Juggling throttle setting and nozzle position: How is it done IRL?

[Nealius]

After quite a bit of flying in the Harrier, I find myself in situations where I am frequently adjusting nozzle position while simultaneously adjusting throttle. The two most common situations for me are:

 

1 -- Nozzling out after takeoff. If I leave throttle at max while nozzling out I will rapidly bust my departure speed unless I nozzle out while simultaneously reducing throttle.

 

2 -- On a STOL approach. Nozzling to 60° programs flaps to 62°, causing an increase in lift. To counteract this I have to reduce throttle as I nozzle to 60°.

 

Looking at the cockpit, it appears to be physically impossible for the pilot to adjust throttle and nozzles at the same time unless he grew a third arm. What procedure(s) do real Harrier pilots use to control departure speed/changes in lift during approach when they can only change one setting at a time?

[RED]

After quite a bit of flying in the Harrier, I find myself in situations where I am frequently adjusting nozzle position while simultaneously adjusting throttle. The two most common situations for me are:

 

1 -- Nozzling out after takeoff. If I leave throttle at max while nozzling out I will rapidly bust my departure speed unless I nozzle out while simultaneously reducing throttle.

 

2 -- On a STOL approach. Nozzling to 60° programs flaps to 62°, causing an increase in lift. To counteract this I have to reduce throttle as I nozzle to 60°.

 

Looking at the cockpit, it appears to be physically impossible for the pilot to adjust throttle and nozzles at the same time unless he grew a third arm. What procedure(s) do real Harrier pilots use to control departure speed/changes in lift during approach when they can only change one setting at a time?

 

The Natops has some answers for you.

1 If you are light you may not need all the power available. Try to set the power after airborne and then rotate the nozzles.

2 that happens if you set vtol flaps late. When slower than 250 kn and above 200, drop the gear. That will set flaps to 25. You can select vtol flaps right after that and will not experience increased lift while slowing down. If you select vtol flaps too late you are compensating the lift thy would produce with engine power. If you then select vtol flaps, they will immediately go to their max position and you will have a increased lift moment. This effect will be even bigger if you don't use your throttle for your pitch attitude but your stick.

 

The Natops says that a fixed 60° nozzle position is the most effective and save approach. If you need to land on a short runway you can select a power setting and only use your nozzle during the final approach. High power settings will result in slower landings than lower power settings.

Gl

[Nealius]

The Natops has some answers for you.

 

2 that happens if you set vtol flaps late. When slower than 250 kn and above 200, drop the gear. That will set flaps to 25. You can select vtol flaps right after that and will not experience increased lift while slowing down. If you select vtol flaps too late you are compensating the lift thy would produce with engine power. If you then select vtol flaps, they will immediately go to their max position and you will have a increased lift moment. This effect will be even bigger if you don't use your throttle for your pitch attitude but your stick.

 

This is the procedure I use and it does not seem to work that way. VTOL flaps do not program at all until around 165kts and greater than around 35° nozzle, with their max deflection not being programmed until nozzles are 50° or greater. VTOL flaps do not immediately go to their max deflection. As a result, I am rotating from 25° nozzle to 60° nozzle while turning base, while also decelerating through 165kts, with the flaps programming from 25° to 62° as I am rotating nozzles--with the flaps not hitting 62° until the nozzles reach 50°. This causes a rather long increased lift moment (as the flaps are programming at the same rate I am rotating the nozzles) requiring me to mess with throttle and nozzles at the same time--which is unrealistic.

 

What is not clear from the NATOPS is precisely when you should rotate to 60° nozzles, and precisely when you should be slow enough for VTOL flaps to program, thus avoiding a situation where the increased lift moment occurs when the pilot would have to reduce power while rotating nozzles to 60°. Apparently it's not while turning base, as I have been doing.

Edited April 1, 2018 by Nealius

[SUBS17]

Some ideas, use a split throttle makes life easier, one for thrust the other for nozzles. Regarding flaps you can set them at 200kts and just concentrate on the nozzles. For me an approach is nozzles down(full) 250kts, then gear, if I'm heavy then I drop flaps and then feather nozzles and thrust to maintain the approach. With nozzles down early you start to build up the cushion of air and it is a type of Viffing technique to use nozzles as a speed brake on approach. As odd as it sounds this procedure works for me. Nozzles down at 500kts is a speed brake as well and combined with speed brake reduces speed rapidly to land quicker.:thumbup:

 

Mr Flaps

[Sarge55]

What angle do you mean when you say "nozzles down (full)"? 82 degrees? Seems a bit extreme at 500kts.

 

But what do I know, I was Infantry, only experience I had with planes was jumping out of them.

[Eagle7907]

Juggling throttle setting and nozzle position: How is it done IRL?

 

According to the NATOPS diagram STOL flaps are selected along with gear down at downwind 800’ AGL airspeed less than 250kts, nozzles are rotated to 60 degrees when abeam touchdown point (the 180). Once below 160 knots, that’s when you check for DROOP and therefore the flaps then extend fully. You will balloon a bit but also slow down quickly as well. Therefore throttle to maintain proper descent rate to reach the base at 500-600’ and final about 300’ AGL at about 1/2nm. Throttle for descent rates, pitch for AOA, rudder for vane. Rotate to about 1-2 degrees nose up for touchdown.

 

To me, you obviously have to reduce throttle to reach below 160kts. Therefore, you reduce throttle to compensate the nozzle rotation to maintain 800’ pattern altitude.

 

 

Sent from my iPhone using Tapatalk Pro

Edited April 2, 2018 by Eagle7907

[Nealius]

That makes more sense. I don't recall the 60° nozzles when on the 180 when I read through the NATOPS and USMC Syllabus.

[Doum76]

That makes more sense. I don't recall the 60° nozzles when on the 180 when I read through the NATOPS and USMC Syllabus.

 

It's actualy between 50 and 60, depends i presume how heavy or light you are, how wind is etc.. for exemple, when i'm light, i go around 50, if i drop to 60 it slows me way too much, if i'm heavier, i go 60, to help slow down a bit and counter the weight requires more thrust when getting on hover states.

 

The following vid is not perfect, far from it, but that is how i do it, can'T remember where or in which document i'Ve read it, since i'Ve read quite a few on the AV-8B when i bought the module i got mssed up from all the guides, but i drop nozzles to 25 as i make the break, read to drop nozzles to at least 25 deg prior to drop flaps to STOL, and also helps slowing down and avoid bubble effect, so when i'm downwind, i'm close to 200 knots, 25 nozzle, so i can drop gear, flaps to stol and focus throttle... i then slowly drop nozzle to 50-60 so by the time i'm abeam, i'm already set, and no surprises as i turn... sometimes i either give a tiny too much throttle so nose lifts more than i want and gain more than 600 ft as i get read for the turn, or like in this situation, i went a bit too light on throttle and droped a bit... my turn for the 90 or base leg, is slow and not that banked angle, wanna aviod giving in too much throttle and gain speed and not sinking too much... still have issue on that part... so i usualy get about 450-460 when i get at the 90, aim around 300-350 for when i get in the groove, i turn water on as i turn into to groove, again anticipating the possible lift from turning water on as RPM raises a bit.. and drop nozzle to hover state more or less 1,000ft-1,300ft from the carrier not to slow way too soon....

 

Not perfect, but sorta do the job in DCS as for early-acess for now... and as much as my skill permits me... but i'm getting better and controling the bubble effect or aircraft reaction when adjusting nozzles, thorttle, droping flaps, gears... and always try to be set before speed drops to 160 not to have the bubble up...

 

Here's one of my so-so atempt:

[Fri13]

It should be easy as you set the nozzle leveler lock bar first to the angle you need to use, and then you just can forget to pull it over.

 

You only operate with the throttle and nozzle separately. Of course a split throttle does all far far easier, but the key IMHO is the lock bar as you only push/pull nozzles in the speed as you require after that.

[Doum76]

It should be easy as you set the nozzle leveler lock bar first to the angle you need to use, and then you just can forget to pull it over.

 

You only operate with the throttle and nozzle separately. Of course a split throttle does all far far easier, but the key IMHO is the lock bar as you only push/pull nozzles in the speed as you require after that.

 

Totaly agree, STO Stop is really helpful, makes my Short and Rolling Vertical Take-Off easier now. :)

[RED]

It's actualy between 50 and 60, depends i presume how heavy or light you are, how wind is etc.. for exemple, when i'm light, i go around 50, if i drop to 60 it slows me way too much, if i'm heavier, i go 60, to help slow down a bit and counter the weight requires more thrust when getting on hover states.

...

Here's one of my so-so atempt:

 

Very well done! Someone is striving for perfection in that video. ;) For me the key really was to arrive at the abeam pos trimmed out with 50°-60° nozzles at 10-12 units of AOA. What I try to do different, is to break a little bit later and do a level break. Then I have more time for trimming and the checklist and can loose the 200 ft in the downwind. NAVAIR says to break after 10 sec passing the carrier.

Getting more precise takes a lot of practice. E.g. you were very slightly too far away at the abeam and started your turn late. Because of that you had to fly a shallow glidepath and less than 20°-25° AOB.

The turn off the 180 should be an instrument-type

turn of 20° to 25° angle of bank to arrive at the 90

at 400 to 450 feet and 10 to 12 units.

a. Greater than 20 knots — Turn prior to abeam the intended landing spot.

b. Ten to 20 knots — Turn abeam the intended landing spot.

c. Less than 10 knots — Delay 2 to 4 seconds past abeam.

All this will get a little bit easier once we get TACAN. That will allow us to check the distances in flight.

[Doum76]

Very well done! Someone is striving for perfection in that video. ;) For me the key really was to arrive at the abeam pos trimmed out with 50°-60° nozzles at 10-12 units of AOA. What I try to do different, is to break a little bit later and do a level break. Then I have more time for trimming and the checklist and can loose the 200 ft in the downwind. NAVAIR says to break after 10 sec passing the carrier.

Getting more precise takes a lot of practice. E.g. you were very slightly too far away at the abeam and started your turn late. Because of that you had to fly a shallow glidepath and less than 20°-25° AOB.

 

 

All this will get a little bit easier once we get TACAN. That will allow us to check the distances in flight.

 

Nice trick.

 

Indeed, perfection is hard to achieve, as long as i'm concerne, i did lots of progress and got to agree, abeam states 0.8 nm-1 nm and i was 1.1 nm, i admit and guilty i was a few hundreeds feet further away (i blame my pen falling from my kneepad and had to find it int he cockpit as i turned to avoid the ground crew the needs to take off the entire ejection seat to find it :), i'm still so used to break with the SuperBug in another flight sim and end abeam around 1-1.5 NM, still got to adjust a few things to this awesome module RAZBAM made :) My trimming is mostly done a lot while i break with trimming inputs entered as speed bleeds, so when i level up downwind 98% of the trimming is done i just need to adjust a bit but i always leave some nose down, same as refueling, easier to deal with it than going up with throttle input. as for the angle i admit i'm having trouble keeping a straight 10-12, i aim between 9-10 units AoA instead of 10-12 as stated, need to adjsut this. But again i wasn't aiming for pefection turotial in the video, but more likey trying to show that the bubble up effect can be counter and avoid and managing nozzle, throttle, trim, gear, flaps and water al together can be done, just need pratice, which i am still at doing and the more i try the more i have respect for RL Harrier pilots. :) As for the turn post abeam, i more or less counted 4 second passed abeam since the carrier is going around 11 knots, if i remembered from the NAVAIR says to delay 2 to 4 seconds, but again i have memory issues i could totaly do that wrong :) Need to buy myself some RAM for my old brain :) One day i'll be good enough to earn some Plastic wings to glue up to my screen :) :pilotfly:

 

As for the TACAN you are totaly right, i'll then be able to take away all the ships in formation with the carrier to align myself easier from a distance when landing up after a mission and to counter the ships wake a bit hard to see on my system. Gotta do with what we have :)

[RED]

Doum76, i think i will try the trimming in the break.

I agree with the nose down on refueling - helps a lot not to have to push the stick forward (i hate that with the Joystick :megalol:). It also prevents trimming up too much while taking fuel.

 

To get back to OPs 2nd question... I reviewed this video again:

If you watch the flaps position (F in HUD) and the vertical speed (FPM and bar) closely you will see that the flaps drop to 62° while he passes through 160 kn. After a little delay you will notice that his FPM will go up to 0 while his attitude, nozzle and throttle position do not change.

 

He sets the nozzle to 60° at 170 kn and the only big change is that his airspeed drops. After that he controls his speed by setting the AOA. At 3/4 mile (entering the groove) he raises the pitch carrot to the horizon and flies a 12 AOA approach with 3°glidepath like we should do in the groove. Changing his AOA from 8-10 units to 12 slows him down from ~120kn to ~80 kn.

 

There are some interesting videos of the TAV-8 to learn from.

 

Side note: Heavy gliders use the change of flaps position while getting towed by a tow plane. Some light tow planes get airborne before the glider. To minimize the bumping and jumping as well as drag the pilot of the glider sets his flaps from normal to the takeoff position at exactly that speed where he can comfortably fly with takeoff flaps. Doing so he gets airborne earlier from a smooth roll into a stable takeoff.

 

edit. OPs 1st question:

He uses the nozzles only for a few seconds. They are at 10° on the ground, rotate to ~55° at ~80 kn rotation speed (marked by the box around the airspeed?) immediately starts to go back to zero (slowly) and keeps 6-8 units of AOA. After that he throttles back.

Edited April 2, 2018 by RED

[Doum76]

Awesome video RED, thanks for sharing. Wounder why i never find those kind of videos when i search them myself :)

 

Second video, the bird must had been heavy as **** :) , 110%RPM+ and almost full hexagon, wouldn't want the bird tp drop on my foot. But glad to see, without knowing i do the same when i take off, raise nozzle up when airbord to avoid the high climbing before reaching the runway threashold. Again great videos man.

[Nealius]

It should be easy as you set the nozzle leveler lock bar first to the angle you need to use, and then you just can forget to pull it over.

 

You only operate with the throttle and nozzle separately. Of course a split throttle does all far far easier, but the key IMHO is the lock bar as you only push/pull nozzles in the speed as you require after that.

 

That works for takeoffs, but not particularly for landings. Clearing the stop is part of the before landing check, and you'll need to be able to move the nozzles beyond 60° for PNB or vertical landings.

[Fri13]

Awesome video RED, thanks for sharing. Wounder why i never find those kind of videos when i search them myself :)

 

Second video, the bird must had been heavy as **** :) , 110%RPM+ and almost full hexagon, wouldn't want the bird tp drop on my foot. But glad to see, without knowing i do the same when i take off, raise nozzle up when airbord to avoid the high climbing before reaching the runway threashold. Again great videos man.

Harrier problem is that it has a 5% (or was it 7%) thrust to weight reserve, while F-35 has 20%. So you are very very limited to landing vertically work harrier.

 

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I usually post from my phone so please excuse any typos, inappropriate punctuation and capitalization, missing words and general lack of cohesion and sense in my posts.....

[SUBS17]

What angle do you mean when you say "nozzles down (full)"? 82 degrees? Seems a bit extreme at 500kts.

 

But what do I know, I was Infantry, only experience I had with planes was jumping out of them.

 

Its known as VIFFING, the use of the nozzles to reduce speed rapidly so full forward to reduce speed is effective especially if combined with the speed brake.

[Sarge55]

Its known as VIFFING, the use of the nozzles to reduce speed rapidly so full forward to reduce speed is effective especially if combined with the speed brake.

 

Sweet, thanks for the info, didn't realize you could go full forward at that speed. :thumbup:

[Doum76]

Harrier problem is that it has a 5% (or was it 7%) thrust to weight reserve, while F-35 has 20%. So you are very very limited to landing vertically work harrier.

 

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I usually post from my phone so please excuse any typos, inappropriate punctuation and capitalization, missing words and general lack of cohesion and sense in my posts.....

 

 

Well not surprising, let's not forget Harrier are old granpas and mostly first Jump Jets... gotta give Granpa's stil thumbs up for what he can do :) While F-35 are young bold teenagers flashing out their stuff. :) But grandpas is more sexy :)

[SUBS17]

Sweet, thanks for the info, didn't realize you could go full forward at that speed. :thumbup:

 

Theres more to the Harrier than many realise its only hurdle is the powerplants reliability and it could do with a few thousand pounds more thrust.:thumbup:

BTW Viffing in a dogfight is more practical than the cobra for the SU27, it does not kill your energy but does act as a speed brake.

[Fri13]

Theres more to the Harrier than many realise its only hurdle is the powerplants reliability and it could do with a few thousand pounds more thrust.

BTW Viffing in a dogfight is more practical than the cobra for the SU27, it does not kill your energy but does act as a speed brake.

Cobra IS other things than slow down.....

 

Some see it only as pretty party trick... Their understudying of the capability...

 

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I usually post from my phone so please excuse any typos, inappropriate punctuation and capitalization, missing words and general lack of cohesion and sense in my posts.....

[SUBS17]

Cobra IS other things than slow down.....

 

Some see it only as pretty party trick... Their understudying of the capability...

 

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I usually post from my phone so please excuse any typos, inappropriate punctuation and capitalization, missing words and general lack of cohesion and sense in my posts.....

 

True its only with a full understanding of the aircrafts capabilities can it be flown to its full potential.