Intuition of AoA/attitude

[sthalik]

Hey, fired up falcon yesterday, wow. Having problems with many things, but that one’s most immediate probably.

Flying angels 39, AoA between 5 and 10. Some blips, close enough to the DMZ to get murdered. So it goes –

• Likely better even from fuel efficiency perspective to turn on burner to reduce AoA for the rest of the flight?
• Much/often push the stick forward to lose aoa-inflicted drag?
• How does cat-iii factor into all this?

[TobiasA]

CAT I or III doesn’t affect fuel usage at all. Only the weight will affect AOA because the more weight, the more lift needs to be generated. More lift, more drag, more fuel usage.

The best to save fuel is stay out of burner, fly smooth, fly straight. If you can’t keep a decent speed, fly lower. With 4 JSOW, 2 tanks + AA loadout, you can barely keep angels 25 with a decent speed. With a pure A/A loadout, you can go a lot higher. Getting into burner is very costly, so you should avoid it.
Avoid high AOA’s during turns and fly a smooth turn with 1.3-1.7G (should give about 30-45° bank most of the time).

I try to keep 250-300 kts at least if possible. Getting too slow leaves you with no energy to react on sudden threats. And of course, it will induce a lot of drag due to a high AOA.
Going full MIL power all the time is not that much of an energy saver either. Generally, as a rule of thumb I try to keep airspeed between 250-400kts depending on the loadout.

If your TOS gives you a very slow speed, watch this:

Edit: Also mind the drag factor in the loadout screen.

[Blu3wolf]

@sthalik:

Hey, fired up falcon yesterday, wow. Having problems with many things, but that one’s most immediate probably.

Flying angels 39, AoA between 5 and 10. Some blips, close enough to the DMZ to get murdered. So it goes –

• Likely better even from fuel efficiency perspective to turn on burner to reduce AoA for the rest of the flight?
• Much/often push the stick forward to lose aoa-inflicted drag?
• How does cat-iii factor into all this?

CAT switch factors your roll rate. Other than that you are looking at drag index and gross weight to achieve either max range or max endurance (which I assume is why you want fuel efficiency).

If you turn on the burner, the increased fuel rate will make that the number one factor in your fuel burn. Never engage burner to increase fuel efficiency, it doesnt work.

You shouldnt be able to push the stick forwards without losing lift and thus altitude. If you want to descend then by all means, set power to IDLE and descend at 215 KIAS (220 KIAS for 50 drag index, 230 KIAS for more than 100 DI). If you want to stay at altitude then you will end up needing to know the speed for either max endurance or max range dependent on your gross weight and drag index. There are charts of such available online, but I am unable to link to them due to forum limitations. Hypothetically speaking, the manual containing such charts may be a 1F-16CJ-1-1. For example, if your Drag Index is 100, and your GW is 30,000lbs, then you will get max endurance flying at 470 KTAS with a fuel burn of 3365 lbs per hour, and max range flying at 486 KTAS, with a fuel burn of 3407 lbs per hour.

Alternatively, if you are in the air and need to know your max range or endurance speed to fly at, you can set the HUD to display an airspeed caret at the speed to fly. This is accessed via the CRUS-5 priority function key on the ICP. Pressing the key repeatedly will cycle through the various display modes available.

This is the TOS mode cruise function. Whilst TOS is the most commonly used mode, and is typically M-SELected at the start of the sim, it is not the only mode available. Pretty sure we all know how that one works, so Ill leave you to it.

This is the RNG mode cruise function. In RNG mode, a caret is displayed showing the airspeed to fly at to maximize range. No altitude guidance is given however, but it does give you fuel remaining at the destination steerpoint.

@A:

2.6.4.3.1 The cruise (CRUS) options are selected from the ICP. The fuel remaining at the currently selected steerpoint after a flight at current conditions (current consumption, current speed, current winds, and current altitude) appears on the DED as well as the current steerpoint.

2.6.4.3.2 When the range option is mode selected, the MMC positions a caret on the HUD velocity scale. The position of that caret relative to the index indicates whether to speed up or slow down in order to maximize the aircraft range at the present altitude. This airspeed guidance assumes current winds at the current altitude.

This is the HOME mode cruise function. This is probably the second most commonly used mode, and is often left displayed by new pilots who have gotten the automatic HOM BINGO warning, after ignoring their manual BINGO setting. If this window is displayed, positioning the asterisks around the word HOME and depressing the M-SEL-0 key on the ICP will cause a caret to be displayed at their optimum cruise altitude, and their best range cruise speed. Climbing at that speed to the optimum cruise altitude, then maintaining that altitude and airspeed until your altitude in angels is about the same as your distance in miles from the airfield, and flying an idle power descent to the airfield, will result in maximum fuel over home plate (or over the steerpoint if you change which steerpoint is selected on that window).

2.6.4.5 Maximum Fuel Above Home. The home (HOM) option provides velocity/altitude guidance that the pilot can use to fly from the present aircraft position to a point above the selected home point using a minimum amount of fuel. This flightpath
consists of a minimum fuel climb at military power, a cruise climb segment where the altitude increases as fuel is burned off, and a programmed descent to a point 5000 feet over the home steerpoint. The home display is also used to set the home point on
which the fuel above destination warning is based. The mode is selected via the UFC.

2.6.4.5.1 The cruise (CRUS) options are selected from the ICP. The DED page includes the selected home point, the optimum altitude for maximum range, and the estimated fuel remaining after an optimum profile to the home point.

2.6.4.5.2 The selected home point can be changed via the increment/decrement switch (also via the keyboard) without also changing the current steerpoint. This allows viewing the estimated fuel at various alternate landing points while continuing to steer toward the present steerpoint.

2.6.4.5.3 When the home option is mode selected, the MMC positions a caret on the HUD airspeed scale and a caret on the HUD altitude scale. The position of the altitude caret relative to the index indicates whether to climb, cruise, or descend and the position of the airspeed caret relative to the index indicates whether to speed up or slow down in order to fly the optimum profile.

2.6.4.5.4 Once the home option mode is selected, the home point is also used as the current steerpoint so that all guidance, lateral steering, velocity, and altitude is to the same point. 2.6.4.5.5 The fuel above home point estimate is computed in all modes. When this fuel is projected to be less than 800 pounds, a warning (the letters FUEL flash) and the fuel remaining prediction (in hundreds of pounds) are displayed on the HUD. In addition, the VMU provides a voice message (BINGO – BINGO) through the pilot’s headset at the same time the warning is displayed on the HUD. This home bingo warning is reset by selecting WARN RESET on the ICP. This will remove the flashing FUEL display but the prediction will remain in one of the lower left HUD windows.

I think this is not currently implemented completely in falcon, specifically the part about when it is mode selected the homepoint selected becomes the current steerpoint, but I cant recall if I tested it or not either.

This is the EDR mode cruise function. This is likely rather neglected in falcon, but I find it useful when holding outside pattern airspace, or waiting for whatever reason and doing my best helicopter impression (flying, but with nowhere to go). Mode selecting this mode will display a caret at your best endurance speed for your current altitude. As with the RNG mode, no altitude guidance is given, but this one does give you a neat countdown to your manual BINGO setting, which is very neat.

@Same:

2.6.4.4.1 The cruise (CRUS) options are selected from the ICP. The DED page includes the mach number to be flown for
maximum endurance at this altitude and the estimated time until bingo fuel at current consumption rate.

2.6.4.4.2 When the endurance option mode is selected, the MMC positions a caret on the HUD velocity scale. The position of
the caret relative to the index indicates whether to speed up or slow down to achieve maximum endurance at the current aircraft
altitude.

So, ultimately the biggest thing you can do to increase your fuel efficiency is to plan your mission thoroughly. Using your performance charts to plan your mission and how much fuel you should have remaining over each steerpoint will allow you to make maximum use of your limited supply of fuel.

[D_Fens]

@TobiasA:

The best to save fuel is stay out of burner, fly smooth, fly straight. If you can’t keep a decent speed, fly lower.

Can somebody explain that to me? I thought if you want to maintain high speeds you maintain high altitudes because of the thinner air?

Regards D_Fens

[Y0UNGBL00D]

lets see how far off i am here:

think difference between ground speed (relative to earth) and airspeed (how fast air is over the wings/into the intake.)

so for a given ground speed, air speed is lower at higher altitudes.
the air is thinner up there, yes, so you pass through it easier when flying level, thus conserving fuel, but you also need to be going a lot faster to get an equivalent amount of air over the wings to get your lift. so theres a tradeoff altitude, above which the airspeed required to maintain 0 deg AOA starts to not be met.
since you will need more airspeed to generate more lift the heavier you are, your AOA will suffer too, and then you get more drag and it goes downhill from there, so to speak.

[Blu3wolf]

well, sorta.

At higher altitudes, you have less air flowing over the wings for any given True Airspeed. This means less drag, and you get a nice high true airspeed as a result.

However, CAS decreases with decreased air pressure, and as a result if you climb at constant TAS your CAS will decrease.

If your CAS drops below about 220~ at altitude, you will not be able to maintain altitude, and the jet will descend. You will likely still have a high ground speed though.

Basically to maintain altitude, you need to have as a minimum lift generated equal to gravity. As lift generated is dependent on airflow, less air pressure means less lift. End result is that there is a max altitude you can maintain in an aircraft.

Ultimately if you want to maintain high speed, climb, but if you climb too high you wont be able to maintain high enough speed.

[Y0UNGBL00D]

much better explained, thank you.

[Blu3wolf]

I keep getting beaten to the punch though haha!!!

I didnt see your explanation before I typed mine out… there is a bit of a lag time on my posts at the moment, as Im slightly tipsy atm…

[Y0UNGBL00D]

well the TAS was a good point. the way i understand it, as described as how fast an object moves through an air mass, please correct me:

for instance, an airplane attached to a 25000’ vertical pole, experiencing a 300kt headwind would have
300KIAS
0 KTAS
0 KGS

and the higher the altitude, technically TAS can be slower than GS because of radius to the center of the earth?

this thread just got way more complicated haha

[Blu3wolf]

No, okay.

an aircraft at the top of a 25,000’ vertical pole, in a 300 KTAS headwind, would have a TAS of 300 knots, and a ground speed of 0 knots. It would have an Indicated airspeed somewhere around 200 knots, as IAS is calculated by the dynamic air pressure in the pitot tube - and as your static air pressure decreases, you start to get error in that.

So, True airspeed is the speed of the wind going past, indicated airspeed is what the gauge says - and Calibrated airspeed is what really smart gauges say, which corrects for air density. There is also Equivalent airspeed, but frankly I never got taught much about either of the last two, as it wasnt really important for my license. Spent a bit of time on wikipedia trying to learn more about them, but I need someone to explain them both properly to me.

[Frederf]

My rules of thumb:

Best range ~ 6 degrees, 250 KCAS
Best endurance ~11 degrees, 210 KCAS

My first instinct is to say best range is generally at maximum altitude where full throttle (MIL, not AB) = [email protected]. That seems kinda dopey reading it back but I can’t think of why it’s wrong. Of course I’m talking sustained rates. There is a penalty for getting up there which matters over short hauls.

MAXAB is never the right answer for saving fuel. It’s specific fuel consumption is worse than anything the regular cycle can produce.

[Guest]

CAS ? Calibrated Air speed?

I would love if posters would have in brackets the wording of these just for the first instance then it makes it easier to understand.

TOS ,time of sortie?

[Frederf]

Yes, KCAS is “knots calibrated airspeed” which is nearly synonymous with IAS or EAS (small corrections). TOS is usually “time over steerpoint.” Sometimes the distinction is made DTOS “desired time over steerpoint.” If your DTOS is 07:30 and your TOS is 07:37 you are 7 minutes late.

I can’t promise I’ll glossary all my acronyms but feel free to ask any time you don’t know one.

[Y0UNGBL00D]

@Blu3wolf:

No, okay.

an aircraft at the top of a 25,000’ vertical pole, in a 300 KTAS headwind, would have a TAS of 300 knots, and a ground speed of 0 knots. It would have an Indicated airspeed somewhere around 200 knots, as IAS is calculated by the dynamic air pressure in the pitot tube - and as your static air pressure decreases, you start to get error in that.

So, True airspeed is the speed of the wind going past, indicated airspeed is what the gauge says - and Calibrated airspeed is what really smart gauges say, which corrects for air density. There is also Equivalent airspeed, but frankly I never got taught much about either of the last two, as it wasnt really important for my license. Spent a bit of time on wikipedia trying to learn more about them, but I need someone to explain them both properly to me.

ah thanks.

[Dee-Jay]

@smasha:

CAS ? Calibrated Air speed?

I would love if posters would have in brackets the wording of these just for the first instance then it makes it easier to understand.

TOS ,time of sortie?

RTFM and Google will help a lot. Would be nice if other posters could be more self educated and less lazy.

Ppl can not write the entire manual and all acronyms each time they are posting because some other ppl can’t open a PDF or do a research on the Web.

Please, consider it, you have a LOT to win by doing this.

[caper]

= [email protected].

I google “AOA LD” and got something about currency exchange rate . LOL

[Guest]

@Dee-Jay:

RTFM and Google will help a lot. Would be nice is other posters could be more self educated and less lazy.

Ppl can not write the entire manual and all acronyms each time they are posting because some other ppl can’t open a PDF or making a research on the Web.

Please, consider it, you have a LOT to win by doing this.

Not a lot to ask just to word what the symbols mean in the first description.

I do google and alot of times ,it doesn’t come up the way you want too.

Same when you search on a pdf.

P.S. Printed the nav checklist booklet.

Now to get stuck in YO.:D

[Guest]

This post is deleted!

[Dee-Jay]

@caper:

I google “AOA LD” and got something about currency exchange rate . LOL

Did you look first into “Docs folder” documents to find the meaning of AOA?

[Dee-Jay]

Into your “Docs” folder:

F-16 COMBAT AIRCRAFT FUNDAMENTALS - Multi-Command Handbook 11-F16 Vol5.pdf

Pdf Page 292 and 288

Title is: ABBREVIATIONS, ACRONYMS, AND SYMBOLS !!!

OMG, this is unbelievable! … I couldn’t imagine being able to find this information there!!!

You can use the Search button of your favorite PDF reader, or use your capabilities to sort the acronym using the alphabetic order (commending by A … Usually ending with Z … Like 1 to 9 but using letters)

… Either you are lazy or dumb. (Don’t know?) … And I didn’t checked the original Falcon4 manual … There are a lot of chance that is it also in there (maybe the Acronym section is still the Spanish one (?) will be in English in future release… Otherwise, you still have the MCH-F16 vol5 which is your new bible guys.)

…

If still no … Google can help …

A the end, you can ask here, but usually, easy common acronyms (like CAS, TAS, AOA, GS, ILS, TOS, ETA, INS, IRS, FPM, RPM, DMPI, CCIP, CCRP, DGFT, MSL, AGL, AAL, MSL, QNH … ) are well known from the begining for the ppl who have (seriously) opened (and read) the manuals at least once in their life.