Rudder pressure low v1 engine failure

[Olendirk]

guys,

wet runway, pretty low v1. passing v1 an engine fails. do i need about the same pressure i need when it fails just after airborne? or only slight pressure to keep it going down the runway?

what to pay attention to?

cheerio


OD

[bflyer]

fuselage-mounted egines,..e.g B727, TU-154..about the same pressure....wing-mounted engines..inner..slightly higher pressure..outers..at full T/O thrust..need real muscle :eek:
watch rwy alignement..use differential braking if needed

[WorldDC10]

I always found that if you try to be too mechanical in dealing with engine failures in the sim (thinking about rudder pressure etc) things don't go very well.

Just look out the window and keep the pointed end facing straight down the runway. This also works at rotation until you transition onto the instruments (even in low viz).

I am sorry if that sounds rather simplistic but it has worked for me in every type I have flown from a Lear 25 up to the DC10. Come to think of it some would say I am rather simple:hmm:

[OPEN DES]

Sorry for my answer.

Answer: it depends..............

But what about just flying the aircraft.

If and when it happens, would you really think about how much footpressure you'd use? Would you even think about this thread on Pprune?

Good luck.

[Capt Chambo]

You don't say which type of aircraft you are asking about, but I seem to recall you have asked questions about 737's before, so assuming your question relates to the 737 series here goes....

An engine failure after a wet V1 will require pretty much full rudder input. (This will be dependant on the model you are flying, a -700 with 27K engines certainly will, whereas a -900 with 24K engines is slightly more benign!). Once airborne the pressure will be slightly less, because your greater speed now gives you greater rudder authority.

Essentially you are correcting the yaw and keeping the aeroplane tracking straight ahead.

WorldDC10 has it right, don't overcomplicate it, just put a healthy amount of rudder in and keep it straight.

Hope that helps.

[barit1]

Ummm -

To be correct in an engineering sense, it's rudder pedal force we're discussing here... not "pressure". (Pressure is force per unit area)

And the answer is: As much as you need to maintain heading! :rolleyes:

[BelArgUSA]

Hola Olendirk -
xxx
How to handle engine failures is an excellent subject. Real life of course.
But we dont play these games in real life. We do that in simulators.
I spend my life in 747 simulators. How much time doing that... I dont log that time.
xxx
And I know how to teach V1 survival and passing grades... or "bust" pilots.
I dont know what you fly. I assume A-320 or B-737...
The plane I know best is the old 747s...
xxx
The "easiest" V1 failures (continuing takeoff, engine-out) are high speed/heavy weight.
Typical speeds V1-VR-V2 are, say 165-176-186 when heavy, 10 flaps...
Your failure occurs at 165, high speed, very responsive rudder effectiveness.
Maybe a "one/half" to "two/thirds" rudder deflecton is sufficient.
xxx
What do you look at (in the simulator) is...
You know that your failures are coming during the PC base check. About half the session gone...
So, a given takeoff, you often get a failure (early) with a rejeted takeoff.
I might do that to you with an inboard engine - why not...
Expect the next one to be a failure at high speed requiring you to continue.
xxx
Takeoff again, look at your runway centerline, but peripheral vision on the engine gages.
V1... me (the bastard) failing an outboard. Dead engine, dead foot.
When you start seeing the row of engine gages going to zero, apply rudder and look at centerline.
No more need to watch engine gages... it is gone, will not relight.
Your hear the call "VR", go to your attitude (for the 747 it is 13º nose up).
Keep your heading. How much pressure on rudder...?
xxx
As you accelerate to V2, will be a little less, because rudder gets more effective.
Meter your pressure on the rudder pedal with your control wheel. It should be horizontal.
That is of course for Boeing, I dont know how goes with an Airbus joystick.
If your control wheel is not horizontal, you have too little, or too much rudder.
xxx
Suppose I want to be a nasty TRE,,,
Let's do a light weight takeoff... Speeds 130-155-165...
VmcG in the simulator/engine combination might be 127 or 128, darn close to V1.
At such a low speed, your rudder will need FULL deflection at "ENG FAILURE" call.
Further, I will select a maximum AFT CG, meaning the yaw axis/rudder arm is shorter.
Meaning increased FULL rudder deflection (or more)... Nasty, nasty...
Engine failed, acceleration 130 V1 to VR 155 takes time.
I might even give you a higher EPR than book number, this making engines more powerful...
This has another consequence (again), a VmcG increase.
As you gain airspeed, rudder becomes more effective, so reduced pedal pressure.
And all that, while you are trying to stay on centerline.
xxx
Or you might run OFF the runway... Full bright lights in simulator.
Retraining tomorrow, new check-ride the next day (maybe) if I am available.
xxx
This old fart disclosed a few techniques.... You owe me a Carlsberg and a biksemad. Sköl
I am a nice TRE, dont worry. "My guys" are briefed as to the above - My pride, when they pass.
:)
Happy contrails

[EMIT]

Like others have already posted: use the amount of rudder that you need to keep tracking in the direction that you desire!
Still it is possible to indicate what to expect:
As you are still rolling on the runway, with all wheels on the ground, you have the tracking force of nosewheels, main wheels and also the sideforce of the rudder available.
At rotation, you lose the tracking force of the nosewheels, so you will have to apply a bit more rudder.
As the main wheels leave the runway, their tracking force is also lost, so you will again have to apply a bit more rudder.
As you gain speed during your climbout, you will not need to adjust rudder force, because your rudder ratio changing sytem will adjust the actual deflection of the rudder for you (assuming that you talk about commercial size jetliners).
Of course, if you change thrust, either increase from reduced T/O thrust to FULL thrust, or decrease thrust from T/O to Max Continous, you will have to adjust the amount of pedal force.

[BelArgUSA]

Shall I once again reinstate that nose wheels (and nose wheel steering) has about the same effectiveness as a piece of wet Kleenex tissue when it comes to their contribution to directional control...
xxx
:rolleyes:
Happy contrails

[EMIT]

Belargusa,

Even that tiny bit of effect is noticeable when you rotate - at least in the SIM it is, and with statistically only one half an engine failure allotted per pilot career, that is as close as most of us will get to the real thing.

Best regards.

[moggiee]

BelArgUSA - you're wrong about the nosewheeel etc. Especially if you talk about an aeroplane where you have a nosewheel/rudder pedal connection (e.g. 737 with its rudder fine steering system).

If rudder pedal inputs also give NWS inputs then the NWS contribute to directional control - to argue otherwise is like trying to state that black is white and vice versa.

The bottom line is that as V1 should never be lower than Vmcg you should be able to control the direction of the aeroplane with the rudder pedals. If the failure occurs before Vr then you just use whatever is required to keep straight - use your eyes and your feet in concert and you'll be OK.

Effectively, it's a trained instinct (learned behaviour) - and that is why you practice, and practice, and practice...........

[Pugilistic Animus]

Moggie, I heard the VC-10 is a baby low Vmc--- very controllable etc.

quite a bit less critical than BelArgUSA's kit I would say!!!

[moggiee]

Well, the designers at Vickers did put the engines in the right place to begin with. However, a low Vmcg or Vmca doesn't actually make much difference - it just means that the same effect happens at a lower speed. For example, Vmca will still require full rudder and up to 5 degrees of bank whether it's a high or low figure.

That notwithstanding, the point about nosewheel/rudder interconnect holds true - if applying rudder also causes a NWS input then the NWS input must help, unless the 747 operates outside the normal laws of the universe!

[BelArgUSA]

Dear Moggie -
xxx
I am wrong... to quote your lines...
Yes, definitely wrong, and probably wrong like my former airline, PanAm was.
That is the way we were trained, and briefed, but "it was just PanAm", not superior UK training.
And instructors were briefed how to train pilots (I was instructing besides flying).
And that is what I do here in Argentina. So this airline is "wrong" too.
xxx
The NWS on rudder pedals was "so effective" that it was disconnected in all PanAm 747s.
Even later, when acquiring 747s from other airlines, rudder pedals were disconnected from NWS.
Was the case of the 747-123s and 212s we got which originally had rudder pedal NWS.
In Argentina, all our 747s have rudder pedal NWS... Like everybody else.
And yes, I know about the 737s having that feature too. Like all Boeings, except 707s.
Read my thread. It is meant to help pilot (trainees) complete simulator training succesfully.
I gave some info on "nasty instructor games" that can be played upon them.
xxx
I say again - nose wheel directional control and steering is worthless during takeoff roll.
Stupid "nose down" elevator inputs during T/O roll achieve only one thing. Increased drag.
PanAm, and here in Argentina, instructs/instructed to do T/O roll with "faired" elevator.
By the way, the only respected book from your part of the world is D.P Davies' "Flying the big jets".
Every PanAm pilot (and my Argentina Gauchos) had/have one on their bedside table.
I fly the line, and training manager, retiring in NOV... You dont issue my paychecks.
xxx
I remember a 747 doing a swing 90º to the left, at start of T/O roll despite nose wheel. I was just behind.
Probably the nº 1 engine remained at idle. Wish it had been a BA aircraft.
:)
Happy contrails

[NSEU]

On a related theme....
The 744 maintenance manual describes the override mechanism connecting the autopilot rollout actuators to the rudder system... It says that the autopilot can be overridden by manual input to the rudder pedals at any time (without disengaging the autopilot).
This was tried in the sim recently by a 747 pilot... and, oddly, the aircraft tracked straight as an arrow. This contradiction was noted by another 744 pilot who tried it in real life during a (ferry) flight.. at 130 and 80kts. The (real) aircraft again tracked straight down the centerline.

Perhaps a possible explanation for this contradiction could be what Bel Arg says... The rudder pedal steering has about the same effectiveness as a piece of wet Kleenex tissue :}

[barit1]

Well, the designers at Vickers did put the engines in the right place to begin with.

... for two (or maybe more) reasons:

1) Minimize the yawing moment OEI.

2) Minimize pitch-up moment from thrust application, to keep more nosewheel traction.

Structural inefficiency? Let the beancounters worry about that! :}

[Pugilistic Animus]

Moggiee, Barit1 has confirmed my thought, due to the basic engine airframe combination the nose wheel steering probably contributes more to LOW SPEED directional control in your former type than it does in a 747/767 type---at speeds near V1 but greater than Vmc [the older requirements allowed V1 to equal Vmc---now it may not be less than 1.10 Vmc or Vs1]--of course Vmc---is Vmc as you say, but it doesn't limit all types Vmc can't be below Vs1 otherwise it's not limiting is it?---don't know the case with as appli VC-10

---the reason therefore is that at the higher velocities the momentum along the flight path is WAY too HIGH to be practically influenced by the nose wheel vectors ---- that is AEO!!

----OEI it's all AERODYNAMIC and As BelArgUSA's CORRECTLY states [in paraphrase [como no:)] NWS is useless for OEI directional control!!!

Please add a g or a where applicable to Vmc, but, Vmc is the only thing the FARs currently describe---that's the aerodyamics/laws of nature on that!!!

PA

[Capt Claret]

Don't think pressure; keep the nose pointing in the desired direction with the wings 'level', either visually or with reference to the PFD/ND/DG

[PantLoad]

BelArgUSA's post to Olendirk is priceless.....Ah, this is what airline instruction is all about. I'd love to have you give me my next sim check.

In fact...I'd like to 'play' with V1 cuts under various conditions...as you say...low weight, high thrust, aft CG. It gets real ugly, real fast!!!! And, in the blink of an eye, you're in the grass. Let's throw in some low viz and wet runway, just to highten the challenge. Good instruction, good experience.

I like sim checks where I can try different scenarios. There are two sim instructors at my present place of employment who allow me to do this.

This is what instruction is all about....not just filling in the squares to pass (or fail), but to learn.

It's a shame you have to retire soon. Maybe you don't see it that way...maybe you're ready to get the XXXX out.

The post directed toward Moggie is OK, too, I guess.......


Yes, the Bus is a bit different...Nicer to fly, easier to fly. I never flew the 747, but have a few hours in the 737 series (like maybe over 12,000), and also enjoyed the 727 (really nice machine).


PantLoad

[john_tullamarine]

I'd like to 'play' with V1 cuts under various conditions

more strength to you, good sir ... the main constraint is dollars ... at the end of the day someone ends up paying for the extra time ... but most of us manage to cheat a bit with the assistance of kind hearted sim techs ..

I always liked to find time on endorsement programs to get the guys and gals comfortable with min V1 aft cg cuts with a requirement to backtrack out along the opposite LLZ for initial climb .. worked up progressively most had no real problem.

The other thing to keep firmly in mind is fidelity .. the particular sim may, or may not, represent the aeroplane's dynamics well. However, provided that the dance appears reasonable there is a generic confidence building benefit to be had ...

As I said to one SAA crew some years ago ... "ok, chaps .. time to call it quits .. that's about as difficult as I can make it for you ..." .. the boys were a bit sweaty but with grins from ear to ear ... sitting in the back, one gets a real buzz when the folks up front

(a) improve

(b) do well

(c) enjoy

[BelArgUSA]

Quoting John T. above -

The other thing to keep firmly in mind is fidelity... the particular sim may, or may not, represent the aeroplane's dynamics well.

Definitely a concern about "some" simulators (sorry, Microsoft Play Station 747 captains)...
xxx
I personally find simulators quite similar to the airplanes (after all, simulators are just training devices) that they are supposed to represent. Some are better than others, obviously. One thing I find simulators to somewhat being exagerating, is "instruments" pitch and/or bank effect on vertical speeds and flight paths. But that exageration is a "plus" in teaching to fly instruments approaches such as an ILS. If you are mastering instrument flying in a simulator, you are likely to do good in the aircraft.
xxx
One thing however is the visual portion of the simulator. That is, the effect on the picture "you see" in front of you... Bank (as seen on the visual) is no problem, you bank 20º, you get 20º with your "horizon". Where there is a lack of "fidelity" is (somewhat) on the pitch axis, and to an extreme on the yaw axis translation of "sim movements/effects" to the picture you see on the visual.
xxx
Let me explain here. And I got an explanation...
Scenario - A takeoff with an "engine failure". You counteract the asymetric trust by a somewhat "slight" rudder input. But visually, your whole picture swerves violently from nose 30º+ left to 30º+ right of the runway. This is definitely not realistic to airplane dynamic reactions.
xxx
In the late 1980s, I had to go through a PanAm classroom/simulator training week of new check-captains/instructors and examiners. We discussed the subject of simulators good and bad points, and the "visual cues". We had that day, the chief simulator maintenance technician to give us some info.
xxx
He explained that the "visual" system was based on the "simulator" hydraulic inputs to the visual system computer (and tons of technicalities). Talking about "yaw axis" visual effect - the picture is using a yaw axis (vertical axis) which is the simulator itself (2 or 3 feet behind the pilot seats). In the "real airplane", the yaw axis (in a 747) is some 110 feet behind your flight deck. If you "yaw" around a "simulator axis", the visual effect is completely different from a real 747 airplane. The "short arm" amplifies the visual effect.
xxx
Same explanation followed for the pitch axis... although the visual inputs for pitch axis seem not to create problems to pilot trainees. The result, as we all discussed, is to pay "less" attention to visual cues, as compared to instrument cues. You basic "T scan" is primordial for any maneuvers.
xxx
No wonder that most pilots say (after their first flight in the "real airplane") that the "actual" aircraft is easier to fly than the simulator at the academy. Definitely my opinion too.
xxx
As John T says, I also try to wrap-up a 2 hrs session in 90 minutes and play funny games with the guys, off curriculum, i.e. 3 engines "out" approaches in a 747... and try myself new "compounded failures and emergencies". Play the scenario of the El Al Cargo Amsterdam double engine failure, and try to survive (which we can often survive). We also try to fly "Al Haynes" no hydraulics approaches, etc... it is your simulator, enjoy, have fun... and learn.
xxx
PantLoad - always be nice to your sim instructors or check-captains, and do not forget after your 2 liters of sweat, and paperwork, the debriefings are at the bar, and the tab is on you, for your F/O, F/E and me. At least 2 rounds, and maybe 3 rounds (to excuse that mistake you made and I closed my eyes for) -
xxx
:)
Happy contrails

[Basil]

(to excuse that mistake you made and I closed my eyes for)
. and there we were thinking you hadn't noticed :):O

[BelArgUSA]

Basil - please - dont try to be politically correct.
xxx
The reason is actually combination of alzheimer, dislexia or digestion "siesta" of the TRE...
Did I really snored that loud...?
xxx
:rolleyes:
Happy contrails - zzzzzzzzzzzzzzzz