After reading through the other post here "737 takes ENTIRE runway to Rotate....", in this forum and thinking on the many jet aircraft I've bought over the years for FS9 I've come to the conclusion that FS9 in some cases doesn't model thrust correctly. I've read through the posts here about how long it takes the PMDG 737NG to get into the air with all kinds of explanations. Bottom line is PMDG entered the correct engine values but FS9 doesn't model those values correctly. I use KMDW as a marker and it shouldn't take the 737NG the length it does to get off the ground. With PMDG's normal engine settings I use almost all the runway with a jet that's not overweight and has only 80% fuel in the center tank. 737's out of KMDW fly as far as KSAN with no problem on takeoff (thank God for KMDW which shines the light on an otherwise subtle problem. KMDW's runways demand performance to get airborne). So I put things to the test... A couple of months ago I was in Chicago and spent some time at KMDW for a connecting flight. I had the pleasure of talking to some Southwest pilots boarding their plane for KSAN. Where the plane was at the terminal allowed me to watch the plane from gate to takeoff. I posed the question to them about fuel, weight, and temps. It would be too much to go into here but I had every intention to compare what I knew about PMDG's version to the real thing. Needless to say the real 737NG is an outstanding climber and can easily get off the runway on the hottest of days with full load within the designed numbers, full tanks in the wings and 75-80% fuel in the center tank (it's designed to climb higher than the old generation 737's). As long as the plane is not overweight per it's POH specs it performs... So the Southwest plane leaves the gate with a full load of passengers and enough fuel to carry it to KSAN. Again the temp was +90 that day and not that much of a head wind. The main landing gear was off the runway (4R) on takeoff inches past runway 13L\31R with runway to spare. When I got home I had to change that thrust setting...I flew on an Airtran 737NG from KMSP-KORL on my vacation to Disney World a month ago with a full load of passengers and can tell you we easily reached 37,000ft in and around 20 minutes or less. The climb performance in the 737NG is amazing... I challenge anyone to either fly on one or do the research at an airport like KMDW and you won't find one 737NG struggling to takeoff or getting to altitude. Go to YouTube and see it for yourself...So here's the bottom line... PMDG did their job concerning the numbers with their engines, FS9 is the problem. To get correct performance I had to increase the engine thrust in the aircraft.cfg file to what I experienced in the real world. I had to do the same with Feelthere's 737-300 series. Some of you may scoff at this but it's a reality with some add-ons I don't know why. Feelthere's E-Jet series is fine the same goes for their ERJ series but some jets are problems (props are fine in the thrust area). I can't explain it... I even had to update my World of AI aircraft thrust for the 737NG series to get them to take off the runway realistically so understand this is not just PMDG's birds. Something about the 737 and FS9 does not jive for some reason. My 737NG is a joy to fly now especially with Des Braban's sound set located here in the Avsim library. You guys can take from this what you want but the real world numbers don't always give an accurate picture of real world performance. You have to do some research to find what's realistic. I would have never caught this if it weren't for Southwest and KMDW. I'll post my engine settings if some of you are interested but I gave up fighting with the add-on concerning weight and temps, that's not the issue. It just didn't perform like the real thing leaving me to increase the settings 'unrealistically' to get performance that's realistic.PMDG you guys might want to look at this with the NGX project. Either way I'm perfectly prepared to increase my engine thrust settings to get off of KMDW's runways the way the real birds do. This is one of those quarks in FS9 that has to be compensated for with best judgment. I don't know about FSX but I'm pretty sure nothing much has changed in this area (although I hope I'm wrong and real world number equate to real world performance)...

Did you find the same problem with the PMDG 747 and/or MD-11?

After reading through the other post here "737 takes ENTIRE runway to Rotate....", in this forum and thinking on the many jet aircraft I've bought over the years for FS9 I've come to the conclusion that FS9 in some cases doesn't model thrust correctly. I've read through the posts here about how long it takes the PMDG 737NG to get into the air with all kinds of explanations. Bottom line is PMDG entered the correct engine values but FS9 doesn't model those values correctly. I use KMDW as a marker and it shouldn't take the 737NG the length it does to get off the ground. With PMDG's normal engine settings I use almost all the runway with a jet that's not overweight and has only 80% fuel in the center tank. 737's out of KMDW fly as far as KSAN with no problem on takeoff (thank God for KMDW which shines the light on an otherwise subtle problem. KMDW's runways demand performance to get airborne). So I put things to the test... A couple of months ago I was in Chicago and spent some time at KMDW for a connecting flight. I had the pleasure of talking to some Southwest pilots boarding their plane for KSAN. Where the plane was at the terminal allowed me to watch the plane from gate to takeoff. I posed the question to them about fuel, weight, and temps. It would be too much to go into here but I had every intention to compare what I knew about PMDG's version to the real thing. Needless to say the real 737NG is an outstanding climber and can easily get off the runway on the hottest of days with full load within the designed numbers, full tanks in the wings and 75-80% fuel in the center tank (it's designed to climb higher than the old generation 737's). As long as the plane is not overweight per it's POH specs it performs... So the Southwest plane leaves the gate with a full load of passengers and enough fuel to carry it to KSAN. Again the temp was +90 that day and not that much of a head wind. The main landing gear was off the runway (4R) on takeoff inches past runway 13L\31R with runway to spare. When I got home I had to change that thrust setting...I flew on an Airtran 737NG from KMSP-KORL on my vacation to Disney World a month ago with a full load of passengers and can tell you we easily reached 37,000ft in and around 20 minutes or less. The climb performance in the 737NG is amazing... I challenge anyone to either fly on one or do the research at an airport like KMDW and you won't find one 737NG struggling to takeoff or getting to altitude. Go to YouTube and see it for yourself...So here's the bottom line... PMDG did their job concerning the numbers with their engines, FS9 is the problem. To get correct performance I had to increase the engine thrust in the aircraft.cfg file to what I experienced in the real world. I had to do the same with Feelthere's 737-300 series. Some of you may scoff at this but it's a reality with some add-ons I don't know why. Feelthere's E-Jet series is fine the same goes for their ERJ series but some jets are problems (props are fine in the thrust area). I can't explain it... I even had to update my World of AI aircraft thrust for the 737NG series to get them to take off the runway realistically so understand this is not just PMDG's birds. Something about the 737 and FS9 does not jive for some reason. My 737NG is a joy to fly now especially with Des Braban's sound set located here in the Avsim library. You guys can take from this what you want but the real world numbers don't always give an accurate picture of real world performance. You have to do some research to find what's realistic. I would have never caught this if it weren't for Southwest and KMDW. I'll post my engine settings if some of you are interested but I gave up fighting with the add-on concerning weight and temps, that's not the issue. It just didn't perform like the real thing leaving me to increase the settings 'unrealistically' to get performance that's realistic.PMDG you guys might want to look at this with the NGX project. Either way I'm perfectly prepared to increase my engine thrust settings to get off of KMDW's runways the way the real birds do. This is one of those quarks in FS9 that has to be compensated for with best judgment. I don't know about FSX but I'm pretty sure nothing much has changed in this area (although I hope I'm wrong and real world number equate to real world performance)...

Rather than be subjective, let's use some actual numbers to test. I don't have the 737 installed at the moment, but can someone with TOPCAT and the 738 installed post some performance numbers and results.I was just looking in TOPCAT and performance out of KMDW looks pretty abysmal for even a modestly loaded 738.

Rather than be subjective, let's use some actual numbers to test.

That is a rock solid advice. It sounds absolutely hilarious to start modifying some files based on YouTube videos, casual conversations in airport lounges or watching takeoffs from inside the aircraft. :(

That is a rock solid advice. It sounds absolutely hilarious to start modifying some files based on YouTube videos, casual conversations in airport lounges or watching takeoffs from inside the aircraft. :(

I welcome getting some actual numbers which is great advice. On average how much runway length at Midway airport does it take an averagely loaded 737NG to take off? Get some real numbers on the KMDW to KSAN flight especially in warm conditions... Time to cruise altitude should be researched as well. I don't have actual numbers nor do I currently have the time to gather all that info. What I can say is in sim performance of the 737NG is far lacking any observation in the real world casual or otherwise. I welcome some solid research here as it would better serve the NGX development.

Did you find the same problem with the PMDG 747 and/or MD-11?

Without an airport like KMDW where these birds have to operate with a limited amount of runway length it's impossible to really tell. Another thing is an airline like Southwest making daily flights with a specific aircraft type makes it easier to pen down weights in various climate conditions equating reasonable performance. Anyone can go to Midway and observe takeoffs and see there's something different going on with the FS9 version. I fly for real so I can make an educated observation understanding that it shouldn't take your wheels almost hitting the blast fence in order to get off the ground on a flight to KSAN with just enough fuel equated to get there. Those Southwest birds are up in the air with room to spare and their not lacking on available power once their in the air either. I welcome some research as I'm unable to do it at this time due to beta test duties...

I welcome getting some actual numbers which is great advice. On average how much runway length at Midway airport does it take an averagely loaded 737NG to take off? Get some real numbers on the KMDW to KSAN flight especially in warm conditions... Time to cruise altitude should be researched as well. I don't have actual numbers nor do I currently have the time to gather all that info. What I can say is in sim performance of the 737NG is far lacking any observation in the real world casual or otherwise. I welcome some solid research here as it would better serve the NGX development.

Ok, I'll bite. I loaded the 738 tonight for a flight mimicking that of DAL1253 (MDW-SLC). I was close to MZFW (~130k lb) and 24k lbs of fuel...not a lightly loaded 738 by any means. I ran the Topcat performance data which I've pasted below. I know that the guy who rights the profiles for Topcat uses RW data (doesn't code for a specific plane) and is top notch, although I suspect the V1,VR speeds are incorrect. The sim gave me 128/136/145...the last of which jives pretty well with the 144 that Topcat gives, so I used the numbers the FMC gives.As you can see, only 21L or 31C takeoffs are allowed and the margin on both for any de-rate was too close for my comfort. I used the MAX PERF numbers which gave me an N1 ~ 99%.I had no trouble with rotate/takeoff/1st/2nd segment climbs....it looks about right for how short that runway is.SO....for all of this rigamarole (I love that word but can't spell it), I think the NG is slightly underpowered but not enough to write home about. I'd say something else is going on if you can't get off the gournd (e.g. not enough flaps for conditions, de-rating where not appropriate, not setting enough trim). Hope this helps!//////FLIGHT REPORT 1253 KMDW-KSLCTOPCAT 2.57 12AUG09 03:36UTCA/C PMDG737-800 B737-800 CFM56-7B26 ALL WEIGHTS IN POUNDS///////// AIRPORTS /////////DEP KMDW/MDW CHICAGO MIDWAY INTL ELEV. 620FT ( 189M)DEST KSLC/SLC SALT LAKE CITY INTL ELEV. 4227FT ( 1288M) 1091 NMALTN1 KHIF/HIF HILL AFB ELEV. 4789FT ( 1460M) 20 NMALTN2 KOGD/OGD OGDEN-HINCKLEY ELEV. 4473FT ( 1363M) 25 NM///////// WEATHER DATA (PROVIDED BY NOAA) /////////KMDW 120251Z 02007KT 10SM CLR 21/15 A3006 RMK AO2 SLP171 T02060150 52012KMDW 112320Z 1200/1224 03010KT P6SM FEW050 FM120200 VRB03KT P6SM SKC FM121400 03007KT P6SM FEW060 FM121900 05012KT P6SM FEW060KSLC 120253Z 02007KT 10SM FEW090 SCT200 27/06 A3010 RMK AO2 SLP137 T0267005655006KSLC 112334Z 1200/1306 33008KT P6SM FEW090 FM120300 15007KT P6SM FEW090 FM122000 33009KT P6SM FEW090 FM130300 15007KT P6SM FEW090KHIF 120255Z 08003KT 10SM CLR 26/04 A3015 RMK AO2A SLP118 T02590041 56008RVRNO $KHIF 080505 11009KT 9999 SCT050 BKN200 QNH3031INS BECMG 1213 12012KT 9999 SCT050 BKN200 QNH3025INS BECMG 1819 12009KT 9999 BKN200 QNH3006INS T09/23Z T02/12Z AUTOMATEDSENSOR METWATCH 0805 TIL 1014KOGD 120253Z AUTO 00000KT 10SM CLR 27/06 A3012 RMK AO2 SLP142 T02720061 56009KOGD 112334Z 1200/1224 29007KT P6SM FEW090 FM120300 17006KT P6SM SCT090 FM121900 29007KT P6SM FEW090///////// TAKE-OFF DATA /////////APT PRWY POAT PWIND PQNH PTOW AIRCOND ANTI-ICE RWY CONDKMDW 31C +26

The 737-700 would be a better test bed out of KMDW...

The 737-700 would be a better test bed out of KMDW...

I'd do it if I had the numbers. DAL1253 is a R/L flight, and I would think that the -800 series would require a bit more room for takeoff. I think that works out ok.

What should I raise the thrust number to in the aircraft.cfg? I didn't see that number posted here.Give me a place to start.To those that question the weight, flaps, trim, etc. I can tell you that this is NOT the issue. I am a pilot and have flown enough to know how to trim an airplane for takeoff--and set the flaps correctly! If this was the case, wouldn't I also have these types of issues in other planes? I don't. This is just a problem when flying the PMDG 737.

What should I raise the thrust number to in the aircraft.cfg? I didn't see that number posted here.Give me a place to start.To those that question the weight, flaps, trim, etc. I can tell you that this is NOT the issue. I am a pilot and have flown enough to know how to trim an airplane for takeoff--and set the flaps correctly! If this was the case, wouldn't I also have these types of issues in other planes? I don't. This is just a problem when flying the PMDG 737.

Steve,I think I've shown in this thread (to some degree) that the PMDG bird works as expected. I responded in your other thread asking for the information needed to look at this from a quantifiable standpoint rather than just "it doesn't work because I know what I'm doing".I'm sure if you took a look in the aircraft.cfg you could easily find the thrust numbers, but beware...changing these numbers will have repercussions throughout all regimes of flight. Most performance information is store in the .air file, and I wouldn't even know where to begin once you dive in there.

Steve,I think I've shown in this thread (to some degree) that the PMDG bird works as expected. I responded in your other thread asking for the information needed to look at this from a quantifiable standpoint rather than just "it doesn't work because I know what I'm doing".I'm sure if you took a look in the aircraft.cfg you could easily find the thrust numbers, but beware...changing these numbers will have repercussions throughout all regimes of flight. Most performance information is store in the .air file, and I wouldn't even know where to begin once you dive in there.

Reminder: The NG was PMDG's first MSFS model. It was originally created for FS2002. The 744 and MD11 are much better examples of PMDG's current level of engine model development.

Can't be that 'off' I just tried it with the weights/temps in the other thread at KHOU 12R with full fuel and flaps 5, 5.8% trim and managed to take off before running out of tarmac. And that was a no winglets model.Probably not doing something right I'd guessAs for performance the 737 had a short field addition a few years back - b737.org so comparison is probably off.John Ellison