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Guest Cantuezel

PNF-commands?

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Guest Cantuezel

Hi,in the Videos at http://a330.net/ I listened to the voice of the Pilot non flying (PNF)during take-offs and landings:1) As it is simulated in the PMDG the PNF at Takeoffs says "80" (knots), then "Go!" and at last "Rotate".My questions:a) Does "Go!" means the same as "V1" or simply "1"? If yes, is it up to every pilot if he says "Go!" or "V1" or is it part of an "airline-philosophy/routine" or does that even differs from pilots in the US and in the EU? (I thought that there is kind of an ICAO-standard for that etc...):( After the command "Rotate" of the POF I miss the command "V2" or simply "2" for indicating V2-speed. So is it possible today to do a correct takeoff without that V2-command?c) Is it kind of a rule that at Takeoffs the speed of "80" is announced or does that differs from Airline to Airline? Generally, for what technical purpose is the speed of *"80"* knots important and so announced for the PNF?2) After landing and (Auto)braking to reduce speed the PNF nearly in all videos says "70" (knots). Is that only important to idle (cut off) reverse engine thrust (braking) or is there another reason (steering etc.)?3)Back to Takeoffs: Until which speed on an airplane taking off has to be steered (to stay on the RWY-centerline) by the nose wheel steering and from which speed on it is steered by the airplane`s rudder (yaw)?4) Is a jet-airplane taking-off or reducing speed on the RWY also steerable by the ailerons? Many thanks GreetingsSusan

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Guest ahmedem

I'll try to answer some of these:1a) Go is the same as V1 its airline standard operating procedure (SOP) as to what you say exactly, Lufthansa use Go.1b) I assume they no longer bother with V2, the PF would (I guess) look into the cockpit after rotation, given PFDs carry so much info, incl speed then there is no need for the call.1c) 80kts is where I believe the aircraft starts to use the rudder as opposed to the nose wheel steering for directional control, they also crosscheck the airspeeds are the same on both sides PF and PNF.2) AFAIK The pilots usually decide what speeds to call on the rollout based on what runway exit they want to use both to cutoff rev thrust and for manual braking (disengage autobrakes).3)see 1c4) not unless you want to lose your job/life.I'll probably be corrected by the more well informed persons on the forum but this is what I've been told by those in the know.Rgds,

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Hi Susan,>a) Does "Go!" means the same as "V1" or simply "1"? If yes, is>it up to every pilot if he says "Go!" or "V1" or is it part of>an "airline-philosophy/routine" or does that even differs from>pilots in the US and in the EU? (I thought that there is kind>of an ICAO-standard for that etc...)I think this is up to the airline's SOP. As long as both pilots are trained on the same procedures. And I don't think the PMDG NG F/O says "Go". I think it is supposed to be "V1". V1 is the speed where the crew/captain decides if it's a GO or STOP run. After V1 all emergencies except the most critical will be handled in the air.>:( After the command "Rotate" of the POF I miss the command>"V2" or simply "2" for indicating V2-speed. So is it possible>today to do a correct takeoff without that V2-command?As PF you should look at your F/D pitch bar and that should give you V2+20. I don't know if it is necessary for the PNF to call out "V2". The earlier call outs I would suspect are done because the PF will be heads up steering straight down the runway! :-)>c) Is it kind of a rule that at Takeoffs the speed of "80" is>announced or does that differs from Airline to Airline?>Generally, for what technical purpose is the speed of *"80"*>knots important and so announced for the PNF?I know for a fact that Scandinavian Airlines SOP doesn't include the 80 knot call-out. So again I would say this is airline specific.>2) After landing and (Auto)braking to reduce speed the PNF>nearly in all videos says "70" (knots). Is that only important>to idle (cut off) reverse engine thrust (braking) or is there>another reason (steering etc.)?I am guessing here but I think this could have something to do with rudder authority as well. Over 80 knots the rudder becomes effective and wheel steering should be avoided and vice versa.>3)Back to Takeoffs: Until which speed on an airplane taking>off has to be steered (to stay on the RWY-centerline) by the>nose wheel steering and from which speed on it is steered by>the airplane`s rudder (yaw)?See above. Guess it varies a bit from A/C to A/C but around 80 knots.>4) Is a jet-airplane taking-off or reducing speed on the RWY>also steerable by the ailerons? I would not try that as it would tend to distribute a large amount of weight/force to one of the main landing gears. As well as getting a bank angle. You want your A/C straight and level during take-off roll. As soon as airborne you'll have to compensate for cross winds etc though.I'm sure more knowledgegable people will correct me if I'm dead wrong here. Would be interesting to see what one of the frequenting real world drivers say about your questions.Cheers,


Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

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Hi Mats. Regarding the part where you said that it is not ok to bank the airplane during takeoff run: I agree with you here, there shouldn;t be a bank, but perhaps not related to landing gears. The reason I say so is because (as you probably know having a good deal more experience than me) whenever landing into a crosswind it is common procedure to bank the aircraft into the wind and use opposing rudder to maintain rwy heading; and many times this is carried throughout touch down such that the landing gears ipsilateral to the lower wing touch the ground first, thus receiving a great deal more stress than usual. The truth is I know this for a fact in the general aviation world where airplanes don't wheigh more than a couple tons; but I'm pretty sure a friend of mine who drives 777 for a living told me the same happens in the big birds. I'll confirm though.Please correct any mistakes.Best Regards,Victor http://www.precisionmanuals.com/images/forum/800driver.jpg


Cheers,
Victor M. Lima
 

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Victor,You are most probably right! And thinking abit more about the weight thingie it makes sense. At higher speeds where the ailerons are effective the lift from the wings are considerate and will relax the gears from stress. And they are, as you rightly state, under much more stress during a crosswind landing. Thanks,


Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

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With regards to the '80 knots' command. I have heard both 80 and 100, and these are generally used to signify what will cause the PF to reject the takeoff...similar to V1.Here is my understanding...Anything less than 80 knots, PF will make a decision as to whether or not to continue takeoff or abot.80 -> V1 only significant emergencies will be refected...e.g. an engine fireV1 -> all emergences get worked in the airI'm am sure there are more knowledgeable individuals that can give more specific examples of emergencies in each bucket.EDIT: A few other items popped to mind...1. This call gives the PF a chance to verify that his ASI is working and crosscheck it against the PNF2. I verify that THR HOLD is annunciated on the PFD indicating that selected takeoff power is set. This annunciation occurs around 82 kts.Hope this helps


Jeff Hepburn

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Guest PittsburghII

Hi Susan, Let me just pitch in here regarding the termination of reverse thrust: One of the primary reasons that reverse thrust is terminated at around 60 kts is that at that speed the reverse thrust is actually powerful enough to blow debris on the runway forward after which it can be sucked up by the engine. I was actually pretty surprised when I head that that was the reason: You have a high tech airplane, and then it is the little piece of rock that causes this :-)Hope this helps,Boaz

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Guest neeraj.pendse

Susan:(A) Everyone talked about crosswind landings but no one said anything about crosswaind takeoffs! One would use ailerons on crosswind takeoffs to lower the wing on the side from which wind is coming. This is follows the same basic principle of "bank into the wind with aileron, keep straight with the rudder". Typically in strong crosswinds you would start with large UP aileron input to the side where wind is coming from, and then decrease this as speed increases and ailerons become more effective.So yes -> AILERONS WILL BE USED FOR DIRECTIONAL CONTROL ON TAKEOFF!(:( Question about rudder effectiveness: Yes the rudders starts to get effective slowly, but the 'pedals' control the nose wheel as well as the rudder ... in most general aiviation planes and in Boeings as well. So all the pilot really does is 'do whatever it takes to keep the airplane tracking centerline' ... whether it's the nosewheel or the rudder that is doing the job no one bothers!Now, interesting question to Airbus (real world) drivers: how does that work on a crosswind takeoff?You are asking very interesting questions by the way, the kind of stuff computer-heads driving NGs don't think about. - Neeraj

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Guest

Aren't you too close to the ground to be dipping the wing down while taking off?

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Guest BobLee

Actually, you are not "dipping" the wing. What you are trying to di is hold the upwind wing level and not allow the crosswind to lift it sooner than the downwind wing. As you approach flying speed, the control inputs are gradually eased until back to neutral.Bob--

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Guest neeraj.pendse

> Actually, you are not "dipping" the wing. What you are>trying to di is hold the upwind wing level and not allow the>crosswind to lift it sooner than the downwind wing. As you>approach flying speed, the control inputs are gradually eased>until back to neutral.That is exactly right. You are only holding it level with the aileron input. Now it might just happen that because of slight imperfections the downwind wheel will lift earlier ... but that is not the intention.One way explain this is that the upwind wing tends "get lifted" by the wind. Although it is a controvesial point of view, it helps to understand ... some times.- Neeraj

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Guest oldngray

>Hi,>>in the Videos at http://a330.net/ I listened to the voice of>the Pilot non flying (PNF)during take-offs and landings:>>c) Is it kind of a rule that at Takeoffs the speed of "80" is>announced or does that differs from Airline to Airline?>Generally, for what technical purpose is the speed of *"80"*>knots important and so announced for the PNF?>If I may....80 knots is generally the speed in "heavy" aircraft where the PNF has scanned all critical systems and all things are "go". (any aircraft that has a max gross weight of 12,500 lbs or less is considered to be a "light" aircraft.>2) After landing and (Auto)braking to reduce speed the PNF>nearly in all videos says "70" (knots). Is that only important>to idle (cut off) reverse engine thrust (braking) or is there>another reason (steering etc.)?The PNF is watching the airspeed, while the PF is watching the runway and controlling the direction of the aircraft. The call for "70" would be to alert all crew that it is safe to terminate reverse thrust and use normal braking.>>3)Back to Takeoffs: Until which speed on an airplane taking>off has to be steered (to stay on the RWY-centerline) by the>nose wheel steering and from which speed on it is steered by>the airplane`s rudder (yaw)?Generally, in heavy aircraft the rudder is not used to effectively steer the aircraft while the weight of the aircraft is on the nose wheel. When the weight comes off the nose wheel, alignment is held by the rudder. >>4) Is a jet-airplane taking-off or reducing speed on the RWY>also steerable by the ailerons? >It is not steerable by the ailerons but holding up aileron into the wind spoils the lift on that wing and conversely, the down aileron increases lift on the downwind wing thus tending to equalize the lift. Every certificated aircraft, regardless of size, must have a demonstrated maximum crosswind component. At some angle and windspeed, depending on the aircraft, it is no longer possible to keep the airplane properly aligned on the runway. Every air carrier has an sop that dictates the crosswind component beyond which no takeoff can be officially attempted.donmac

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I should have remembered that "lowering" the upwind wing is common procedure during takeoffs as well. Took a real flight in my light single-engine yesterday during a crosswind takeoff to remember though. ;)I wonder how 777 drivers have the guts to do it considering the ground allowence of those monsters under their wings!http://www.precisionmanuals.com/images/forum/800driver.jpg


Cheers,
Victor M. Lima
 

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Guest frankathl

Hi Susan,Some more comments below."a) Does "Go!" means the same as "V1" or simply "1"? If yes, is it up to every pilot if he says "Go!" or "V1" or is it part of an "airline-philosophy/routine" or does that even differs from pilots in the US and in the EU? (I thought that there is kind of an ICAO-standard for that etc...)"Well, I don

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Guest Cantuezel

Hi all,thanks again for all your input being sent here...:) :)>As a side note, in the ITVV Go 737 video, the PNF does not>call V1, either!>But I realy don`t understand that even the V1 call-out can be left nowadays: I thought that the PF has to watch only at the RWY until the plane has finished to rotate and positiv V-SPeed has been confirmed by the PNF! So until that point the PF realy has no time to look down to check V1, doesn`t he? >Above 80 knots, stop only for>Takeoff Config warning>Any fire warning>Control difficulties or blocked runway>PF needs to use the bathroom>Yea, great Frank!!! :) :) :) Mega-LOL!!>>"2) After landing and (Auto)braking to reduce speed the PNF>nearly in all videos says "70" (knots). Is that only important>to idle (cut off) reverse engine thrust (braking) or is there>another reason (steering etc.)?">>This is the speed at which the transition should be made from>autobrakes to manual brakes...>That leads to another question: Does the PF "feels" the braking actions of the *Autobreaks* (Mode 1 or 2) with his feet on the pedals? Or is it that way that there is no pressure/vibration at the pedals (that can be felt) when the plane is autobraking until that moment the pilots switch autobrake off and use the brakes (pedals) manually?Thank & greetingsSusan

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