Flap Maneuver speeds

[Guest Domino]

I believe that the EADI Flaps Maneuvering Speeds Logic on the EADI is not correct.E.g.Flap retraction during TakeOffTakeOff Flaps setting:20The maneuvering Speeds displayed on the Speed Tape of the EADI works at the moment as follows:After LiftOff and starting acceleration you can see at first the Flaps "10" Maneuvering speed displayed.Normally at this speed marker you retract Flaps 10 (Flap Sequence 10 > 5).By PMDG the Flaps 10 Maneuvering Speed "10" Marker is removed immediately after Flaps 20 retraction.Remark:"As a result the other Flap retraction speeds are also affected and faulty e.g."5" normally indicates that at this point Flaps 1 should be selected"I asume that PMDG has interchanged the Minimum Maneuver Speed with the Flap Maneuver Speeds?! If the Boeing 747-400 Flap Retraction Logic is the same as by all other Boeing types this behavior is wrong.Note:The Flap extension logic is correct.I am waiting for your commentsWith best regardsMichael from Austria

[Airbrakes 0]

The 747-400 (as with all other Boeings) schedules the flap retraction speeds based on increments of 20KTS and in landing configuration. On the 744, this is Vref30. Vref30 + 20 = flap 20 retraction speedVref30 + 40 = flap 10 retraction speedVref30 + 60 = flap 5 retraction speedVref30 + 80 = flap 1 retraction speedThis is the information that is relayed to the PFD. The flap extension speed for a particular detent is not important when you are accelerating, and serves no real purpose. As some CFI's say; "The runway behind you is useless". Flap extension speeds will only appear on the PFD after you select a landing runway and a Vref. After you reach the AH, your focus should be set on cleaning up that airplane ASAP. On a side note, there is a pitch limit indicator that appears on the attitude indicator while the flaps are extended. The pitch limit indicator notates the highest AOA you can endeavor without stalling the aircraft.It is also worth noting that these speeds aren't the minimum or maximum maneuvering speeds. The minimum and maximum maneuvering speeds are indicated by the amber and magenta lines next to the speedtape.

[stefltt 11]

According to the real B744 FCTM, the flap maneuvering speed is the recommended operating speed during take off and landing operations. These speeds guarantee at least full maneuver capability or at least 40° of bank (25° of bank and 15° overshoot) to stick shaker within a few thousand feet of the airport altitude. The following is flap maneuvering speed for various flap settings :Flaps UP = Vref30 + 80Flaps 1 = Vref30 + 60Flaps 5 = Vref30 + 40Flaps 10 = Vref30 + 20Flaps 20 = Vref30 + 10Flaps 25 = Vref25Flaps 30 = Vref30Takeoff Flap Retraction Speed ScheduleAccording to Boeing :During flap retraction, selection of the next flap position is initiated when reaching the maneuver speed for the next flap position. The flap retraction schedule for the 747 differs from other Boeing models because the flaps are not retracted until the maneuver speed for the new maneuver flap position is reached. For example, flap5 is selected after reaching flaps 5 maneuver speed.The maneuver speed for the existing flap position is indicated by the numbered flap maneuvering speed bugs on the airspeed display.Takeoff Flaps 20at "display" 10 (Vref30 + 20) ==> select Flaps 10at "display" 5 (Vref30 + 40) ==> select Flaps 5at "display" 1 (Vref30 + 60) ==> select Flaps 1at "display" UP (Vref30 + 80) ==> select Flaps UPTakeoff Flaps 10at "display" 5 (Vref30 + 40) ==> select Flaps 5at "display" 1 (Vref30 + 60) ==> select Flaps 1at "display" UP (Vref30 + 80) ==> select Flaps UPFlap Extension ScheduleDuring flap extension, selection of the flaps to the next position (flap transition speed FTS) should be made when approaching, and before decelerating below the maneuvering speed for the existing flap position. The flap extension speed schedule is based upon Vref30 and provides full maneuver capability or at least 40° of bank (25° of bank and 15° overshoot) to stick shaker at all weights.Current flap position UPat "display" UP (FTS Vref30 + 80) ==> select Flaps 1 ==> Command speed for selected flaps "1"Current flap position 1at "display" 1 (FTS Vref30 + 60) ==> select Flaps 5 ==> Command speed for selected flaps "5"Current flap position 5at "display" 5 (FTS Vref30 + 40) ==> select Flaps 10 ==> Command speed for selected flaps "10"Current flap position 10at "display" 10 (FTS Vref30 + 20) ==> select Flaps 20 ==> Command speed for selected flaps "20"Current flap position 20at "display" 20 (FTS Vref30 + 10) ==> select Flaps 25 or 30 ==> Command speed for selected flaps (Vref25 or Vref30) + wind additives

[Guest Domino]

This is correctAccording to the real B744 FCTM, the flap maneuvering speed is the recommended operating speed during take off and landing operations. These speeds guarantee at least full maneuver capability or at least 40° of bank (25° of bank and 15° overshoot) to stick shaker within a few thousand feet of the airport altitude. The following is flap maneuvering speed for various flap settings :You have not understand it correctly?But this is not the answer.You have nit interpreted correctly.Sorry but it is so.When you read as an example the B737NG FCOM you will find the truth!TakeOff Flap Retraction Speed Schedule (B737Ng ALL) TakeOff Flaps At Speed (display) Select Flaps25 V2+15 15 "15" 5 "5" 1 "1" UPDo you see it?!At "15" you select Flaps 5 not Flaps 15!!!!At "5" you select Flaps 1 not Flaps 5!!!!And so on.The same display logic you will find by all other Boeing Aircraft (B777,B767 and so on).Why the Boeing 747-400 should have an other display logic?????????????I am waiting for your hopefully "proffesional" commentsMichael

[Guest Domino]

Think logicalWhy my described Display logic must be the correct ones?As you have written in your replay the Flap Maneuver Speed is an indicator for maneuver capability of the aircraft.Is it logical that this Maneuver reference is removed when you fly actually with the corresponding Flap setting?No!Actually by PMDGs B747-400 it works in this way that the Flaps 10 Maneuver capability indicator is removed from the display when you deselct Flaps 20.Okay you fly now with Flaps 10 and have no reference?!Note:In the PMDG 737NG the TakeOff Flap retraction Display logic is correct > Test it if you do not believe :-)In my last replay the Flap retraction speed schedule is not clearly readable so I try it know a second time TakeOff Flaps / At Speed (display) / Select Flaps........25........... / .....V2+15................./ ..........15............................... / ......"15"..................../ ...........5................................. /........"5"..................... /...........1................................./.........."1"................... /............UP.......LIMIT bank angle to 15° until reaching V2+15You can see it when you have actually Flaps 15 selected the Flaps 15 Maneuvering Speed Indicator is not removed due to the fact that it is needed as a reference for the actual Maneuver Capability!That the Flap Maneuver Speeds are referenced to VREF30 by the B747-400 I know.The same VREF logic you will find also by the B737NG the B777 and B767 and so on..e.g.B737Ng Flap Maneuver Speeds FLAPS UP.....VREF40+70Flaps1...........VREF40+50Flaps5...........VREF40+30Flaps10.........VREF40+30Flaps15.........VREF40+20Flaps25.........VREF40+10Flaps30.........VREF30Flaps40.........VREF40This Flap Maneuver Speed indications are very important to assist flight crews in flying the aircrafts safely.If the PMDGB747-400 indications are not working correctly (I believe so) it is not a smal error it is a big error and must be corrected!Thanks for your replays Michael

[Airbrakes 0]

This Flap Maneuver Speed indications are very important to assist flight crews in flying the aircrafts safely.If the PMDGB747-400 indications are not working correctly (I believe so) it is not a smal error it is a big error and must be corrected!

It is also worth noting that these speeds aren't the minimum or maximum maneuvering speeds. The minimum and maximum maneuvering speeds are indicated by the amber and magenta lines next to the speedtape.

[Guest Domino]

Hello ThBat...Okay the minimum maneuver speed is also an usefull information but should not be overrated.In any case you do not retract Flaps refferenced to the minimum maneuver speed I hope so:-)You are alive?The Flap Maneuvering Speed is the recommended operating speed during takeoff and landing operations. Best regardsMichael

[Airbrakes 0]

Hello ThBat...Okay the minimum maneuver speed is also an usefull information but should not be overrated.In any case you do not retract Flaps refferenced to the minimum maneuver speed I hope so:-)You are alive?The Flap Maneuvering Speed is the recommended operating speed during takeoff and landing operations. Best regardsMichael

You're confusing the Vspeeds. Flap extension/retraction speeds aren't anywhere near the minimum or maximum maneuver speed. There is a difference between Vfe and Vf. You're looking at Vf expecting it to be Vfe. Vfe isn't displayed on the PFD of any aircraft. Vfe is a placarded speed that is placed on the glareshield. Vf is displayed on the PFD, but ONLY after you select a arrival runway and Vref. If the AFDS doesn't know you're intending to land, then it isn't going to assume you are.And yes, the design flap speeds are reversed on takeoff. Vref30+80 is your minimum clean speed, and that should be your target speed after you reach the AH. During acceleration, Vref30+80 is when you would select flaps 0, or the clean configuration. On descents and during deceleration, Vref30+80 is where you would select flaps 1. This is not your stall speed, or Vso, but design flap speed, Vf. You can clean up the airplane at Vref30+60 and not stall it.If your concern is stalling or overspeeding the aircraft, then you're looking at the wrong section of the PFD. Vso, Vsi, Vno, and Vmo are represented by the amber and magenta lines next to the speed tape.

[Airbrakes 0]

My apologies for the double-post but one more item needs to be noted....Why are you flying around after T/O with the flaps out? You want to get rid of the added drag created by the flaps ASAP. If your clean speed is over 250KTS then you can get a 'free speed' clearance from the controller.You only need the flaps out longer depending on which noise abasement procedure is in use. ICAO-A calls for climb thrust to be set at 1500' and clean up at 3000'. ICAO-B calls for climb thrust and clean up at 1000'. For the sake of the sim, ICAO-B is the most commonly used procedure. At 1000' AGL, get rid of those flaps and accelerate to Vref30+80. :(

[martybuzz 2]

Kevin, I don't think you can explain it any more clearer than you have. Good read by the way.

[Guest Domino]

Hello AllVFE the maximum Flap extension speed is displayed on the PFD.You really do not know from what you are speaking about.Sorry for that but it is so.Do you know the term "Maximum maneuvering speed" (Structural limited)Flap limit placard speed (VFE) for the NEXT NORMAL flap setting.The display logic is based on a normal flap setting sequence of 1,5,15,30 (Boeing737NG).The bar is removed when the Flaps lever is moved to the landing flap selected (30"normal" or 40 detremined by the selected Landing Flap position on FMC APP REF page) or when the flap lever is moved to flaps 40 (B737NG).The term VF is not used?!Original Boeing Statement and recommendation (FCOM B737NG) During Flap retraction,selection of the next flap position is initiated when reaching the maneuver speed for the existing flap position.Therefore,when the new flap position is selected,the airspeed is below the maneuver speed for that flap position.For this reason,the airspeed should be INCREASING when selecting the next flap position.During flap retraction,at least adequate maneuver capability or 30° of bank (15° angle of bank and 15° overbank) to stick shaker is provided at the flap retraction speed.FULL maneuvering capability or at least 40° of bank (25° of bank and 15° overshoot) to stick shaker is provided when the airplane has accelerated to the recommended maneuver speed for the selected flap position.During takeoff begin flap retraction at V2+15kts,except for a flaps 1 takeoff,begin flap retarction when reaching the flaps 1 maneuver speed.With airspeed increasing,subsequent flap retarctions should be initiated when airspeed reaches the maneuver speed for the existing flap position.The maneuver speed for the existing flap position is indicated by the numbered flap maneuver speed bugs on the airspeed display.Note:No serious pilot fly without entering the Performave data in the FMC!My question was why is the PMDG B747-400 display logic different to all other Boeing types during Flap retraction.Is the actual programmed logic correct or not?Is there anybody how knows the answer to this question.It is not logic to remove the Flap 10 Maneuver Speed from the PFD when deselecting Flaps20 and selecting Flaps10!!Please give me a serious answer to my question.I am waiting for your serious feedback Best regardsMichael

[Matt2218 4]

You really do not know from what you are speaking about.Sorry for that but it is so.Please give me a serious answer to my question.I am waiting for your serious feedback

Several people have already given you your "serious answer" but you keep saying that they are wrong! The PMDG 747 is correct.Per page 9-9 of the manual, on the takeoff/initial climb the PFD cues the pilot to select the next appropriate flap setting once the appropriate speed has been reached. When you pass "10" on the speed tape, you can select Flaps 10. When you pass "5", you can select Flaps 5. When you pass "1" you can select Flaps 1, when you pass "UP" you can select Flaps 0. How much simpler could they have made this?The function is to INFORM THE PILOT WHEN TO RETRACT FLAPS on climbout based on Vref30 + 20, Vref30 + 40 etc. , not tell him/her what their safe maneuvering airspeed is at that time. As others have already noted, the PFD has amber/red markings for that which automatically account for the current flap setting. Let it go. Fly the airplane and retract your flaps on schedule.

[FLEX1978 373]

Hello AllVFE the maximum Flap extension speed is displayed on the PFD.You really do not know from what you are speaking about.Sorry for that but it is so.Do you know the term "Maximum maneuvering speed" (Structural limited)Flap limit placard speed (VFE) for the NEXT NORMAL flap setting.The display logic is based on a normal flap setting sequence of 1,5,15,30 (Boeing737NG).The bar is removed when the Flaps lever is moved to the landing flap selected (30"normal" or 40 detremined by the selected Landing Flap position on FMC APP REF page) or when the flap lever is moved to flaps 40 (B737NG).The term VF is not used?!Original Boeing Statement and recommendation (FCOM B737NG) During Flap retraction,selection of the next flap position is initiated when reaching the maneuver speed for the existing flap position.Therefore,when the new flap position is selected,the airspeed is below the maneuver speed for that flap position.For this reason,the airspeed should be INCREASING when selecting the next flap position.During flap retraction,at least adequate maneuver capability or 30° of bank (15° angle of bank and 15° overbank) to stick shaker is provided at the flap retraction speed.FULL maneuvering capability or at least 40° of bank (25° of bank and 15° overshoot) to stick shaker is provided when the airplane has accelerated to the recommended maneuver speed for the selected flap position.During takeoff begin flap retraction at V2+15kts,except for a flaps 1 takeoff,begin flap retarction when reaching the flaps 1 maneuver speed.With airspeed increasing,subsequent flap retarctions should be initiated when airspeed reaches the maneuver speed for the existing flap position.The maneuver speed for the existing flap position is indicated by the numbered flap maneuver speed bugs on the airspeed display.Note:No serious pilot fly without entering the Performave data in the FMC!My question was why is the PMDG B747-400 display logic different to all other Boeing types during Flap retraction.Is the actual programmed logic correct or not?Is there anybody how knows the answer to this question.It is not logic to remove the Flap 10 Maneuver Speed from the PFD when deselecting Flaps20 and selecting Flaps10!!Please give me a serious answer to my question.I am waiting for your serious feedback Best regardsMichael

Michael, I'm not sure why you keep referencing the 737, it's a different beast so let's leave it out of the topic. It sounds like your getting confused, I'm going to a have a read of the FCOM a little later, also up until last year my old man was a Captain on the 744 for five years so I'll forward this topic to him.Regards

[stefltt 11]

Several people have already given you your "serious answer" but you keep saying that they are wrong! The PMDG 747 is correct.

In the FCOM, Boeing has also provided a graphic (that I can't reproduce here unfortunately) that helps to understand the logic behind the flaps maneuver speed and flaps position. And YES, the B744 is different from other Boeing aircraft, it's the way the aircraft, the wing and the flaps are designed.The airplane maneuver margin or bank capability to stick shaker depends on the airspeed and the flaps position. Note that :- There is a direct correlation between bank angle and load factor (G's) in level, constant speed flight. For example, 1.1G corresponds to 25° of bank, 1.3G equals more or less 40°, 2.0G's equals more or less 60°.- Stick Shaker activates prior to actual stall speedFor the B744at V2 with Flaps 20 : the maneuver margin to stick shaker is 1.2Gat Vref30+20 with Flaps 20 : the maneuver margin to stick shaker is 1.53Gat Vref30+20 with Flaps 10 : the maneuver margin to stick shaker falls to 1.4Gat Vref30+40 with Flaps 10 : the maneuver margin to stick shaker is 1.68Gat Vref30+40 with Flaps 5 : the maneuver margin to stick shaker falls to 1.48Gat Vref30+60 with Flaps 5 : the maneuver margin to stick shaker is 1.72Gat Vref30+60 with Flaps 1 : the maneuver margin to stick shaker falls to 1.48Gat Vref30+80 with Flaps 1 : the maneuver margin to stick shaker is 1.7Gat Vref30+80 with Flaps UP : the maneuver margin to stick shaker falls to 1.3GWith a Flaps 10 takeoff, when you reach Vref30+40 (display "5") you select flaps 5, the flaps position goes from 10 to 5, the maneuver margin goes from 1.68G to 1.48G. But as the aircraft's speed is increasing towards Vref30+60, the maneuver margin is also increasing to 1.72G.When you reach Vref30+60 (display "1") with flaps 5, the margin is 1.72G, you select flaps 1. The flaps are retracting from 5 to 1, the maneuver margin goes from 1.72G to 1.48G. But as the speed is increasing towards Vref30+80, the margin is increasing from 1.48G to 1.7G.When you reach Vref30+80 (display "UP") with flaps 1, the margin is 1.7G, you select flaps UP, the maneuver margin falls to 1.3G but as the airspeed is increasing to 250KT or more, the margin is increasing again.In every case we cannot be below the 1.3G maneuver margin. This is the logic of the B744, the way the aircraft is built. The B738 is different and more complicated. The flaps position are not the same as the B744For the B738Speed - Flaps position - maneuver margin-----------------------------------------V2 - Flaps 15 - 1.4GV2+15 - Flaps 15 - 1.7GV2+15 - Flaps 5 - 1.54GVref40+30 - Flaps 5 - 1.7GVref40+30 - Flaps 1 - 1.6GVref40+50 - Flaps 1 - 2.0GVref40+50 - Flaps UP - 1.26GFor a flap 15 (or 10) takeoff : at V2+15 you select flaps 5, the margin drops to 1.54G.The speed is increasing with flaps 5.When you reach Vref40+30 (display "5") with flaps 5, the margin is 1.7G, you select flaps 1. The margin drops to 1.6G.the speed is increasing with flaps 1.When you reach Vref40+50 (display "1") with flaps 1, the margin is 2.0G, you select flaps UP. The margin drops to 1.26G.As the speed continue to increase with flaps UP the margin is increasing accordingly.

[Southwester 0]

Hi Michael,Some of the previous posters have explained it quite nicely already.To put it very simple...the logic on PMDG 747 is CORRECT !The 747 and 737 differ in their logic !I have a friend who flew 737 and now flies 747 and he has confirmed this !Hope this answers your question ?Happy landingsSouthwester