Boeing 720/707 family flaps question

[nickac1092]

Hi. Im pretty good at editing and installing stuff on the aircraft cfg files. Anyways, I am wondering which is the slats and flaps in the flaps section of the aircraft config. Under normal circumstances, type=1 is flaps while type=2 is slats. However in the 707/720 cfgs I looked at are all type=1. I just want to make a small change to the slats and flaps area.

Below is the aircraft flaps section of the 720B cfg:

[Flaps.0]
type=1
span-outboard=0.500
extending-time=30.000
system_type=0
damaging-speed=250.000
blowout-speed=300.000
lift_scalar=0.000
drag_scalar=0.000
pitch_scalar=1.000
flaps-position.0=0.000, 0.000
flaps-position.1=20.000, 0.000
flaps-position.2=30.000, 0.000
flaps-position.3=40.000, 0.000
flaps-position.4=50.000, 0.000

[Flaps.1]
type=1
span-outboard=0.500
extending-time=30.000
system_type=0
damaging-speed=250.000
blowout-speed=300.000
lift_scalar=0.500
drag_scalar=0.000
pitch_scalar=-0.400
flaps-position.0=0.000, 0.000
flaps-position.1=27.200, 0.000
flaps-position.2=39.200, 0.000
flaps-position.3=44.500, 0.000
flaps-position.4=50.000, 0.000

[Flaps.2]
type=1
span-outboard=0.500
extending-time=30.000
system_type=0
damaging-speed=250.000
blowout-speed=300.000
lift_scalar=0.000
drag_scalar=1.000
pitch_scalar=0.000
flaps-position.0=0.000, 0.000
flaps-position.1=5.000, 0.000
flaps-position.2=10.000, 0.000
flaps-position.3=30.000, 0.000
flaps-position.4=50.000, 0.000

[aerofoto - HJG Admin]

Ordinarily you'd be right .... at least in the case of modern full span LE slats like those on an DC9/MD80 or L1011, but, in the case of the B707/720 at least, these LE devices are really "panel segments" (only) .... rather than full span (type) LE devices/slats.

For this reason I think you'll find they're actually modelled as part of the flap system .... on these B707's/720's.

I'm not sure (since I've never messed with any of the B707/720 data .... George is really the best person to answer this), but, I assume the first FLAP section, among the CFG based "FLAP" data, must relate to both FLAP 20 (or there-abouts) as well as the LE panels/flaps too.

I could be wrong though.

Mark C
AKL/NZ

[Mike Monce - HJG]

If I might chime in here As Mark says these planes did not have the more modern leading edge devices, so how does one model this within the limitations of FS? What George did is, I think , is to use Flaps.1 and Flaps.3 as the LE analogs. I say this because if you look at the lift scalars, only Flap.2 has a non-zero value; so I would say these are the TE flaps providing the lift, while 1, and 3 contribute only to pitch and drag.


Mike

[nickac1092]

il play around with it then to see which is which then.

[aerofoto - HJG Admin]

I know all the LE panels do extend per the "first" flap increment/FLAP 20 ....



The above view shows LE edges extended .... during a FLAP 30 T/O.

I'm not sure, but, I think you'll also find that the number of LE panel segments represented on some of these B707/720 3D models may differ too .... as Gary CARLSON (having worked on these airframes with the USAF) modeled them all "pretty accurately".

Mark C
AKL/NZ