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GusRodrigues

Takeoff trouble out of Midway Airport...

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Guest Water Mango

Midway Airport has some short runways. I was looking on Wikipedia at Southwest destinations out of this airport. For a flight from say KMDW to KLAS you would have to have full tanks to make sure you reach your destination (All three tanks of Feelthere's 737-300 is actually more than enough)... I factored end a full load of passengers as Las Vegas is a popular destination for vacationers. Low and behold on a hot July day I can't seem to takeoff of any runway with the 737-300. The bird won't leave the runway in time. If I cut back on passenger weight that still doesn't solve the problem. If I cut back on both fuel and passenger weight then I barely make it off the runway before running out of runway...So what gives??? How can Southwest who operates flights to destinations like KLAS and Orlando takeoff from Midway in real life??? I'm at work now so I don't have exact weights but unless the 737 in question is very light meaning not enough fuel to get to the destination, it's not getting off the runway at Midway. I've started using FlyTampa's Midway as a test airport to how good an FDE is because of the short runways. The airport is very fun and challenging.So tell me guys what am I missing with the 737 and KMDW (my test include the PSS, FeelThere, and Ariane versions. All aircraft have the same problems with weight on takeoff)...Thanks to anyone who can enlighten me on this one...

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Guest tcable

All of the SWA flightw to LAS LAX, SAN and PHX from Midway are on -700's. They might be load restricted in Summer due to the runway length.They should have about 23K in gas for SAN based on yesterday's routing from www.flightaware.com

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Guest cadaha

Things to check are:1. Trim, increase take off trim2. May need more flaps3. more powewr on the brakes until you get enough power4. Major one that you can do nothing about is relative humidity more water in the air the less dense which will cause problems in combustion and lift. (I think ;) )

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1 - Is There obstacle in your climb profile?2 - Is There a climb limit weight?1 - Obstacle clearance in the SID/DP profile can limit your ATOW, further you can load your aircraft to the maximum.2 - the OAT and the Airfield elevation can limit your ATOW, such as your flap selection. More flap means more drag. Because of that, you may want a lower flap setting to keep your climb profile.So, flaps 15 (737 classic) is the optimum flap for short runways. BUT, flaps 15 give to you the worst climb gradient because of drag.now we can have two options.IF my runway is not the ATOW limiter, I can select a lower flap setting to have a better second take-off segment. flaps 1 gives you the bestest Climb segment.But, if your field is the only thing that can reduce your ATOW, the best is use flaps 15, and do not assume OAT.Just assume an OAT if you have the Field Analysis.another point.The destination Field length AND elevation can limit your MLW, and you will have a ATOW limit in your departure.


Gustavo Rodrigues - Brazil

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For short take-offs I do not know how well this is modeled but a BLEEDS OFF takeoff might be used (for no icing hot days). A/C packs should be off until your up a few hundred feet. Down low ram air can be used. You can use bleed air from the APU until you get going.


Ron Ginsberg
KMSP Minnesota, Land of 10,000 Puddles
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Guest Water Mango

Guys before the days of the 737-700 Southwest used the -300 series for long haul flights within the US (O.k. long domestic flights). I'm trying to figure out how they got off the ground with such a limited runway length. As far as trim, Ram Air, etc., I've done all that. From what I see going on at the real Airport when I flew through there versus what I see in FS is two different things. I've never seen a jet barley get over the fence at the real airport. With flights to places like KSAN and such, how in the world is it possible from KMDW on a hot day??? :-hmmm O.K. I got one guys... Can someone at least tell me the typical takeoff weight of a 737-300/700 flying out of Midway for a destination like KPHX? Another big plus is if someone knew the fuel load for a flight like this...

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A takeoff from a short runways is a 'short field takeoff'. On short field takeoff, you usually rotate a tad earlier and use flaps for takeoff. As said earlier, you rotate earlier and have to pitch up to the best ANGLE to climb while holding airspeed. It is pretty tricky, because you increase the risk of stalling. After you clear any obstacles (buildings, poles, etc), you pitch down slowly to accelerate to the best climb SPEED.I cannot comment on large airliners from my PPL experience, but my guess is that the CG (center of gravity) might have to be adjusted as well with bigger airliners along with less fuel load. However, for an average small airliner like the 737 KMDW should have even enough runway length to not consider it to be a short field takeoff.Hope this helps,Pat

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I came up with a fuel load of 24,000 with added taxi, extra, holding, alternate.With an all economy and some cargo I came up withy a ZFW of 118186, On an 80 degree day the 6500 foot runway at midway becomes a 6200 foot including up to a ten knot tailwind. That will support a 140,000 GTOW so a few adjustments might be necessary.


Ron Ginsberg
KMSP Minnesota, Land of 10,000 Puddles
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just a quick analisys.86 F rwy04R/22L - Flaps 5, Bleeds of AC - ONRWY Correct Length (wind and slope): 6895ftMTOW - 130,5 lbs2200nm routeLW - 105,000lbsMFOD - 102,000 lbsMFZW - 93,250lbsInitial FL320, bellow 115,000lbs, climb for FL360108F , same flaps, rwy and bleedsMTOW 122,7lbs115F, same flaps, rwy and bleedsMTOW 120,4lbsadjust your MFZW for OAT and distance.22K onlyregards


Gustavo Rodrigues - Brazil

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