Stabilator?

[Harlikwin]

So, Im using the chucks guide vertical landing tutorial for vertical landing on the tarawa. And for the life of of me i cant figure out how to set the "stabilator" is there a key binging im missing? Is it just trim? Am I a dope? Is it a typo?

 

Ive managed the landing a few times but usually with some fwd velcoty 20-60mph.

 

Any other pro tips on landing?

[Captain Orso]

This may be a bit of the blind leading the blind, as I am a total n00b to the AV-8B, but looking through both Chuck's Guide and the Pocket Guide, the stabilator basically refers to pitch trim, just not using trim tabs the same way most aircraft do.

 

But at very slow speeds, when control surfaces are of very little use, pitch and yaw are controlled through air-jets in the "tail bullet" --that bullet-like protuberance pointing out to the rear of the tail assembly. There are also air-jets on the wing-tips for controlling roll.

 

From my understanding, the control stick will operate all of these air-jets, or 'air control-valves' as they are called in the pocket guide-- but while landing or doing AAR you should be using the trim hat, bc the stick will cause too radical pitch and roll corrections. That's my understanding anyway.

[Harlikwin]

I guess that makes sense, I'll map that to my stick controls.

[Sadist_Cain]

the Stabilator is the "elevator"

 

It's called a horizontal stabilizer, if it has a moving control surface attached to it, then that part is the elevator.

If the whole stabilizer moves, then it's a Stabilator.

 

The trim responds at a rate of 1° per second.

You have a readout for stabilator angle on the upper right of the console near the analogue nozzle angle needle, along with a second readout on the Engine page.

 

Two ways you can go about getting that 4° nose down.

You could slap it around and centre the stick, check the stabilator angle and adjust trim as necessary to get it at 4°.

Or preferably, centre up your trim so that your gauges read 0 trim angle with the stick centered and then hold the nose down trim and count out 4 seconds whilst adjusting on the stick to stay level, centre stick and check the angle, adjust if needed.

 

I prefer the second method, less bouncy and I tend to use the moment I check the trim as the moment I start to descend from 800ft to 600ft whilst on the downwind abeam the carrier

[Lixma 06]

There seems to be a conflict of advise here.

 

According to Chuck's guide during a vertical landing you should apply 4° nose down while in-flight.

 

According to the official pocket-guide it says 4° only once you're down.

 

I've tried applying 4° nose-down during approach and for the life of me I can't understand why I should; beside the problems in radically upsetting the aircraft or knowing when you've dialed in negative 4° trim it also means flying with the stick jammed back into your private parts.

 

:joystick:

[OStateBandit]

Trim is used as needed during flight to maintain desired control forces; typically to keep the stick in a fairly neutral position. In DCS, without stick forces, you basically trim to hold the nose wherever you want it with little-to-no stick input. Try trimming so that it takes very little stick deflection to keep the nose level. The required trim will change as your airspeed changes.

 

With the nozzles deflected, -2 degrees or more stab trim closes the nose RCVs, so on the ground -4 degrees is used as a practical setting to ensure that they stay closed during ground ops, particularly without your hand on the stick. You want the nose RCVs closed to reduce the likelihood of FOD ingestion.

[Eagle7907]

I am still very confused about this. When I actually do the -2 trim I can barely rotate off the ground at the nras. Once I am able to get it off the ground it’s a constant battle to clean up to wingborne flight and trim out the forces.

 

Is this really the correct behavior for the sim? Please correct me if you think I am doing something wrong.

 

 

Sent from my iPhone using Tapatalk Pro

[OStateBandit]

The -2 (2 ND) is correct per the aircraft, and works in the sim. When performing a STO, you only 'guard' the stick rather than pull the nose up as in a conventional takeoff. Basically hold it neutral.

The rotation of the nozzles at NRAS is what gets you airborne, then you begin an accelerating transition.

[Eagle7907]

Stabilator?

 

Okay. Last time I did that, the jet just bounced down the runway and eventually broke.

 

When I don’t put in the -2 stab, it does exactly as you describe without any input. So, again I’m confused and wondering what I am doing wrong. I even use the VREST data to determine NRAS and noz angle. Use STO flaps. Most of the time I do dry TO unless I absolutely have to do wet.

 

Sent from my iPad using Tapatalk Pro

Edited December 3, 2018 by Eagle7907

[Ramsay]

When I actually do the -2 trim I can barely rotate off the ground at the nras.

Not sure what you mean by "I can barely rotate off the ground at the nras.", at NRAS, you rotate the nozzles (not the aircraft nose) and it should lift off the runway (with the witch's hat more or less on the horizon, and FPM at 4-6° on the pitch ladder). If the Stab is set wrong, the nose will try to pitch down/up and need pilot input/trimming.

Once I am able to get it off the ground it’s a constant battle to clean up to wingborne flight and trim out the forces.

I usually set | 1° | less than the real, so set -1° Stab for takeoff. The aircraft has small upward pitch moment that needs to be controlled as the gear is retracted and nozzles rotated back to 25° before switching to Auto flaps, and continuing the nozzle rotation to 0°

 

Okay. Last time I did that, the jet just bounced down the runway and eventually broke.

What was your weight ? was this with 10° nozzles for the takeoff roll ? What RPM, 103% is sufficient in most cases.

 

I even use the VREST data to determine NRAS and noz angle.

The VREST>STO page is likely WIP, most info is correct but nozzle angle is not !, IIRC I've only seen 60°

 

The STO nozzle angle is approx.

 

• 60° (25,000lb or less),

• 55° (26,000-29,000 lb)

• 50° (30,000 lb or above)

 

Ref: Figure 3-14. Short Takeoff Rotation Speed, STOL Flaps (Sheet 2 of 2), p73, NATOPS Flight Manual AV-8B Performance Charts, A1-AV8BB-NFM-400

 

The chart on page 70 of Chuck's AV-8B Guide is for the 406 engine but close enough.

 

I mostly set nozzle stop to 55°

 

Use STO flaps. Most of the time I do dry TO unless I absolutely have to do wet

I'm the same, without a track, it's hard to see the details of why you are having issues but I can list my STO sequence

 

VREST>STO page

• NRAS wet 93kts dry 102kts -->NRAS approx 100 KTAS

• GWT approx. 26700 lbs

 

On Runway

• Nozzles set @ 10°

• Nozzle Stop @ 55°

• Flaps to STO

• Stab set to -1° (set to -2° then inc to -1°)

• Water to TO (Take Off)

 

• Wheel brakes ON

• Throttle up to 80% RPM

 

• Wheel brakes OFF

• as speed increases, increase the Throttle to 103% RPM

 

• @ approx 100 KTAS - Rotate Nozzles to Stop (55°)

 

Once Airborne

 

• Witch's hat maintained near horizon +/- 2°

• Gear UP

• Nozzles slowly to 25° (controls FPM climbing the pitch ladder)

• When nozzles reach 25°, Flaps to AUTO

 

• Continue rotating nozzles to 0°

• Adjust Trim as necessary

 

Takeoff checklist

• Clear Nozzle Stop

• Water OFF

 

Continue Climb adjusting throttle/trim as req'ed.

 

Here's a track, it's not very good as I rotate the nozzles late (+114 KTAS) but it may be of use ?

Edited December 3, 2018 by Ramsay

[Captain Orso]

Thanks Ramsay! That clears some things up for me.

 

A couple of notes from me:

• Wheel brakes ON <- toe-brakes

• Throttle up to 80% RPM <- doesn't say this in either the pocket guide nor Chuck's guide. I've been just kind of winging it, but getting away with that :D

 

• Wheel brakes OFF

• as speed increases, increase the Throttle to 103% RPM

 

• @ approx 100 KTAS - Rotate Nozzles to Stop (55°)

 

Once Airborne

 

• Witch's hat maintained near horizon +/- 2°

• Gear UP

• Nozzles slowly to 25° (controls FPM climbing the pitch ladder) <---

• When nozzles reach 25°, Flaps to AUTO <- both guides are again either ambiguous or silent. Chuck's guide says no flaps with nozzles at less than 25°, but not when you should switch FLAPS from STO to AUTO, so I've been more-or-less doing this, but not so exactly

 

• Continue rotating nozzles to 0°

:thumbup:

[Eagle7907]

Stabilator?

 

Oh wow! Thanks Ramsay. Umm where to start?

 

Oh first, poor choice of words on my part. I meant when the jet lifts off the ground on its own. In my experience down -2 on stab, it didn’t. I had to yank it off the ground. The first attempt I tried it by the book, it wouldn’t lift off so I pulled back then quickly let go and that’s when the PIO down the runway occurred. After that, I made another attempt and just left the aft stick in and let it climb more, but then I started doing oscillations just at altitude until trimmed out, which didn’t seem right to me.

 

I didn’t realize the noz angle is wrong on vrest. I’ve taken note on that. But if that’s the case, wouldn’t the jet lift off easier if I am supposed to do 55 but do 60 instead at nras?

 

As far as the clean up phase after TO, I do the same. Control climb rate with noz angle to 25. Then flaps auto, noz angle zero, water off, Sto stop stowed, throttle below max continuous.

 

Addendum: I always do 10 degree noz for takeoff.

 

Sent from my iPhone using Tapatalk Pro

Edited December 3, 2018 by Eagle7907