Legacy Bashfest - Bring it on!

[GVFlyer]

WSCoD

Originally Posted by GVFlyer

The strakes on the Legacy empennage and the vortilons on the wing leading edge were installed to compensate for yaw instabilities occuring as the result of adding poorly engineered winglets to the EMB 135 wing in an attempt to extend the range of the Legacy.

GV

You are definitely wrong here. The strakes were added because they allow us to dispatch WITHOUT a yaw damper. Without them the damp would be required due to the winglets.

And this differs from what I said in my post exactly how? Yaw dampers are installed to compensate for yaw instabilities such as Dutch Roll and aerodynamic anomalies such as those generated by the winglets on the Legacy.

The vortilons are to energize airflow over the ailerons at low airspeeds (since we don't have roll control spoilers). It's a matter of doing the smart thing and the drag penalty is apparently not enough to matter or they would have done something else I am sure.

Ordinarily, I would agree with you. The GIV has vortilons because a certain test pilot named Lee (AKA Torch, but as the resultant of another incident) managed to get a GIV to roll-off at low speed and high angles of attack on an approach during GIV developmental test. During G450 development, I flew a white GIV named "Casper" doing flow visualization and drag reduction tests. Casper had the vortilons removed and I didn't miss them. I suggested that since Lee was gone and there was no further risk of him flying our aircraft, that the vortilons could safely be removed from the rest of the GIV's, but my pleas fell on deaf ears.

I am sure that the vortilons on the Legacy assist in reducing spanwise flow and increase control surface effectiveness at high angles of attack as they do on the GIV, but I am also sure that they they perform an additional duty to add increased directional stability (remember that directional stability refers to the behavior of the aircraft in yaw).

Remember also, that Legacy certification was done by the FAA's Atlanta Aircraft Certification Office, the same office that did certification for the Gulfstream GIII, GIV, GV, G550, G450 and G350. A certain amount of shop talk occurs among test pilots who work aircraft certification, whether they work for the FAA or an airframer. I was told that the vortilons on the Legacy assisted in providing directional stability.

This comment is further supported by the remarks of Embraer factory pilot, Marelo Romanelli to Aviation International New's Robert P. Mark during a written and flight review of the Legacy conducted by the magazine:

Strakes have been added beneath the rear fuselage and vortillons beneath the leading edge of the wings to increase stability, especially because of the yaw produced by the winglets. Although the ventral strakes do detract somewhat from the aircraft’s clean lines, they make up for it in dispatch reliability, since the strakes can negate the need for a yaw damper on the MEL list for short periods.


By the way, LegacyDriver, you are always refering to how "rugged" the Legacy is and how no business jet could stand up to the cycles that the Legacy endures in it's true role as a regional airliner. If this is the case, why is the Legacy fuselage only warrantied for 5,000 hours or five years while the Gulfstream's Primary and Secondary structures are warrantied for 20 Years with no hour limitations?

It seems like Embraer doesn't think the Legacy is going to last either...



GV










~

 

[LegacyDriver]

If that is not a DIRECT quote from Romanelli then I would consider it apocryphal. Magazines get lots of things wrong in the translation.

Direct your other questions to EMB since they are above my pay grade.

 

[CatYaaak]

If that is not a DIRECT quote from Romanelli then I would consider it apocryphal. Magazines get lots of things wrong in the translation.

Direct your other questions to EMB since they are above my pay grade.

WSCoD Driver, you are SO out of your league and weight-class debating with GVFlyer at every level you've tried here, it ain't even funny....well, actually it's funny as he11! He knows more about your aircraft than you do, and you know absolutely nothing...nada..zilch...about his, let alone the Challengers and Falcons that can also eat a WSCoD's lunch (and for a lot fewer dollars).

Hey, are you gonna answer his question regarding life-limits/durability on your respective aircraft?.....or will you once again avoid, evade, deflect, and ignore that one too in your effort to gloss-over the WSCoD's deficiencies and sub-par performance? After all, YOU'RE the one who made the original claim (STILL unsubstantiated after a zillion posts) that "no way is a Gulfstream as durable/reliable as a Legacy".

C'mon boy, back it up! Or are you just going to tell us how you "feel" again?

 

[AA717driver]

This thread needs a visit from Dr. Kevorkian...

GV tried to be nice early on but he pulled out the big stick and WSCoD driver has been vanquished! TC

 

[banned username 2]

WSCoD driver has been vanquished!

i.e. Skull-One

 

[SPBRIAN]

http://www.airliners.net/open.file/709773/M/

You know you are in trouble when even the peeps over at airliners.net are pointing out the obvious. WScoD forever!! This thread is hilarious, long live the entertainment value.

-Brian

 

[GVFlyer]

http://www.airliners.net/open.file/709773/M/

You know you are in trouble when even the peeps over at airliners.net are pointing out the obvious. WScoD forever!! This thread is hilarious, long live the entertainment value.

-Brian

LOL! Great Post! For those that don't want to go to the link, this is what Airliners.net says about the Legacy:

N928CW (145528) One of the largest business jets, yet you can't stand up in the cabin even if you are of average height. What's up with that?




GV

 

[mmmdonut]

jesus..... 21 pages of this **CENSORED****CENSORED****CENSORED****CENSORED**?

 

[CatYaaak]

LOL! Great Post! For those that don't want to go to the link, this is what Airliners.net says about the Legacy:

N928CW (145528) One of the largest business jets, yet you can't stand up in the cabin even if you are of average height. What's up with that?

GV

LIke I said before, the WSCoD is probably a perfect airplane for Willie Wonka's flight department if he needs to shuttle Oompa Loompas between his chocolate factories. It looks like something they'd ride in too.....kind of "Dr. Suess-ey".

 

[LegacyDriver]

Talk about opinions... "Poorly engineered winglets on the Legacy"? Dude, I love how your opinions are considered facts.

I thought this was a rhetorical question since our resident "test pilot" (HA!) should know this. But...

Winglets are designed to be efficient in cruise. In high-AOA and/or low airspeed conditions winglets are not operating in their target regime. All winglets (at least until full-circle winglets come out, and they, too will probably suffer when slow), including those on the G-Whiz, have some tradeoffs for low speed/high AOA conditions. In the Legacy's case it is a stability issue. Hence the strakes. Airplanes from the Learjet and Excel to the F-16 and *GRUMMAN* F-14 have ventral fins and none of those airplanes (with the exception of the Lear, and my recollection is those are there to put the nose down when you get it *too* slow) can blame it on winglets. The Legacy winglets do their job. The improve CRUISE efficiency. Period. Nuff said.

As for cabin height... How much time does one actually spend standing up in an airplane any way? Not much. If we look at our shrinking population (immigration and so forth are just dragging the average U.S. height down--Norway is now #1 we are #2) then the Legacy cabin accomodates over 90+% of the population and as we shrink it will only accomodate more...so let the other 5-10% decide if it is that important to them. Perhaps they need a BBJ.