Just tested the 737-800 with a SFP equipped into SBRJ and the only thing i can say is wow, The approach in was difficult, and when i looked at the runway i thoughtm hang on a minute, this is gonna be a epic fail, then i touched down, and the thing just slowed down rapidly Well done to PMDG for this excellent addon, enjoying it immensely!!! I reccommend trying the 800 with a SFP into SBRJ (i'm gonna attempt a 900 soon!!) cheers guysEnjoy your day!

Does the installation of the SFP affect the vref speed calculation in the FMC? I suppose that with the same payload/fuel configuration Vref would be lower with the SFP installed? /Lasse Kronborg

I thought the SFP didn't do anything performance wise, just a visual enhancement (adds the tail-skid. At least that is what I remember from the manual.

I would be interested to know. I don't know all the functions the SFP does to the NGX.

I believe the SFP alters things such as engine output (more powerful/higher ratings), flaps settings, etc. I don't think it is a cosmetic thing in the PMDG NGX.

Easy to test. Try with SFP and without. Something to entertain me tonight perhaps. Martin Wilby

well, it doesn't. The FMC calculated Vref does not change if I enable/disable the SFP. It really should, because part of the idea about the SFP is to decrease Vref. Am I completly wrong, or?

well, it doesn't. The FMC calculated Vref does not change if I enable/disable the SFP. It really should, because part of the idea about the SFP is to decrease Vref. Am I completly wrong, or?

Well, how? You can't slow down even more with the same weight and same wings when flaps 40, which is still the max flaps I believe with SFP (I stand to be corrected)

From what I remember reading, the spoilers deflect higher or something, the engines spool down faster, brakes come on faster or something, and are "beefier" or something along those lines.

From what I remember reading, the spoilers deflect higher or something, the engines spool down faster, brakes come on faster or something, and are "beefier" or something along those lines.

Correct, but those things don't lower your VRef... perhaps it doesn change your V1 or VR, and roll distance, but that's about it.

Correct, but those things don't lower your VRef... perhaps it doesn change your V1 or VR, and roll distance, but that's about it.

Nope, exactly, flaps 40 is flaps 40.

Short-field Performance Enhancement ProgramThe Short Field Performance improvement package was developed in 2005/6 to allow GOL airlines to operate their 737-800s into the 1,465m (4,800ft) Santos Dumont airport. The modifications enable weight increases of approx 4,700kg (10,000lbs) for landing and 1,700kg (3,750lbs) for take-off from short runways. It includes the following changes:

• Flight spoilers are capable of 60 degree deflection on touchdown by addition of increased stroke actuators. This compares 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.

The SFP package has now become an option on all 737-800s (known as 737-800SFPs) and standard on the 737-900ER. Some of the features may also be fitted to the 600/700 series. The first SFP was delivered 31st June 2006. To date over 250 aircraft have been ordered with this package as either factory build or retrofit.A trailing edge flap modification from AeroTech has been available for the 737-2/3/4/500 series since 2004. The modification slightly extends and lowers the aft segments of the trailing edge flaps thereby increasing wing area, camber and importantly lift-to-drag ratio. The original modification had one fixed position for the aft flap segments. However it is now adjustable/tunable to fit a wide spectrum of flight operations. The cruise angle of attack is reduced by approximately 0.5 degree which reduces induced drag. There are no changes to operational procedures and every pilot that has flown this mod (FAA, test pilots, and line pilots) says that the aircraft handles better. Fuel savings vary with series and route structure but may average up to 4.3%. Actually it does lower vref via the tail skid. That's why the sfp model has a higher body angle on a 3 degree glide path. 800=2.4 and sfp=3.6. Check the training manual. 2.4/3.6. the slash represents the sfp.

Nope, exactly, flaps 40 is flaps 40.

Correct. Flaps 40 is flaps 40 and the wing creates the same amount of lift, SFP or not in full flap conf.. But in the SFP aircraft you are allowed a steeper angle of attack during landing and thus a lower Vref. It's in the documentation. The question is not if the Vref is lower, because that's supposed to be a fact, the question is: shouldn't the FMC Vref calculation take the SFP into account?

It should since there was a revision to the FMC software on the real aircraft. If PMDG has access to the changes in the FMC, maybe they can adjust it for sp1.

Well, I'm not sure about PMDG's SFP implemention lads, but thanks very much for pointing me in the direction of Santos Dumont SBRJ. These ast couple of nights I've had geeat fun landing there. Martin Wilby