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Never do something stupid fast.

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Old 17th Apr 2008, 02:03
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Never do something stupid fast.

These discussions on in flight emergencies such as engine failures and failures of other components in airplanes has brought me to sharing what I have learned over the years about PDM and how to handle these issues.

My first advice is when something goes wrong don't do anything until your brain recognizes what is happening and then act.

An airplane has inertia...be it either in motion or standing still.

The heavier the airplane the more inertia will either help or hinder you.

So lets look at a failure I had many decades ago in a PBY water bomber carrying long term retardant off a gravel forestry strip.

During a take off with a very strong X/wind fully loaded with long term retardant just as we were almost at VR the left hand throttle broke off, with the result being I was about to get airborne with an engine at full power and no throttle control.

In this case inertia was working against me as it was increasing very fast.

I took the few split seconds to identify the problem and make the correct decision on how to handle the problem...and that was to abort the take off as there was enough room ahead of me to stop before I went outside the boundaries of the airstrip.

.....my training over the years had been that to reject a take off you closed the throttles first.....but in this case I would have lost control because if I closed the throttles one of them was not connected to the quadrant anymore and I would have been riding in a 1200 HP tree cutter as the airplane tore its way through the trees alongside the runway with one engine at full take off power.

That short time I did nothing except think, gave me the opportunity to make the correct decision which was to turn all the mags off with the emergency cut off pull button and at the same time select idle cut off on both mixture controls.

With both engines dead I then punched the emergency retardant drop button and got rid of ten thousand pounds of long term retardant and applied full braking...we ended up about two hundred feet past the end of the runway on the grass and fortunately not in the trees.

That moment of doing nothing until my brain got in gear allowed us to live to fly another day.

So the lesson to be learned is never do something stupid fast.

By the way the airport was real easy to identify after that with almost half the runway bright red from the load of retardant we dumped down it.
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Old 17th Apr 2008, 06:01
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Why didn't you get airborne, and then you'd have lots of time to think.

Shut down the uncontrollable engine with its mag switch or mixture (or use the mixture alone to reduce its power to something manageable - if one pulls the lever back fast one doesn't spend more than a second in the detonation region, which is typically only above 75% power), and then do an assymetric landing?
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Old 17th Apr 2008, 07:46
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Taking time to think

Hi Chuck,

I seem to recall that one of the famous American test pilots involved in flight testing the Bell X series, (I forget who it was, probably Crossfield or Everest,) said exactly the same thing. Namely, that it was best not to respond to an emergency instantly but to take just a second to get your brain into gear and then assess the situation first.

Broomstick.
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Old 17th Apr 2008, 09:30
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A high speed rejected takeoff is one of the worst places to find ones self. Based on the limited information available, which resulted in a runway overrun with most of the stopping distance already behind you, getting airborne with the load may well have been a better choice.

As you know, dumping retardant during a rejected takeoff means that often the brakes are coated with retardant, reducing brake friction to nearly zero, as well as creating a very slick surface for the aircraft. This is one reason that tanker pilots are strongly advised not to jettison during a rejected takeoff...plus the fact that as the weight leaves the aircraft, the effectiveness of the brakes is further reduced (the exact opposite reason of why ground spoilers are employed in some airplanes, or why we often raise flaps right after touchdown in tankers).

Doing nothing fast would have meant getting airborne, climbing clear of obstacles, jettisoning the load at that point over a safe area, and returning to land at your leisure. Rushing into a high speed rejected takeoff instead puts one in a very dangerous position.
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Old 17th Apr 2008, 09:47
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Not only can you land at your leisure, but you can also choose to where to land in many cases, and that might well be a better equipped field than the one you are flying from, with more space and plenty of fire trucks....
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Old 17th Apr 2008, 12:28
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A rejected takeoff is more appropriate to a situation in which going airborne is unsafe; an engine fire, an engine failure, loss of directional control or other situations which affect safety of flight.

Two functioning engines at takeoff power don't create an unsafe takeoff condition, but certainly do create an unsafe stopping condition. If you wish to reject the takeoff, even at lower speeds, there should generally be a very good reason. As one is approaching Vr with a stuck (or in this case broken) throttle/power lever and two good, functioning engines, it's the time to get airborne, safely dispose of the load, and then return.

I've flown a variety of air tanker equipment, and universally we always remind pilots that dumping retardant during a rejected takeoff can create far more problems than it usually solves, for reasons previously mentioned. This is particularly true on older airplanes with less than effective expander-tube brakes.

We had a propeller roll back to about 1,200 RPM at takeoff power in Florida on an active fire, once. It turned out to be a short in the wiring in the stephead motor for the old hamilton standard hydromatic prop. During the roll, as I saw it roll back, I attempted to push it up with the prop switch, no effect. I attempted to move the switch the other way, to no avail. As we crossed the departure end and slightly airborne we then jettisoned the load and shortly thereafter shut down and feathered the #1 engine. With that accomplished, we were able to enter a low downwind and perform an engine-out landing...something for which we all train regularly, and which permits a full runway ahead on which to stop.
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Old 17th Apr 2008, 13:59
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This is a very interesting discussion. On the point of go, no go. I would have thought that Chuck made the right decision because it worked. 20, 30, 40 feet further it might not have. But the real lesson is exactly as he said 'Never do something stupid fast'.

But why is this topic in the private flying forum? Why isn't there a generic catch all flying forum for stuff like this. Rumours and News is for 'real airline pilot' stuff. Jet Blast is a place where mentioning aircraft can get you killed. Then there's all the specialised flying forums. What we really need is, I suppose a 'Hangar flying' forum. about anything as long it's about flying!

How about it moderators, surely there's room for a generic flying forum?
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Old 17th Apr 2008, 14:10
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Corsair - did you try to read the LHR 777 glider thread? - a total nightmare....
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Old 17th Apr 2008, 14:33
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To come in on the other side of the discussion than a couple of later posters, it is surely better to run off the end of the runway at 20 kts than to crash at flying speed doing a difficult asymmetric circuit.

Thank you cjboy, that is exactly why I chose to reject the take off, there was sufficient smooth grass remaining at the end of the runway to allow for the over run and I had enough years flying that type of airplane to know beyond any doubt that the reject could be done safely......getting a PBY fully loaded airborne with that problem to deal with can quickly turn into a far more difficult task should any other factor enter the equation once airborne.

I chose to post this story on the private pilot forum because I feel that private pilots are as capable of a cognitive thought process and thus capable of learning through example as the most experienced high time pilots in aviation.

That is why all the sim courses I have been on emphasize the decision making process as a rigorourous rule, problem below V1 reject, above V1 take off. That rule is based on the premise that you stop if you can, and avoid flying round in a faulty aeroplane if at all possible!

I appreciate that there probably wasn't a V1 calculation in the almost bush flying situation described, but the outcome illustrates a good decision to me.


The PBY on land fully loaded has the most fool proof V speed recognition you could hope to have....no need to look at the airspeed because if the nose wheel has not left the ground it ain't gonna fly......

I would like to add just one more comment to this post, I am very aware of the propensity of pilots to second guess any decision made by other pilots and have no problem with that as that is fair comment and through discussion we can learn.

But to those of you who for some unfathomable reason just have to " one up " every other pilot who posts here I personally am not all that impressed with your poweress as top guns because you do not have the self confidence to post using your real names.....you could be the lost village idiot that some village wants back for all I know.
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Old 17th Apr 2008, 14:49
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Chuck,

Clearly you walked away. That says something. However, for whatever reason you picked the private pilot forum to post a glory days story which appears to have the sole purpose of strutting your stuff. Whether you did it for that purpose, you certainly did open yourself up to observation by posting it (even if it's not the best choice of places to post). Don't whine when others comment on your post. Nobody's one-upping you here...you don't need to feel so competitive. Nobody's diminishing what you did, or did not accomplish. You laid out the details as much as you deemed necessary, and those details did and do merit comment.

Deal with it.
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Old 17th Apr 2008, 16:49
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as the weight leaves the aircraft, the effectiveness of the brakes is further reduced
SNS3G can you elaborate on the reasoning?

I can understand that dumping the weight reduces the downforce on the tyres but by the same token it greatly reduces the amount of energy that has to be converted to heat by the brakes. Chuck will probably be able to tell us what happens to brake effectiveness on a PBY when they get very hot.
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Old 17th Apr 2008, 17:25
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Mike the brakes on a PBY are very powerful and need to be applied very carefully or you will rip the tires right off the thing.

The laws of physics dictate that to stop an object in motion requires less force as the weight of said object is reduced....my decision to dump ten thousand pounds of fire retardant was based on that simple law of physics.

The following was not my most pressing worry at that point in time....


as the weight leaves the aircraft, the effectiveness of the brakes is further reduced


Maximum braking is achieved just prior to the wheels locking up.....I had enough experience on type to ensure I did not lock up the wheels during the time I was bringing the thing to a complete stop, therefore an empty airplane will stop in a shorter distance than a fully loaded one.

Empirical evidence would indicate that the decision to reject the take off was sound.

Ergo my advice to think before acting is also sound advice.
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Old 17th Apr 2008, 19:58
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Second-guessing someone's actions not having been there and with only a minimum of information is not a nice thing to do.

At any rate, something I was taught on my day job is that there are situations when the important thing to do is to make a decision. It does not have to be the best decision, but if freezing and doing nothing will get you killed, any decision you make can only improve the situation (it's not going to get you more dead than dead). In those circumstances, being able to say afterwards "I screwed up, I should have done this or that instead", is a truly wonderful thing. I know this might not be directly relevant here, but hopefully you get the idea.

Having said that, and without questioning in any way Chuck's decision, from my very meager experience I think that faced with a similar failure and for discussion purposes not taking into account any specifics as regards aircraft type, location, etc., if everything else looked normal and I was already near Vr I like to think I would have attempted a lift-off rather than cutting the engines, the reason being I wouldn't know if they are both going to cut off at roughly the same time. If they decide not to, then we're back to square one as regards asymmetric thrust--bad news, especially if below Vmcg.

Again, I'm not saying that's the right thing to do or questioning in any way anyone else's point of view, just sharing what I think my reaction would be, FWIW.

Last edited by LH2; 17th Apr 2008 at 20:00. Reason: typo
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Old 17th Apr 2008, 20:22
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Hi LH2:

Let me clarify why I rejected at that point in the take off roll....remember I was still on the runway and not at VR with sufficient room ahead of me to stop safely before I would reach the airport boundary.


the reason being I wouldn't know if they are both going to cut off at roughly the same time
.

The PBY has a dead man switch on the mag selector that kills the magnetos on both engines.

If one engine had quit and the other had not it would have been instantly evident and I could have pushed the push pull switch back to the live position. Furthermore if you read my post again you will note that I also selected ICO ( idle cut off ) on both engine mixture controls......the odds of either engine not stopping in the above scenario are remote to say the least.


If they decide not to, then we're back to square one as regards asymmetric thrust--bad news, especially if below Vmcg.


Had I been unable to shut down both engines I would still have had the option of continuing the take off.......

Remember each of these situations are airplane specific and we react based on knowledge of the airplane systems and performance, then make decisions based on what we decide will give the safest outcome.....


The not doing something stupid part of this story was meant to point out had I acted by rote which is to close both throttles to reject a take off I deffinately would have had a directional control problem on my hands.

Therefore it is advisable to think before acting was my message.
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Old 17th Apr 2008, 20:23
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Sometimes you do have to act quickly

My so far worst flying moment was my third flight in my third single seat glider and my first one in that glider behind a Pawnee.

The trim setting (as recommended in the manual) that worked fine behind a Citabria had me way above the Pawnee in the blink of an eye and I very quickly got my nose down. Yes, a little bit too much correction as I bounced off the ground. Doing nothing was not an option as there was a distinct danger that I would pull up the Pawnee's tail and cause a propstrike. I could have released, but that comes with its own set of problems, especially establishing sufficient airspeed from low altitude and not much airspeed.

After the bounce I was established in the proper position without further oscillation. The glider did not feel right and I discovered that the spoilers had come unlocked, likely from the bounce.

Put the spoilers back, continued the tow and parked in a thermal to let the adrenaline come down.

So while in most cases, doing nothing and thinking for the first few moments is the best option when faced with bad news, sometimes you have to be quick.

And these days, I err on the side of forward trim.
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Old 17th Apr 2008, 21:51
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Let me clarify
That's fine, as I said I was not questioning your actions. For all my stupidity, I like to think I know better than telling someone with orders of magnitude more experience than I have how to fly a plane. Much more so when I wasn't there (when did this happen, btw? chances are I wasn't even born then).

That said, cheers for the additional details on the Catalina. How I would love to fly one someday!

it is advisable to think before acting was my message
Yep, I understood that, just got sidetracked as usual.
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Old 17th Apr 2008, 21:58
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(when did this happen, btw?

Jeeses you had to ask.

I think it was in 1975 or 76, it is a lot easier to remember the details than it is to remember the date......just take a minute and remember one of your more exciting sexual encounters and I bet the details will be easy to remember but just try and put a date to it.

Anyhow I'm pleased you are interested ...if you want to fly a PBY the Dutch are still flying theirs and money will do wonders for making that wish come true.
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Old 18th Apr 2008, 06:57
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Hmmm,

One of the few circumstances in which a very rapid assessment and action is essential, is near rotation speed on take-off.

I hesitate to criticise any action with a safe outcome, but fundamentally, the decision to reject - above - was wrong.

Yes, reject for an engine malfunction, of course. But this was not an engine malfunction, it was an engine control malfunction, leaving the engine running at takeoff power. There are too many takeoff accidents, often involving an unnecessary high speed reject. This was very nearly another one.

Chuck's fundamental message is very valid. A highly respected TRE of my acquaintance has a favourite question about emergencies in general. He uses it to introduce a discussion on decision-making...

"What should you do when something goes wrong?"

He then allows the gathered trainees to hold forth with their opinions, before stating the correct response:

"Absolutely nothing at all, for very much longer than you might think".

He goes on to discuss gathering the required information, and confirming the correct course of action, before acting. Crucially, he also talks about the circumstances in which this is not relevant, namely, during takeoff at high speed, during approach near the ground, and anytime you have a TCAS, windshear, or GPWS warning (there are others, but these are the principal ones).

Well done to Chuck for not crashing, but I hope others would have taken the problem where it belonged: in the air.
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Old 18th Apr 2008, 07:47
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The point Chuck was primarily making is
Never do something stupid fast.
I'm quoting that in case it's got lost in the discussion of what he should have done in this particular situation. It doesn't really matter in this case: it's a subject for another thread.

I said something similar in an article I wrote a bit back on dealing with emergencies. My version was that we say you should 'aviate, navigate, communicate', but we miss out the bit before 'aviate', which is to deal with what's going on in your brain and then make a correct decision. Chuck said it far better than I did, in far fewer words. I hope anyone who needed it was listening.

Years ago, low hours pilots were crashing R22s by throwing them into autorotation and messing it up, and investigation was showing that an auto wasn't required. The Robinson Safety Course now teaches that if the low rotor RPM warning horn goes off, you open the throttle and make sure you have an engine failure before you throw the machine into auto in a panic.

Now, don't turn this thread into a discussion of how long you've got to do that in an R22; start another thread. The point is, even in a situation like that, you have a fraction of a second to think what to do, and make the correct decision, and to not 'do something stupid fast'.

I spend a lot of my working life teaching students to respond quickly to emergencies. It never hurts to be reminded of what they should do first. Thanks, Chuck.
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Old 18th Apr 2008, 12:56
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Broken Throttle Lever

I am not really qualified to offer advice as a low hours single spamcan pilot but I guess I can make a reasoned comment ref the rejected take-off.
I was always taught to keep a hand on the throttle during climb out to prevent it backing off uncommanded.
Having no lever would have presented this possibility and I suppose assymetric thrust at low alt could be a major problem,so maybe keeping it on the ground was the best option.

Comments that the OP was starting this thread as a 'shop window' for his personal flying skills add nothing to this debate.

Let's hear more about peoples' (successful) handling of difficult situations.You generally only read about the unsuccessful ones on the AAIB/NTSB sites.

MM
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