I have had the NGX for a week now and WOW what an airplane, from someone who started flying FS when I was 10 years old with FS2000 how far FS as gone amazing what you guys at PMDG have done with FSX.Anyway my question is with the short field performance package. With a light load lets say 60% capacity or so with fuel for a 200nm flight + reserve how much runway does the 737-700 need to takeoff with the SFP? Would 4,500ft be enough? Also given if that is enough I am guessing flaps 10 or 15 takeoff? Been looking through the documents and online and cant seem to find any info on this.Thanks for the help

Same here! I live out in the Teton national park. Our local field, KJAC, is 6300 feet length, elevation 6451 feet. Our temps have been around -10c to -20c. TOPCAT doesn't even give me choices (e.g the listing of the different derates). I eat up almost the entire rwy. I have flew from here numerous times in United's AB fleet, and they have no problem picking up speed and getting off. I have also flown on the 75x as well. I try to leave fuel at the lowest possible level. Obviously the 75s have more powerful engines. I am even going with flaps 10-15. Any education would be wonderful.P.S. I thought the MD-11 was amazing, but I am completely blow away. PMDG has upped the standard again.Nothing even close to her. Thank you for your extremely hard work!Dana Palmer, KJAC

I have to wonder, how exactly does SFP help for take-off? Apparently it helps for landing by allowing lower Vref thus lower stop distance, but I am unclear how it works on take-off.

One of the contributing factors of the SFP during takeoff is the ability to select flaps 15 for takeoff. On the normal NG, this would be limited to flaps 10. Also, the leading edge flaps will only travel to fully extended when the trailing edge flaps reach flaps 25, compared to the flaps 5 detent on a normal NG, that's quite a big difference.

Thomas I believe you could select up to 25 for take-off at ANY NG? Maybe not the case for 900? Good point about slats though.

It's here chaps...

Flight spoilers are capable of 60 degree deflection on touchdown by addition of increased stroke actuators. Thiscompares to the current 33/38 degrees and reduces stopping distances by improving braking capability.Slats are sealed for take-off to flap position 15 (compared to the current 10) to allow the wing to generate more lift at lower rotation angles.Slats only travel to Full Ext when TE flaps are beyond 25 (compared to the current 5). Autoslat function available from flap 1 to 25.Flap load relief function active from flap 10 or greater.Two-position tailskid that extends an extra 127mm (5ins) for landing protection. This allows greater angles of attack to be safely flown thereby reducing Vref and hence landing distance.Main gear camber (splay) reduced by 1 degree to increase uniformity of braking across all MLG tyres.Reduction of engine idle-thrust delay time from 5s to 2s to shorten landing roll.FMC & FCC software revisions.

http://www.b737.org.uk/flightcontrols.htm#Short-field_Performance_Enhancement_Program

I have heard some real BBJs are based at 4500 foot strips!

One of the contributing factors of the SFP during takeoff is the ability to select flaps 15 for takeoff. On the normal NG, this would be limited to flaps 10. Also, the leading edge flaps will only travel to fully extended when the trailing edge flaps reach flaps 25, compared to the flaps 5 detent on a normal NG, that's quite a big difference.

SFP can use F25 for takeoff without the slats going to full extend. That's probably the big boost for T/O performance off of short runways.Classics and NGs can use up to F15 for takeoff without the SFP.

SFP can use F25 for takeoff without the slats going to full extend. That's probably the big boost for T/O performance off of short runways.

How is limiting high-lift devices going to help short field performance?

Well, the Extend position is probably better for drag vs C/L, I'd guess than the Full Extend. Maybe? Got your Aerodynamics for Naval Aviators handy? For Takeoff: Zero flaps is not good. Flaps 40 is not good. Somewhere in the middle is best. Same for LEDs.

Well I know Air Tran flys their 737-700s into Key West with a 4,800ft runway. I am sure their are some serious wieght restrictions but I do not know if they have the SFP or not.Well took off the 737-700 from Key West with a 75% load and 10,000lbs of fuel more than enough for a Key West-Orlando flight and took off in probably about 2/3 of the runway at a very low VR speed around 115 flap 15 takeoff. Turned back around and landed flap 40 max autobrake with plenty of runway to spare. Temp was 31c too.

Thanks for the info guys, greatly appreciated. Very educational about the SFP and how it affects the slats.

GOL had the short-field package made for them so they coold use 737-Ngs at SBRJ which is 4300 ft long. I have landed and taken off from there. There is a thread about SBRJ here: http://forum.avsim.net/topic/348297-forget-keywest-santos-here-i-come/page__p__2107429__hl__santos%20dumont%20here__fromsearch__1#entry2107429

The amount of flap used is a trade off between the ground roll distance and the initial climb performance. Less flap = longer ground roll but better initial climb performance. Good for when you have a long runway with obstacles off the departure end. More flap = shorter ground roll but less initial climb performance. Good for when you have a short runway but no obstacles off the departure end.

How is limiting high-lift devices going to help short field performance?

I would guess it reduces the pitch attitude required during rotation to get airborne. Shorter rotation time to get airborne means less distance and also provides more margin for tail strike prevention at the lower lift-off speeds achieved from the higher TE flap settings. Remember, when you lower slats, you actually decrease the AoA of the wing. The AoA is the angle formed between the chord line and the relative wind / flight path. The chord line is drawn from the tip of the LE to the tip of TE. So if the tip of the LE is drooped, as in when you deploy slats, then the chord line would drop a few degrees as well. That is why if you are in un-accelerated straight and level flight and you deploy only the slats, you will need to pull the nose up to keep the aircraft from descending. Very noticeable and a common newbie mistake in aircraft that deploy only slats in the first selections of Flaps (like the 747 and the 737 flaps 1 settings.) When you call for "Flaps 1", or only for slats, you should anticipate needing to raise the nose, otherwise you will start descending. Basically, the opposite as you would expect when selecting TE flaps, when you need to decrease pitch attitude to compensate for the "ballooning" with TE flaps deployed. And keep in mind that LE slats don't increase your coefficient of lift for a given AoA. What LE slats do is to increase the critical AoA of the wing. So if your wing stalls at 15 degrees AoA, then fitting LE slats might allow you to reach 20 degrees before the wing stalls. If you want to increase your coefficient of lift for a given AoA, then you need TE flaps, of which slotted fowlers are currently the best at achieving - hence why it is the most common flap system in swept wing airliners these days. With the 737, which I suspect is the same as the 744, any position after 25 degrees adds mostly drag with little or no gain in coefficient of lift. Which I suspect is why they limit the flap setting on the SFP to 25 degrees. It is quite interesting to see the tweaks manufacturers apply to squeeze more performance from aircraft. Take the 777-300ER. Boeing has a SFP feature in the ER that locks the main gear trucks to reduce TO length. During a normal TO, the aircraft rotates on the trucks during liftoff. By locking this gear tilting mechanism, the aircraft rotates on the aft tires of the main gear (sort of the same effect as moving the main gear mounting points aft a few feet back). This provides more tail clearance for TO, which in turn allows a further reduction in Vr - hence the shorter TO distance. Quite useful when operating the aircraft at its limits, especially in high elevation airports where the big twin starts to loose a lot of performance.