Hornet HUD

[[email protected]]

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.)

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?

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.

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

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

[FatKat]

wrote:
>
> 1) What is on-speed AoA for the Hornet?

Wouldn't AoA vary depending on aircraft weight and weather conditions?
Also, are you sure about that documentary? Last night, I was watching
this documentary that started talking about the MiG-25, but showed
footage of the MiG-29. So many cable shows just mindlessly rehash
simplified versions of books that I've barely watched them at all. The
only ones I could stand were the "Wings of the Red Star", and that was
probably because I hadn't read any books about soviet aircraft.

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

Wouldn't it have to be manual? Did low-flying Intruder pilots use
their radar altimeters over hostile territory in VN?

[John Carrier]

"FatKat" > wrote in message
oups.com...
>
> wrote:
>>
>> 1) What is on-speed AoA for the Hornet?
>
> Wouldn't AoA vary depending on aircraft weight and weather conditions?
> Also, are you sure about that documentary?

They whole point of flying AoA vice airspeed is that its independent of
gross weight. Optimum angle of attack is optimum angle of attack. I'm not
sure what you think weather conditions would have to do with AoA.

Last night, I was watching
> this documentary that started talking about the MiG-25, but showed
> footage of the MiG-29. So many cable shows just mindlessly rehash
> simplified versions of books that I've barely watched them at all. The
> only ones I could stand were the "Wings of the Red Star", and that was
> probably because I hadn't read any books about soviet aircraft.
>
>> 4) Radar altitude. Is this a switchable thing, or does it show up only
>> when below a certain altitude, or... something else?

Most radalts go into standby mode climbing through 5000' AGL. You can set
radalt warning for any altitude you want. USN typically 5000' (platform)
for descent, perhaps and intermediate for FAF whatever, then perhaps 80% of
MDA or 200' DH. Low level, usually 10 - 20% below desired agl altitude.

R / John

[[email protected]]

FatKat wrote:
> wrote:
> >
> > 1) What is on-speed AoA for the Hornet?
>
> Wouldn't AoA vary depending on aircraft weight and weather conditions?

Yes, it would, but I probably wasn't clear with what I was asking. Navy
pilots fly AoA in the pattern, not airspeed. AoA gives a more
consistent picture of the aircraft's state in relation to stall, and
there's one certain AoA that always puts the nose (and thus hook) in
the best position for catching a wire. (This is regardless of weight
and speed.) I'm just trying to figure out what that AoA is. I believe
it is 8.1, but am not sure. The other thing I'm interested in is the
sensitivity of the AoA bracket - is it one degree AoA within the whole
bracket, one degree on either side of the optimum, something else...?
And how do the indexer donuts and chevron correspond, precisely? Is it
a solid yellow donut when AoA is anywhere within the bracket, or do the
chevron/donut combinations begin to appear within (but near the edges
of) the bracket? That all sounds goofy, and these are nit-picky
questions, I know! I would just like to do it right....

> Also, are you sure about that documentary? Last night, I was watching
> this documentary that started talking about the MiG-25, but showed
> footage of the MiG-29.

Yep, I know what you mean, but the part I'm referring to wasn't talk;
it was HUD footage from a Hornet, possibly Superhornet, on final.
(Maybe the superhornet's on speed AoA is different?) Anyway, the on
speed AoA looked to be closer to 6, possibly slightly below. On the
other hand, I have HUD footage from a CF-18, and he clearly lands with
the bracket centered around 8. So who knows... <shrug>

>So many cable shows just mindlessly rehash
> simplified versions of books that I've barely watched them at all. The
> only ones I could stand were the "Wings of the Red Star", and that was
> probably because I hadn't read any books about soviet aircraft.
>
> > 4) Radar altitude. Is this a switchable thing, or does it show up only
> > when below a certain altitude, or... something else?
>
> Wouldn't it have to be manual? Did low-flying Intruder pilots use
> their radar altimeters over hostile territory in VN?

No idea!

[John Carrier]

I'll have to confer with my Bug driving friends for some of the specifics of
your question (actual degrees AOA, etc) and bracket response. (My educated
guess is one degree either side).

As to the indexers. On speed, plus or minus 1/2 degree is a donut. When
you're 1/2 to 1 degree fast or slow, both the donut and the appropriate
chevron (green for slow, red for fast) will illuminate. A full degree or
more, and only the slow or fast chevron will illuminate. There are approach
lights on the nose to duplicate this function for the LSO's. Only diff is
that you don't get two lights (extra credit if you know the one aircraft
that deviates from this ... it no longer flies), just a green light for a 1
degree slow and a red light for 1 degree fast.

As to "optimum" AOA, its a function of several factors. A good landing
attitude for hook engagement w/o adverse effects, an AOA that's comfortably
faster than L/D max (so that you don't immediately enter the region of
reverse command power wise), pilot visibility (F-8 drivers, raise your
hand) are foremost.

R / John

> wrote in message
oups.com...
> FatKat wrote:
>> wrote:
>> >
>> > 1) What is on-speed AoA for the Hornet?
>>
>> Wouldn't AoA vary depending on aircraft weight and weather conditions?
>
> Yes, it would, but I probably wasn't clear with what I was asking. Navy
> pilots fly AoA in the pattern, not airspeed. AoA gives a more
> consistent picture of the aircraft's state in relation to stall, and
> there's one certain AoA that always puts the nose (and thus hook) in
> the best position for catching a wire. (This is regardless of weight
> and speed.) I'm just trying to figure out what that AoA is. I believe
> it is 8.1, but am not sure. The other thing I'm interested in is the
> sensitivity of the AoA bracket - is it one degree AoA within the whole
> bracket, one degree on either side of the optimum, something else...?
> And how do the indexer donuts and chevron correspond, precisely? Is it
> a solid yellow donut when AoA is anywhere within the bracket, or do the
> chevron/donut combinations begin to appear within (but near the edges
> of) the bracket? That all sounds goofy, and these are nit-picky
> questions, I know! I would just like to do it right....
>
>> Also, are you sure about that documentary? Last night, I was watching
>> this documentary that started talking about the MiG-25, but showed
>> footage of the MiG-29.
>
> Yep, I know what you mean, but the part I'm referring to wasn't talk;
> it was HUD footage from a Hornet, possibly Superhornet, on final.
> (Maybe the superhornet's on speed AoA is different?) Anyway, the on
> speed AoA looked to be closer to 6, possibly slightly below. On the
> other hand, I have HUD footage from a CF-18, and he clearly lands with
> the bracket centered around 8. So who knows... <shrug>
>
>>So many cable shows just mindlessly rehash
>> simplified versions of books that I've barely watched them at all. The
>> only ones I could stand were the "Wings of the Red Star", and that was
>> probably because I hadn't read any books about soviet aircraft.
>>
>> > 4) Radar altitude. Is this a switchable thing, or does it show up only
>> > when below a certain altitude, or... something else?
>>
>> Wouldn't it have to be manual? Did low-flying Intruder pilots use
>> their radar altimeters over hostile territory in VN?
>
> No idea!
>

[[email protected]]

You didn't say whether you wanted the "regular" Hornet, or the Super
Bug...

From the NATOPS for the Super, I get the following numbers:

Slow - 9.3 to 90

Slightly Slow - 8.8 to 9.3

On-Speed - 7.4 to 8.8

Slightly Fast - 6.9 to 7.4

Fast - 0 to 6.9

It says on-speed should be about 136 KCAS at 44,000lbs GW, subtracting
1.5 KCAS for each 1,000lb under GW.

The "manual" for Jane's F/A-18 has the exact same numbers for the
regular Hornet - but no airspeed listed.

Yes, I know it was a game, but their test-pilot/tech expert (Jim
Campisi) was an actual Hornet driver and the lead developer was a
former Hornet radar guy (Matt Wagner) who was stickler for getting it
as right as they could...

Snerdley


On 23 Sep 2005 13:03:56 -0700, wrote:

>FatKat wrote:
>> wrote:
>> >
>> > 1) What is on-speed AoA for the Hornet?
>>
>> Wouldn't AoA vary depending on aircraft weight and weather conditions?
>
>Yes, it would, but I probably wasn't clear with what I was asking. Navy
>pilots fly AoA in the pattern, not airspeed. AoA gives a more
>consistent picture of the aircraft's state in relation to stall, and
>there's one certain AoA that always puts the nose (and thus hook) in
>the best position for catching a wire. (This is regardless of weight
>and speed.) I'm just trying to figure out what that AoA is. I believe
>it is 8.1, but am not sure. The other thing I'm interested in is the
>sensitivity of the AoA bracket - is it one degree AoA within the whole
>bracket, one degree on either side of the optimum, something else...?
>And how do the indexer donuts and chevron correspond, precisely? Is it
>a solid yellow donut when AoA is anywhere within the bracket, or do the
>chevron/donut combinations begin to appear within (but near the edges
>of) the bracket? That all sounds goofy, and these are nit-picky
>questions, I know! I would just like to do it right....
>
>> Also, are you sure about that documentary? Last night, I was watching
>> this documentary that started talking about the MiG-25, but showed
>> footage of the MiG-29.
>
>Yep, I know what you mean, but the part I'm referring to wasn't talk;
>it was HUD footage from a Hornet, possibly Superhornet, on final.
>(Maybe the superhornet's on speed AoA is different?) Anyway, the on
>speed AoA looked to be closer to 6, possibly slightly below. On the
>other hand, I have HUD footage from a CF-18, and he clearly lands with
>the bracket centered around 8. So who knows... <shrug>
>
>>So many cable shows just mindlessly rehash
>> simplified versions of books that I've barely watched them at all. The
>> only ones I could stand were the "Wings of the Red Star", and that was
>> probably because I hadn't read any books about soviet aircraft.
>>
>> > 4) Radar altitude. Is this a switchable thing, or does it show up only
>> > when below a certain altitude, or... something else?
>>
>> Wouldn't it have to be manual? Did low-flying Intruder pilots use
>> their radar altimeters over hostile territory in VN?
>
>No idea!

[sp]

Thanks for the info John and Snerdley. That's exactly the kind of stuff I
was looking for.


> wrote in message
...
> You didn't say whether you wanted the "regular" Hornet, or the Super
> Bug...
>
> From the NATOPS for the Super, I get the following numbers:
>
> Slow - 9.3 to 90
>
> Slightly Slow - 8.8 to 9.3
>
> On-Speed - 7.4 to 8.8
>
> Slightly Fast - 6.9 to 7.4
>
> Fast - 0 to 6.9
>
> It says on-speed should be about 136 KCAS at 44,000lbs GW, subtracting
> 1.5 KCAS for each 1,000lb under GW.
>
> The "manual" for Jane's F/A-18 has the exact same numbers for the
> regular Hornet - but no airspeed listed.
>
> Yes, I know it was a game, but their test-pilot/tech expert (Jim
> Campisi) was an actual Hornet driver and the lead developer was a
> former Hornet radar guy (Matt Wagner) who was stickler for getting it
> as right as they could...
>
> Snerdley
>

[[email protected]]

sp wrote:
> Thanks for the info John and Snerdley. That's exactly the kind of stuff I
> was looking for.
>
>
> > wrote in message
> ...
> > You didn't say whether you wanted the "regular" Hornet, or the Super
> > Bug...
> >
> > From the NATOPS for the Super, I get the following numbers:
> >
> > Slow - 9.3 to 90
> >
> > Slightly Slow - 8.8 to 9.3
> >
> > On-Speed - 7.4 to 8.8
> >
> > Slightly Fast - 6.9 to 7.4
> >
> > Fast - 0 to 6.9
> >
> > It says on-speed should be about 136 KCAS at 44,000lbs GW, subtracting
> > 1.5 KCAS for each 1,000lb under GW.
> >
> > The "manual" for Jane's F/A-18 has the exact same numbers for the
> > regular Hornet - but no airspeed listed.
> >
> > Yes, I know it was a game, but their test-pilot/tech expert (Jim
> > Campisi) was an actual Hornet driver and the lead developer was a
> > former Hornet radar guy (Matt Wagner) who was stickler for getting it
> > as right as they could...
> >
> > Snerdley
> >

On speed is around 8 alpha. You always fly with the e bracket centred
(unless a single engine approach)from the center of the bracket to each
top/bottom edge is about 4 kt, so about 8 total. the pitch ladder can
move with the wind or it can be "caged" to remain centred in nav master
mode. our sop is to leave it caged and use the ghost vv to measure
wind. radalt can be selected by a switch under the hud, far right. Ils
needles are centred on the vv if you are on the loc/gp and centred on
the wl if you are doing a backup approach (eg ins to stby/no vv)
hope this helps, this info is all for the canadian hornet
monkey

[[email protected]]

sp wrote:
> Thanks for the info John and Snerdley. That's exactly the kind of stuff I
> was looking for.
>
>
> > wrote in message
> ...
> > You didn't say whether you wanted the "regular" Hornet, or the Super
> > Bug...
> >
> > From the NATOPS for the Super, I get the following numbers:
> >
> > Slow - 9.3 to 90
> >
> > Slightly Slow - 8.8 to 9.3
> >
> > On-Speed - 7.4 to 8.8
> >
> > Slightly Fast - 6.9 to 7.4
> >
> > Fast - 0 to 6.9
> >
> > It says on-speed should be about 136 KCAS at 44,000lbs GW, subtracting
> > 1.5 KCAS for each 1,000lb under GW.
> >
> > The "manual" for Jane's F/A-18 has the exact same numbers for the
> > regular Hornet - but no airspeed listed.
> >
> > Yes, I know it was a game, but their test-pilot/tech expert (Jim
> > Campisi) was an actual Hornet driver and the lead developer was a
> > former Hornet radar guy (Matt Wagner) who was stickler for getting it
> > as right as they could...
> >
> > Snerdley
> >

On speed is around 8 alpha. You always fly with the e bracket centred
(unless a single engine approach)from the center of the bracket to each
top/bottom edge is about 4 kt, so about 8 total. the pitch ladder can
move with the wind or it can be "caged" to remain centred in nav master
mode. our sop is to leave it caged and use the ghost vv to measure
wind. radalt can be selected by a switch under the hud, far right. Ils
needles are centred on the vv if you are on the loc/gp and centred on
the wl if you are doing a backup approach (eg ins to stby/no vv)
hope this helps, this info is all for the canadian hornet
monkey

[[email protected]]

sp wrote:
> Thanks for the info John and Snerdley. That's exactly the kind of stuff I
> was looking for.
>
>
> > wrote in message
> ...
> > You didn't say whether you wanted the "regular" Hornet, or the Super
> > Bug...
> >
> > From the NATOPS for the Super, I get the following numbers:
> >
> > Slow - 9.3 to 90
> >
> > Slightly Slow - 8.8 to 9.3
> >
> > On-Speed - 7.4 to 8.8
> >
> > Slightly Fast - 6.9 to 7.4
> >
> > Fast - 0 to 6.9
> >
> > It says on-speed should be about 136 KCAS at 44,000lbs GW, subtracting
> > 1.5 KCAS for each 1,000lb under GW.
> >
> > The "manual" for Jane's F/A-18 has the exact same numbers for the
> > regular Hornet - but no airspeed listed.
> >
> > Yes, I know it was a game, but their test-pilot/tech expert (Jim
> > Campisi) was an actual Hornet driver and the lead developer was a
> > former Hornet radar guy (Matt Wagner) who was stickler for getting it
> > as right as they could...
> >
> > Snerdley
> >

On speed is around 8 alpha. You always fly with the e bracket centred
(unless a single engine approach)from the center of the bracket to each
top/bottom edge is about 4 kt, so about 8 total. the pitch ladder can
move with the wind or it can be "caged" to remain centred in nav master
mode. our sop is to leave it caged and use the ghost vv to measure
wind. radalt can be selected by a switch under the hud, far right. Ils
needles are centred on the vv if you are on the loc/gp and centred on
the wl if you are doing a backup approach (eg ins to stby/no vv)
hope this helps, this info is all for the canadian hornet
monkey

[Doug \Woody\ and Erin Beal]

On 9/22/05 9:23 PM, in article
. com,
" > 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.

[[email protected]]

Thanks again. Great info. One more, if you don't mind: does the ACLS
tadpole act more like a flight director (like, say, the intersection
point of standard civilian jet ADI needles), or does it simply act more
like supersensitive ILS needles? I know it's the little cue that ends
up (hopefully) on top of the velocity vector, with a dot in the middle,
but am not sure which of the above it actually functions as.

FYI, I'm also investigating to see if there's a way to record the
deviations from AoA, lineup and glideslope every, say, 10th of a second
or so, and then use statisitcs (root mean square, probably) to
calculate a landing grade. (A kind of mathematical LSO!) There's almost
certainly a way, but I doubt if Microsoft created those variables in a
way that would make it as easy as it seems.

[Doug \Woody\ and Erin Beal]

On 9/29/05 9:41 AM, in article
. com,
" > wrote:

> Thanks again. Great info. One more, if you don't mind: does the ACLS
> tadpole act more like a flight director (like, say, the intersection
> point of standard civilian jet ADI needles), or does it simply act more
> like supersensitive ILS needles? I know it's the little cue that ends
> up (hopefully) on top of the velocity vector, with a dot in the middle,
> but am not sure which of the above it actually functions as.
>

It's raw ACLS data plain and simple. No roll-summed steering or flight
director commands are given. Also, on course/on glidepath are represented
by the tadpole being perfectly centered inside the velocity vector
(concentric circles). Many pilots castle priority to the HUD in order to
get the dot in the VV for reference too.

> FYI, I'm also investigating to see if there's a way to record the
> deviations from AoA, lineup and glideslope every, say, 10th of a second
> or so, and then use statisitcs (root mean square, probably) to
> calculate a landing grade. (A kind of mathematical LSO!) There's almost
> certainly a way, but I doubt if Microsoft created those variables in a
> way that would make it as easy as it seems.
>

United Airlines used that technique in their fixed-based simulators in the
interview process. It's not entirely accurate. The flaw with the United
sim was that pilots tended to get better scores if they didn't fly it like
an airplane and muscled the jet back and forth above, through, and below the
glideslope then back through to high and so on (and likewise with
courseline). This minimized the RMS errors (less time spent in the
deviation area), but made for a crappy approach that would have made pax
wonder what monkey was at the controls.

You'll have the same problem with your method in the Hornet CV
approach--e.g. no sane carrier aviator would fly from a high ball to a low
ball ON PURPOSE. They're taught to lead that correction in order not to
descend below the centered ball. Food for thought.

--Woody

[sp]

Thank you all for your input. I just recently uploaded the Hornet HUD panel
to avsim.com, flightsim.com, and simviation.com. I think it turned out
pretty well - very similar "look and feel." Any of you who tinker with such
things, let me know what you think needs improvement. Also, someone was kind
enough to point me to the Hornet's NATOPS flight manual, so of course now
I'm just going to HAVE to model the HUD/vector steering arrow, and maybe the
basic modes of the HSI, also. Thanks again.