Hornet HUD

On 9/22/05 9:23 PM, in article
,
" wrote:

Hi all. I'm just about finished with what I think is going to be a
pretty realisitc freeware Hornet HUD for the MS flight simulator. Being
the newbie wannabe Hornet pilot that I am (heheh), I have a few
questions that may seem silly, but I would like to get some of these
finer details right. I was hoping maybe someone in here might know. I
have the ladder, vector, AoA bracket and other basics working
properly, but....

1) What is on-speed AoA for the Hornet? I've seen 8.1 degrees, but have
seen video (Military channel, probably) that had the AoA bracket
centered on the vector, with the jet on final to the carrier, on
glideslope, and with the waterline only about 2 degrees above the
horizon. Now I'm no mathemetician, but... that's only about 6 degrees
AoA, right. So what gives? ;-) Is this a case of units AoA vs. degrees
AoA or something... (in which case, what's the conversion?) Or is there
something else I'm missing? (I can't imagine that something so
fundamental would be adjustable in cockpit.)

The waterline represents the aircraft datum line. I'm not sure what you're
seeing, but the math is simple. When the aircraft is on approach to the
carrier (3 degree glideslope taking wind into account), and the AOA is the
optimum 8.1 degrees, the W should be 5.1 degrees above the horizon. That's
the way it works unless there's a problem with the ADI that's generating the
W symbol.

2) Pitch ladder drift with yaw.... I like when the ladder drifts left
and right with the vector, because it gives such clear trend info with
heading, wind, etc., but I know many will whine that the ladder
sometimes drifts off the side of the HUD. Is ladder drift always ON, or
can it be switched off by the pilot?


The pitch ladder will drift with the velocity vector when it is uncaged.

3) ILS needles. Are they centered on the waterline, or on the velocity
vector? I believe I've seen this both ways too, even with the gear
down, but wouldn't bet too much on that.... Right now I have it
switchable, but prefer them on the waterline mark since it seems too
cluttered when they're on the vector.


Both SPN-41 (ILS) needles and SPN-46 (ACLS) "tadpole" are centered on the
velocity vector unless the HUD is in standby mode (e.g. after an INS
failure)... then they're centered on the waterline symbol.

4) Radar altitude. Is this a switchable thing, or does it show up only
when below a certain altitude, or... something else?


Switchable. RADALT can be selected to the HUD with the flip of a switch.
There are HUD cues to delineate what the altitude source is. For instance,
an R next to the altitude box indicates that the jet thinks the RADALT is
valid and the AGL altitude is displayed in the HUD. A flashing B indicates
that RADALT has been selected to the HUD and that baro altitude is displayed
instead.

--Woody

Any hints with any of this? Anyone... ;-) Thanks for any info.