Jump to content

Archived

This topic is now archived and is closed to further replies.

RobbieHe

Flap retraction schedule

Recommended Posts

It's great to see that FS9 is still being used by so many!My questions have to do with the flap retraction schedule.My take off reference is the following:V1 = 126Vr = 134V2 = 143The flap retraction schedule says:Vref30 + 20.....set flaps 5Vref30 + 40.....set flaps 1Vref30 + 60.....set flaps 0In reference to flap retraction, what does Vref mean?What specific airspeeds then do I need to use for the above situation?Thanks in advance! Hope all of you (Americans at least) are enjoying a great ThanksGiving! RH

Share this post


Link to post
Share on other sites

Hi,Vref30 is your Flap 30 landing speed. If you don't have the luxury of an onboard FMC then you need to calculate your vref from your Take off weight. So for example if your current weight and ambient conditions are giving you Vref30 150 knots you would select flaps 5 at 170 knots etcWhat aircraft do you fly? here's a handy tool for the 747, A320, 767http://www.topcatsim.com/?page=downloadRob


Rob Prest

 

Share this post


Link to post
Share on other sites

Thanks for the response. I will not associate the Vref30 with landing speeds and not flap retraction.I am using the Level D 767 and am wanting to know about flap retraction speeds. Based on the information given in my initial post, how would I figure out the flap retraction speeds? With the Level D, is there an easier way? Thanks,RH

Share this post


Link to post
Share on other sites

> how would I figure out the flap retraction speeds? Exactly as Rob explained...You need to have a table with Vref30 landing speeds.Vref is used in a lot of calculations and flap retraction speeds is one of them.


Location: Vleuten, The Netherlands, 15.7dme EHAM
System: P3D V4 - 80386 DX2 - 4MB RAM - 3dfx Voodoo5 - Windows 3.11

Share this post


Link to post
Share on other sites

EDIT:I have uploaded a Vref30 table for you.Click save as on picture:763_vref.gif


Location: Vleuten, The Netherlands, 15.7dme EHAM
System: P3D V4 - 80386 DX2 - 4MB RAM - 3dfx Voodoo5 - Windows 3.11

Share this post


Link to post
Share on other sites

Hi,If you are using the Level D 767 all your speeds are calculated through the FMC and it's all in the Documentation. If for some reason I decided to fly the 747-400 with all automatics and F/D off (and no FMC) as long as I knew the gross weight of the aircraft I could look at the performance charts find vref30 and then calculate my flap retraction speeds from there.But as I stated before 'TOPCAT' will do this all for you. A large number of real world airlines provide there crew with laptops with software providing the Performance Calculation'sYour asking if there is an easier way but I assume if you paid money for a complex sim surely you want to do it the way real crew do?Rob


Rob Prest

 

Share this post


Link to post
Share on other sites

Thanks for the table, but what exactly does VREF30 + 80 or the VREF25 stand for? I am trying to get a sense of what it means.Thanks,RH

Share this post


Link to post
Share on other sites

On what part (page) of the FMC are the flap retraction speeds listed? Is it the V1 Vr and V2 speeds listed?Thanks,RH

Share this post


Link to post
Share on other sites

>Thanks for the table, but what exactly does VREF30 + 80 or>the VREF25 stand for? I am trying to get a sense of what it>means.>>Thanks,>>RHVref30 stands for the reference speed at Flaps 30.Vref is the landing reference speed and is minimum safe landing speed. It is calculated based on the stall speed of the selected flap setting.If I recall correctly Vref = Vs * 1.3For example, you TOW is 360k lbs, Vref30 is 159So Vref30 + 80 = 159 + 80 = 239ktshttp://en.wikipedia.org/wiki/V_speeds#VREF


Location: Vleuten, The Netherlands, 15.7dme EHAM
System: P3D V4 - 80386 DX2 - 4MB RAM - 3dfx Voodoo5 - Windows 3.11

Share this post


Link to post
Share on other sites

>On what part (page) of the FMC are the flap retraction speeds listed? They are not listed in the FMC.You either calculate them, or on most ADI's they are visible on the speed tape as little green numbers (Boeing style)


Location: Vleuten, The Netherlands, 15.7dme EHAM
System: P3D V4 - 80386 DX2 - 4MB RAM - 3dfx Voodoo5 - Windows 3.11

Share this post


Link to post
Share on other sites

OK, I will look for them. I am running a flight right now. Thanks, buddy for your responses.Much appreciated!RH

Share this post


Link to post
Share on other sites
Guest UKPilot

The way its calculated in real aviation for landing is for example on the 737 is that you look at the progress page 1 and work out how much fuel you will burn between now (usually done just before top of descent in the arrival brief) and the fuel you will arrive with, then go to the init ref page and write the new landing weight over the current gross weight, this then gives you new VRef speed for flap 15, 30 and 40. you can the adjust the amount you will fly in accrodance with the wind. At my company we always fly at VRef + 5 for landing regardless of which flap setting (usually 30 on the 737's), for the wind its usually half the headwind plus ALL the gust increment up to a maximum of VRef + 20.Hope this helps.

Share this post


Link to post
Share on other sites
Guest UKPilot

Well, again from the real world, we have laptops that caculate the real 'v' speeds because as I'm sure your aware they are dtermined by a lot of external factors. However with the 737 take off flap is 'normally' 5 or 1, retraction speeds for flap 5 is based on being above v2 + 20 and accelerating to go to flap 1 and then once your above 190 and again accelerating to go flap up.With bigger a/c like 76 and 74 you have to be aware of flap limiting speeds as high weights can mean you can easily bust through these speeds.Hope this helps!

Share this post


Link to post
Share on other sites
Well, again from the real world, we have laptops that caculate the real 'v' speeds because as I'm sure your aware they are dtermined by a lot of external factors. However with the 737 take off flap is 'normally' 5 or 1, retraction speeds for flap 5 is based on being above v2 + 20 and accelerating to go to flap 1 and then once your above 190 and again accelerating to go flap up.With bigger a/c like 76 and 74 you have to be aware of flap limiting speeds as high weights can mean you can easily bust through these speeds.Hope this helps!
Interesting, thanks again!RH

Share this post


Link to post
Share on other sites

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    28%
    $7,080.00 of $25,000.00 Donate Now
×
×
  • Create New...