Interpreting HUD

[dswo 0]

I've read the manual through a couple of times, but still have some questions about the HUD:

1. What is the NAV Steering Cue, and how do I use it?

2. What is Peak G? Is this a "do not exceed" rule, or just history for this flight?

3. What is the Flight Path Marker? How is it different from Steer Point?

[saprintz 82]

I've read the manual through a couple of times, but still have some questions about the HUD:

1. What is the NAV Steering Cue, and how do I use it?

2. What is Peak G? Is this a "do not exceed" rule, or just history for this flight?

3. What is the Flight Path Marker? How is it different from Steer Point?

************************

I'm assuming you have the manual and can refer to the pictures in it, so I'll describe only what they do and what they're for.

1) Also called the "tadpole," the NAV Steering Cue is the symbol that sits near the flight path marker and gives you instantaneous information as to where the currently active NAV station is. It should be interpreted as a top down symbol, like an HSI, and the tail always points to the NAV station. It is roll stabilized, so interpret it without regard to your bank angle; compare it to something like the vertical of the HUD glass, and it will give you the relative bearing to the NAV station.

**Note that ILS's and DME's (without radial info) send no 360 degree azimuth data, so if you have one of these types tuned, the tadpole will not be visible.

2) Peak G is just the max number of G's you've pulled so far on the current flight.

3) The Flight Path Marker (FPM) is the same thing as a Velocity Vector (VV). FPM is a term which tends to be used by the U.S. Air Force, and thus appears in the docs for the F-16 in many countries. VV is a term which tends to be used by the U.S. Navy. But they each look pretty much alike, a circle with 2 wings and a tail, and each do the same thing: represent, with respect to the outside world, your true flight path. At any instant, your aircraft is moving towards the point on the ground or in the air that this symbol overlays.

As a note, the Aerosoft F-16's HUD operates very much like the real thing, in that it is both conformal and collimated. This was a "big deal" in development and testing, and many people worked their behinds off to make this happen. And we're seeing that simmers are definitely noticing and commenting on the benefits of this. "Conformal" just means that the HUD symbology overlays the outside world accurately, in such a way that the HUD horizon matches true (theoretical) scenery horizon, the FPM marks the true flight path, the target box actually overlays the target, and so on. Collimation is a WONDERFUL achievement by the modelers which makes the HUD symbology appear to be focused at infinity... the natural side effect of which is that conformality is maintained no matter where the eyepoint is moved to. This HUD is the first HUD in any MSFS aircraft to have achieved these two characteristics, and personally, I have trouble going back to anything that does not have both.

[dswo 0]

Thank you for the explanation, and for the extra information on collimitation and conformality.

4. One last question, if you don't mind, what is the steer point?

[saprintz 82]

Thank you for the explanation, and for the extra information on collimitation and conformality.

4. One last question, if you don't mind, what is the steer point?

Just a different term for waypoint. The current steerpoint is the place you're going, the place that your GPS or Nav radios are tuned to.

[JamesChams 108]

....

... the Aerosoft F-16's HUD operates very much like the real thing, in that it is both conformal and collimated. This was a "big deal" in development and testing, and many people worked their behinds off to make this happen. And we're seeing that simmers are definitely noticing and commenting on the benefits of this. "Conformal" just means that the HUD symbology overlays the outside world accurately, in such a way that the HUD horizon matches true (theoretical) scenery horizon, the FPM marks the true flight path, the target box actually overlays the target, and so on. Collimation is a WONDERFUL achievement by the modelers which makes the HUD symbology appear to be focused at infinity... the natural side effect of which is that conformality is maintained no matter where the eyepoint is moved to. This HUD is the first HUD in any MSFS aircraft to have achieved these two characteristics, and personally, I have trouble going back to anything that does not have both.

Mr. Scott,

I fully support your decision ; I would like to begin trying to replace the FSDT/CaptainSim F/A-18A/D HUD's with yours; Any suggestions?

Amazing work!

[dswo 0]

Just a different term for waypoint. The current steerpoint is the place you're going, the place that your GPS or Nav radios are tuned to.

That cleared it up. The steer point is where you should be going (according to the flight plan), and the flight path marker is where you are going. I like it. Thanks again, too, for explaining about conformality: it really is a big deal, and should be a selling point for the model.

[saprintz 82]

Mr. Scott,

I fully support your decision ; I would like to begin trying to replace the FSDT/CaptainSim F/A-18A/D HUD's with yours; Any suggestions?

Amazing work!

Thanks for the kind words James!

The HUD *gauge* is what gets us conformality. The F-16 *model* is what gets us collimation. So it's a two-pronged effort. I'm almost positive no other yet-released aircraft addons have collimation built in to the HUD glass, so the best we could do is to get you conformality, using this HUD gauge. That alone is still more than most any other HUD will do, and everything will be accurate as long as the eyepoint doesn't change too much, but TrackIR users, especially, will notice the difference when collimation isn't present.

Scott

[expor 0]

Not sure this has been answered / posted / asked before but I'm really wondering the following. My HUD pitchladder is going to the far left of my hud, every single time I'm flying. Sometime's it's slowly recentering but mostly it's far far to the left and sometimes not even inside my HUD view. Why is it going offcentre? I know of the steerpoint etc but never heard of the whole pitchladder going out of 'screen' (HUD).

[saprintz 82]

Not sure this has been answered / posted / asked before but I'm really wondering the following. My HUD pitchladder is going to the far left of my hud, every single time I'm flying. Sometime's it's slowly recentering but mostly it's far far to the left and sometimes not even inside my HUD view. Why is it going offcentre? I know of the steerpoint etc but never heard of the whole pitchladder going out of 'screen' (HUD).

********************

Expor:

In one word: wind. To elaborate...

As in real life, the HUD pitch ladder rotates around the flight path marker (FPM). This is whether Drift Cutout (switch on bottom right of UFC) is engaged or disengaged. Drift C/O is disengaged by default, meaning that both the FPM and pitch ladder are free to move laterally, left and right. And if the flight path marker is to do its real job (MARK the true FLIGHT PATH), we have to consider that the flight path may be out of the line of sight of the HUD. This is what's happening with you. Either wind or rudder are pushing your flight path off the HUD. Your ground track is differing from your heading by more than about 5 degrees. Your jet is not going where its pointing. In fact it rarely ever does. But your particular situation is most likely to happen at high altitude, though CAN happen anytime.

If it really bugs you, engage Drift Cutout and everything will instantly be centered. Just realize that your flight path marker (FPM) has now been "demoted" to a climb-dive marker(CDM), and is no longer referenced to the outside world. While the FPM is Earth- (or FSX scenery-) referenced, the CDM is merely aircraft-referenced. The CDM-based HUD is still internally consistent; it shows your accurate climb / dive angle, and it shows your accurate angle of attack. But horizon correlation is lost, and all conformality with the scenery is lost. Basically, the HUD symbology no longer accurately overlays the outside scene. And when Drift C/O is engaged, the green HUD horizon can differ significantly from the true Earth (theoretical) horizon, especially in FSX (let's not go there... whole other post ;-). And this deviation will be greatest when angle of bank, beta, and/or angle of attack are greatest. So be careful with Drift C/O. It can be disorienting. I find it easier, with the CDM based HUD, to focus almost entirely on the symbology itself until I'm almost level and lined up with the runway.

Scott

[dswo 0]

Some of this would make a good sticky (or better still, an addendum to the manual).