Can you wobble while landing?

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pelmet
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Can you wobble while landing?

Post by pelmet »

Have flown a couple of aircraft now with a wobble pump. On both types they were located on the left side. But, if your engine-driven fuel pump does fail, you now need three hands to land the aircraft doing a power-on approach. Of course, you could ask a passenger to wobble for you but if alone......

Well, this guy had to deal with that exact scenario which obviously is not easily handled. Anybody else encountered this situation?

"C-FWAC, a de Havilland DHC-2 MK. I Beaver aircraft operated by Harbour Air was conducting a ferry flight from Vancouver Harbour, BC (CYHC) to Vancouver Intl, BC (CAM9) with 1 flight crew member on board. During the aircraft’s initial climb from CYHC, the low fuel pressure warning light flickered, and the fuel gauge indicated low and decreasing fuel pressure. The flight crew member responded by using the wobble pump to bring fuel pressure back into the system, then confirmed that the fuel selector was selected to the appropriate fuel tank to ensure that there was a sufficient fuel quantity. Continuous use of the wobble pump was required to maintain fuel pressure, and ATC was advised the aircraft was returning to land. While maneuvering for landing a power loss occurred. The pilot conducted a landing without incident, restarting the engine to taxi back to the dock. The operator’s maintenance conducted a post-flight inspection, and confirmed that a mechanical fuel pump failure had occurred."
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pdw
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Re: Can you wobble while landing?

Post by pdw »

That must have been the right thing .. to keep it wobbling at least until safe proximity to glide the rest of the way down if the engine went off or not, which availed both hands onto the control column to set up an optimum glide path range (and for roundout / flair) for whether it died or it didn't.
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Re: Can you wobble while landing?

Post by phillyfan »

Ya, wobbling is not that difficult. He should have finished the ferry flight.
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Cat Driver
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Re: Can you wobble while landing?

Post by Cat Driver »

which availed both hands onto the control column to set up an optimum glide path range (and for roundout / flair) for whether it died or it didn't.
Why would anyone need two hands on the control column to round out?
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Re: Can you wobble while landing?

Post by switchflicker »

I have criticized every pilot that I flew with who would take his or her hand from the throttles to grip the control column with both hands. No one is that weak. Well maybe in the PBY two hands on the wheel for landing. I can't remember. Cat???
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Re: Can you wobble while landing?

Post by pdw »

I'd figured he let it go out so as not to take the chance losing the power short final .. with a load
Cat Driver wrote: Sat Dec 02, 2017 1:35 pm
which availed both hands onto the control column to set up an optimum glide path range (and for roundout / flair) for whether it died or it didn't.
Why would anyone need two hands on the control column to round out?
Ohh ... which one was it that gets real tough to handle when the engine goes out short final full flap ?
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Re: Can you wobble while landing?

Post by Cat Driver »

Well maybe in the PBY two hands on the wheel for landing. I can't remember. Cat???
The PBY was the heaviest on the controls of any airplane I ever flew and I never ever needed two hands on the control column in any realm of flight to fly it.

One hand on power and one hand on the control column was always my method of maintaining control of any airplane I ever flew.

I find it shocking that so many pilots use two hands on the control column during take off and landing, for sure I would never give them an airplane of mine to fly if that was their idea of how to fly.
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Re: Can you wobble while landing?

Post by photofly »

Someone should go through the AvCanada archive and compile a list of “you can’t fly for Cat if you ...” sins. It would make great reading :)
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Re: Can you wobble while landing?

Post by Cat Driver »

Never mind all my " You can't fly for me comments photofly.

What do you do, do you use two hands on the control column on take off and landing?
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Re: Can you wobble while landing?

Post by complexintentions »

photofly wrote: Sat Dec 02, 2017 5:35 pmSomeone should go through the AvCanada archive and compile a list of “you can’t fly for Cat if you ...” sins. It would make great reading :)
Sure, right after we make a compilation of all your posts chasing him around with bitchy little comments taking shots at him. Just as many and equally, uh, fascinating. :roll:

Can't really see where you find fault in the concept of keeping one hand on the throttles during takeoff/landing? And yeah, it IS shocking that anyone would think otherwise, pretty basic stuff.
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Re: Can you wobble while landing?

Post by pelmet »

Even if one has only one hand on the control column, the other is usually on the throttle while continuous wobbling is required(at least I think continuous wobbling is required, I'm not sure). Anybody have a particular plan if such a situation occurs. Maybe the Beaver pilot had no choice but to let the engine lose power.
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goingnowherefast
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Re: Can you wobble while landing?

Post by goingnowherefast »

He had one hand on the control column, one hand on the throttle, both feet on the rudder pedals and used his "3rd leg" to wobble. You aren't allowed to fly for Cat unless you are well equipped.
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Re: Can you wobble while landing?

Post by CLguy »

One hand on power and one hand on the control column was always my method of maintaining control of any airplane I ever flew.

Guess you never flew one with nose wheel steering or 2 crew SOP's. That's the way it's done in Beavers and Otters!
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Re: Can you wobble while landing?

Post by photofly »

complexintentions wrote: Sat Dec 02, 2017 8:49 pm
photofly wrote: Sat Dec 02, 2017 5:35 pmSomeone should go through the AvCanada archive and compile a list of “you can’t fly for Cat if you ...” sins. It would make great reading :)
Sure, right after we make a compilation of all your posts chasing him around with bitchy little comments taking shots at him. Just as many and equally, uh, fascinating. :roll:
That comment wasn't bitchy and for what it's worth, I challenge you to find three that are. And I meant exactly what I said. I should like to read a compilation of things that Cat considers important, but I'm too lazy to do it myself. You can apologize to me in your own time.
Can't really see where you find fault in the concept of keeping one hand on the throttles during takeoff/landing? And yeah, it IS shocking that anyone would think otherwise, pretty basic stuff.
I'm not finding any fault, and there are many ways to fly an airplane.

I don't expect you to give a shit, but I'm in favour of hands off the throttle on approach. Learn to pick a power setting that will take you where you want to go, and stick to it. Thereafter If you need extra or less power, make a throttle adjustment and then take your hand off the thing. It's an engine control, not a finger rest. If you do need full power for a go-around it's mixture and prop first, then throttle, so you're holding the wrong control in any case.

For takeoff, one finger lightly holds the throttle forward until through circuit altitude. Again no need to hold the throttle, which is not a hand rest.
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Last edited by photofly on Sun Dec 03, 2017 11:42 am, edited 1 time in total.
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
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Re: Can you wobble while landing?

Post by Cat Driver »

For takeoff, one finger lightly holds the throttle forward until through circuit altitude. Again no need to hold the control, which is not a hand rest.
And if there is more than one throttle do you still just lightly hold them forward with one finger during the critical take off period??

For sure there are lots of different ways to handle the controls and power control / levers while flying.

But in my experience with flying airplanes there are times when I was happy I had my hand on the throttles when I suddenly lost all power on one engine during a critical phase of flight.

Mind you I did have over thirty thousand hours flying airplanes to have experienced such problems.

That does make a difference does it not?
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Re: Can you wobble while landing?

Post by photofly »

When flying in a piston powered single engine airplane I mostly do it while not gripping the throttle for any of the flight time except when I'm making a power adjustment, as I described. I'm fairly confident I know where to find the throttle again when I need it.

Of course it's not my place to advise anyone else what to hold while they fly.
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Re: Can you wobble while landing?

Post by Cat Driver »

For sure having the engine suddenly quit producing power in a single engine airplane is far different than having it happen in a multi engine airplane.

Thus having ones hand on the power levers in a multi engine airplane during the critical phases of flight gives one better control response if an engine fails.

Do you agree with that photofly?
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Re: Can you wobble while landing?

Post by Cat Driver »

Back to the original question.

When wobble pumping a 985 you can quit wobbling to attend to another problem for a short period of time because the fuel pressure does not immediately go to zero when you stop wobbling, so you can pause without the engine quitting completely.
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Re: Can you wobble while landing?

Post by photofly »

Cat Driver wrote: Sun Dec 03, 2017 12:19 pm For sure having the engine suddenly quit producing power in a single engine airplane is far different than having it happen in a multi engine airplane.

Thus having ones hand on the power levers in a multi engine airplane during the critical phases of flight gives one better control response if an engine fails.

Do you agree with that photofly?
I won't argue with it. Hopefully by that stage a pilot knows when to make - and when not to make - power adjustments.

I do know that student pilots who are in the habit of maintaining a death-grip on the throttle of the Cessna 150 they're flying get all sorts of in-out-in-out-shake-it-all-about bad habits when learning to fly circuits. And as soon as they put a hood on to work on maintaining control using the instruments alone, yep - there goes the right hand to the throttle. it's like a kind of baby pacifier and surrogate cock at the same time. "Please, take your hands off it and just let the airplane fly; it will do quite well without your help."
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Re: Can you wobble while landing?

Post by switchflicker »

I think we're still talking about the takeoff and landing phase of the flight. On true two pilot operations the PF handles the power to V1 and after that the PNF will fine tune if necessary and ensure that the power setting remains where it should be. This continues until airborne and after that the friction is set tighter because the power will not be reduced until after a set point which is usually around 400'. On landing the PF will handle the power and adjust according from the decent to around a couple of hundred feet. Then the PF will keep his hand on the power levers until after the thrust reversers (if you have em) are stowed or the props are out of beta/reverse and the aircraft is at a taxi speed.
In older jets such as the Citation II the power must be controlled throughout the entire climb because the fan speed increases above the max permitted as fast as a toddler can get his self into trouble. Typically the PF looks after the climb power adjustments because the PNF is doing other stuff like the dreaded checklist.

This information and a bus ticket will get you a ride home.
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