Recording vertical speed at touchdown

[DavidK]

Hi.

I'd like to accumulate a record of my vertical speeds at touchdown. I can't see, though, how to do this using the Logging tab in the FSUIPC Options and Settings window. Help!

I tried searching the forum (and the FSUIPC manuals) for an answer, so, if I missed it, apologies. I'm running FSX SP2.

David K

[Pete Dowson]

I'd like to accumulate a record of my vertical speeds at touchdown. I can't see, though, how to do this using the Logging tab in the FSUIPC Options and Settings window. Help!

There's no simple way like switching on a log in FSUIPC. Those logging options aren't utility things like that, but aids to debugging problems with applications, and assistance for those developing applications. There are hundreds of variables available through the application interface to FS which FSUIPC provides, and there's no way FSUIPC, as the interface, will provide individual user needs for logging any specific one in a friendly form.

You can certainly ask FSUIPC to monitor specific offset values (up to four at a time), and those can go to the log, but the "vertical speed at touchdown" offset is a variable which is the same as the vertical speed whilst you are in the air, and which merely freezes when you are on the ground. So if you monitored that you'd get thousands of lines logged and a huge file until you landed, when you could look it up. Additionally it is in units of 256ths of a metre per second, not the normal feet per minute you'd be wanting, so you'd need to convert it.

There are two answers. You can either write a small Lua plug-in to do the job. It would only be a few lines of code. One of the examples provided in the FSUIPC install is a program which records many flight variables to a CSV (comma separated variable) file. You could strip that do to its basics and add the test for "on ground". so you only make entries then.

The other answer is to use an existing application, such as FS FlightKeeper (there are probably others) which makes records like that.

Regards

Pete

[Andydigital]

FS Flight Keeper is a must have in my opinion if you take Flight Simulation even remotely seriously, it does a whole lot more than just logging your flights for you, the moving 2d map/ACARS that you can install in all your aircraft is worth the price alone in my book.

[DavidK]

Thanks, Pete and Andy, for your replies.

I was hoping there'd be a straightforward way (i.e. without using a plug-in) to extract what I'm after via FSUIPC, but appreciate that its need to be very flexible and comprehensive in order to be very informative means that a particular combination of information (such as vertical speed on touchdown) needs custom-written extraction.

Recording vertical speed on touchdown is all that I'm after, so FS Flight Keeper feels like buying the proverbial sledgehammer to crack a very small nut -- certainly when compared with all the sophistication it seems to offer.

I'm surprised that FSX's own Flight Analysis feature doesn't include vertical speed on touchdown -- at least, I hope I haven't missed it.

Sincerely,

David

[Pete Dowson]

I was hoping there'd be a straightforward way (i.e. without using a plug-in) to extract what I'm after via FSUIPC, but appreciate that its need to be very flexible and comprehensive in order to be very informative means that a particular combination of information (such as vertical speed on touchdown) needs custom-written extraction.

If you just want it logged then quite a short Lua plug-in will suffice. here:

function logvs(off, val)
   if val ~= 0 then
    	-- if on ground flag just set, get VS, convert it and log it
   	vs = ipc.readSD(0x030C)
   	vs = vs * 60 * 3.28084 / 256
   	ipc.log("Vertical speed at touchdown = " .. vs)
   end
end

-- set to call above routine whenever "on ground" flag changes
event.offset(0x0366, "UW", "logvs")

I've not had a chance to test this -- ask me later if it doesn't work. Just save it as "ipcReady.lua" to your FS Modules folder. and run FS. (Your FSUIPC must be registered).

The log entries will go to the FSUIPC log file. If you want them separate, check the Lua logging option in the FSUIPC Logging tab. The file will then be "ipcReady.log".

Regards

Pete

[Ho]

Hi, I found this script somewhere on the Internet. It's pretty useful when comes to calculate the touchdown vertical speed and acceleration. However, in PMDG 777 I've always got very high G (about 2.5-2.9) though my V/S was just around 100fpm. I don't know why, but I'd like to share the script with you. If you have any idea about my issue, please let me know.

Sincerely,

Thinh.

 

armed = false

 

function landingflaps(off, val)

if (val > 5000) and not armed then

if ipc.readUW(0x0366) == 0 then

armed = true

ipc.display("Touchdown monitor armed", 10)

end

end

end

 

event.offset(0x0BDC, "SD", "landingflaps")

 

function onground(off, val)

if val ~= 0 then        

airspeed = math.floor((ipc.readSD(0x02BC) / 128) + 0.5)

        if (airspeed > 30 ) and (armed == true) then

armed = false

landvs = -math.floor( (ipc.readSD(0x030C) * 60 * 3.28084 / 256) + 0.5)

landG = math.floor((ipc.readSD(0x02BC) / 62.4) + 0.5) / 100

ipc.display("Touchdown:  " .. landvs .. " fpm   " .. landG .. " G   " .. airspeed .. " knts   ", 30)

end

end

end

 

event.offset(0x0366, "UW", "onground")

[abax2000]

The vertical speed at touch down is best captured using offset 31A0.

Offset 030C (and 02C8 also) seem to contain the vertical speed displayed on the VSI, which has a time lag (as in RL).

Try to experiment by capturing all offsets at touchdown moment, and you will see the differences. They can be substantial (with a firm landing and/or steeper glidepaths), or smaller (with a greaser and/or shallow landings).

[dazzz]

It works good, thanks