Threshold Speed
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There’s no such thing as an “E” bracket. The AOA symbol on the F-16’s HUD consists of one vertical line segment and two horizontal segments, not three. The picture in the first post shows a “[” symbol with the -2.5° dashed pitch reference line in the background. The proper names are for the AOA displays are “AOA indicator” “HUD AOA bracket” and “AOA indexer.” I find it helpful to use precise terms in technical discussions. In the F-16 the Velocity Vector (VV) or Total Velocity Vector (TVV) is known as the Flight Path Marker (FPM). An engineer describing the difference between the motion of the airplane compared to the HUD symbol you might say that the display to the pilot is the FPM and the physical motion needs a different name, but for pilots in a working airplane they are the same.
I see there’s a confusion between “backward” like it is wrong and “backward from what I am used to” which is simply a personal statement. I was reading carefully the first post (which maybe is significantly edited since it was first made) to try to find out “OK what’s the actual problem?”
I’m really curious what other models of airplane have a different kind of symbol mechanics. What is the F-16 "backward’ compared to?
You can think of the HUD AOA bracket as an extension of the gun cross symbol. They are both fixed in the airplane reference frame the same distance apart. The HUD AOA bracket is not dynamic or smart in any way; it’s just a dumb mark on the HUD. You could almost get the same effect with a felt tip marker on the canopy. It’s impressive to come up with an empirical alternate method to get on-AOA but you should really get familiar with its use.
For example you are on final approach at maybe 5° AOA, but otherwise everything else is fine, on glideslope and FPM on runway. This AOA is too low for approach so you want to increase it. If you pitch up only you might get more AOA but the FPM will raise off the runway. If you decrease throttle the FPM will sink. The technique is to do both in a balanced way to prevent the FPM from rising or sinking. Power decreases, pitch increases, FPM stays still. The staple is barely needed, just looking at the difference between the FPM and the gun cross provides the exact same information.
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I imagine a noob pilot saying to his instructor : i dont like the aoa indexer it seems.inverted
LOL
for a proper landing you shall use aoa bracket. Period
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I used to land looking at the FPM relative to the gun cross to see my AOA until I learned about the AOA bracket. But after all this time using the bracket, I never realized what you were saying about the bracket being in a fixed position. That is awesome. Thanks for that epiphany.
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I imagine a noob pilot saying to his instructor : i dont like the aoa indexer it seems.inverted
LOL
for a proper landing you shall use aoa bracket. Period
No wonder RL instructors are saying “it’s like that, period”. If RL student pilot are only half as picky as virtual ones, I’d do that too.
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I see there’s a confusion between “backward” like it is wrong and “backward from what I am used to” which is simply a personal statement. I was reading carefully the first post (which maybe is significantly edited since it was first made) to try to find out “OK what’s the actual problem?”
I’m really curious what other models of airplane have a different kind of symbol mechanics. What is the F-16 "backward’ compared to?
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Thanks for your inquiring post.
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I imagine a noob pilot saying to his instructor : i dont like the aoa indexer it seems.inverted
LOL
for a proper landing you shall use aoa bracket. Period
Your correct He is not in retirement.
:?:
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GUYS GUYS GUYS! Everyone calm down.
Not once did I say anyone should use the discussed method instead of the bracket! Get off your high horses. It was purely just a post to outline some other VERY valid ways of doing things IF you don’t want to use the bracket.
It’s got some interesting information in it and people might find it useful, especially when you lose your HUD in the video game due combat damage.
I tired to make this more obvious in the original post but everyone here is so fast to try shoot anyone else down around here you guys can’t see it. Chill
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The Poster has been a long stand member of the 801st,* He just doesn’t have the time for posting on forums and I don’t really can’t speak for Him, and I think it was actual His first Post which came about after a discussion we had after a flight yesterday.*
At first I didn"t understand what He was talking about,* He is referring to the Hawk 127 Lead-in Fighter used here prior to transition to the F-18A/B & F/A-18/F Super Hornets.
Well, now Im interested in the other aircraft being compared. Thats gonna suck.
So how does the bracket in the Hawk work then?
I tired to make this more obvious in the original post but everyone here is so fast to try shoot anyone else down around here you guys can’t see it. Chill
You might have gotten a warmer response if you hadn’t been replicating work already done. This has been included with BMS since its first release… not that its not good to have, but both charts and the fast rule of thumb are included with the BMS checklists by Red Dog, in your Docs folder of your install.
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Well, now Im interested in the other aircraft being compared. Thats gonna suck.
So how does the bracket in the Hawk work then?
You might have gotten a warmer response if you hadn’t been replicating work already done. This has been included with BMS since its first release… not that its not good to have, but both charts and the fast rule of thumb are included with the BMS checklists by Red Dog, in your Docs folder of your install.
This makes no sense whatsoever. Instead there’s 2 pages of posts about “no you shouldn’t and real pilot do…”
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What part makes no sense?
I see one page of people defending the F-16s instrumentation as not being backwards (its a rather important caveat, that “to what Im used to” part).
As far as interest in the other aircraft, for an aircraft other than the F-16, I wasnt too worried about how it worked - but if its a Hawk he’s talking about then he has my full attention. Any gouge is good.
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Don’t get me wrong, all the info here is more than useful, I learn everyday on here.
But if what the OP has done and contributed was already there than it would’ve sufficed to tell him that.
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So you’re saying that we should have said RTFM quicker? Good feedback that, cheers.
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Anyway in 4.32 the approach speed charts are a bit off due to a -not so detailed- modelization on TEF.
So better use bracket to land
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:drink:
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I fail to see what is “backwards” about the BMS E bracket. If you don’t want to use it, fine. Use the indexers. It’s not difficult, they display the same information and can actually be more beneficial than the E bracket since the AOA indexers are not quite as sensitive.
The Hawk, or at least the Goshawk, displays the information in at least the same basic way, though the numerical on-speed AOA values obviously differ.
I don’t know where this guy’s getting his information from, but AOA will adjust based on aircraft weight whether because of fuel, stores, etc. To achieve the same relative AOA, a heavier aircraft must maintain a higher airspeed. The indexer and the bracket on the HUD get their information from the same source.
Stop making up random numbers and fly the jet on-speed per the AOA indexers or HUD.
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What is backwards about the Viper E bracket (and it’s true in the real airplane as well) is that it in fact indicates in reverse from the indexer wrt what to do with the nose of the airplane - as a rule of thumb for using the indexer it’s: nose in the direction of the arrow, throttle in the direction of the light. Try that gouge with the Viper bracket and you will get totally gooned up - you have to reverse the logic…though the indexer operates the same in both USAF and USN jets. It’s a “nose-centric” vs “throttle centric” orientation thing…if that makes any sense…
If you get a chance to fly a properly set up Navy sim (T-45, Hornet, etc.) you will find that the FPM (or Velocity Vector) is at the top of the bracket when the upper indexer light is lit and at the bottom when the lower light is lit, and as such the technique for capturing on-speed becomes quite different if you are just looking at the HUD…what I personally do in the Viper is hit the break fast, pull power, and let the FPM fall into the bracket - then I push the throttle up until I get a green indexer. Then I totally ignore the bracket and fly on the indexer only.
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Then I totally ignore the bracket and fly on the indexer only.
And if you do that you will find the fpm is more or less in the center of the bracket.
So i still dont get what the fuss is about.
But if you use the indexer you will touchdown with the right aoa
(And thus the right speed)
So thats fine i supposeSnowman
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I’m still against calling it an “E” bracket. It looks like a “C” if any letter.
And you’re right it doesn’t match the indexer. The indexer and the AOA gauge (between your knees) are a match. Not only are they painted the same colors at the same values, but they get their data from the same source (ADC). With some mirrors you wouldn’t need the indexer at all since the strip gauge is the exact same info. It would be very contrary to convention for the AOA gauge tape to read higher values on the lower portion of the tape. This is why the indexer also has arrows, to suggest nose movement.
I never gave it a second thought looking at the F-16 indexer. Low AOA is low on the gauge, high AOA is high on the gauge. This stems from the fact that a pilot with good airmanship is not adjusting the FPM on approach; he’s got the direction of travel correct but he’s changing the AOA regime to set up the plane for landing. And so for a pilot landing the FPM is a fixed thing. What he is trying to do is alter the nose position for the landing attitude without disturbing the flight path from the correct one.
If a USN 3-value lighted AOA indicator is reversed from the F-16’s convention that is understandable. I think the F-18’s AOA gauge is a round one anyway unlike the F-16’s linear strip which means there’s not something to match. The HUD bracket is the same though.
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Landing really isn’t as complicated as people make out. Why do you need to be working things out? Just fly the fpm in the centre of the staple and at the runway threshold and land. This takes into account any weight variables and you touch down at the appropriate aoa and speed for any given weight. Keep it simple and you free up any capacity for malfunctions.