Gulfstream G-450 for Pakistan.

[shaheenmissile]

What happened to those Hawker 850 of PN?
I think they were to by conveted to ELINT role but Raytheon refused the kit. I read them being sold,but need confirmation.

 

[Donatello]

FL350 is the norm for most airliners, some can go up higher, but not many.
And for Gulfstream specifically, it pressurizes to 6000 ft. And the air is recycled every two minutes. 787 and the new 350 are both composite aircraft so yes they can do that easily. G450 is still made from aluminum alloys. There aren't many airplanes which can match Gulfstreams specs.

I wish they would bring back the concorde! They can add those F135 engines from F-35, it would become a rocket!

Gulfstream can use aluminium and pressurize more because it is much smaller than a wide body. FL400 is also norm for LH and ULH flights. The only limiting factor is the payload plane is carrying.....passengers, fuel, cargo etc. A fully loaded 772LR cannot reach 40,000 right after take off without burning too much fuel (and hence reducing flight economics) but once they are carrying less fuel, they go to FL400. At FL400 you have less drag as well, so it adds to your cost advantage.

But yea, exec jets and wide bodies are different classes anyway. I'm more of a wide boy admirer and of course the Concorde. What sad times we live in, that a plane like Concorde doesn't exist in commercial service. Not even in the executive category.

The norm it is not

The only aircraft you will regularly see top 40k are the A380, A330, and Boeing 788. The reason these aircraft feature so prominently at those altitudes is because they have relatively lower wing loadings.

Occasionally, towards the end of a sector or on a domestic, a 767, 777, A340 or B747 may get up there.

I've been on a 777-300ER travelling at 40,000ft.
Same with A330.

There is no point in going to FL400 towards the end of the sector, because then you have to start your glide into the airport too early.

Try looking at widebodies on flightradar24, you'll see their real time altitude.

 

[My-Analogous]

Good addition in PAF and we badly need these for out armed forces

 

[imiakhtar]

I've been on a 777-300ER travelling at 40,000ft.
Same with A330.

As I said, you will only get up to those altitudes when you are really light, ie towards the end of a flight

There is no point in going to FL400 towards the end of the sector, because then you have to start your glide into the airport too early.

Actually there is.

Prior to the War on Terror and the implementation of BOBCAT procedures over Afghanistan, aircraft serving Pakistan/India (Islamabad/Lahore/Delhi) from Europe would regularly request FL400 towards the end of the flights even though they only had a few hundred miles to go. This is Boeing's reasoning:

\\\\\\\\Note the part where it say the increase in cruise altitude results in a greater time at idle descent which equals lower fuel burn.

Also, as I said, aircraft can only reach higher altitudes SAFELY, when they are light enough. See the QRH for the 787:

A fully loaded 772LR cannot reach 40,000 right after take off without burning too much fuel

A 772LR can't reach service ceiling after MTOW departure full stop.

Try looking at widebodies on flightradar24, you'll see their real time altitude.

At 20:13 hours UTC here is a snap shot for traffic over Pakistan and their cruise altitudes:

Etihad 402 Abu Dhabi-Bangkok Boeing 77W 35000ft

Finnair 82 Helsinki-Bangkok A330 39000ft

Emirates 512 Dubai-Delhi 77W 37000ft

Emirates 374 Dubai-Bangkok A380 39000ft

Etihad 876 Abu-Dhabi-Seoul 772LR 37000ft

CargoLux 794 Baku-Singapore 747F 33000ft

Etihad 888 Abu-Dhabi-Peking A330 39000ft

Qatar 562 Doha-Delhi B788 39000ft

Singapore 305 London-Singapore 77W 35000ft

Air India 116 London-Delhi 77W 37000ft

None of those aircraft are above 39000ft.

Not very common at all.

 

[ACE OF THE AIR]

FL400 is standard for a lot of wide body commercial airliners when they are en-route long haul, and half way through have burnt enough fuel that they can go that high. So a B777/A380/A330/A340 etc also fly at 40,000 ft.
Some executive jets can do 50,000ft......but FL400 is norm for widebodies.

Their cabin is pressurized at 8000ft above sea pressure level, but the new B787 has it at 6000ft as well, along with the new A350

Faster is relative, since most fly subsonic anyway.

1960s Concorde would beat the shyt out of these puny exec jets in speed or altitude.

Normally all calculations are done for FL350 = 35000 feet.
Max operating altitude is 40000 - 42000 feet. Though the Structure may be able to fly a lot higher.
These days with the new flight management systems (FMS) optimum altitude is calculated for each leg of a flight. Normally this is done keeping in view the age of the aircraft and various other factors. This system gives 3 types of quick settings i.e Min. Time, Econ and Min Fuel. along with the designated altitude to fly. Though you might not be allowed that due to traffic hence these calculations remain valid for upto +- 2000 Feet.

Currently the fastest business Jet is Cessna Citation X.

As far as Concorde was concerned it was not allowed to fly supersonic over land and it was to fly in a block altitude i.e 40000 - 50000 feet.

As I said, you will only get up to those altitudes when you are really light, ie towards the end of a flight


Actually there is.

Prior to the War on Terror and the implementation of BOBCAT procedures over Afghanistan, aircraft serving Pakistan/India (Islamabad/Lahore/Delhi) from Europe would regularly request FL400 towards the end of the flights even though they only had a few hundred miles to go. This is Boeing's reasoning:

View attachment 161618

\\\\\\\\Note the part where it say the increase in cruise altitude results in a greater time at idle descent which equals lower fuel burn.

Also, as I said, aircraft can only reach higher altitudes SAFELY, when they are light enough. See the QRH for the 787:

View attachment 161619


A 772LR can't reach service ceiling after MTOW departure full stop.



At 20:13 hours UTC here is a snap shot for traffic over Pakistan and their cruise altitudes:

Etihad 402 Abu Dhabi-Bangkok Boeing 77W 35000ft

Finnair 82 Helsinki-Bangkok A330 39000ft

Emirates 512 Dubai-Delhi 77W 37000ft

Emirates 374 Dubai-Bangkok A380 39000ft

Etihad 876 Abu-Dhabi-Seoul 772LR 37000ft

CargoLux 794 Baku-Singapore 747F 33000ft

Etihad 888 Abu-Dhabi-Peking A330 39000ft

Qatar 562 Doha-Delhi B788 39000ft

Singapore 305 London-Singapore 77W 35000ft

Air India 116 London-Delhi 77W 37000ft

None of those aircraft are above 39000ft.

Not very common at all.

Good that you have shown these but this is in winter. Try finding during Monsoon season.

I have flown on PIA A310 BKK-KHI at 41000 Feet due to Severe Weather.

 

[imiakhtar]

Normally all calculations are done for FL350 = 35000 feet.

There is no set altitude for which flight planning calculations are done.

The flight dispatchers/pilots/Flight management system/computers will look at aircraft weight at Top of climb from where, once the temperature, winds and airline cost index is factored in will give an optimum cruise altitude.

So, in most instances as you can see from the 787 cruise performance chart I inserted above, at high take off weight with a top of climb weight of 500 000lbs, the optimum cruise altitude is around fl350.

As I said, cruise altitude performance is largely determined by the wing loading. Think of it as weight per wing area or the amount of work the wing has to do.

As such there is a large variation for aircraft on the optimum altitude depending on how heavy they are at top of climb.

The Boeing 777 (all models) will struggle to climb above 33000ft when it is heavy. The Boeing 747 is even worst and pilots will tell you they struggle above 31000ft when heavy.

Good that you have shown these but this is in winter. Try finding during Monsoon season.

Aircraft engine perform best at cold temperatures.

Optimum cruise altitudes are highest when the temps are closest to an ISA day.

Try finding during Monsoon season.

Any pilot that tries to out climb a cumulonimbus during the monsoon season over the Bay of Bengal is an idiot.

As far as Concorde was concerned it was not allowed to fly supersonic over land and it was to fly in a block altitude i.e 40000 - 50000 fee

Make that 55000-60000ft

 

[Donatello]

As I said, you will only get up to those altitudes when you are really light, ie towards the end of a flight


Actually there is.

Prior to the War on Terror and the implementation of BOBCAT procedures over Afghanistan, aircraft serving Pakistan/India (Islamabad/Lahore/Delhi) from Europe would regularly request FL400 towards the end of the flights even though they only had a few hundred miles to go. This is Boeing's reasoning:

View attachment 161618

\\\\\\\\Note the part where it say the increase in cruise altitude results in a greater time at idle descent which equals lower fuel burn.

Also, as I said, aircraft can only reach higher altitudes SAFELY, when they are light enough. See the QRH for the 787:

View attachment 161619


A 772LR can't reach service ceiling after MTOW departure full stop.



At 20:13 hours UTC here is a snap shot for traffic over Pakistan and their cruise altitudes:

Etihad 402 Abu Dhabi-Bangkok Boeing 77W 35000ft

Finnair 82 Helsinki-Bangkok A330 39000ft

Emirates 512 Dubai-Delhi 77W 37000ft

Emirates 374 Dubai-Bangkok A380 39000ft

Etihad 876 Abu-Dhabi-Seoul 772LR 37000ft

CargoLux 794 Baku-Singapore 747F 33000ft

Etihad 888 Abu-Dhabi-Peking A330 39000ft

Qatar 562 Doha-Delhi B788 39000ft

Singapore 305 London-Singapore 77W 35000ft

Air India 116 London-Delhi 77W 37000ft

None of those aircraft are above 39000ft.

Not very common at all.

As you can see, there are a number of flights at FL390. You tell me, what is FL390 near to, FL400 or FL350?
Nowhere did i post that commercial airliners fly at FL400 all the time, that is why i precisely mentioned the mission load ...it varies a lot. But like i said, i have been on flights which flew at least 5 hours of their 14 hour trip on FL400. That is alot of time....and yes weather conditions will have their own variations.

There is no set altitude for which flight planning calculations are done.

The flight dispatchers/pilots/Flight management system/computers will look at aircraft weight at Top of climb from where, once the temperature, winds and airline cost index is factored in will give an optimum cruise altitude.

So, in most instances as you can see from the 787 cruise performance chart I inserted above, at high take off weight with a top of climb weight of 500 000lbs, the optimum cruise altitude is around fl350.

As I said, cruise altitude performance is largely determined by the wing loading. Think of it as weight per wing area or the amount of work the wing has to do.

As such there is a large variation for aircraft on the optimum altitude depending on how heavy they are at top of climb.

The Boeing 777 (all models) will struggle to climb above 33000ft when it is heavy. The Boeing 747 is even worst and pilots will tell you they struggle above 31000ft when heavy.



Aircraft engine perform best at cold temperatures.

Optimum cruise altitudes are highest when the temps are closest to an ISA day.



Any pilot that tries to out climb a cumulonimbus during the monsoon season over the Bay of Bengal is an idiot.



Make that 55000-60000ft

I've repeatedly stated, it varies on a LOT of factors. There are ATC regulations and air space regulations that airliners must meet....beyond that, it is up to the individual airlines on how they plan their flights.

 

[imiakhtar]

i have been on flights which flew at least 5 hours of their 14 hour trip on FL400. That is alot of time....and yes weather conditions will have their own variations.

Post me the flight details like route, time of the year, aircraft type, rough idea on number of pax.

NO WIDEBODY AIRLINER in service is able to climb to Flight level 400 or above after 5 hours on a 14 hour leg.

Not the 787 (which I proved above), not the 777, not the A340, not the A380 and not the 747.

Pray tell, if the 787 which has the "best" wing can't reach FL400 after 5 hours of a 14 hour long haul flight, how can any other aircraft?

 

[Donatello]

Post me the flight details like route, time of the year, aircraft type, rough idea on number of pax.

NO WIDEBODY AIRLINER in service is able to climb to Flight level 400 or above after 5 hours on a 14 hour leg.

Not the 787 (which I proved above), not the 777, not the A340, not the A380 and not the 747.

Pray tell, if the 787 which has the "best" wing can't reach FL400 after 5 hours of a 14 hour long haul flight, how can any other aircraft?

I didn't say it reached the FL400 5 hours after take off, i clearly said 5 hours of its 14 hour journey time. Now you automatically assume it is the first 5 hours, where as it could be the cruising 5 hours before descent.

 

[ACE OF THE AIR]

There is no set altitude for which flight planning calculations are done.

The flight dispatchers/pilots/Flight management system/computers will look at aircraft weight at Top of climb from where, once the temperature, winds and airline cost index is factored in will give an optimum cruise altitude.

Any pilot that tries to out climb a cumulonimbus during the monsoon season over the Bay of Bengal is an idiot.

Flight Planning calculations are done normally on assumed weights as still the actual load factor is not available along with actual wind speed and temperature / weather briefs and aircraft performance manuals.

Pilots have the actual trim sheet at the time of departure so they correct the differences. They do a recheck at Top of Climb because by that time the aircraft is in level flight and the CG position is most accurate. As far as wind and temperature calculations are done by the pilots where as the airline cost index is stored in the FMS program that is updated every 21 days.

Performances that you have mentioned are provided by the manufacturer. You have taken the example of full weight take off but in reality the weight may not be full due to other conditions they may require the same performance.

There is a option of MAX CLIMB, The Maximum height of cumulonimbus clouds over Equator is 54000 feet which is the limit of Tropopause and at the Poles it is 35000 feet. Bay of Bangal \ India \ Pakistan is above the Tropic of Cancer which means the Troposphere is about 40000 - 41000 feet. On the other hand Monsoon clouds tend to dissipate when they encounter higher temperature when they come over land and the directions is EAST to WEST hence it is not idiocy to climb on top when flying from Bkk to Khi. If you are going the other way Khi - Bkk then it is much more difficult.

 

[imiakhtar]

Flight Planning calculations are done normally on assumed weights as still the actual load factor is not available along with actual wind speed and temperature / weather briefs and aircraft performance manuals.

Pilots have the actual trim sheet at the time of departure so they correct the differences. They do a recheck at Top of Climb because by that time the aircraft is in level flight and the CG position is most accurate. As far as wind and temperature calculations are done by the pilots where as the airline cost index is stored in the FMS program that is updated every 21 days.

Performances that you have mentioned are provided by the manufacturer. You have taken the example of full weight take off but in reality the weight may not be full due to other conditions they may require the same performance.

I'm a CPL holder and former employee of British Airways flight planning dept.

There is a option of MAX CLIMB,

Again I'm aware of that.

The 787 performance chart posted is for max climb thrust settings.

 

[ACE OF THE AIR]

I'm a CPL holder and former employee of British Airways flight planning dept.



Again I'm aware of that.

The 787 performance chart posted is for max climb thrust settings.

I am not aware of the requirements and weight loading BA has asked on B787 but in PIA they normally do not procure aircraft with Maximised weights.
PIA B737-300 had only 116 pax configuration where as it was designed to have 149 pax.
PIA A310-300 has 220 pax where as it is designed for upto 280 pax.
So now you would be able to calculate more accurately the performances of PIA aircraft.

 

[imiakhtar]

PIA B737-300 had only 116 pax configuration where as it was designed to have 149 pax.
PIA A310-300 has 220 pax where as it is designed for upto 280 pax.

Pax configurations have no bearing on aircraft MTOWs.

I used the PIA 772 as an example of an excess capacity problem at the moment.

The rest of PIAs fleet, the 77W, the 772LR, the A310 and the ATR are operated at their maximum regulatory take off weights.

The only reason they put less pax in the A310 is to extend the range (trade payload for fuel).

 

[ACE OF THE AIR]

Pax configurations have no bearing on aircraft MTOWs.

I used the PIA 772 as an example of an excess capacity problem at the moment.

The rest of PIAs fleet, the 77W, the 772LR, the A310 and the ATR are operated at their maximum regulatory take off weights.

The only reason they put less pax in the A310 is to extend the range (trade payload for fuel).

Less pax may be giving indirect financial advantage in reducing fuel consumption \ less maintenance, but financial loss of revenue. As far as B737 is concerned it is limited due to high temperature at airports in Pakistan and single engine flight performance limitations. Normally the average temperature is +15 - 20 ISA at all airports.

 

[Thəorətic Muslim]

These tiny planes are used alot in North America generally find them very uncomfortable , noisy and lacking entertainment however , the particular plane had a luxry interior

But the planes that are flown in North America are really like Mini Bus in Pakistan

Gulfsteam has a reputation as the one of the best private executive jet makers.

They can easily be reconfigured to meet the client's demand.