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teropa

How is it really done?

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Hi all, a question for people who really know how to fly heavies...I understand that after calculating V speeds for take-off, pilots aim to fly the aircraft a V2+10 or V2+15 immediately after take-off until reaching acceleration altitude. I mainly use the LDS767, Wilco A320 (new version) and PMDG737 and I regard myself as an experienced user with these aircraft. I am also half way through my PPL at the moment.I find it difficult to maintain V2+15. I rotate the aircraft to the desired pitch when Vr is called, usually 15 degrees, or sometimes use the FD as the guide to the initial pitch. I find, by the time I get a positive rate I'm usually well over V2+15 and have to pitch the aircraft higher to slow it back down. Does the aircraft behave differently in real life, or do pilots ignore the V2+15 and just keep the aircraft stabilised at the speed they find after take-off? Thanks for reading and I hope someone can clear this up for me.Sam.

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Sounds to me like you are maintaining your T/O thrust throughout your climb out. Retard your throttle(s) when you have established your desired rate of climb to the airspeed you wish to hold.You can also engage your auto-throttle once the aircraft is established in a stabilized climb.John M

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I maintain my T/O thrust until thrust reduction altitude, usually set at 1500/2000 feet.

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There are many factors that come into play that determine what the attitude/airspeed of an airplane is during all phases of flight. Weight, windspeed,air density,obstacle avoidance and noise restrictions are some of the things we need to keep in mind during takeoff when we start talking about thrust and airspeed. Practice establishing the rate of climb first (the whole object of the takeoff is to get away from the ground as safely and quickly as possible) then manipulate the throttles to get the airspeed you want for your climb out. You will find that after a little practice you will get a feel for what attitude to set for your climb out and when to reduce your throttle settings to maintain your airspeed. Do this until it becomes one simultaneous motion. Use your VSI for pitch atitude and your throttles for airspeed. Depending on the factors I mentioned above you may find that you will need to retard your throttles earlier than what you've been doing.

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Whats the highest pitch you can achieve whilst regulating with airline requirements. I know that if you've got enough thrust behind you, pitch isnt really a factor, but in normal airline operations, what do they determine as a "max pitch"?

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>Whats the highest pitch you can achieve whilst regulating>with airline requirements. I know that if you've got enough>thrust behind you, pitch isnt really a factor, but in normal>airline operations, what do they determine as a "max pitch"?Those v speeds you ask about come into play only if you lose an engine. If all your engines are working, and you're not too heavy, you will normally blow through all those speeds near V2 very very quickly, often before you even leave the ground. As long as your engines are all working, just keep a comfortable nose up angle is all you will have to do and accept the accelerating speed. Usually, a 15-18 degree nose up angle is about as high as you want without making things uncomfortable for the passengers. Once you climb through the acceleration height, you can make the callouts for all those V+whatever speeds that you've gone through already all at once and start cleaning up the plane. It is only if you lose an engine on takeoff will you end up looking and waiting for each of those V+whatever speeds one by one to come up.

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In the USA, the FAA doesn't have a set "max pitch" attitude other than you can not operate an aircraft in an unsafe or reckless manner. So you can pitch your aicraft as high as it will go within the parameters set by the manufacturer (and ,of course, ATC restrictions). However, for the comfort (and possibly safety) of your passengers you will probably want to limit your max deck angle to 12-15 degrees. Again, this depends on the type aircraft and other factors.My personal experience is in light turboprops and jets flying mainly charters. Although not common, we have established 30* deck angles, or higher, going 5000'/min plus to get to altitude ASAP whether due to traffic or weather conditions....or to just show off.;) John M

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FAR 91.307 would limit the max pitch to 30deg unless everyone has a parachute, which they don't in an airliner.

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Pipersam: Do you takeoff using Autothrottle, TO/GA? And, if so, at what point do you activate/deactivate the Autothrottle?I usually set needed thrust to spool to stab. manually, and then engage autothrottle TO/GA all the way till Autopilot to Command. And maintaining/accelerating to desired speed using pitch only.

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You are correct. The only time you can exceed the 30* pitch/60* bank angle rule without having parachutes onboard is if the only people onboard are required crew members or for the purpose of flight training manuevers.John M

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Johan, what I tend to do is spool up to maybe 40% N1, and once things have stabilised, hit the TO/GA button. The engines then spool to take-off thrust, and i maintain that thrust using autothrottle until thrust reduction altitude. I also usally use a de-rated take-off thrust, plus a de-rated climb thrust. Unless I have an immediate altitude constraint, ie. level off at 3000ft to adhere to the SID, i will always use 100% of the thrust available (climb thrust) during climb, and use pitch to control speed. (I say I do.... I usually hit VNAV and LNAV after reaching 2000ft.)

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>Johan, what I tend to do is spool up to maybe 40% N1, and>once things have stabilised, hit the TO/GA button. The engines>then spool to take-off thrust, and i maintain that thrust>using autothrottle until thrust reduction altitude. I also>usally use a de-rated take-off thrust, plus a de-rated climb>thrust. Unless I have an immediate altitude constraint, ie.>level off at 3000ft to adhere to the SID, i will always use>100% of the thrust available (climb thrust) during climb, and>use pitch to control speed. (I say I do.... I usually hit VNAV>and LNAV after reaching 2000ft.)OK. So at thrust red. alt. you go manual and set thrust to desired speed? But the 100% climb thrust, is that With the de-rated climb?Anyhow.. After 2000ft AGL I usually arm LNAV & VNAV but still fly manually up to around 10 000. Then I go A/P to CMD.How do you manage the aircraft on approach/landing?Here I disengage A/P and autothrottle when I

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Johan, I usually let autopilot do the work for me after reaching 2000 feet. Am I lazy? Using the decent add-ons now available, for example, the new Wilco Airbus series 1, I program thrust reduction altitude to 2000 feet, and acceleration altitude to 3000 feet. The autopilot will automatically change the thrust settings appon reaching these altitudes. This also depends on the SID i'm flying. If short legs, and tight turns are in order, i leave the aircraft flying below 200 IAS so that it can complete the turns without overshooting them, and after that I will let the aircraft accelerate to 250IAS. Answering your question regarding the approach, it really depends on what mood i'm in. Usually I don't file a flight plan with the defualt FS9 atc, but instead just use flight following for traffic information, and fly the FMC stored flight plan as accurately as possible. Other times i will file a flightplan for ATC, for vectors to final. I usually let autopilot establish the aircraft onto the ILS and glideslope, and once the aircraft is in full landing configuration, (I like that to be usually 2500' indicated on the radio-altimeter) i will disengage the autopilot, and fly the approach myself, and then once at about 1000' i will disengage the autothrottle.

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This is specifically for the 763, initial climb:After liftoff, use the FD as your pitch reference (cross checking ind. airspeed and other instruments). If the FD is NOT used, your airspeed and attitude are you're primary pitch references.The FD commands pitch after liftoff to maintain a target speed of V2+15 to 25 knots until another pitch mode is engaged. In other words, don't engage LNAV or VNAV before takeoff. V2+15 is the optimum climb speed with takeoff flaps. It results in the max. alt. gain in the shortest distance from takeoff. Acceleration to higher speeds reduces the altitude gain. If the airspeed exceeds V2+15 during the initial climb, stop the acceleration but do not attempt to reduce airspeed to V2+15. Any speed between V2+15 and V2+25 knots does not significantly affect the takeoff profile. Retract the gear after postive rate of climb, as indicated on the instruments. Do NOT apply brakes after becoming airborne, as it's automatically applied when the gear lever is placed in up. For an immediate turn after T/O, start the turn at the appropriate alt. (normally at least 400 AGL) and maintain V2 + 15 to V2 + 25 with takeoff flaps. Note the max bank angle of 30 degrees is permitted at V2+15 with takeoff flaps. After the turn, go ahead and your at or above flap retraction alt., accelerate and retract flaps whilst you climb.For your Autopilot engagement:It's FAA certified to allow engagement at or above 200ft AGL after takeoff. XXXXXX airlines recommended min. alt. for autopilot engagement is 1,000 AFE. The plane should be in trim, and the FD commands should be satisfied prior to turning it on. On the flap retraction schedule:At flap retraction altitude, which is usually 1,000 feet, select climb thrust, accelerate and retract flaps on the flap retraction schedule. VNAV is the recommended technique for acceleration. If VNAV is NOT used, then select FLCH and set the command speed to flaps up maneuvering speed. Check to make sure that the thrust reference changes from TO to CLB on the EICAS. If it doesn't change automatically, then go ahead and do it by hand. With your speed increasing, your probably wondering when to retract the flaps. Here's a few rules of thumb:For both the 757-200-767-300, when the airspeed reaches the maneuvering speed "F" for the existing flap position. Note that the maneuver speed gives you adequate buffet margin for bank angles up to 40 degrees.Here's a nice little schedule:Flaps 20 or 15:---------Flaps 5 at VREF+20Flaps 1 at VREF+40Flaps up at VREF+60Flap 5 T/O----------Flap 1 at VREF+40Flaps up at VREF+60----------Final climb - VREF+80Hope this helps ya. If you have any more questions on flying the 767-300, let me know some way, some how (PM)!

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Pipersam: Interesting. You seem like an "airbus-dude" while I

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Thanks for the replies guys its really helped me out!!I'm actually definately more of a boeing guy!! I've just enjoyed flying the wilco/feelthere a320 recently. Its no where near as good as level-d or pmdg, but then i guess i'll have to wait till pmdg do the airbus'!!

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One thing that hasn't been mentioned yet I think is the usage of proper derated thrust for takeoff.If you do max power takeoffs on a light or semi-light 767, you will not be able to arrest the speed for V2+15 to V2+25 in any sensible climb angles.However, if you use a properly calculated assumed temp (I am talking Level-D here), you will see a much attenuated takeoff performance, which should leave you to anywhere between 15 to 20 degrees nose up on initial climbout, and speed arrested between V2+15 and V2+25.Rotation should be swift at Vr, but no more than 2.5-3 degrees per second. Do not chase the flight director, but after liftoff gently pitch up to 15 degrees and as you see the speed building up even approaching 15 deg, pitch up until the acceleration is halted. But no need to pitch up so much that you would decelerate to or below V2+25. Just accept the speed you end up with when you finally arrest the acceleration.On a very light aircraft with max takeoff thrust you could be needing as much as 25 degrees nose up or more, but Boeing recommends arresting pitch up at 25 degrees ANU. Hope this helps.rgdsTero

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Thanks for the info. The trouble is I don't understand how to calculate the assumed temperature. I don't usually fly the LDS for trips longer than 2000nm so the aircraft is usually very light, and I punch in between 52 degrees C for the assumed temperature. Is there a calculation sheet out there to correctly determine the temperature? Many Thanks,Sam.

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For the 747.. I'd handle my takeoffs a little differently.. Normally LNAV and VNAV are armed at the gate before I even taxi out to the threshold.. Climb thrust is set at the gate.. flaps are set just after start or on route to the threshold... Once crossing the threshold strobes go on and I arm the autothrottle at this point and line up..Once lined up with runway I advance the throttles to about 70% N1.. and wait for the engines to spool up and become stable.. (doesn't take too long).. at that point I activate TO/GA and the autopilot holds the desired thrust for take off.. as it's setting that THR REF is shown.. There is a thrust setting shown within the FMC pages and this must correspond to that shown on the EICAS, when it does.. "Power Set" is called.. after 80 knots.. THR REF becomes HOLD as the autothrottle is now holding the current thrust requirement for takeoff.. it's not armed to aquire a target speed at this point.. V1 passes.. and VR passes.. and I slowly pitch the nose up to a quite gentle ascent first.. no more than 12 degrees and usually less.. to ensure no tail strikes.. Once the Radio Alt shows 40 feet.. I bring the pitch of the nose up gently to maintain the current airspeed whatever that might be.. Usually within the V2+10 - V2+20 range.. call "Postivie Rate" and retract the gear.. As the gear is stowed you'll find there is a bit more pitch to apply as the drag reduces with the gear out the airflow.. After about 500 feet I can engage the A/P (you can of course fly SIDs maually too)..NOW.. depending on my weight.. and the SID.. I make an assessment as to where I will set the acceleration height.. IF my weight is high.. and the SID profile requires a steep climb.. for example WOBUN 2F/2G at Heathrow.. (3000 feet at the first big turn) then I'll set acceleration height higher and flaps 20.. As a result in my climb after leaving the runway.. the climb rate will be higher for the initial stages and allow me to reach my first altitude target without too much difficulty.. Flaps from 20 to 10 are retracted fairly early.. but the acceleration beyond flaps 10 is limited till my new acceleration height is reached as a result the initial climb out is maintained for a longer period, this is all adjustable in the FMC at the gate.. I'd probably use 2,500 as my acceleration height in this situation.. as I am likely to reach 2,500 well before the turn at 3,000 ahead of me due to my more aggressive initial climb out.. so I won't fall short of the altitude set in the SID.. On this particular SID.. after the turn at BUR the aircraft will have just started it's acceleration.. flaps 10 to flaps 5.. de-rate thrust kicks in.. and the acceleration is reduced further but on this SID the next altitude target is a way away and as a result a slower climb isn't a problem..If I am light.. Acceleration height is set to somewhat more normal limits.. and flaps 10 used on departure.. However climb out and leaving the runway is done in the same manner.. but the setup of the autopilot for the SID will depend on weight, weather and the SID requirements.. Even in a light airplane the autopilot may need "encouragement" to get to the initial 3000 feet target of the SID.. albeit a LOT less than for a heavy airplane..Not sure if that helps you..CheersCraig

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