Jump to content

Archived

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

rsrandazzo

06MAY13 - PMDG 777 External Model Preview #1 of 2

Recommended Posts

("This" being- retracting the flaperon to shift the center of lift and increase the AoA?)

Okay, this might be a totally wild off the mark answer, but in the A321, some of us use a technique known as "De-Flaring" where by we actually push forward on the sidestick just before touch down to get a smoother landing.

 

This is due to the fact that if you push forward on the stick in the A321, the MLG actually raises up relative to the pitch axis due to their location relative to the point about which the aircraft is pitching, making for a smoother landing. Am I getting on the right track here, or barking up the wrong tree? Is this an automatic action in the 777? Does de-flaring make for a smoother landing?   :huh:

 

Regards,

Rónán.


Rónán O Cadhain.

sig_FSLBetaTester.jpg

Share this post


Link to post

Love them photos, How on earth will i avoid admiring the exterior during along haul flight, causing an appcrash, app hang in FSX followed by lots of sobbing etc. Can't wait!


Banner_FS2Crew_NGX_Driver.jpg

Share this post


Link to post

I have bought but not read. lol

haha lol.

 

It would be weird if someone had written " I read it but didn't bought it ".^^ :blink:


- René Mosek -
Future Owner Of: 'The PMDG 747-400 V3'  B)

 

Boeing777_Banner_Pilot.jpg

Share this post


Link to post

I believe the flaperon retracts to decrease AOA as part of the tail strike prevention system found on the 777...tail strikes are definitely chief pilot office visits ;)

 

Tail strikes are costly business, I can't remember what carrier it was but they incurred $12 million dollars in damages in one tailstrike!

 

Erik Otterson

KMSP

Share this post


Link to post

Well I've talked myself out of that answer as well, it would increase AOA, nuts

Share this post


Link to post

Flaprons control roll?

 

Jason is coming in to fast because there is a strong cross wind

 

the 777 is automaticly aligning it's self with the runway by a slideslip or crab angle


William Coade
Boeing777_Banner_Pilot.jpg

Share this post


Link to post

Okay guys- Mike is on it... but WHY... WHY is the airplane doing this?

 

("This" being- retracting the flaperon to shift the center of lift and increase the AoA?)

Let's see. If I'd venture an extremely wild guess, I'd say that Jason is going around at the time the screenshot was taken, and the flaperons get out of the way to prevent them from being blown to smithereens by the prodigious amounts of thrust generated by those underslung monsters. Either that, or he has inadvisedly deployed the speedbrakes during short final, causing the flaperons to retract in response (kind-of-source: http://www.airliners.net/aviation-forums/tech_ops/read.main/114281/114287, second post). I do not claim any expertise in these matters, so feel free to ridicule my foolish attempt at informed discourse.

Share this post


Link to post

Okay guys- Mike is on it... but WHY... WHY is the airplane doing this?

("This" being- retracting the flaperon to shift the center of lift and increase the AoA?)

I think mike alluded to it, but flaperon retraction causes an increase in AOA, which causes an increase in lift as well as an increase in induced drag, slowing the aircraft. As to why the 777 does this, I would guess that any speedbrake would increase v/s too much in a landing flaps config and reducing thrust may produce an excessive spool up time in case of G/A, whereas flaperon retraction would allow the aircraft to maintain glideslope/flightpath.


Chris Towers

 

 


Banner_MJC5.png

Share this post


Link to post

Okay guys- Mike is on it... but WHY... WHY is the airplane doing this?

 

("This" being- retracting the flaperon to shift the center of lift and increase the AoA?)

 

Come on Mike- I know you got it... LOL

 

And the glowing brakes was a different flight- unrelated to this... Although if you landed fast enough to overheat the brakes- then you definitely saw this mode of the flaperon control logic... LOL

 

If full flaperon droop has been removed and he's at flaps 25 or flaps 30 - which it looks to be the case - then it's because James is 20kts faster than the approach speed for the current weight?

Carl Beeby


Carl Beeby

Share this post


Link to post

Your change in avatar and signature image is throwing me off!  I didn't even realize it was you who posted that until I looked at the user name.

Luke Pabari: Disorienting Avsim users for 18 years! :-P


Boeing777_Banner_Betateam.jpg
 

- Luke Pabari

Share this post


Link to post

Gents-

 

Okay- a couple of you are close- but you are getting confused as to whether the airplane is increasing or decreasing pitch by retracting the flaperons...

 

Since Jason is exhibiting an extraordinary case of poor pilot technique, and has exceeded the landing flap Vref by more than 20 knots, the flaperon controller has gone into Landing Attitude Mode. This mode incrementally reduces flaperon droop as the overspeed progresses eventually winding up with the flaperon in the neutral position.

 

This has the effect of shifting the pitch up, which protects the pilot from hitting the nosewheel on the runway due to an excessively flat deck angle as a result of the undesired speed...

 

Key points for you guys who were guessing: This is a completely different function than overspeed protection... This is all about making sure you don't wheelbarrow the airplane down the runway if (like Jason!) you suffer from speed control problems....


Robert S. Randazzo coolcap.gif

PLEASE NOTE THAT PMDG HAS DEPARTED AVSIM

You can find us at:  http://forum.pmdg.com

Share this post


Link to post

Wow that is very impressive! Thank you for the knowledge, Robert. You guys never cease to amaze me in the detail you put into these planes. Wish I could have thanked you in person last weekend!


Best regards, happy flying,

Wallace

Share this post


Link to post

@rsrandazzo  :Nail Biting:  :Drooling:


Boeing777_Banner_Betateam.jpg
 

- Luke Pabari

Share this post


Link to post
Guest
This topic is now closed to further replies.
  • 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.


    39%
    $9,950.00 of $25,000.00 Donate Now
×
×
  • Create New...