Is anybody getting the impression that the 737 is overpowered? I took it up with a gross weight of about 85,000 lbs and ended up with a climb rate well above the range of the VSI. I was climbing a thousand feet in just a few seconds--it was like flying a fighter jet. Is there a flight dynamics mod to correct this?

Yes. They're like a rocket ships!

I have changed (decreased) the static_thrust settings for all of the 737's. These:

737-100 - 14500
737-200 - 16000
737-200C - 16000
737-200F - 16000
737-200 ADV - 17400

Even with those settings, they still feel overpowered, but not as much as they are with the original settings. ;D

Thanks for the numbers. This actually makes the EPR settings in the PDCS usable.

boeing247 wrote on Dec 15^th, 2012 at 2:24am:

Is anybody getting the impression that the 737 is overpowered? I took it up with a gross weight of about 85,000 lbs and ended up with a climb rate well above the range of the VSI. I was climbing a thousand feet in just a few seconds--it was like flying a fighter jet. Is there a flight dynamics mod to correct this?

The FDE needs to be done properly. There are some user tweeks but the plane needs CS to finish it and fix the bugs. I thought it would have been done by now. No such luck. I haven't given up on CS, just want the plane finished.

I just finished a flight in the 737-100 (Continental) from KSEA - KSFO as a part of my checking out Captain Sim FSX products in Windows 8. I was 81,400 ZFW with 20,400 pounds of fuel (101,800 GW) and it took a while to reach FL300.

It certainly did not feel like a rocket ship using the 14500 for the static_thrust. It may not be perfect or realistic, but it "feels" better to me. Same applies to the rest of them, although by the time you get 737-200ADV, it feels quite zappy.

I am noticing the "zippy-ness" but it doesn't bother me too much. I will give the new thrust values a shot.

Thanks for the new values, Mark! Are there any other variables that should be adjusted? (e.g. drag variables)

And as a side note, the door coordinates seem to be off. Does anybody have fixed coordinates so the jetways properly lines up with the door? The jetways seem to want to line up right between the front entrance and the wing for me.

Two threads sum up the current FDE variants. Happy testing.  :)
1) Bud's mod. http://captainsim.org/yabb2/YaBB.pl?num=1339198966
2) Ryan's mod. http://captainsim.org/yabb2/YaBB.pl?num=1354222724
Additionally, check Paul's work on the Vref gauge and callouts. http://captainsim.org/yabb2/YaBB.pl?num=1353062742

Thanks CoolP. I will try that out. I'm not enjoying the process of testing different config settings.

I really wish people didn't have to go through all this trouble. Isn't it enough that they tested it, as well as paid for it?

I guess you have a point. From reading, the 0.9 values were fine and the 1.0 ones then incorporated the high power FDE. I don't know about the reason behind it though. Maybe some of the testers can tell. Same as you, I'd wish for a refined FDE in 1.1, getting rid of the 'need' for user mods.

boeing247 wrote on Dec 15^th, 2012 at 7:10pm:

Thanks for the new values, Mark! Are there any other variables that should be adjusted? (e.g. drag variables) And as a side note, the door coordinates seem to be off. Does anybody have fixed coordinates so the jetways properly lines up with the door? The jetways seem to want to line up right between the front entrance and the wing for me.

There is one other value that I changed in the [TurbineEngineData] settings. I'm not sure if it makes a difference though.

[TurbineEngineData]
fuel_flow_gain = 0.002                          //Gain on fuel flow
inlet_area = 9.6                               //Square Feet, engine nacelle inlet area //19.6
rated_N2_rpm = 29920                            //RPM, second stage compressor rated value
static_thrust = 17400                        //25000
afterburner_available = 0                       //Afterburner available?
reverser_available = 1                          //Thrust reverser available?
ThrustSpecificFuelConsumption = 0.385             //Thrust specific fuel consumption (Jets)
AfterBurnThrustSpecificFuelConsumption = 0      //TSFC with afterburn/reheat engaged

I remember someone else saying something about the inlet_area being only about 9.6 square feet, so I changed that too. I'm not sure if it makes much difference because I never tested it. I might give it a try so I can see if it does.

@CoolP. I try t keep it relatively close to the original (so I can change them back to help someone if necessary), so I don't install MODS (except for the V-One MOD). ;)

Markoz up your fuel fiow upto .510 as the JT8D likes its fuel alot
There is a reason the NGX can get a lot more miles out of only 13,000 more fuel lol

RyanJames170 wrote on Dec 16^th, 2012 at 4:57pm:

There is a reason the other can get a lot more miles out of only 13,000 more fuel lol

Not sure I get what you mean there. :-/

Yesterday, I flew the 737-100 from KSEA to KSFO (~600nm). With the amount of fuel it used to go that distance, I would be worried that it would be very low on fuel by the time I flew it 1540nm, which is the maximum range for the 737-100.

If your running the -100 the thrust should be fairly low around 12000-14000lbs IIRC I'll look it up to be sure

Markoz wrote on Dec 16^th, 2012 at 1:59am:

@CoolP. I try t keep it relatively close to the original (so I can change them back to help someone if necessary), so I don't install MODS (except for the V-One MOD). ;)

Makes perfect sense, Mark. As stated above, I'm hoping that 1.1 renders the mods and tweaks unnecessary.

Markoz wrote on Dec 16^th, 2012 at 1:59am:

[TurbineEngineData] fuel_flow_gain = 0.002                          //Gain on fuel flow inlet_area = 9.6                               //Square Feet, engine nacelle inlet area //19.6 rated_N2_rpm = 29920                            //RPM, second stage compressor rated value static_thrust = 17400                        //25000 afterburner_available = 0                       //Afterburner available? reverser_available = 1                          //Thrust reverser available? ThrustSpecificFuelConsumption = 0.385             //Thrust specific fuel consumption (Jets) AfterBurnThrustSpecificFuelConsumption = 0      //TSFC with afterburn/reheat engaged

The values in the above quote are the settings for the 737-200ADV.

For the 737-100 this is what I use:

[TurbineEngineData]
fuel_flow_gain = 0.002                          //Gain on fuel flow
inlet_area = 9.6                               //Square Feet, engine nacelle inlet area //19.6
rated_N2_rpm = 29920                            //RPM, second stage compressor rated value
static_thrust = 14500                        //16000      23000
afterburner_available = 0                       //Afterburner available?
reverser_available = 1                          //Thrust reverser available?
ThrustSpecificFuelConsumption = 0.385             //Thrust specific fuel consumption (Jets)
AfterBurnThrustSpecificFuelConsumption = 0      //TSFC with afterburn/reheat engaged

So the poor 737-100 has trouble climbing higher than 32,000 but can get to 35,000 feet (it's service ceiling). I wouldn't want to try to get higher than that, it might not get there.

If I fly it at a maximum speed of about M0.78 (~465 - 480 knots GS), it would be hard pressed to exceed the maximum range of 1540nm. It consumed about 40-45% of the maximum fuel in 600nm (I do know that an awful lot of fuel was consumed in the takeoff and climbing phase), but I still wouldn't push for much more than 1200nm flight just be sure I won't run out o fuel, especially if I'm encountering strong head winds. :)

FSX paul's V-one gauge requires setting a reduced thrust value.

Everything seems much better now and the gauge is awesome! :D

Markoz wrote on Dec 16^th, 2012 at 6:31pm:

Markoz wrote on Dec 16th, 2012 at 1:59am: [TurbineEngineData] fuel_flow_gain = 0.002                          //Gain on fuel flow inlet_area = 9.6                               //Square Feet, engine nacelle inlet area //19.6 rated_N2_rpm = 29920                            //RPM, second stage compressor rated value static_thrust = 17400                        //25000 afterburner_available = 0                       //Afterburner available? reverser_available = 1                          //Thrust reverser available? ThrustSpecificFuelConsumption = 0.385             //Thrust specific fuel consumption (Jets) AfterBurnThrustSpecificFuelConsumption = 0      //TSFC with afterburn/reheat engaged The values in the above quote are the settings for the 737-200ADV. For the 737-100 this is what I use: [TurbineEngineData] fuel_flow_gain = 0.002                          //Gain on fuel flow inlet_area = 9.6                               //Square Feet, engine nacelle inlet area //19.6 rated_N2_rpm = 29920                            //RPM, second stage compressor rated value static_thrust = 14500                        //16000      23000 afterburner_available = 0                       //Afterburner available? reverser_available = 1                          //Thrust reverser available? ThrustSpecificFuelConsumption = 0.385             //Thrust specific fuel consumption (Jets) AfterBurnThrustSpecificFuelConsumption = 0      //TSFC with afterburn/reheat engaged So the poor 737-100 has trouble climbing higher than 32,000 but can get to 35,000 feet (it's service ceiling). I wouldn't want to try to get higher than that, it might not get there. If I fly it at a maximum speed of about M0.78 (~465 - 480 knots GS), it would be hard pressed to exceed the maximum range of 1540nm. It consumed about 40-45% of the maximum fuel in 600nm (I do know that an awful lot of fuel was consumed in the takeoff and climbing phase), but I still wouldn't push for much more than 1200nm flight just be sure I won't run out o fuel, especially if I'm encountering strong head winds. :)

Does changing the inlet area affect anything with FSXpaul's v-one gauge?

wrote on Dec 18^th, 2012 at 6:54pm:

Does changing the inlet area affect anything with FSXpaul's v-one gauge?

Yes, but not much.
I'm currently using inlet_area = 9.6 and static_thrust = 15650.

I've set my OptEprOffset to -0.020 in the V-One gauge XML.

You should use whatever settings seem to work best for you  ;)

Ok sounds good.

I've tried all the recommended mods, but I'm still way overpowered. Anything else that can be done?

You would have thought that something as simple as "the aircraft is way overpowered" would have been picked up during beta testing a long time ago...

Christopher Low wrote on Dec 29^th, 2012 at 4:42pm:

You would have thought that something as simple as "the aircraft is way overpowered" would have been picked up during beta testing a long time ago...

It wasn't as bad in v0.9. It changed dramatically in v1.0! :(

boeing247 wrote on Dec 27^th, 2012 at 7:41pm:

I've tried all the recommended mods, but I'm still way overpowered. Anything else that can be done?

I'm curious, do you normally fly short flights (light fuel load)? When I was doing FDE modifications I noticed fuel load makes a huge difference in power requirements and fuel burn. With a light fuel load (empty center tank) I can climb at 3000 fpm or more all the way up to about FL180.

bud7h7 wrote on Jan 3^rd, 2013 at 1:09am:

boeing247 wrote on Dec 27th, 2012 at 7:41pm: I've tried all the recommended mods, but I'm still way overpowered. Anything else that can be done? I'm curious, do you normally fly short flights (light fuel load)? When I was doing FDE modifications I noticed fuel load makes a huge difference in power requirements and fuel burn. With a light fuel load (empty center tank) I can climb at 3000 fpm or more all the way up to about FL180.

I've only been flying short flights (empty center tank, right and left tanks each half-full), but I'm still getting way over 3000 fpm at all altitudes. I can maintain over 4000 FPM (often much more than 4000) with throttles at about 80-90%. I did some quick research on the 737-200, and apparently it did have a very good climb rate, but I can't imagine it was as high as the rate I'm managing.

I just flew a 4+ hour flight (about 1700nm) in the 737-200, so I started with full tanks. Although the initial climb to 10000 feet was done at about 4000 fpm, using full power, by the time I reached FL310, I was struggling to maintain 1000 fpm with an airspeed of about 240 KIAS or less. That was using the settings I mentioned above (regarding the inlet_area = 9.6 and the static_thrust = 17400). I wouldn't call it overpowered any more. Certainly not like it is when using inlet_area = 19.6 and the static_thrust = 25000. So I'm pretty happy with the performance now. It may not be exactly right, but it isn't too bad.

I'm using static_thrust=15650 and that seems quite realistic. I can't climb over 3000 fpm above 10000'. By FL 320, it struggles a little to maintain 250 knots.

10 years later...  Try this:

rated_N2_rpm=12250

You will definitely no longer see rocket ship performance.  I loaded up to max TOW in ABQ in 20 degree C and it was a real struggle to get through the flap retraction.  Keeping thrust at mac continuous, the best she could do at 270 knots was 2K.  Bu the time I got to 2000, 1K was about it.

For the first time ever, my jet is actually UNDER powered.

I got the number here:en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D

mjl1966 wrote on Apr 18^th, 2022 at 4:56am:

10 years later...  Try this: rated_N2_rpm=12250 You will definitely no longer see rocket ship performance.  I loaded up to max TOW in ABQ in 20 degree C and it was a real struggle to get through the flap retraction.  Keeping thrust at mac continuous, the best she could do at 270 knots was 2K.  Bu the time I got to 20000, 1K was about it. For the first time ever, my jet is actually UNDER powered. I got the number here:en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D

Nice bit of info there, but I got the following engine thrust rating figures for the

737-100 @14,000 lb (62 kN)

737-200 @14,500–16,400 lb (64–73 kN)

from wikipedia https://en.wikipedia.org/wiki/Boeing_737#Specifications

I assume that the higher thrust rating is for the 737-200ADV.

Also, a search on google for the thrust rating of the 737-100 (https://www.google.com/search?client=firefox-b-d&q=b737-100+thrust+rating) came up with this:

How much thrust does a 737 engine have?

The engine chosen was the Pratt & Whitney JT8D-1 low-bypass ratio turbofan engine, delivering 14,500 lb (64 kN) thrust.

So that's 2,250 lb above your suggestion. If you're talking 737-200, then the difference is 5,150 lb (I found that 17,400 lb was the thrust rating for it (google search)), although that could be the 737-200ADV, and perhaps 16,400 lb is more relevant to the 737-200 (a difference of 4,150 lb above your suggestion). ;)

The  problem is JT8D is not electronically limited, so you can push much higher EPR, and in CS732 there would be no consequence for that.
If you use proper EPR from realworld table, it feels much reasonable