Bombardier New Aircraft

[GVFlyer]

Premium Package-Is that akin to the Gold Package?
Now, I wonder what the Bombardier canned answer is. I mean, come on G-V, there must be "some" value in having 20% more cabin volume, besides being .05 Mach slower. Anyone know what the backlog happens to be for the G5000?

The Premium package includes all Pilot, Mechanic, MedAire and Flight Attendant training for 5 years.


The next Gulfstream will have more interior volume than the Global XRS and Fly-By-Wire. By value I meant not only quality, and current technology as opposed to last generation technology found on the Global Express (have you seen the 8" displays on the XRS?, no auto descent mode, no automatic fuel heating, the uncooled EVS - ad infinitum ad naseum) but also retained value, GV's on the pre-owned market are pretty much selling at their original new purchase price. Have you checked the price of a used Global lately?


At any altitude above 37,000 feet the Gulfstream is faster than the Global by virtue of thrust. At any altitude above 43,000 feet the Gulfstream is faster than the Global by virtue of certification.



Let me tell you how the Global Express ended up M 0.005 faster than the GV at some altitudes. During GV development Mmo was determined by a control reversal at Mach 0.955 (rudder Cl Beta went positive, fundamentally if you pushed right rudder at that speed the aircraft will roll left not right). Part 25 requires that Mmo be reduced by M 0.07 from such an aerodynamicaly limiting event or M 0.05 if a "lower margin is determined using a rational analysis that includes the effects of any automatic systems". The Global encountered buffet, a much more serious aerodynamic quality in that it can be destructive or cause departure from controlled flight, at Mach 0.94 and chose to claim they could show “equivalent safety” and so backed Mmo off M0.05 to arrive at a Mmo of M0.89.



As for the rest of it did you miss my post on the "Santulli visits South Carolina" thread? The Gulfstream is just plain safer.

The first reason [the g550 out performs the Global Express XRS] is simple physics - the G550 weights 7.5% less and has 5% more thrust. The Basic Operating Weight for the G550 is 48,000 lbs and it has 30,770 pounds of thrust giving it a basic power loading of 1 pound of thrust for each 1.56 pounds of airplane. The BOW for the Global Express XRS is 51,500 lbs and it has 29,500 pounds of thrust. Thus the Global has 1 pound of thrust pushing 1.75 pounds of Canadian jet. Of course this doesn’t account for some of the trick stuff on the G550 like the Thrust Recovery Outflow Valve which vectors outflow air at up to 10.48 psid for additional thrust or the blunt edged flap trailing edges which reduce drag above M 0.85.

The comparison is worse at max gross take-off weight – the G550 takes off at 91,000 lbs, the Global XRS has less thrust pushing 98,250 lbs at take-off.


Number two and more importantly is Gulfstream's basic design philosophy. Let me explain. The thrust deck or propulsive power (Wpa) available determines the aircraft volume that can be propelled through the air at a given speed. As such, with the same engines, the volume of the GV and the GEX is roughly equivalent. Bombardier spent more of their volume on cabin, Gulfstream spent theirs on wing. The Gulfstream has 1136.6 sq ft of wing, the Global has 1022 sq. ft. The resultant is that the GEX is a high wing loading, point design, buffet limited airplane and the Gulfstream is not. The Global also pays for this large cabin with increased total parasite drag.

Design limit speed on the GV occured when rudder CL beta went positive (fundamentally a control reversal) not because of buffet or flutter. As a matter of fact, serial number 501 went to Mach 1.07 during developmental test. What this means to you is a much more generous height velocity diagram.

For example, in a 63,000 lb G550 at M.080 at 45,000 feet you can perform a 60 degree (2 g) bank without encountering buffet. With the same conditions in the Global you would encounter buffet at 52 degrees or 1.62 g. In a 55,000lb G550, you can still do sustained 45 degree banked turns at 51,000 feet.

Why this is important is that it gives you a huge window between compressibility and stall at altitude. These margins keep you safe if you encounter turbulence and mean that you don't have to descend if it gets hot. No Gulfstream pilot has ever had to look at a buffet chart to see if he could climb. Performance is paramount at Gulfstream.

My biggest personal beef against the Global line is that it is a buffet-limited jet and does not offer the kind of margins found in the Gulfstream GV and it's derivatives. On the G550 there is over a 100 knot window between compressibility and stall at 51,000 feet. Gulfstream has never departed a GV/G550 during development or any other phase of flight. Pete and his test boys had to pull the chute on the Global to regain controlled flight when it pitched-up during FAA required stall testing.

When we did a closed loop handling qualities evaluation of the Global, we got impending indications of an aerodynamic stall prior to shaker and had to knock it off for the test. The Global actually speeds up in a turn at a constant power setting showing that it is aerodynamically operating in the wrong part of the “drag bucket." We could not get the jet to 49,000 feet with only a crew of two and four flight test engineers on board. The area rule design on the Global, while a good idea on fighters, is a design emergency procedure on a transport category jet to reduce excessive drag.

We also found that Max cruise speed was lower than expected. At FL450 and 65,000 lbs, the cruise manual shows the jet should be able to achieve M 0.87+, the Global could only get to M0.865.

During GV altimetry certification we had to fly close formation at various altitudes with a known source. We used the FA-18 for these tests. After completion of the tests at 51,000 feet, the Hornet driver thought he was going to make a run on us. He quickly learned that the FA 18 won’t turn with a Gulfstream at that altitude…and no, we didn’t use “After Fan” (Alternate N1 Control which gives us an additional two-tenths [!] of EPR).

I didn't mention that Bombardier Flight Test in addition to departing controlled flight, managed a gear-up landing and drug a wing tip during certification. Gulfstream runs a non-destructive developmental test program.

After their gear up landing I half way expected to see a Bombardier Press Release touting their test of their Non-Sparking Sked - "A test Gulfstream refuses to do!"

It's also not a widely publised fact that the Global Express barely made it through Canadian Certification because any leading edge contamination materially and adversely affects stall characteristics.

It should tell you something that the Bombardier CEO Paul Tellier resigned, followed closely by the resignation of the President of Bombardier Business Aircraft, Peter Edwards. I know Peter pretty well, he served 20 years at Gulfstream prior to going to Bombardier, and when he's dealt a losing hand, he folds.


GV


PS: Way to go, Falcon Capt!

 

[mzaharis]

I'm in no place to "truth-check" the claims here, but it seemed that Larry Ellison's switch from a G-V to a GEX didn't provide many clear advantages, and may have had some disadvantages. I couldn't figure out why it was worth the effort to switch. GVFlyer listed a couple of possible reasons why, and it could have been that he just wanted those extra 10 inches of cabin space badly enough (and didn't need the maximum range). The decision always baffled me, and that's why I asked.

 

[banned username 2]

PS: Way to go, Falcon Capt!

I'm learnin! I may only have 40 or so hours in the G-V, but I like what I see so far!

 

[broken spoke]

What??!!!

I STILL, after all these years, stand amazed at the ability of those that post on this site to take a question posed by another and completely twist it around to a topic that NOBODY REALLY CARES ABOUT!! Who cares about "who builds a better aircraft?!" C'mon, gents.

Flyboy

 

[banned username 2]

I STILL, after all these years, stand amazed at the ability of those that post on this site to take a question posed by another and completely twist it around to a topic that NOBODY REALLY CARES ABOUT!! Who cares about "who builds a better aircraft?!" C'mon, gents.

Flyboy

I STILL, after all these years, stand amazed at the ability of those that post on this site to respond to a thread by another that THEY REALLY DON'T CARE ABOUT!! Why respond if you don't care?!?!?! C'mon, spoke.

 

[semperfido]

keep posting GVFlyer as i also find your posts a helluva lot more interesting than a fsi gnd school. i am learning a lot, which i am sure i will promptly soon forget

 

[AA717driver]

Well, at least now I know I can turn with those F/A-18's up at 510. Now, what do I do when I get on their tails?

Thanks for the info GVflyer. It is appreciated.TC

 

[RTRHD]

Well, I am impressed keep it up V Flyer and Falcon Cpt.

I really need to read more........

 

[GVFlyer]

Well, at least now I know I can turn with those F/A-18's up at 510. Now, what do I do when I get on their tails?

You key the mic and say, "Fox One!" ... wait a short count then say, "Splash One!" Next, find the guy that evening in the MCAS Beaufort Officer's club and see if he wants to talk about it.

GV

 

[rice]

Well, at least now I know I can turn with those F/A-18's up at 510. Now, what do I do when I get on their tails?

Hope and pray that he doesn't go vertical on you and squeeze one off on that pretty G-String of yours:laugh: . So to speak.