EMB-145 thrust settings

[Knob]

Anybody have any suggestions for thrust settings in the Emb-145?
Speeds such as 220, what would be a target N2? N2 during an ILS? Thanks in advance.

 

[LAXSaabdude]

Anybody have any suggestions for thrust settings in the Emb-145?
Speeds such as 220, what would be a target N2? N2 during an ILS? Thanks in advance.

Well, at Eagle we use N1, not N2 for power settings. Couldn't really give you a number for 220 in level flight. When I went through training, most of the instructors said not to worry too much about memorizing a lot of power settings. The most important one to learn in training is 65%. This will give you 200 knots level (typical speed in the training environment), and will also get you pretty close to your approach speed on an ILS with flaps 45.

Hope that helps!

LAXSaabdude.

 

[FlamingFUPA]

Easiest way for me is to look at the fuel flow. take the first two digits of the fuel flow for each engine add them together add a zero to that and you have your airspeed. ei. 220kias=1100lbs/hr a side. Try it out, seems to keep the airspeed within a few knots.

Use it for any speed clean, seems to work pretty well. Have fun!

 

[Afixedwing]

The fuel-flow method works really well.
Additionaly, to maintain airspeed in your descent, reduce the fuel-flow by 500 lbs/hr per side for each 1000 fpm.

It kind of works in the sim too.

 

[PCL_128]

Fuel flow is always the best way to set power in any jet. The FF that maintains 290 kts at FL310 is the same FF that will maintain 290 kts at 10,000. If you know a few FF numbers, then setting the power is easy. N1, N2, EPR, etc... all changes based on temp and altitude. The FF numbers are always the same though.

 

[Alchemy]

I don't look at N2 or Fuel Flow much to tell you the truth, mostly N1. N1 is the biggest indication on the EICAS and it's right there at the top, so it's easiest to see.

In a clean configuration, 70% N1 holds about 250 knots and 60% holds about 200 knots. On an ILS configured with flaps 45, 65% N1 usually holds target, give or take 5% for weight.

 

[Whydoitry]

I use the FF as well but it seems that I always need to add 100 per side. So to maintain 250 I set FF aprox 1350 instead of 1250 per engine. But as mentioned above, don't get too caught up in the numbers.

 

[five-alive]

not so much about thrust settings but useful in descents:

1) thrust idle, a v/s of 3500 fpm gives you 315 knots (5 knot buffer below Vmo)

2) below 10000', 1800 fpm and idle gives you 245 knots

 

[RP 04]

Fuel flow is always the best way to set power in any jet.

how come then FF is not displayed on the priamary EICAS on quite a few jets?

 

[FlamingFUPA]

jeezuz, didn't take long for a thread with usefull suggestions to turn into a pissing contest

 

[Yank McCobb]

Fuel flow is always the best way to set power in any jet.

Have you flown a large number of jets from which you can draw this conclusion?

 

[PCL_128]

Have you flown a large number of jets from which you can draw this conclusion?

Don't need to, it's just a basic fact of the physics involved. A given FF will always yield the same speed no matter the temp or altitude. N1, N2, etc... all change depending on your alt and temp for a given speed. Do you disagree?

 

[aewanabe]

Don't need to, it's just a basic fact of the physics involved. A given FF will always yield the same speed no matter the temp or altitude. N1, N2, etc... all change depending on your alt and temp for a given speed. Do you disagree?

Sure do. It's a good ballpark figure for maneuvering-type speeds (200-250, for example), but for higher IAS there's quite a bit of difference. For example in our aforementioned E145, it takes around 1900pph/side to maintain 315 kias in the low-mid teens, whereas that number decreases to 1500-1600 in the mid-twenties (before the mach number becomes limiting, depending on temp). YMMV

For the OP, if you're looking for 220 and want to use the N1, try~63 percent at lower altitudes, this'll at least get you into the ballpark.

 

[Nova]

Don't need to, it's just a basic fact of the physics involved. A given FF will always yield the same speed no matter the temp or altitude. N1, N2, etc... all change depending on your alt and temp for a given speed. Do you disagree?

Even in a descent, climb, gear down, flaps down in different increments, in a turn, icing, etc....??

 

[PCL_128]

Even in a descent, climb, gear down, flaps down in different increments, in a turn, icing, etc....??

Sorry, should have specified level flight for a given configuration. Throwing out gear and flaps will obviously change the situation.

 

[ATRedneck]

It's really not as complicated as everybody's trying to make it.

If you're slow, push 'em up. If you're fast, pull 'em back. If the resulting change is too much, split the difference; if it's not enough, move 'em a little more.

 

[PCL_128]

For example in our aforementioned E145, it takes around 1900pph/side to maintain 315 kias in the low-mid teens, whereas that number decreases to 1500-1600 in the mid-twenties (before the mach number becomes limiting, depending on temp).

I can't imagine this being the case in level flight. In a climb, absolutely. The FF will decrease as alt increases while you maintain a given speed in the climb. In the CRJ you will start out with a FF of around 2200/side when you accelerate to 290 at 10k. By the time you get into the 20s, that number has dropped to around 1700 or so. On the other hand, 1350/side will always maintain 290 kts in level flight in the CRJ no matter what altitude you're at as long as you're clean. It might vary by 50-75/side depending on the individual airframe and different weights, but not by more than that.

 

[LAXSaabdude]

jeezuz, didn't take long for a thread with usefull suggestions to turn into a pissing contest

Huh? Seems like it's been pretty civilized to me!

And T-Gates, you are right about the trend vectors. One of my instructors taught us to "pinch" the trend vector between the airspeed pointer and the target speed, i.e.as the tip of the trend vector reaches the target speed, gradually add or reduce power so that the tip of the trend vector stays touching the target speed, and the vector shrinks down to nothing as the airspeed pointer reaches the target speed.

Sounds more complicated than it really is, but that's my best explanation.

LAXSaabdude.

 

[scotts]

Think of those TL's as speed pumps...

Like ATRedneck was saying...

I also use the trend vectors.

 

[JetBlast2000]

Huh? Seems like it's been pretty civilized to me!

And T-Gates, you are right about the trend vectors. One of my instructors taught us to "pinch" the trend vector between the airspeed pointer and the target speed, i.e.as the tip of the trend vector reaches the target speed, gradually add or reduce power so that the tip of the trend vector stays touching the target speed, and the vector shrinks down to nothing as the airspeed pointer reaches the target speed.

Sounds more complicated than it really is, but that's my best explanation.

LAXSaabdude.

Works great for both AS and Alt. After that a little fine tun'n as needed.