AV-8B flight model discussion

[ouPhrontis]

It's from Jane's All The World's Aircraft, 1988;

Time to climb to 40,000 ft (12,200 m): 2 min 23 s

 

This was a record set, and there are events for different altitudes and aircraft types; but I cannot find any source material at the moment.

 

Across the variants the initial rate of climb is approximately 50,000 feet per minute, of course that cannot be sustained, but it demonstrates how incredibly powerful the Pegasus is, especially with later variants (like the AV-8) where they lightened the airframe further with carbon composite wings etc.

 

You could've gotten a better time-to-climb and gone further of course, with managing energy, but then also factored in (in reality) would be preserving the engine so it could be used again and not scrapped after.

Edited June 28, 2018 by ouPhrontis
disabled smilies because of 8) looking like glasses emote

[Holbeach]

I've done brakes off to 30,000' in the F-15 in 57 secs.which is in line with official records, so the Harrier time seems feasible, but without any data it's not possible to tell.

So find the data, do the test and then see how it compares.

Sounds like an interesting project.

..

[ouPhrontis]

Also here, at chapter 'Another Racing Start' is described in detail a record attempt back in the day, with some parts of the flight coming close to your recording;

Harrier Boys; Another Racing Start

[ouPhrontis]

Art Nalls privately owns an ex Royal Navy Sea Harrier XZ439 and has demonstrated getting to 10,000 feet from ground level in 1 minute. Of course these time-to-climbs are competitive and they'll be carrying very little fuel for anything other than the record attempts, let alone anything else in there.

[Holbeach]

Also here, at chapter 'Another Racing Start' is described in detail a record attempt back in the day, with some parts of the flight coming close to your recording;

Harrier Boys; Another Racing Start

 

 

What a fascinating account, of a detailed, time to height record attempt, with the unique Harrier. Just what I'm looking for.

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[ouPhrontis]

What a fascinating account, of a detailed, time to height record attempt, with the unique Harrier. Just what I'm looking for.

..

 

It is isn't it? There's an interview on YT with the chap that put this together for the book, who himself flew Harriers in combat. Great read.

 

For the curious, here are some records set with the GR.5

 

• 3,000 metres 36.38 seconds Andy Sephton
  
• 6,000 metres 55.38 seconds Heinz Frick
  
• 9,000 metres 81.00 seconds Andy Sephton
  
• 12,000 metres 126.63 seconds Heinz Frick
  

[Katmandu]

Keep it shiny side up olde bean.

 

Fully agree, thank you for your posts!:thumbup:

[SUBS17]

At least for this one I think this is "induced roll".

You're activating rudder with high yaw rate.

Your wing external to the turn is taking more speed and lift than the one inside the turn, so the roll.

 

 

You can also experience this flying glider with large wingspan :smilewink:

 

No he's in VTOL mode, the roll is produced by the cushion under the aircraft if you push it slightly sideways it causes a roll which can be countered by the Harriers design which allows roll/pitch/yaw correction in hover.

[jojo]

No he's in VTOL mode, the roll is produced by the cushion under the aircraft if you push it slightly sideways it causes a roll which can be countered by the Harriers design which allows roll/pitch/yaw correction in hover.

 

I don’t think so.

NATOPS acknowledges ground effect for vertical landing at 20ft. He is doing his aerobatics over 300ft :joystick:

[SUBS17]

NATOPS is wrong the cushion exists in VTOL regardless of altitude and forms over time when the nozzles point down. So its a hover he's doing and there is a cushion underneath otherwise he would not be hovering..no cushion..no VTOL simple and the aircraft departs.:music_whistling:

[ouPhrontis]

I think there's some confusion of terms, cushioning is an in-ground-effect occurrence. Out of ground effect in VTOL with near or no forward air-speed for wing-borne; with the Pegasus supporting the Harrier, there is no cushioning affect, it's pure thrust.

[Holbeach]

It is isn't it? There's an interview on YT with the chap that put this together for the book, who himself flew Harriers in combat. Great read.

 

For the curious, here are some records set with the GR.5

 

• 3,000 metres 36.38 seconds Andy Sephton
  
• 6,000 metres 55.38 seconds Heinz Frick
  
• 9,000 metres 81.00 seconds Andy Sephton
  
• 12,000 metres 126.63 seconds Heinz Frick
  

 

 

In my 4th T/O and landing flight since buying the Harrier.

 

Brakes off to 30,000' AGL, was 88secs, passing through at 174 kts TAS, Tacview, so I would say the Harrier looks pretty good against the GR5 times and should allay any fears about it's FM. landing time was 3'.45'', which will easily improve with practice.

 

 

..

[SUBS17]

I think there's some confusion of terms, cushioning is an in-ground-effect occurrence. Out of ground effect in VTOL with near or no forward air-speed for wing-borne; with the Pegasus supporting the Harrier, there is no cushioning affect, it's pure thrust.

 

In VSTOL I find that there is a cushion and the effect is that if you lose it even out of ground effect the aircraft falls from the sky. When using thrust the effect out of ground effect is still very similar in behaviour. You can do some cool things with the cushion when doing aerobatics in VSTOL.

 

Edited June 29, 2018 by SUBS17

[Vatikus]

Where the sideslip? Why he rolling without sideslip?

 

 

Looking at natops (second half of given paragraph), given video indeed shows problem with FM...

 

[Vatikus]

Roll, where are you from? Track file pleasehttps://dropmefiles.com/i5Kdy

I would even say that what we have now is even too stable... real life trademark of yaw induced roll departure is not much a threat in dcs.

 

[MAD_MIKE]

I would even say that what we have now is even too stable... real life trademark of yaw induced roll departure is not much a threat in dcs.

 

 

There is no intake momentum at all.

[bkthunder]

https://forums.eagle.ru/showthread.php?t=203105

 

Here was a thread I started a while ago, with some of the same questions asked here. I hope it's just a matter of time and the FM will be ironed out, right now I have many questions about it...

[SUBS17]

Regarding side slip, is it possible that the FCS or SAS counters side slip with the rudder automatically?

[sirscorpion]

 

Harrier test pilot on side slip, and induced roll at low speeds "24:20 time"

[MAD_MIKE]

Regarding side slip, is it possible that the FCS or SAS counters side slip with the rudder automatically?

 

In my Harrier videos except one I flying in full manual mode, without any roll, yaw, pitch assists. And if autopilot helping it should be visible at external views by rudder movement.

[CoBlue]

Harrier test pilot on side slip, and induced roll at low speeds "24:20 time"

And just 50sec after...."The problems were overcome".

 

Besides he's talking about the AV-8A, not B that was extensively redesigned.

[SUBS17]

In my Harrier videos except one I flying in full manual mode, without any roll, yaw, pitch assists. And if autopilot helping it should be visible at external views by rudder movement.

 

You're still flying with SAS yaw, try turning it off.

 

I just tried out with SAS Yaw off and in a hover it can lead to some rapid yaw movement without the governors kicking in. Regarding sideslip with SAS Yaw off in forward flight the sideslip does not appear to be happening from where I'm sitting but mostly I am impressed with the Harrier. BTW with all of SAS off it is very difficult to control.

4 7 18 AV8B yaw SAS off.trk

Edited July 4, 2018 by SUBS17

[MAD_MIKE]

You're still flying with SAS yaw, try turning it off.

 

I just tried out with SAS Yaw off and in a hover it can lead to some rapid yaw movement without the governors kicking in. Regarding sideslip with SAS Yaw off in forward flight the sideslip does not appear to be happening from where I'm sitting but mostly I am impressed with the Harrier. BTW with all of SAS off it is very difficult to control.

 

Do you saw my track file at first page? Why I should waste my time to get home, load game and load track? Why don't load video in YouTube?

[sirscorpion]

And just 50sec after...."The problems were overcome".

 

Besides he's talking about the AV-8A, not B that was extensively redesigned.

 

The problem solved was talking about the whole project from prototype to production. a wing will still generate lift as long as it has air momentum, A Or B it does not matter this is fundamental stuff.

[MAD_MIKE]

Holy shit, after updating release version some sidesleep did appear in normal airplanish flight. Slow speed hovering roll still exist, but now it kind of little bit lesser. Now FM better, but still far from ideal.