Whats wrong with my landings?

[pimp]

Hello All,

 

I am having consistency issues with landing. Most of the time I land successfully and then there are times where I don't have a clue what went wrong. I use the same type of approach every time. I have my nozzles at 82, water on, and non-aggressive with my AoA. All of a sudden my lift disappears and I start dropping like a rock, which of course you cannot recover from. I have no clue of what happened. One second I'm working my throttle up & down to lower altitude safely and the next second I get no lift and start dropping even with my throttle full blast. So I attached a link to the track because it's a 14MB file. I would appreciate if someone can take a peak at it and let me know what I'm doing wrong. Again, most of the time I can land successfully.

 

This is a VR track in 2.2 Normandy and it consist of me VTO, practice refueling, head back to carrier and land, rearm, and go shoot some missiles. On my way back from shooting missiles is where my second landing goes wrong. I really wish DCS provided a UI to interact with the replay tracks. Since, it does not, fast forward to 2560 seconds is where my 2nd landing starts.

 

P.S. I always dump fuel to about 3000-3500lbs and no ordinance before landing to account for weight.

 

Thank you in advance!!!

 

http://www.mediafire.com/file/b6vbg6savs3r6az/AV8B_WTH.zip

[Nealius]

Do you happen to have external fuel tanks loaded?

[pimp]

No, I have nothing loaded on my landing approaches.

[Flamin_Squirrel]

Your track seems to be corrupted. If I fast forward you crash shortly after your first takeoff.

[Sephyrius]

By using nozzles 82 on your approach, what do you mean? Going from 0 directly to 82 and trying to glide all the way in using the momentum?

I can remember having some of those 'falling like a rock' moments the first few days, but after making more use of the 50-60' nozzles first to bleed off speed and altitude and eeking out every ounce of flap benefit before going vertical it hasn't happened since.

Not sure what caused it though, felt like running into hot gas ingestion when working the throttle too heavily causing a sharp drop that just snowballs (not unlike VRS).

[kylekatarn720]

Did you check your rpm during landing? Maybe you are degrading your engine before attempting vtol.

[Nealius]

By using nozzles 82 on your approach, what do you mean? Going from 0 directly to 82 and trying to glide all the way in using the momentum?

I can remember having some of those 'falling like a rock' moments the first few days, but after making more use of the 50-60' nozzles first to bleed off speed and altitude and eeking out every ounce of flap benefit before going vertical it hasn't happened since.

Not sure what caused it though, felt like running into hot gas ingestion when working the throttle too heavily causing a sharp drop that just snowballs (not unlike VRS).

 

 

I concur. I do a standard approach that has never failed me:

 

-350kts 800' passing by the starboard side of the ship

-10 seconds past the bow, left break 3G to downwind

-about 230-250kts 600' downwind, 25° nozzles, drop the gear then STOL flaps, H20 to Landing

-about 2 seconds past the stern, left turn target 400-450' about 8-10 units AoA

-as I'm turning to final, smoothly rotate nozzles to 60° and reduce power anticipating 62° flaps

-try to maintain 8-10 units AoA on final approach, coming up the port side of the ship

-when the stern gets close to the Flaps/Nozzle indicator in the HUD, rotate nozzles to 82°

-Witch Hat on the horizon (or higher if you need to slow down faster)

 

The rest is standard vertical landing.

[74th_Lunatic]

Watch your flap settings it could be forward momentum being lost when the flaps change.

 

If you still have lift under your wings due to momentum and this is then bled off by the flaps....could be the point of no return.

[TheSkipjack95]

Happens to me too sometimes, was in the hover advancing at 40 ish knots, slowly adjusting descent rate with the throttle, and then the lift drops and I go from 500fpm to 1500, water flickering on and off until I hit the drink.

 

I think it might be an error with the water/wet thrust values alternating with the dry thrust. and thus killing the thrust we have.

 

It also only happens some of the time. Dry thrust landings go without a hitch.

[pimp]

Thanks all for the advice. To be clear, on final approach, my nozzles are at 60° at ~150-180 knots from about a 1-1.5 miles away and then I transition to 82° position. I'll try to follow Nealius' steps and report back. I'll make a smaller size track in case I continue to fail my landing.

 

Thanks again!

[pimp]

Happens to me too sometimes, was in the hover advancing at 40 ish knots, slowly adjusting descent rate with the throttle, and then the lift drops and I go from 500fpm to 1500, water flickering on and off until I hit the drink.

 

I think it might be an error with the water/wet thrust values alternating with the dry thrust. and thus killing the thrust we have.

 

It also only happens some of the time. Dry thrust landings go without a hitch.

That's what exactly happened. I was hovering around 40 knots and all of a sudden my lift disappeared. I'll try only landing with no water and see if that helps. Thanks!

[smallberries]

I suspect engine performance degradation too, I don't think it's quite modelled right atm and might be a randomish gremlin.

[Mars Exulte]

 

 

Don't know if it helps, my landings are still pretty sloppy. Maverick has some better tutorials. As you can see, I changed my mind part way down and ended up dicking around for a minute while I settled on a landing location, so simply "dropping for no reason" isn't usually what happens. In fact, in this particular video I was very light and it was staying within temperature margins even without H2O.

 

In my experience, there a few primary contributors to "falling stone syndrome".

 

 

 

#1 The engines are currently very sensitive to over power, and it seems to be a hard cutoff, after a certain period of time, you lose thrust. This is easily avoided by not firewalling the throttle, though, and typically you can make many passes if you've been rationing your engines properly. However, if you've spent a fair amount of time at redline, you can easily end up losing power mid-hover or something else unpleasant.

 

 

#2 Allowing attitude to get out of whack. When you're on the ground, note the position of your attitude indicator. When you're trying to maintain a hover, this is the approximate position you need to hold your nose in (several degrees BELOW the horizon). Being in a non-level position results in both drift and loss of lift. If you're already kind of marginal on weights or something, it's enough to get you started sinking.

 

-edit for addendum

Also, be advised the Harrier has Lift Improvement Devices (those strakes on the belly and the brake that descends during hovering) that catch the ground effect and generate a bit of extra lift. Obviously, this requires you to be relatively low in order to benefit from it. So, any hovering you attempt to do should begin no higher than 50-100ft AGL, and preferably a bit lower. Attempting to transition into hover from too high an altitude is a common mistake. In the video I posted, you'll notice the actual transition into hover took place around 50ft AGL

 

 

#3 Allowing the aircraft to start dropping too quickly and having insufficient time to recover. It takes a moment or two for the engine to switch between power curves, it's possible for your throttle position and actual RPMs to not be in sync. Try to make your movements as gentle as possible.

 

 

#4 Put your nozzle control somewhere easily accessible for on the fly corrections. It doesn't matter what it's "supposed to be" or or or. You need to be able to readily put it where it NEEDS to be. In the video I posted, while my handling is obviously less than expert, you'll notice I'm moving the nozzles rapidly back and forth as necessary to achieve the hover, ranging from forward braking to a 80ish to match speeds with the LHD.

Edited January 6, 2018 by zhukov032186

[cromhunt]

hello:)

Please checkout the parametrers shown on the video.And take care about your vertical speed.

Pay attention to keep it around 500 Fpm and never exceed 600 fpm.

Use your engine to keep it under 500 fpm during descent.

Remember a fact that is your approach speed depend of your total weight,and of the power available.

Your vertical speed during the approach can, if you increase it too much, increase the wing load, and act as if the weight of the aircraft increased.

Choose a speed looking like the speed shown on video.

Too high speed and need too many power to use to slowing approach.

Not enough speed and need too many power to slowing vertical speed.

With a little practice you will see that the nozzles determine the efficiency of your reactor. Even if it seems obvious to say that, many people mix the aerodynamic effects with the effects of propulsion.

The speed gives you the lift, and the thrust gives you the speed. With the harrier it's the combination of the two that allows you to fly, first like a normal plane, but also in its vertical flight phase.

Even with the low speed you give lift and you need less engine power, but if at the same time you choose a vertical speed too great to go down, you increase the wing load and thus you decrease the lift. For to make up for the error you must either increase the engine speed, or increase the horizontal speed to compensate. .But if you have already used all the power of the engine, the increase in your horizontal speed will depend on the height of the flight.

On therefore see that all these parameters must be stabilized in sufficiently average values to make it possible to catch a steering error.

Do not be too disappointed by your beginnings and persevere, the practice will do the necessary if you always choose the same flight configuration.

I mean always the same flight parameters, that you can choose yourself by staying in the range indicated by the video.

The secret is to keep these parameters constant to be aware of errors and corrections to your driving

With the Harrier you have to be even sweeter than with a helicopter, and be patient. The brutal and hasty maneuvers do not work.

 

Follow this link to see other videos:

http://cromhunt.proboards.com/thread/343/dcs-world-av8b-harrier?page=1&scrollTo=1120

See you and have a good game

Edited January 6, 2018 by cromhunt

[Warmbrak]

I have found that even with empty pylons, attempting to execute a vertical landing with more than 3000lbs of fuel can be challenging. I only do vertical landings with 2500lbs of fuel or less, which does not even activate the water system with lots of power to spare.

 

Many good comments in this thread, especially with regards to throttle movement. Only make very subtle throttle changes in the descent; big movements in throttle up ok, big movements in throttle down are bad.

 

Being too heavy in this aircraft can ruin the best of intentions quickly!

[Shrike88]

Agree with Small changes and check the NATOPS manual for your time limits and power settings on the limitations page. Engine Performance Degradation I believe has effected my landings several times. Now i carefully watch and fly the profile (check weights beforehand) and keep engine within limitations as you slow and are on the low end of the profile typically <2000ft from the ship you will notice your on the upper limit of the power curve and can easily fall outside of the performance margin.