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Old 12th Dec 2011, 04:57   #21 (permalink)
 
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Quote:
Originally Posted by Rudderrat
Surely it depends on the features installed on the aircraft? Most modern manufacturers have bothered to fit autobrakes. Why not use that feature and avoid running the risk of applying the brakes unintentionally during the 99.99% of your successful take offs?
We don't have AB on most of our jets.

Quote:
Have you never come across a low experience pilot, who didn't have their heels on the floor, and who applied the brakes unintentionally during the rudder control check during taxy?
Nope. FOs don't do the rudder checks here!

Quote:
If the RTO is performed below the autobrake threshold speed, then there is plenty of runway ahead and time to sort out your feet transition from floor to brakes.
Agree. But the issue is a V1 cut/fire.

Punkalouver's post further makes my point about moving feet up during a max-brake reject. Practically, it can't be done.

Quote:
Originally Posted by Tee emm
I thought a recent Boeing document recommended pilots should be Go-minded rather than REJECT minded - due to the propensity of pilots to abort unnecessarily. The general rule in the 737 FCTM was to use 80 knots as a trigger to stopping for any master caution. In that case why have your feet "ready" on the brakes when there is no problem with pulling up.
The general rule is that if you have a fire or a large loud bang before V1 you stop. That means max braking. The issue is not what happens 80kts (or even up to V1-10), surely that's obvious?
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Old 12th Dec 2011, 06:44   #22 (permalink)

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Quote:
OK465

The static rudder pedal position is not adjusted properly or this is a very short pilot munchkin.

4Dogs

I guess they don't teach them to adjust the pedals to allow full brake with full rudder anymore...probably interferes with their social life!
Possibly correct but equally possibly Bloggs had the seat adjusted so that s/he could apply brake & rudder statically but once full rudder was applied dynamically, with gusto, and the leg tensed there was no ability to slide the foot up the pedal to apply brakes.

It's a bit chicken and egg. Did the rudder input lead to the asymmetric braking to maintain directional control, which was a bit wobbly, or did some initial asymmetric braking lead to full rudder for directional control thus subsequently preventing the application of symmetrical braking?

Last edited by Capt Claret; 13th Dec 2011 at 03:04. Reason: Brake not bake!
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Old 12th Dec 2011, 13:13   #23 (permalink)
 
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Quote:
Originally Posted by Capn Bloggs
Agree. But the issue is a V1 cut/fire.
I don't see the issue here. First item is to close all thrust levers ... asymmetry no more.

Punkalouver's post is about a frozen brake at touchdown.
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Old 6th Apr 2012, 03:12   #24 (permalink)
 
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Quote:
Originally Posted by CONF iture View Post
Do you have reports or anecdotes in mind which would support the mention of big problems ?
Very foolish to keep heels on the floor. That is why this Dash-8 went off the runway.

From captain's report...

Usually I perform rudder operation during landing with my heels in contact with the cockpit floor. As I had to use full rudder to maintain the direction in case of this incident, I performed simultaneous rudder and brake operations without a chance to change my foot position on the brake pedal. As a result, I think braking effect was not sufficient.


From safety board analysis...

It is estimated that the PIC could not apply force on the brake pedal with sufficient force when he noticed the inoperative steering because it was his habit to control the pedals with his heels on the floor up to shortly after touch down. The movement of the brake pedals was not sufficient due to the positioning of his feet.

http://www.mlit.go.jp/jtsb/eng-air_report/JA841A.pdf
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Old 6th Apr 2012, 09:06   #25 (permalink)
 
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Feet resting on brakes for takeoff ? 'kin dangerous
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Old 6th Apr 2012, 19:46   #26 (permalink)
 
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Landing actually.
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Old 7th Apr 2012, 10:36   #27 (permalink)
 
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My 1976 edition of the Boeing 737-200 FCTM which was much more detailed with explanatory notes than the current dumbed down FTCM Boeing 737 series, displayed a diagram showing where the heels should be for take off and landing.

In both cases the heels were on the bottom of the rudder pedal and the toes were obviously higher up but just clear of the top of the brake pedal. In practice this was a most uncomfortable feet angle and most of the crews I worked with on the 737-200 in those days disregarded that FCTM advice. Mind you the -200 did not have the RTO facility.

Later editions of the FCTM had that diagram removed. In my experience there is a demonstrable danger of inadvertent rudder pedal pressure being applied if the heels are not on the floor as experienced in the first post. Accident records appear to show that there is more risk involved in a high speed rejected take off than with a continued take off. In any case, with the RTO facility up there with weather radar as one of the most significant advances in flight safety in recent years, there are now less risks involved in rejected take off's than in the old days.

Nevertheless it is usually better in the long run, to be go-minded. Yet I still see pilots in the simulator that during the take off run have their hand wrapped around the thrust levers like a claw poised to rip the thrust levers back right up to V1. This is a learned gimmick and looks rather quaint as well as useless, considering it only takes a fraction of a second to close the thrust levers using normal hand grip
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Old 9th Apr 2012, 01:06   #28 (permalink)
 
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Talk about over-engineering things...

Heels on the rudder, toes on the brakes; need to brake pronto? Don't waste a little extra time you can gain by attempting to move your toes to the brake pedals. Be as ready as you can be for any outcome.

Don't need to brake? Don't step on the bloody brakes! It's really not that hard

Not once I've been told to remove my heels off the pedals and not once I have had any type of scare because of that. But I've been mighty glad, though, that I have been able to brake just at the moment I wanted to and not wasted time and effort trying to move/slide/whatever my feet to the brake pedals.

Don't over-complicate really simple issues. Please
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Old 10th Apr 2012, 02:47   #29 (permalink)
 
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Thanks for that last report punkalouver.
I can see now there are 2 schools for that matter, I would not have thought so. As sheppey wrote, the FCTMs do not seem to specify anything on that subject. My way to do it is heels on the floor, toes clear of the brakes as long as braking is not necessary. That's the way I've been teached and I'm very comfortable that way. It provides me a more accurate control, like the need to use the armrest to get a more precise control on the sidestick.
But actually I don't know how are doing the guys I'm working with, so I will take a few months to observe and question, and I'll be back here to report ...
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Old 24th Apr 2012, 12:43   #30 (permalink)
 
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Page 7, near bottom of page for another runway excursion(SF340).

http://www.mlit.go.jp/jtsb/eng-air_report/JA001C.pdf

"I pressed the left brake pedal more firmly to stop the Aircraft from veering, but this attempt had no effect and the Aircraft continued veering and went off the runway. I don’t use the brake pedals while controlling the rudder, because doing so is rather difficult."
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Old 24th Apr 2012, 16:08   #31 (permalink)
 
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A320 Sim session,wet runway and crosswind of 20 kts,Up wind engine failure at low speed.To maintain on the runway, along with full tiller and full rudder, differential braking was required. Found it much easier to handle the situation if the feet were on the rudder pedal,rather then raising them from the floor.

As is being discussed here we also have two school of techniques since the FCTM and FCOM are silent on this. Therefore, wouldn't it better to start T/O roll with feet on the rudder pedal and slide them down at about 75- 80 kts as rudders become effective.Suggestions please!!
Thanks in advance.
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Old 25th Apr 2012, 09:30   #32 (permalink)
 
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Hi 320p,
Quote:
Therefore, wouldn't it better to start T/O roll with feet on the rudder pedal and slide them down at about 75- 80 kts as rudders become effective.
You'll need most rudder deflection at low speed during the take off roll and will therefore have a bigger chance of applying unintentional braking.
Using the same logic, why don't you drive with your left foot covering the brake pedal on your car whilst driving on the motorway?

It's the delay in recognising the engine failure, before the TLs are closed which causes the problem. In real life, the change in heading will be felt early, whereas the sim points in the same direction (no clue there). You'll also feel the sideways acceleration immediately, the sim has to roll in order to simulate the yaw and consequently lags.
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Old 25th Apr 2012, 09:54   #33 (permalink)
 
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Quote:
Originally Posted by Rudderrat
It's the delay in recognising the engine failure, before the TLs are closed which causes the problem. In real life, the change in heading will be felt early, whereas the sim points in the same direction (no clue there). You'll also feel the sideways acceleration immediately, the sim has to roll in order to simulate the yaw and consequently lags.
Eh? The SIM yaws dramatically into the dead engine (twists horizontally). Roll is not required, nor is it used by the SIM mechanism to simulate an engine failure on TO.

I've never had an issue inadvertently putting on the brakes when using lots of rudder. In fact, as stated before, trying to move one's feet up from the floor whilst putting in near-to full rudder is all-nigh impossible unless you've got very shiny soles and very shiny rudder pedals.

No question in my mind; feet up all the time; just don't toe the brakes inadvertently. Heels push the rudder, toes put on the brakes. If you have to stretch so much that you can't stop your toes moving forward and applying the brakes, you're sitting too far back.
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Old 25th Apr 2012, 10:29   #34 (permalink)
 
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Eh? The SIM yaws dramatically into the dead engine (twists horizontally)
Through how many degrees can it twist horizontally?
Once it is at the limits of motion, the sensation is that you've arrested the heading change even though the picture may show you are still turning.
Quote:
Roll is not required, nor is it used by the SIM mechanism to simulate an engine failure on TO.
How do you simulate a prolonged sideways acceleration?

Edit:
It may be a different story when we get these.
Simulators get real - Learmount
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Old 25th Apr 2012, 10:45   #35 (permalink)
 
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Quote:
How do you simulate a prolonged sideways acceleration?
the sim banks to one side and the display as well the instruments tell you that you are turning and not banking.

its pretty the same like it pitches up on take off roll ( without showing you the pitch on instruments or visually) and you get gravity force as a feeling for dynamic accleration.

i remember being first time in a bae146 simulator and was amazed that it gives you accleration during the whole take off run and asked myself how it can be possible until one technician explained me how its done.

cheers
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Old 25th Apr 2012, 11:47   #36 (permalink)
 
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Rudderrat, when at the SIM next, stay outside and watch one in action. Being a pilot, you'll quickly pick up what's going on inside without even seeing the instruments.

Heading change during takeoff? You'll get about 20° (quick twist by the SIM) and then you're in the grass anyway. You won't be doing a 180° on the SIM jacks.
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Old 25th Apr 2012, 19:41   #37 (permalink)
 
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Hi Capn Bloggs,

Have a look at Page 9 http://www.simdesign.nl/pubs/integra...ing_system.pdf.
"For example, a pitch up attitude of 20 degrees (common for the simulation of a take off) will reduce the available motions in all other directions and rotations to nearly zero,"

During a RTO, the pitch down of the box to simulate the retardation can be about 20 degs. That reduces the available rotations, causing the loss of vestibular feed back.
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Old 25th Apr 2012, 23:42   #38 (permalink)
 
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Suffice to say, after 15 years in two different SIM types, I've never had a problem working out what the aircraft is "doing" during a reject or anything else, for that matter. Have you?

Lets get back on thread, shall we?
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Old 26th Apr 2012, 10:45   #39 (permalink)
 
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Hi Capn Bloggs,
Quote:
I've never had a problem working out what the aircraft is "doing" during a reject or anything else, for that matter. Have you?
You must be a genius, because most crews find keeping the "aircraft" (the sim) straight during a normal landing more difficult than real life. Once a heading oscillation starts, it is very difficult to damp out during braking because of the lack of sim fidelity caused by the lack of motion cues (reasons given above).

During an RTO, you will probably build a heading oscillation in an attempt to keep it within the width of the runway. If keeping your feet on the brake pedals during all normal take offs works for you - then carry on.

I'm simply trying to point out that "fixing" a sim fidelity RTO problem by keeping your feet on the brake pedals during the acceleration phase, might not be the best solution for all normal crews in normal everyday operations. See post #1.
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Old 29th Apr 2012, 15:30   #40 (permalink)
 
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For those who are arguing in favor of having heels on pedals: the was a fatal crash exactly for this reason. September 2011 Yak-42 in Russia ( 2011 Lokomotiv Yaroslavl air disaster - Wikipedia, the free encyclopedia ). Pilot previously flew on Yak-40, which had pedals designed in such a way, that heels could only stay on rudder pedals:



Yak-42 however had conventional pedals, but pilot still followed his technique from Yak-40, and erroneously applied brake pressure during takeoff roll. 44 died, 1 survived.

Official visual reconstruction by Russian investigation committee. Note there is brake-pressure indicator on the third row, on the left.




Last edited by GSLOC; 30th Apr 2012 at 00:31.
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