough. On an 8,000-foot, low-altitude runway, I believe any King Air pilot should be able to abort even at 100 KIAS and have absolutely no trouble slowing to a stop with many feet to spare. Furthermore, the abort procedure would not have to be a rushed or scary event at all: Just come to Idle, lift and enter Beta, then Reverse (don’t hesitate to use it all at first!) and finally start applying brakes about the time you start leaving Reverse to get back to Beta. The Pilot’s Operating Handbook (POH) says that we should not be in Reverse below 40 KIAS, so I start moving the power levers forward from Maximum Reverse at 60 and have them at Flat Pitch – the bottom of the Beta range, called Ground Fine on the later models – by 40. As the power levers leave Max Reverse and start coming forward, that’s the time I start using brakes – even getting on them hard, if needed – at 40 knots and below. By 40 knots, the wing’s lift is small enough that the aircraft’s weight will be mostly supported by the tires, meaning that the chance of locking up a tire causing it to be scuffed or even blown is small.
If you search, you can also find a BeechTalk thread concerning “The Maddening Story of 200 Takeoff Data.” That is a lengthy and educational article I wrote specifically discussing the testing and certification of the 200’s takeoff data. One of the surprising events that I talk about there is the fact that in a high-speed abort, the airplane tends to rotate to a positive angle-of-attack and become airborne! This is due to the fact that the engine and propeller were raised four inches as compared to the 90- and 100-series, to accommodate the larger diameter prop. But this extra height puts the thrust line enough above the wing that positive thrust produces a strong nose-down rotation tendency whereas negative thrust (drag) tends to rotate the airplane nose-up. We Beech instructors were taught that an abort should be a combination of right hand back and left hand forward, to keep the plane firmly on the ground. (This is not as needed in the 90- and 100-series, but it is still a good habit pattern to ingrain. The 200- and 300-series, including the B300 or 350, exhibit this self-rotation tendency noticeably.)
In answer to question two, then, there is absolutely no reason – other than some brake malfunction – to experience a blown tire when aborting at 60 knots! A 200- and 300-series King Air has enough ground effect or “wing cushion” that a lot of weight does not get transmitted onto the tires until rather slow. That’s why I want to only start with the brakes at 60 and not get aggressive on them until 40 and below. Badly scuffing or blowing a tire – and it is virtually always an outboard, never an inboard – is unfortunately quite common with pilots new to King Airs, especially if they come from a background of jet operation with anti-skid braking systems and limited, if any, reverse thrust capability. Even normal landings on reasonably long runways have had their share of tire problems with low-time King Air pilots. I make an effort to always tell newcomers to keep their heels on the floor and only use the bottom of the rudder pedals until approaching taxi speed. Then they can slide their feet up and apply brakes.
Let me add an important comment: During a “for-real,” high-speed abort on a runway of sufficient, but not excessive, length, blowing a tire while braking is not going to cause me to give any pilot a black mark! Look, the brakes are sensitive, the airplane tends to be light on the tires until slow, and maybe the braking on the other three main tires was what helped in stopping the airplane before it hit the overrun. In the overall scheme of operating costs, a new tire now and then makes hardly a ripple!
Aborting at 60 knots on an 8,000-foot runway? There’s not even a remote chance of tire failure when done correctly. As one responder to this BeechTalk thread wrote, “just coming to Ground Fine alone would probably have led to more taxi thrust being required later to make the turnoff!”
Now let’s look at question one: Was the abort justified? Realize that the only reason given for the abort was the illumination of the “HYD FLUID LOW” caution light, that also triggered the Master Caution, yellow flashers on the glareshield in front of each pilot. In my opinion, yes, it certainly was justified and was the correct thing to do. Not everyone will agree, so let me present my reasons for believing as I do.
First, do you realize that the only aborted takeoff procedure in the King Air POHs follows an engine failure?! No other reason is given! Brake lock-up? Runaway rudder boost? Pitch trim runaway? Hitting a deer? Having another airplane on the runway in front of you? No! None of those possibilities is addressed in any way, shape, or form! So, what this implies is that we, as pilots, must make our own decision about justified reasons for an abort. A large, multi-pilot flight department should have published Standard Operating Procedures (SOPs) in an attempt to get everyone on the same page, making the same go/no-go decisions. Standardization of procedures in a flight department with more than one pilot is such an important and admirable goal but one that, based on my observations, is extremely difficult to achieve.
Second, there’s that old adage, “Would you rather be on the ground wishing you were in the air, or in the air wishing you were on the ground?!” I’ll always opt for the former. So when an abort is done at a speed that makes it an absolutely easy slam dunk, then that’s what I will do. But what is that “speed that makes it an absolutely easy slam dunk?” Here is where all of the takeoff conditions – runway length, airport elevation, OAT, wind, airplane weight, runway surface and slope – must be taken into account.
After that disclaimer about all the takeoff conditions that play a role, to now give a hard-and-fast answer may make me look foolish, but here goes: Up to 60 KIAS – even on 3,000-foot-long Catalina Island – I’ll abort for anything not expected. Any annunciator coming on? Abort. An engine gauge reading incorrectly? Abort! Feeling that acceleration is sluggish? Abort. Cracking a windshield? Abort. Why heck, the other pilot making an unexpected loud noise from some body orifice, I might be pulling those power levers aft!
After 60 knots it gets trickier because, depending on runway length and the other takeoff factors, now the abort is not as easily accomplished. In this 60- to 80-knot range, my abort will only follow a strong yawing tendency – lack of directional control – or damage to the airplane, such as hitting an animal or a taxi light or having the door pop open. A red warning flasher? If aborting in this 60- to 80-knot range is not a certain slam dunk, then no, I am not stopping due to a red annunciator with one exception: Inverter Failure when faced with a low ceiling. G1000 or Pro Line 21-equipped machines don’t even have an inverter. Nice!
Blasphemy! Take that crazy Clements behind the woodshed for a good thrashing! Of course, we abort up to V1 for any red annunciator! Our Ops Specs – for you 135 operators who have them – tell us to! It is also in the suggested SOPs that the NBAA publishes.
Now hold the tar and feathers for just a moment. I will not take space here to list all of the warning annunciators, each of which trigger the master warning flasher, but that would be a good homework assignment for you to do. In a quiet hangar or during your next boring, cruise segment, examine all your red annunciators and review what they are telling you. I hope you will conclude that none of them says that the airplane won’t continue to accelerate and fly. “Fuel Pressure?” Golly, I only have 10 hours to sort that one out! “Bleed Air Fail?” No problem to wait a while to address that at a safe altitude. “Oil Pressure?” (For those models that have it.) The engine is not in immediate probability of seizing. We have time to monitor the gauge and look for oil residue on the cowling at a safe altitude. I have yet to see a “Wing Fell Off” light in a King Air. I’d abort if I saw that one!
Inverter failure? The inverter light is a unique case. For the majority of King Airs, the main pilot-side flight instruments depend on AC power along with at least the torque gauges, the most important engine power instrument. If Visual Meteorological Conditions (VMC) exist and power had already been set – as it should have been, long before – then the plane will fly just fine with no alternating current. Yet departing into low clouds would not be nice, especially if you don’t have another qualified pilot in the right seat to temporarily take control using that side’s instruments, most of which will be working fine. So I encourage you to brief carefully, even if it is just talking to yourself, about the highest speed at which an inverter light would trigger an abort reaction. Keep in mind, too, that this should be a temporary problem only, until the other inverter can be selected.
Finally, that big, scary nemesis – “Engine Fire.” Surely, I’d abort for that one, right? No! And here’s why.
To the best of my knowledge – and I have talked with a lot of other high-time King Air pilots and mechanics – there has never been an in-flight engine fire in a PT6! Even if there were a large fuel leak, what would ignite the fuel? The hot exhaust stacks are forward, not aft. (Well, except for the Piaggio and Starship.) If there had been a large fuel leak downstream of the Fuel Control Unit (FCU) and upstream of the nozzles, it is questionable whether you’d be able to make takeoff power normally.
Combine that thought with this one: King Airs have a horrible history of false fire warning lights. This tendency to illuminate when no engine fire is present was rectified when the newer, gas-filled tube warning system was installed, beginning with the 300 model in 1984. But the older system that was triggered by infrared radiation – or, in some cases triggered by flickering light – was known to yield many false warnings. (“Look! I see fire! Oh, wait, it’s the sun, ninety-three million miles away.”)
Here is my bottom line: Once the speed is such that an abort is no longer a slam dunk, easy procedure for the particular takeoff conditions that exist, then I am aborting for one reason and one reason only … inability to control the airplane.
Now one would normally think that “inability to control” would be experienced as a yaw that cannot be corrected by rudder input. Of course, that’s correct. But also, it could happen in the pitch direction: Perhaps something jammed the elevators and liftoff/rotation attitude could not be achieved. Control lock overlooked and still installed? A rigging pin left in the tail cone accidently?
The control wheel lock that prevents elevator and aileron movement in the earlier models was designed such that the control wheel was level with the lock pin installed. After some reports of accidents caused by the control lock still being installed at takeoff – in all sorts of airplanes – Beech decided to put the hole in the control wheel shaft in a different position, one that would require noticeable left-wing-low (CCW) displacement of the wheel when the lock was inserted. That change made it much less likely to make the horrid mistake of overlooking the removal of the lock.
When a true loss of engine power is experienced after the decision speed has been reached and thus the decision is made to continue, now’s the time that immediate and forceful input on the wheel and the pedals is mandatory. Obviously, the control requiring the most abnormal input is the rudder. Let me finish by leaving you with this thought, similar to what I wrote on the BeechTalk thread. It is likely that 100 percent of us were taught and have used the memory aid, “Step on the ball.” Sure, if we are yawing horribly to the left with the wings level (or close to level) the ball will be skewed well to the right and we should apply right rudder to achieve a reasonable state of coordination. My experience has taught me, however, that there is a better, more useful, more instinctive memory aid to make the airplane fly correctly when dealing with a power loss soon after decision speed: Step on the Heading. I always set the HSI’s heading marker on the runway heading. If the bug moves right of the lubber line, it tells me that I have allowed the airplane to turn left; I do not have sufficient right rudder force applied. By stepping on the heading “bug” with enough force – applying a strong dose of right rudder – I can make the nose swing back where it should have been. I will now know that the dead foot is the left one and that I have lost power on the left side. Practice this in the airplane or during your next simulator training session: Stepping on the Heading. I think you will likely agree that it is a more intuitive reaction to make than suddenly emphasizing the ball’s position in your instrument scan.
Final reminder: What is the leading cause of loss of engine power in a King Air soon after liftoff? Power Lever Migration. What is this Power Lever Migration? It is the action of one or both power levers moving aft without pilot input. The cause? Friction knobs that are too loose, that were never snugged up sufficiently before the takeoff roll began. Due to the fact that (1) both power levers sit slightly to the left of the cockpit centerline, and (2) that the end of the appropriate power lever cable connects to the right side of each engine, there is a significantly longer cable length on the right versus the left. This extra length adds more friction. Thus, the spring that is trying to pull the engine’s FCU to idle has more of an effect on the left side than the right.
If the moving power levers are visually caught by the pilot and he moves his hand away from the landing gear handle and back to the levers, pushing them up correctly, no accident takes place and a good lesson is learned. On the other hand, if the spring back of the levers goes unnoticed, tragedy may result. In the pilot’s mind, the “Power” step of the engine failure procedure has already been done. Furthermore, just as he or she has experienced in the sim, autofeather kicks in to quickly remove the drag of the windmilling propeller. Thus, there’s little for the pilot to do other than hold the proper pitch attitude, step on the heading, and watch the houses get smaller.
Here’s the kicker, friends: That power lever migration not only turned the autofeather system off – since the arming switches in the pedestal are no longer being activated – but it likely also reduced power on both sides, but with more of a loss on the left due to less friction resisting the spring’s pull. Now, just holding the proper pitch attitude and stepping on the heading may well not be enough to prevent a crash. The total reduction in power may leave the airplane in a state such that maintaining airspeed and climbing is impossible while experiencing the windmilling propeller’s drag.
If you don’t have “Friction Knobs – Tightened” on your Before Takeoff or Runway Lineup checklist or flow pattern, you surely should! Not doing so can lead to a tragedy that should never have happened.
Be alert, folks!
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