Max speed for Bombardier Learjet 45

Hi: is there any rule of thumb to stablish the maximum speed depending on altitude you are flying? Example: max speed for 10.000 feet is XXX. Max speed for 15.000 feet es XXX an so on.

Thanks for help.

kiri.

Max speed at 10,000 feet and below is 250 knots. Max cruise speed both KiAS and MACH are listed in the aircraft.cfg.

Max indicated is 330, max Mach is 0.81.

 

Altitude is irrelevant other than you typically use IAS up to the mid-20s then switch to Mach.

 

peace,

the Bean

In jets, I generally max cruise at .75-.78 Mach. Don't want to overspeed the plane.

Hi: is there any rule of thumb to stablish the maximum speed depending on altitude you are flying? Example: max speed for 10.000 feet is XXX. Max speed for 15.000 feet es XXX an so on.

Thanks for help.

kiri.

 

To amplify on both mrzippy's and StringBean's answers: The max speed at 10,000 and below is the U. S. FAA regulation, not an aircraft limitation as such, and FS normally goes by U.S. rules. Other countries may have different speed restrictions.

 

All aircraft have a Vne (Never Exceed speed) in IAS. Faster aircraft (jets and, often, turboprops) will also have a max Mach. These limitations (real world, of course) have to do with handling and/or structural strength or both. So you may not ever exceed either of these indications, though at higher altitudes you normally will exceed the mach number before you're even close to Vne indicated, thus the switch from using IAS to mach.

 

The differing temperatures and air pressures as you change altitudes will adjust these speed indications but, as Bean says, altitude as such is irrelevant. Hope this helps your understanding.

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For more on this, see this Wikipedia article about V-speeds, which probably has more than you will need for FS.

Thsns guys for response.

kiri.

I fly it at 315 up to the mid 20's. Then you can use the mach button to set for .80. But if you get a nice tail wind it will over accelerate. So flying it at .75 or .78 is prudent. My mach button doesn't work too well though. I've noticed that I had to cycle mach and speed a few times. So I just got fed up with that and use IAS and watch the mach hit .80. Typically, 30,000 is around 280 knots and above that your airspeed goes to around 250 knots. Remember, there's less air up there.

But if you get a nice tail wind it will over accelerate.

 

What does a tailwind have to do with it? Are you using GROUND speed? It's irrelevant.

What does a tailwind have to do with it? Are you using GROUND speed? It's irrelevant.

 

+1!! We always hope for a tail wind!! That produces less atmospheric drag on the aircraft!

 

It's the atmospheric drag against the aircraft that is the issue here!!! Which is exactly why planes can fly faster when they fly higher. Less atmospheric pressure equals less drag!! ;)

We always hope for a tail wind!! That produces less atmospheric drag on the aircraft!

 

Not really.

 

Think of an airplane moving through the air as a fish swimming in a fish tank.

 

If you put the fish tank in a moving car the fish will get from point A to point B faster.

 

However, the movement of the car will have no impact on what drag the fish feels.

 

Same thing with an airplane. Regardless of a headwind, tailwind, or no wind the aerodynamic forces on the plane, at any given IAS, are the same.

 

The only realistic impact caused bythe wind, in cruise, is ground speed. While we pilots are concerned with ground speed, our airplanes could not care less.

 

peace,

the Bean

What does a tailwind have to do with it? Are you using GROUND speed? It's irrelevant.

 

Maybe it was a head wind that caused my IAS to spike?

 

Correct me if I'm wrong, but wouldn't a tail wind cause the pitot tube to have more air rush in since you are being pushed through the air faster?

Go back and reread what Bean just wrote: the wind does not affect the drag or aerodynamics of the aircraft when airborne. The aircraft has become part of the air mass. Headwinds and tailwinds affect the path of the aircraft over the ground (because the air mass is moving) and its speed over the ground (because the air mass is moving), but that is irrelevant to the way the aircraft flies -- its behavior is ALWAYS as it would be in still air, with steady winds. Gusts can cause brief disturbances, but they are not steady state, only momentary.

 

So if you saw a momentary change in airspeed, it may have been caused by a gust, but it would quickly return to its previous state. If you had airspeed too high in a steady state, it was through too much power, descent, etc., not from any winds. But that's AIRspeed I'm talking about, which is all the plane "knows" about.

 

Groundspeed's entire use is in determining how long it takes to get somewhere. How the aircraft behaves, AIRspeed limitations, etc. are all related to AIRspeed, most things to Indicated AirSpeed (IAS), a few to True AirSpeed (TAS), NONE to groundspeed.

Thanks for the correction.

Not really.

 

Think of an airplane moving through the air as a fish swimming in a fish tank.

 

If you put the fish tank in a moving car the fish will get from point A to point B faster.

 

However, the movement of the car will have no impact on what drag the fish feels.

 

Same thing with an airplane. Regardless of a headwind, tailwind, or no wind the aerodynamic forces on the plane, at any given IAS, are the same.

 

The only realistic impact caused bythe wind, in cruise, is ground speed. While we pilots are concerned with ground speed, our airplanes could not care less.

 

peace,

the Bean

 

Mr. Bean,

 

As is true much of the time you are correct. In this case, I am certainly aware but didn't correctly state that the aircraft only reacts to the forces upon it & KIAS is that indication.

 

I should have said We always hope for a tail wind!! "That produces less atmospheric drag on the aircraft!" while providing a higher RW Speed Over Ground.

 

On more than one occasion I have traveled eastbound while indicating a KIAS of 115 kph but been passed by automobiles below traversing the "Grapevine" in So. Cal. at a "posted legal speed" of 65mph. Kids waving at you through the back window of a station wagon as they pass you when you're doing "115" isn't a happy feeling!!!!

 

Those Santa Ana winds blowing East to West through that pass can really ruin a good day of flying!! Not to mention trapping smog in the LA basin for days or weeks at a time!!

 

Michael

If you fly 200kt with headwind the drag is the same as when you fly 200kt with tailwind. So are all other forces. All the same with the same IAS.

 

Only the ground speed is different. Sometimes you make use of that. For example, landing in headwind the lower speed over ground gives a shorter stopping distance.

And departing on a day with tailwind makes you arrive at destination in a shorter time.

 

But, again, aerodynamic forces are dependant on IAS only. And are the same as log as IAS is the same. Lift, drag, etc.

 

A 'funny' example of that is that if your small aircraft is tied down, and is parked in a 70kt headwind, the it will lift off from the ground. (And speed gauge will indicate 70kt as well. Wings produce lift if air pusher over then at that speed.)

I should have said We always hope for a tail wind!! "That produces less atmospheric drag on the aircraft!" while providing a higher RW Speed Over Ground.

 

Only partially correct.

 

Yes, a tail wind will give you a higher ground speed. Not because of a reduction in drag, only because the "fish tank", or air mass, is moving in the same general direction as you are.

 

Another analogy would be what happens when you walk thru a moving train car.

 

If you walk at 5 knots forward thru a train car moving at 50 knots, you will cover the ground at 55 knots yet the air pressure you feel on your skin will only be 5 knots.

 

peace,

the Bean

Sorry I bothered to even reply! Just for my info, who died and appointed you God of this sim world? How many RW hours do you have in aircraft? Etc. Etc.

 

Sorry, we're done!

Sorry, we're done!

 

Easy, buddy -- he's just doesn't want to see misinformation here, if it's avoidable. There are several of us who have said the same thing -- a steady wind has no effect on the aircraft aerodynamics.

.. who died and appointed you God of this sim world?

Nobody.

 

How many RW hours do you have in aircraft?

More than you.

 

Jeez, I come back after a while and try to explain something in terms most people would be able to understand and get treated like this?

 

Why bother?