G550 vs Global Express/Xrs

[GVFlyer]

Hey GV,


BTW, you seeing a lot of corporations doing stalls and steep turns up there at FL510? Only one guy I can think of ever flies (or tries to fly) at 510; most of the time the airplane would never make it up there.

The only reason we do that stuff is to instill confidence in you guys about the capabilities of the product. It's nice to know that if you're topping a thunderstorm at altitudes above 47,000 feet and you get bumped in an attitude like that - you've seen it before and recovery is easy.

GV

 

[G4G5]

I always program the climb at 300/.80 (except when max range is required, I then use 300/.75 to FL400 then 1.3 Vso above that) and I climb on the weight for speed charts in the Quick Reference Handbook and I have no problems. As a technique, I'll request block FL490 - FL510, then select Metric Altitude on the Display Controller so the Altitude Selector will display in hundreds of feet rather than in 500 foot increments, then climb the jet to exactly match the optimum altitude on the FMS Cruise page.


GV

Excellent tip!!!!!!!!!!!!!!!!

 

[GVFlyer]

This is all fine and dandy, but I believe all this happened during flight testing! To date, I don't believe any Challenger, Global Express, or CRJ has departed controlled flight while operating within its certified flight envelope. Correct me if I'm wrong, but it's the engineers and test pilots that define the envelope; but it's the test pilots who risk life and limb, confirming the boundaries that the rest of us are to live within. Is that not what shakers and pullers are all about......to prevent us from joining the ranks of test pilot if we stray outside those set boundaries?

True enough, but design philosophies come into play as well. For instance Boeing builds jets which keep the pilot in the loop, Airbus builds airplanes which exclude them.

Although it has three hydraulic systems Gulfstream makes a jet that can be flown with a total hydraulic failure, the Global design team built one that could not be flown in that situation.

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 flutter, a much more serious aerodynamic quality in that it is destructive, at Mach 0.94 and chose to claim they could show equivalent safety and so backed Mmo off M.05 to arrive at a Mmo of M0.89.

I wonder if Gulfstream might struggle somewhat also if they ever decided to build an airplane from stratch?

Like the Boeing 737 New Generation, the Airbus 319/321, the Falcon 2000 (which is the 900 fuselage mated to to GE 738's), the Lear 40 and Lear 60, the Fokker 100, the MD 11, the Global 5000, or the Global Express which is two Chalenger 604 fuselage sections joined to a center fuselage and wing assembly manufactured by Mitsubishi Heavy Industries in Japan?


Gulfstream has received DARPA funding for a "stratch" built SSBJ

 

[banned username 2]

Gulfstream has received DARPA funding for a "stratch" built SSBJ

Well get on it, would you! I only have 23 1/2 years until I retire...

I'd like to give one of those a spin before retire! (Even if it is a Gulfstream! )

 

[Jack Schitt]

Cl Beta, rational analysis, equivalent safety, blah..blah...blah.......
Who's the brain surgeon that came up with the BBW system on the IV? HMAB isn't much better. While we're at it, who's the clown that designed the environmental system?

 

[GVFlyer]

Cl Beta, rational analysis, equivalent safety, blah..blah...blah.......
Who's the brain surgeon that came up with the BBW system on the IV? HMAB isn't much better. While we're at it, who's the clown that designed the environmental system?

I could tell you who those engineers are, but I suspect that your question is rhetorical. However, we solved that brake issue a long time ago - we have not built a jet with Brake-by-Wire since July 1992. We offered an ASC for those who wanted to change to the new HBCM control brakes and developed a new linear transducer for those who did not.


I think the HMAB do pretty well- they last for on average 1,500 landings (as opposed to 800 for steel brakes) and will stop a landing 33 ton Gulfstream IV in 3186 feet.


G550 brakes will stop the aircraft at maximum gross takeoff weight from 188 knots in just over 3000 feet on a dry runway without the use of thrust reversers. They are the same brake assembly used on the Boeing 717.


I'm not sure what you want from the environmentals - all current large cabin Gulfstreams offer three- zone automatic temperature control and the G500/G550 provide a 5980 foot cabin altitude at 51,000 feet.


GV







.

 

[banned username 2]

However, we solved that brake issue a long time ago - we have not built a jet with Brake-by-Wire since July 1992. We offered an ASC for those who wanted to change to the new HBCM control brakes and developed a new linear transducer for those who did not.

Looks like "someone" works for Gulfstream after all... Things that make you go "Hhhmmm..."

 

[Jack Schitt]

Thanks G. Never flown the V but I'm glad they worked out those problems. Just curious, why doesn't the V have autobrakes like the Global? Or does it?

 

[Mudworm]

Cl Beta, rational analysis, equivalent safety, blah..blah...blah.......
Who's the brain surgeon that came up with the BBW system on the IV? HMAB isn't much better. While we're at it, who's the clown that designed the environmental system?

I have 2000 hours in 2 IV's with BBW and have no complaints. Works good lasts along time

 

[fokkerjet]

Like the Boeing 737 New Generation, the Airbus 319/321, the Falcon 2000 (which is the 900 fuselage mated to to GE 738's), the Lear 40 and Lear 60, the Fokker 100, the MD 11, the Global 5000, or the Global Express which is two Chalenger 604 fuselage sections joined to a center fuselage and wing assembly manufactured by Mitsubishi Heavy Industries in Japan?

OK........I give! I concede that the Gulfstream 350, 450 and 550 were all derived off of the orginial G159, that Grumman designed, certified and produced back in the mid 50's and early 60's; just like the examples you mentioned, that too were all derived off of earlier designs that were designed, certified and produced in the mid to late 60's, 70's and 80's.

 

[GVFlyer]

Thanks G. Never flown the V but I'm glad they worked out those problems. Just curious, why doesn't the V have autobrakes like the Global? Or does it?

The autothrottles on the G350/G450/G500/G550 work from take-off to landing as they did on the GV. The feature set on the GV/G550 was determined to a large extent by the Customer Advisory Board. While Autoland/Autobraking are reasonably low tech (as compared to say, EVS) and easy to apply to the jet, the customers didn't want them. As a matter of fact most customers don't want to do the extra training and maintenance required to maintain CAT II standards.

GV

 

[GVFlyer]

OK........I give! I concede that the Gulfstream 350, 450 and 550 were all derived off of the orginial G159, that Grumman designed, certified and produced back in the mid 50's and early 60's; just like the examples you mentioned, that too were all derived off of earlier designs that were designed, certified and produced in the mid to late 60's, 70's and 80's.

Grumman began development on the G-I in 1957 and the first one entered service in 1959. Production ran until 1969. In 1965, Grumman began production on the G-II which entered service in December 1967. Gulfstream American purchased the rights to the Gulfstream line in 1978 and introduced the G-III the following year.

As an interesting aside, the G-I fuselage diameter was based on the Douglas DC-3 which entered service in December 1935, which in turn was a derivative
of the DC-2 which entered airline service in July 1934.

Some things are just classic...

GV