Harrier Pilots here please

[MightyGem]

Can anyone tell me why the Harrier has so many vortex generators on its' wings? Is it anything to do with the anhedral?

Ta muchly

[massingbird]

Sorry, all the Harrier pilots have left the Air Force.

[Emerson Cahooners]

Could try the SHAR boys for an an answer, oops my mistake!

[Pontius]

It's the same reason every other aircraft with vortex generators has them. Squiggle up the air over the wing, re-energise the boundary layer and marvel at the results of linear flow air with new life. The anhedral is not the direct reason for it needing so many, although I'm sure some boffin out there will no doubt have the formula for 'number of VTs required' and the di/anhedral of a wing may well come into the procedure. The girt great things on a Harrier's wing (fences) are there to stop span-wise flow and therefore reduce the size of the Ram's Horn vortex.

It's been a few years now, but maybe all that nagging by the QFIs during a couple of thousand hours on the things did sink in after all.

Chocolates aweigh,

Pontius

PS:Squiggle is a very complicated term and can be understood by undertaking a degree in Aeronautics and Astronautics at Southampton University.

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You Ain't Seen Me - Right !!

[Big Green Arrow]

Look at rotorheads forum on V22 crash, John Farley has some gen onmit.

[SATCOS WHIPPING BOY]

:) :) The Harrier has so many vortex generators to give sad folk something to talk/write about. :) :)

Besides don't blame Anne Hedral, it was her sister's fault, Di!

[John Farley]

Mighty Gem

Pontius has given you the good aero stuff on how VGs work. But if you are after any more specific Harrier detail read on, if not cheers!

All that follows applies to the 201sq ft metal wing that currently adorns the SHARs the Indian Navy and Thai Navy jets and was on all RAF aircraft pre the GR5 (which was their first with the completely new plastic ****** 230 sq foot job)

When the RAF OR for the P1127(RAF) surfaced back around 1964/5 time there was a very firm requirement specifying the manoeuvrability of the new aircraft. It was required to pull 6g at 400kts at 10,000ft and at a weight of 16,800lb. Those numbers are for ever etched on my brain because when we came to fly it (XV276 being the first in Aug 66) the thing would only hack 5g. This was still a lot of lift from such a small wing, but not enough. So there was a big tunnel and flight programme to get the extra. This took the form of the standard things, like leading edge notches and fences all aimed at reducing the spanwise flow and so making the tips stall a little later. In conjunction with this various arrays of VGs were used. We only flew the ones that the tunnel said were good bets, but the tunnel looked at must have been some 30 different wing dressing configurations (I remember they ran out of the alphabet)

In the hangar at Dunsfold they would change a whole set of fences/VGs overnight and off you went again. Without wishing to teach granny to suck eggs, getting more lift from a wing is really about delaying the stall (or some related handling deficiency like pitch up or yawing off or wingrock or excessive buffet etc). That’s were the wing dressing becomes important. In the end the dressing got us up to 5.5g. Putting the nozzles down produced more than enough to get to 6g but the Dunsfold pilots rejected a solution that inevitably made you slow down when you used it.

The final fix was a mid or combat flap setting that produced the lift without noticeable drag effects. End of broadcast.

History repeated itself with the Hawk family, especially the T45 for the USN. There the slow carrier approach requirements took it beyond the realm of dressing fixes and into leading edge slats and major flap mods. But all to get more lift plus good handling at the stall.

Anhedral/dihedral wings are about getting the right dihedral effect for the whole aircraft. In other words how much does the aircraft roll for a given rudder input or sideslip. Sweepback often produces much more dihedral effect than one would like, as does a high wing on a tubby jet. So the Harrier (with the metal wing) needed a fair bit of anhedral to reduce the dihedral effect from other bits and get sensible lateral and directional handling. It still had too much in mid transition but the guys had to live (and die) with that until the more advanced aero of the plastic wing which has a very high tolerance to sideslip.

These days with modern flight control systems the tool of choice to get good handling across the board is likely to be flight control software changes which result in pilot actions and the associated aeroplane response combinations that everybody cheers about. A little example of this that impressed me was when the Israeli’s found that kicking off drift during a cross wind landing on their Lavi resulted in a fair bit of roll which the pilot had to be pretty sharp to counteract with aileron they said - OK when the gear is down we change the software so that it commands the bank angle to stay constant when you kick the rudder. That way the nose comes round to the runway heading but the wings stay level, but with the gear up pilots can still use their feet in air combat the way they are used to. Ain’t science wonderful?

Happy New Year.

JFF

[John Farley]

Mighty Gem

How interesting that it won’t let me write ****** in the post above but produces all those stars instead.

If you get stars again in this they stand for the company that Boeing took over! I know it prints that!!!!!

JF

[Pontius]

SATCO's Wipping Boy,

There's those that have and those that are NEVER going to!!

John,

Although not the original question poser, I found your reply very interesting. Until now I never knew the whole reason for leaving the flaps at 'Mid'; obviously it did provide the a bit more lift for almost zero penalty but we were never given the history behind it.

Keep up the aerodynamics lectures, I for one can actually understand it for once in my life.

Cheers,

Pontius


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You Ain't Seen Me - Right !!

[Snapshot]

All this talk of the Harrier, I felt the need was there and also a great excuse to show the aircraft doing its 'stuff'! All those in the 'know', its Harv in the loop.
Kind regards
AB.
http://members.tripod.co.uk/Buccaneer/harv.jpg

[MightyGem]

Many thanks for the info guys, especially JF, whatever those stars mean. I knew what wing fences did and more or less about VGs. It just seemed odd that the Harrier needed so many.

Ta.

[fobotcso]

Just come back to find that smashing photo; thanks! From our vantage point we can see that the VGs are quite small considering the significant effect they had.

May I venture to suggest that there may also be a spin-off benefit for the ailerons at low IAS/high alpha from the re-energised boundary layer? I seem to remember that the "super-critical" wing was great for cruise but the BL would separate early as one would expect.

But VGs aren't only for wings. Remember those on the roof of the Argosy? Put there to improve the Range Performance I believe - again to meet an Air Staff Requirement figure. Seemed an odd fix, but it apparently worked.

[Snapshot]

fobotcso,
thanks for the comment on my photograph of the GR7. Plenty more on my website.
Kind regards
Andrew Brooks
www.AvCollect.com (http://www.AvCollect.com)

[SSSETOWTF]

While there's someone talking Harrier aerodynamics, can anyone explain in any detail what intake momentum drag is?

Whenever I find a couple of lines written down about it, it usually goes along the lines of : below 150kts the fin becomes next to useless and intake momentum drag, acting in front of the c of g causes problems. But I've never found a very satisfactory physical description of what it is. Anyone ?

Single Seat Single Engine The Only Way to Fly

[SATCOS WHIPPING BOY]

Pontius

Don't forget those that NEVER WANTED to!!!

SSSETOWTF
So you like microlights do you ?
ps Were you up near Andselv (69N) recently?

Edited because i carnt flocking spelll!

[This message has been edited by SATCOS WHIPPING BOY (edited 02 January 2001).]

[Helmut Visorcover]

Slightly off thread but seeings how Harrier chaps have no doubt congregated here. Is a certain young chap by the name of Scott A still knocking around, old man was CSM in the Angle irons?? If your on here, mail me, you might remember Dartmoor Oct '94 and two pongos helping out! Remember the drinking OXO cube from a Bic pen and the 4 tonne disco two step routine?

Just remembered the other thing. In the mess at the end of it all. Witt's Station Commander remarked that whilst poor Scott was taking a rest in his pit, the two pongos had destroyed a public school education and a years worth of knife and fork course at Cranwell and reduced him to swearing like a trooper, expectorating and smoking rizlas to the extent of an addiction so he would have to send him back to get him 're-educated'! Who takes 20 Silk Cuts out on a seven day E+E???????

[This message has been edited by Helmut Visorcover (edited 02 January 2001).]

[Pontius]

SSS..you know the rest,

Yaw Intake Momentum Drag, now let's see how much I can remember.

The 'danger period' exists principally between 30-90 knots (accelling or decelling). During this time if the nose is allowed to get out of relative wind then the huge mass-flow of air going into the engine has to be 'bent' from it's incoming direction, to that going straight down the donk. Since Newton was right, there is an equal and opposite reaction and a force acts sideways on the aircraft at the engine intake area. So if the wind was coming from the right side then the nose would yaw left. Now I know that's what lots of aircraft do and it's probably not a bad reason for sticking a fin on the other end, but your mighty Harrier is in a nasty little regime where it's aerodynamic controls are very little use ('cos it's going so slowly) and the little puffers aren't powerful enough either. Result: steely, good looking and great in bed Harrier Ace lets his aircraft get out of wind. It yaws further OUT of wind (and, of course, decides to roll the same way as it's yawing). Steely, good looking...etc Ace tries to counteract with opposite controls but neither is 'strong' enough to roll/yaw him back into wind. Bad, killing sitch. A/C rolls further and further and pilot either (a)ejects or (b)ends up with the boyz drinking on his bar bill.

Early recognition helps (been there, bought the new boxers). As the aircraft goes the opposite way you are asking it to, a thinks bubble arises. No time for that. Simultaneous full power, boot the vane straight (back into relative wind) and a great big push on the stick to 'break' the angle of attack and living results.

Come on John, what did I miss/get wrong?

Toodle Pip,

Pontius

PS:Wipping Boy; yeah right, you ALWAYS wanted to be an air trafficker. Just like all those others really wanted to fly helicopters (but joined the RAF instead of the Navy/Army) and the truckies. No, really, we were desperate to fly a petrol station for the chosen ones. Why don't you admit it; you failed pilot AND nav.

PPS: Okay, so the Truckies may have got it right when it comes to allowances, HOTAC and future airline careers. See, I'm big enough to admit it....know what I mean girls.

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You Ain't Seen Me - Right !!

[SATCOS WHIPPING BOY]

Pontius
A nice description of YIMD and a sound enough reason for sitting at a radar console thank you very much.
Just for the record I said 'Don't forget those that never wanted to'; I did not mean to imply I never wanted to. I joined RN as Observer, got chopped and eventually went RAF ATC. I am now, they might say, 'as happy as Larry!'
ps I passed aptitude for Pilot Nav and ATC, and I know quite a few pilots that failed the ATC aptitude tests (and not deliberately either).

Girls
Remember that Pontius was a Roman governor incapable of making decisions and I believe he prefered little boys anyway (or should that be any way?)! :)

[noprobs]

Risking sounding like a QFI, I offer a little clarification on some Bona topics. The 30-90 kt danger zone is specifically to do with sideslip-induced roll (back again to high wing, sweepback, anhedral) because at lower speed, the reaction controls can stop it, at more the ailerons cope. If IMD or anything else starts sidelip in this area, roll can be uncontrolled. Danger exists as a product of sideslip, AoA and airspeed. Reduce any one to zero to remove danger. IMD makes the beast directionally unstable at low speed; its natural tendency is to turn tail into wind, as students trying their first spot turn soon found. IMD can also work in pitch, but control authority stops it being a problem.

Even more interesting for the spotters: JF doesn't explain the numbering of the GR3 vortex generators. From the top, I think the 13 were numbered 8,7...1, then A,B...E. Apparently, the first fix of 8 was found insufficient, so 5 were added, but had to go on the bottom end. Or was it the other way round? Anyhow, with these, and the fences, and the leading edge extensions, and the tip washout, you ended up with a wing with a symmetrical lift curve, so that you didn't feel a thing as you stalled the wing during most approaches to land. A remarkable piece of kit for its time. JF used to tell interesting stories of his first experience of the American product by comparison.

Now, how do you explain wing rock at high AoA?

[John Farley]

SSSEATOWTF

A physical description of intake momentum drag using only words and no diagrams is not for the fainthearted. But then nor are single seat single engined aeroplanes.

All jet engines have intake momentum drag (IMD) because the air as it enters the intake is decelerated violently and redirected by the compressor into a radial flow. If you are an old centrifugal compressor guy (ah! ..Vampires/Meteors… ;) then this is quite easy to visualise because the rotor on those compressors blocked the whole intake and the air had no option but to move out radially on its journey towards the combustion chambers. With todays axial compressors it seems as if the air could just wiggle largely straight on through. In fact the first stage rotors are designed to grab the incoming air and deliver it at high radial velocity towards the waiting first row stators that act like a brick wall to this largely radial flow. This stator induced reduction in velocity results in a sudden pressure rise (Bernoulli). This now higher pressure but slower air slides off the stators into the path of the next row of rotors which add speed to it again only for the second row stators to “stop” it again. The process is repeated for as many stages as you use, upping the pressure each time.

As to why the IMD should make a Harrier directionally unstable at low speeds (more like 120 and below - not the 150 you mentioned) the IMD drag is aligned with the direction the air is coming towards the aircraft, not the long axis of the fuselage. So if you have a bit of sideslip (for whatever reason) the IMD has a small component ACROSS the long axis and so if the nose goes (say) a tad left it wants to go even more left and at high RPM (which maximises IMD) it beats the fin restoring moment so round you twizzle if you do not keep it straight with your feet using the yaw puffers which are connected to the rudder.

Any help?

JF

[noprobs]

Going back to the original question about the reason for the many VGs: if you step out of the cockpit, back over the intake, aiming to dismount down the wing, on a rainy day, it can be very slippery, so your feet can lose grip. The VGs are very effective in halting your progress to the wingtip and ground, albeit in a very painful way!

Remember:
Lift is a gift, but thrust is a must.

[G Zip]

-Vane, vane!!

-Shut it!


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George Zip was on that mission...

[StopStart]

I know absolutely cock all about Harriers and wings and drag etc etc. Thank you.
Moving swiftly on, Satcos Whipping Boy, from reading your career history, you're not the chap we bought back from a place in the desert a few months ago via some Lobster Thermadore and an aircraft carrier are you?

[Snapshot]

Boo Hiss, doesn't anyone like my photograph of Harv? :)How about an Sea Harr?
If there is a request, I shall post one up, if not i'll just sulk http://www.pprune.org/ubb/NonCGI/frown.gif
SS.

[SATCOS WHIPPING BOY]

StopStart

No.

[The Roach]

Go on Snapshot, show us a pic of the Mighty Sea Jet

You know you want to :) :) :)

[StopStart]

SWB.

Right.

Obviously a lot of chopped RN observers end up as RAF ATCers.

[Snapshot]

Roach, Go on then, if you insist, not to disappoint :).
Here's a couple...
First, 3 899 over the Alps, cheers Kev!
http://members.tripod.co.uk/AvCollect/harr899sqn01.jpg

Then one of Russ E on a recce pass! Trust you liked your pic Russ?
http://members.tripod.co.uk/AvCollect/seaharr_russ.jpg

Any more requests?
SnapShot.

[MightyGem]

It was only a simple ?. So here's another: what does SHAR stand for?

[dubbledeka]

Blimey JF,

And I thought anhedral was so the outriggers touched the ground!!

[SSSETOWTF]

Many thanks to all ref IMD. I can definitely bluff my way through Trappers this year.

[Junglie]

MightyGem is that a bite?

It stands for Sea Harrier, god bless em all!!

[SATCOS WHIPPING BOY]

Stopstart
How right you are!
Can you remember the name of the guy you are talking about and perhaps e-mail me, I may know him! TVM

[Pontius]

Whipping Boy,

Alright mate, I give in. You can't be all that bad if you went for the best Service first.

Snapshot,

Yeah, but where's the ones with the 'proper' nose on it and a static system that worked and a radar that was excellent for telling people you were coming but no good for anything else?

PS:If it's a picture of Russ he's bound to love it!! Junior filth :-)

Oh bring back the days of 'Mate', 'Vane' and flaps on boots.

Pontius

[John Farley]

Dubbledecker

Apologies, you are right of course. It was just that I was not sure that the military forum was really the right place to get into such technicalities. After all that approach could result in being sucked in to why can’t the average Harrier mate manage to keep his balance with just two mainwheels when PPLs manage OK.

JF

[Soup Dragon]

Ah Pontius, after many months of wondering who the author of all those eloquent postings is I think you've finally given the game away! Are you planning on bidding off the 75 this year?

And don't forget HOTASARC (Hands On Throttle And Stick And Radar Controller)

[This message has been edited by Soup Dragon (edited 07 January 2001).]

[Radhaz]

Is Russ Bleatwell still around, and what would he know about recce, anyway?

This thread indeed proves that you viff nozz boys did work harder than the rest of us at school. I still stick to my theory that if you can build 7500ft of tarmac to fly planes off, then you can certainly build decent accommadation for the boys (not that it works in Kuwait).

Interesting stuff all the same.

[Snapshot]

RADHAZ,
I believe he is the SHAR Display Pilot. I know he was last year. Nice shot though would you not agree?
Regards
Snaps

[MightyGem]

I suppose SHAR/Sea Harrier is fairly obvious,
but having asked an RN helo pilot, he thought it was Support something And Reconnaisance. Hence the question.


A question's only simple if you know the answer http://www.pprune.org/ubb/NonCGI/cool.gif

[Snapshot]

Mighty Gem,
did you receive my mail that was sent, I believe to your works address?
Snapshot.

[Pontius]

Dear Mr Soup Dragon,

I'm afraid you've only figured out half the story. The chap that has been writing all this Harrier stuff is not the same person as me. Naturally I know who he is, especially since the cheap bar steward has been using my computer, as his is in the 'shop' being upgraded.

Just to set you a little more straight, without giving too much away. He's an ex-SHAR boy and now flying for a major airline (don't necessarily think of anyone with 75's either). Me? I fly bigger Boeings than that and trained in a completely different way.

I must compliment you on a good try, Mr Dragon, but I'm not daft enough to give too much away.......now where did I put that Airbus manual.

Chocolates.....ah, you know the rest,

Pontius


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You Ain't Seen Me - Right !!

[Soup Dragon]

Intriguing Pontius, very intriguing. I of course assumed that you were the true author of all of your posts, here and in other fora. They have all been very eloquent I must say. It is however, fairly obvious from those posts who your employer is (hence my reference to bidding and the 75) and as the number of ex SHAR wallahs in that company is relatively small I thought I had you sussed.

As to your friend, indulge me just a little longer please. Was he a ballet dancer or a girl?

Yours Aye

Soup Dragon

[Pontius]

Soupy,

My mate is on a trip at the moment (somewhere a long way away, with lots of snow and lovely looking girls that you can't understand unless they say 'Suzuki'), so unfortunately I can't answer your question regarding 'Ballet dancers or girls' - I presume this is some form of Senior Service banter.

As for me, well just to titilate you a little; I was once on the 75/76 (and you managed to get the company right) but now reside on something bigger but still with 2 engines. I won't be bidding off it for quite some time as a conversion to the other seat is fairly imminent.

You're obviously an ex-Navy person, did you perchance fly with my mate on the noisy beast?

Keep the 'Whodunnit' game board out!

Toodle pip,

The Real Pontius

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You Ain't Seen Me - Right !!

[Soup Dragon]

Yes Pontius, I too flew the bona-jet for a while. It was a few years ago now and like Pilate's Pal I have fond memories of the original, before the days of big rockets and fancy TV screens and when flaps on boots were de-rigeur. I also have moved on to bigger and less exciting things but at least no pier-head jumps or sh!tt!ng myself getting back on the boat via ELVA in a hoolie. http://www.pprune.org/ubb/NonCGI/eek.gif

Snapshot,
do you have any punchy pics of the FRS1 you could post so that we can reminisce. I would myself but I'm a bit of a computer pygmy and I would probably end up fragmenting my floppy or something equally as exotic.

Pontius, you're not an ex-crab with about five years to go are you?

P.S. Please pass my regards to our friend whoever he is. (I have an idea but the cast list in that outfit is a bit larger)

Soup Dragon

[This message has been edited by Soup Dragon (edited 11 January 2001).]

[Snapshot]

Mr Dragon,
>>Snapshot,
do you have any punchy pics of the FRS1 you could post so that we can reminisce. I would myself but I'm a bit of a computer pygmy and I would probably end up fragmenting my floppy or something equally as exotic.<<

Afraid not, well not like the other stuff I have photographed in recent years. I was still trying to get the courage to write to Jimmy Saville for a fast jet ride when the FRS1 was doing its thing. If you want to send me any of your own photographs, I would be happy to post them onto the Harrier section of my website for ALL to sigh in wonder!
Kind regards
Andrew Brooks
(Snapshot)
www.AvCollect.com (http://www.AvCollect.com)

[Snapshot]

All this Harrier talk made me remember that I have some photographs that I took on the VJ 50th Anniversary Flypast over London on 19th August 1995! Most of my photographs find their way to the subjects but I never did locate the four individuals of this one. If anyone knows where the following are, please contact me and I can forward some shots to them.
I have uploaded only 3 (and small ones) so not to hog the download times, if anyone wants to see bigger versions, just drop me a line.
Crews were all 3 Squadron Laarbruch
Gp Cpt Loader
F/L Sampson
F/L De La Cour (that was the spelling given by the Auth)
Capt Duntman (USAF)

http://members.tripod.co.uk/Buccaneer/vjx3.jpg

I can remember being so pleased with the 'sunset' shot, thinking at the time as we rolled on down the Thames towards Tower Bridge, how lucky I was to get that so poignant photograph as the awesome words "...at the going down of the sun, we shall remember them" flashed into my mind.
I sent the photographs to RAF News expecting them to be so pleased with this distinctive image, as I was proud to have taken part in the flypast (sorry for the geekability factor of 10.0). They didn't even print it! I think AirClues put it inside the front cover though.
Regards
Andrew Brooks
(Snapshot)
www.AvCollect.com. (http://www.AvCollect.com.)
Apologies for all the 'edits', I could not remember how to get the images up!

[This message has been edited by Snapshot (edited 16 January 2001).]

[This message has been edited by Snapshot (edited 16 January 2001).]

[This message has been edited by Snapshot (edited 16 January 2001).]

[This message has been edited by Snapshot (edited 16 January 2001).]

[Tobbes]

Gentlemen, a quick question.

I'm rewriting an UNCLASSIFIED piece on aircraft of the RAF and I'm confused as to whether the GR7 has a MIL-STD-1760 databus or whether this has to wait for the GR9. If anyone knows this at UNCLASSIFIED, please email me.

Thanks

Tobbes

[take5]

SnapShot

Are you sure that SHAR had Russ E inside it? The Pegasus can't produce enough thrust to carry his large carcass into such a climb without stalling!!

Satcos Whipping Boy

Initials C.K. ???

Stab in the dark

[Snapshot]

Take5
'tut tut', what are u like?! Yes it was him. Photo was for a leaving pressie.
Have a rather pleasent 'head-on' one as well.

All

Come on you lot, little response to my VJ photographs. I have found two but can anyone help me find Cpt Duntman in the US? Also, where's Sammy Sampson these days?
Witt / Cott?
SnapShot
www.AvCollect.com (http://www.AvCollect.com)