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I have a problem at landing... I am very bad for control thrust lever...

so I think I have to know N1 percent. takeoff and climb and cruze is not matter.

But desent and approach and landing N1 is problem because engine display do not notice that to me and I do not know how to control throttle. Anyone can help me??

 

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Don't worry about the thrust levels, just monitor your airspeed and pitch.

Also, I'd suggest that before you load up this forum with a bunch of PMDG questions as you have three espérate PMDG related problems posted here, you can post in the PMDG section of the Avsim forums. Link below.

https://www.avsim.com/forums/forum/432-pmdg-737ngx/

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5 hours ago, cmpbellsjc said:

Don't worry about the thrust levels, just monitor your airspeed and pitch.

but we have to move thrust lever for control speed.

 

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2 hours ago, Chowonwoo said:

but we have to move thrust lever for control speed.

 

I didn't say you don't have to move the throttles, I just said that you don't need to worry about the actual N1 percent.

If you don't have a throttle lever on your joystick or a stand alone throttle control then you'll have to use F1 to F4 keys to control the throttles. It would probably be easier to set the airspeed in the MCP and turn on the auto throttles and let the plane manage the throttle for you. You can still hand fly the plane on approach with the auto throttle handling the throttles for you.

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20 hours ago, Chowonwoo said:

but we have to move thrust lever for control speed.

 

When I was learning to fly many years ago, the instructor kept reminding me of his rule, which I remember to this day, for managing an approach:

"Use pitch to control airspeed and power to control rate of descent"

Although it is a somewhat simple rule I think it can be applied equally well to large as well as small aircraft.

Bill

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1 hour ago, Chowonwoo said:

but we don't have N1 for landing or approaching??

The FMC doesn't calculate an N1 value for approach and landing but it gives the reference speeds depending on flap selection.

As mentioned to you a few times already, don't obsess with the N1 values when landing, just make sure to hold the proper pitch and speed. 

If you're having trouble keeping the speed where it needs to be use the auto throttle and set the speed you want in the MPC. So if the FMC says your vRef is 145kts with Flaps 30, use the vRef 145+5kts=150kts (+5kts is average with light wind but will change depending on wind speed) and set 150kts in the MCP.

No need to make it any harder than it actually is. I'd recommend flying the tutorials that come with the aircraft to help you get more accustomed to flying it and how to use the autopilot/autothrottle functions to reduce the work load until you become more proficient at hand flying it.

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2 hours ago, cmpbellsjc said:

The FMC doesn't calculate an N1 value for approach and landing but it gives the reference speeds depending on flap selection.

As mentioned to you a few times already, don't obsess with the N1 values when landing, just make sure to hold the proper pitch and speed. 

If you're having trouble keeping the speed where it needs to be use the auto throttle and set the speed you want in the MPC. So if the FMC says your vRef is 145kts with Flaps 30, use the vRef 145+5kts=150kts (+5kts is average with light wind but will change depending on wind speed) and set 150kts in the MCP.

No need to make it any harder than it actually is. I'd recommend flying the tutorials that come with the aircraft to help you get more accustomed to flying it and how to use the autopilot/autothrottle functions to reduce the work load until you become more proficient at hand flying it.

can you explane why FMC do not culculate Approach and Landing N1??

I want to know that. And can you give me some tips ot control throttle, please??

 

(P.S- I have joystick and It contain throttle...)

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On 14/10/2017 at 9:06 AM, cmpbellsjc said:

Don't worry about the thrust levels, just monitor your airspeed and pitch.

I understand what you are saying here, but I would also just chuck in: the approximate power setting for a particular phase of flight is a very good thing to know. Power (N1) + Attitude = Performance; if you know the rough pitch attitude and power setting you should have fully configured on the glidepath then you have a very good starting point and will also very quickly be able to determine if the aeroplane is not performing as it should.

3 hours ago, Chowonwoo said:

can you explane why FMC do not culculate Approach and Landing N1??

Because the FMC provides you with a thrust limit (which on final approach will be the go-around thrust limit). The autothrottle, if engaged, will (should) be in "Speed" mode, which means that thrust is varied (up to the appropriate limit) to maintain the set airspeed.

Power + attitude = performance. In other words, in a particular configuration (gear, flap, weight etc), a given power setting (N1) and pitch attitude (viewed on the artificial horizon) will always result in approximately the same flight path and airspeed. I don't know the numbers for the 737NG as I've never flown it, but it is easy to find out: just fly the ILS on the autopilot with the autothrottle engaged and once you are stabilised on final approach with landing gear and landing flap extended, at the appropriate airspeed (typically Vref + 5) just make a note of the approximate values of N1 and pitch attitude. These are your datums from which you can then tweak as required to maintain the correct flight path.

3 hours ago, Chowonwoo said:

can you give me some tips ot control throttle, please??

Set the pitch attitude and N1 power setting required (see above) and just make small adjustments from there as required. Bear in mind that with underslung jet engines there is a thrust-pitch couple which will cause the nose to pitch up when you increase thrust and pitch down when you decrease thrust; therefore generally speaking you do not want to be jockeying the thrust levers up and down all over the place, because this will likely destabilise your flying. As with all flying: quickly get it approximately right, then make small adjustments as required. Keep the airspeed in your instrument scan; if the speed is lower than target, add a small amount of thrust, if the airspeed is above target then reduce thrust slightly. The larger the deviation the larger the required correction, but the aim is to keep your scan rate high enough to pick up deviations early so that only small, smooth corrections are required. It is always better to make a small correction early than a large correction late.

On 15/10/2017 at 11:10 AM, scianoir said:

When I was learning to fly many years ago, the instructor kept reminding me of his rule, which I remember to this day, for managing an approach:

"Use pitch to control airspeed and power to control rate of descent"

Although it is a somewhat simple rule I think it can be applied equally well to large as well as small aircraft.

I would slightly disagree with this for large aircraft, and particularly for attitude instrument flying.

The main reason this is preached (and indeed is good technique) in primary training is because your typical light trainer (i.e. C152/C172/PA28 etc) is very draggy, has very little inertia and is equipped with a piston engine that will respond very quickly to throttle changes. As such, what instructors above all do not want students to do is to get in to the habit of thinking "I'm low -- so I'll yoink the nose up" as the most likely outcome of this in a draggy, low-inertia trainer is stall/spin/crash. These types of aircraft react much more quickly to power changes and lose airspeed very quickly when the nose is pulled up without additional power, and therefore it is much better to lead with power.

In a slippery, high-inertia jet, however, the situation is rather different. In this case, a very small change in pitch attitude/angle of attack (even of just a degree or so) will have an immediate and pronounced impact on flight path, but very little immediate effect on airspeed. Conversely, large high-bypass fans take a long time to spool up or spin down and so power changes are far from instant, and as discussed above the thrust-pitch couple is much greater than on a SEP type aircraft. As such, especially when flying on instruments in a large jet it is much easier and much more effective to pitch for the glidepath and adjust power for airspeed.

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22 minutes ago, skelsey said:

I understand what you are saying here, but I would also just chuck in: the approximate power setting for a particular phase of flight is a very good thing to know. Power (N1) + Attitude = Performance; if you know the rough pitch attitude and power setting you should have fully configured on the glidepath then you have a very good starting point and will also very quickly be able to determine if the aeroplane is not performing as it should.

Because the FMC provides you with a thrust limit (which on final approach will be the go-around thrust limit). The autothrottle, if engaged, will (should) be in "Speed" mode, which means that thrust is varied (up to the appropriate limit) to maintain the set airspeed.

Power + attitude = performance. In other words, in a particular configuration (gear, flap, weight etc), a given power setting (N1) and pitch attitude (viewed on the artificial horizon) will always result in approximately the same flight path and airspeed. I don't know the numbers for the 737NG as I've never flown it, but it is easy to find out: just fly the ILS on the autopilot with the autothrottle engaged and once you are stabilised on final approach with landing gear and landing flap extended, at the appropriate airspeed (typically Vref + 5) just make a note of the approximate values of N1 and pitch attitude. These are your datums from which you can then tweak as required to maintain the correct flight path.

Set the pitch attitude and N1 power setting required (see above) and just make small adjustments from there as required. Bear in mind that with underslung jet engines there is a thrust-pitch couple which will cause the nose to pitch up when you increase thrust and pitch down when you decrease thrust; therefore generally speaking you do not want to be jockeying the thrust levers up and down all over the place, because this will likely destabilise your flying. As with all flying: quickly get it approximately right, then make small adjustments as required. Keep the airspeed in your instrument scan; if the speed is lower than target, add a small amount of thrust, if the airspeed is above target then reduce thrust slightly. The larger the deviation the larger the required correction, but the aim is to keep your scan rate high enough to pick up deviations early so that only small, smooth corrections are required. It is always better to make a small correction early than a large correction late.

I would slightly disagree with this for large aircraft, and particularly for attitude instrument flying.

The main reason this is preached (and indeed is good technique) in primary training is because your typical light trainer (i.e. C152/C172/PA28 etc) is very draggy, has very little inertia and is equipped with a piston engine that will respond very quickly to throttle changes. As such, what instructors above all do not want students to do is to get in to the habit of thinking "I'm low -- so I'll yoink the nose up" as the most likely outcome of this in a draggy, low-inertia trainer is stall/spin/crash. These types of aircraft react much more quickly to power changes and lose airspeed very quickly when the nose is pulled up without additional power, and therefore it is much better to lead with power.

In a slippery, high-inertia jet, however, the situation is rather different. In this case, a very small change in pitch attitude/angle of attack (even of just a degree or so) will have an immediate and pronounced impact on flight path, but very little immediate effect on airspeed. Conversely, large high-bypass fans take a long time to spool up or spin down and so power changes are far from instant, and as discussed above the thrust-pitch couple is much greater than on a SEP type aircraft. As such, especially when flying on instruments in a large jet it is much easier and much more effective to pitch for the glidepath and adjust power for airspeed.

OMG I am Korean!!! too hard to read. . .

but I think really thank to you~~

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There is no approach and landing N1 to compute. It is not a constant value. If you use autothrottle, it will adjust power as required to maintain parameters such as speed and descent rate. The power will vary as configuration changes are made, and will vary between flights as weather and payload will vary.

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