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xclusiv8

Harriers and hovering?

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Hii guys

 

I was just wondering why the harriers in SF2E cant takeoff vertically. The only way i can do it is if take away all the external loads and lower the fuel to 25%. Ive seen harriers take of with external droptanks, rockets and sidewinders easily. How come its not possible ingame?

 

Is there somekind of fix for this??

 

Thank you

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The real planes have better engines, highly trained pilots, and water injection, but they are still limited as to what loads they can carry for a vertical take-off. Most of the time they use a short, rolling take-off.

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Our sea harriers in goa used to have one long rollicking roll for take off!

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No.

 

These are early model Harriers. I'll bet the video you saw was of later model Harriers, and/or they were doing STOL takeoffs with very short runs.

 

Don't believe me? Take a closer look at the Harriers you see doing VTOs and see which model it is.

 

The AV-8B/GR7/GR9 versions of the Harrier gained 1900 pounds of weight over the eariler AV-8A/GR1/GR3...but gained 4500 pounds additional thrust...almost 2600 pounds difference.

 

FC

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No.

 

These are early model Harriers. I'll bet the video you saw was of later model Harriers, and/or they were doing STOL takeoffs with very short runs.

 

Don't believe me? Take a closer look at the Harriers you see doing VTOs and see which model it is.

 

The AV-8B/GR7/GR9 versions of the Harrier gained 1900 pounds of weight over the eariler AV-8A/GR1/GR3...but gained 4500 pounds additional thrust...almost 2600 pounds difference.

 

FC

Your post is kinda arrogant. Im no idiot sir.

 

What do you say about this then? http://www.youtube.com/watch?v=tOXke5CvxzU

Its the early model and it clearly has droptanks and some pod underneath it. Not only that but ive seen gr1 and gr3 models with my own eyes taking of with the same configurations.

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Really? Your video proves my point. Show me somewhere in that video where that Harrier is doing a VTO with a significant load.

 

FC

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Really? Your video proves my point. Show me somewhere in that video where that Harrier is doing a VTO with a significant load.

 

FC

 

Well it is landing with that load so its safe to assume it can take off with the same load isnt it?

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Not really, landing will likely be on near emtpy tanks take VTO with empty tanks is pointless. That and Its coming down so isnt really carrying its full mass on landing, for take off there has to be excess thrust mass over aircraft mass to land it only has to have enough thrust to allow for a slow decent.

 

Craig

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Nope, but just for the hell of it, lets run the numbers, shall we?

 

First, lets determine the excess thrust requirement of the Harrier.

 

Listed for the Harrier II is a thrust of 23500 lbs at sea level, but the aircraft is rated for a max VTO weight of 20755 lbs.

 

Which means that percentage-wise, weight cannot exceed 88% of max engine thrust at sea level for a safe VTO.

 

Now, lets look at the thrust ratings for the AV-8A and GR3 - respectively at 19000 lbs and 21500 lbs. We'll be conservative and assume the excess thrust requirement is percentage based and not a straight 2750 pounds.

 

Doing the math, it means the AV-8A has a max VTO weight of 17660 lbs, and the GR3 is 18990 lbs.

 

Okay, now taking the basic weight of the aircraft (fully serviced, but no fuel, pilot, or payload) of 12190 lbs and subtract it out.

 

AV-8A - 5470 lbs / GR3 - 6800 lbs total VTO payload capacity.

 

Next, subtract the max internal fuel capacity - 5060 lbs.

 

AV-8A - 410 lbs / GR3 - 1740 lbs

 

Subtract the pilot (assume with all his gear, he weighs about 150 lbs).

 

AV-8A - 360 lbs / GR3 - 1590 lbs

 

Now, lets put on 2 455 liter fuel tanks, which hold 804 pounds of fuel EACH (total of 1600 pounds).

 

Assuming you don't take the weight of the actual drop tanks, JUST the fuel itself.

 

AV-8A - negative 1240 pounds / GR3 - negative 10 pounds.

 

So now both aircraft, carrying nothing but fuel, have exceeded their safe rated VTO weights.

 

Ever wonder why Harriers normally do STOL takeoffs instead of VTO all the time?

 

FC

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Well it is landing with that load so its safe to assume it can take off with the same load isnt it?

 

 

Not to beat you down on this, but landing vertically with two drop tanks (typically EMPTY) can be very different from a vertical take-off with drop tanks (typically FULL).

 

Like FC said, ya gotta crunch the numbers :cool:

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Your post is kinda arrogant. Im no idiot sir.

 

 

LOL Its not that bad - FCs a jet pilot so tends to know a fair bit about these things.

 

 

I think 331Killerbee worked on the Harriers for years - and from what I remember, one reason they don't take off Vertically with much of a load is also because of the amount of water required according to him.

 

Also warmer climates mean less engine thrust - for example - in the Falklands the temperature may have been cold enough to allow for max engine performance.

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Im sure I also read somewhere (maybe on here) that harriers rarely take off vertically simply because it tends to damage the surface of the runway/taxiway they are taking off from. Don't know whether its correct mind...

 

 

By the way very informative post with the numbers FC good.gif . Ive never taken the time to work that one out.

 

Mike

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Maybe this will also help to visualize the issue (just trying to help).

 

Wiki states the thrust of the Pegasus 10 engine as around 19,000#'s.

Whereas the Harrier GR 1 weighs:

gallery_574_60_20593.jpg

 

The Pegasus 105 (which versions power the GR7 series) develops 21,500#'s of thrust.

gallery_574_60_9374.jpg

 

 

And for the AV-8B's, this is straight from the NATOPS

The F402-RR-406A/F402-RR-406B engine, with water injection providing thrust boost, develops a nominal (static test bed) thrust of 21,550 pounds in optimum ICAO conditions or 20,280 pounds without water injection.

 

The F402-RR-408 series engine, with water injection providing thrust boost, develops a nominal (static test bed) thrust of 23,400 pounds in optimum ICAO conditions or 22,200 pounds without water injection.

gallery_574_60_44656.jpg

 

gallery_574_60_11458.jpg

Edited by DWCAce

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Don't give me too much credit...I can still be wrong about a lot of stuff (I don't know what I don't know)...

 

xclusiv8 - Welcome to CA, but please realize that there folks here that have been doing this sort of thing for a LONG time, either virtually or for real, some of them probably longer then you have been alive.

 

FC

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Don't give me too much credit...I can still be wrong about a lot of stuff (I don't know what I don't know)...

 

xclusiv8 - Welcome to CA, but please realize that there folks here that have been doing this sort of thing for a LONG time, either virtually or for real, some of them probably longer then you have been alive.

 

FC

 

Thank you =)

I did not mean any harm. But yeah one cannot argue against numbers :P

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First of all this has been discused to death. As a person with first hand knowledge of the Harrier. I can tell you this. A "B" Model (Gr5-7) will take off VTO with a Combat Load with Empty Tanks. Durning OPVAL of the AV-8B with VX-5 at NAS Pax River, MD. It was done sucessfully a dozen times. But as Migbuster has stated, The Engine requires so much Water for this type of Operation. Just about every time it's done, The Engine has to be changed. The requirement to change an Engine in a Harrier contails alot. It means that Aircraft is in a "Down" Statis until the Change is made. But is a Capability. USMC Harriers have the ability to operate from "FOB's" that are just alittle larger than the size of a Tennis Court. The main reason One doesn't see Harriers do it. Or do it "Slicked" or with empty Tanks is COST. It cost for Engines to be reworked, Changed and the "Down Time" of the Aircraft factor in. The Rolls Royce Pegasus Engine is an expensive Componet of the Platform. The Engines from the "A-C" Models had to be sent back to the UK to be reworked back in the Old Days.

 

Empty Tanks save Weight. The old "A-C" Models had to have a bolt-on IFR Probe Installed. Later on the "B" Model, The Marines required a Retractable IFR Probe. It's still Removeable, But comes as a part of the Airframe. The old "A" Model IFR Probes where an after thought.

 

 

MCAS Cherry Point, NC has a Hover Pad that is made of Concrete in the Middle of the Base where two Runways intersect. VMAT-203 is the Harrier Trainning Squadron and is based there. The now operate AV-8B II Pluses and TAV-8B two seaters. They conduct Hover (VTO) every day at the base. It's part of the Trainning of every Marine Harrier Pilot to become familiar with this Operation. Also, VMAT-203 is the biggest user of RR Pegasus Engines in the Marine Corps due to this Trainning. Engines are changed every Day at 203. BTW, The TAV-8B has the same Engine as the AV-8B and can Take-Off Vertical. I wounder how much the extra Ejection Seat, Cockpit, Airframe Strech weighs?

 

Engines are frequently changed aboard Ships (LPH-LHA-LHD's) because of high Stress these Engines go through durning STOL and VTOL Operations.

 

 

The advent of the Ski-Ramp by the Brittish have helped eliminate alot of the Stress on Harrier Engines. This is in STO Operations and have been taken up by the Marines since the Falklands in 1982. The Marines deployed their first Ski-Ramp in Combat durning Desert Storm.

 

 

Many in the Avation Community say that Landing a Aircraft on a Carrier by a Naval Aviator is the most Hair-Raising event one could do. Especially at Night. I differ from that Statement. I say, a VTL by a Marine Harrier Pilot at Night aboard a LHA or LHD is it.....

 

It's bad enough that Hovering in normal conditions is Work Overload in the Cockpit. As one Pilot has described it as balancing a Elephant on the end of a Needle. Now, mulitply that by adding more Weight with External Stores and You have a Recipe for alot of Problems. The "B" is "Fly-by-Wire". The old "A's" were not.

 

 

Conclusion:

 

The early "A's" could do it, But the Gun Pods were empty of Ammo, Drop Tanks Empty. No other Ordnance. The only exception would be the Addition of LAU-7's on the Outboard Stations, Empty. No AIM-9's loaded. The Early Pegasus just didn't have enough "Emph!" (Thrust) in it......

 

AV-8B's could do it under Load, But You'd be changing the Engine after the Mission/Sortie is done. Water Injection Cooling is the Key. Durning Hover, The Water does two things, It boost Combustion and also Cools the Engine under high Stress use. One more Factor is that the Water Tank on the "B" is only so big. You need the Water to sustain Vertical Flight. Once the Water is gone, Thrust is reduced, Engine could seize up and Your Aircraft could fall from the Sky. Be Sure to throw Your Wallet out the Cockpit if You don't know where the Ejection Handle is.....

 

 

An AV-8A/C can do it slick. No Ordnance of extra weight what-so-ever......

 

An AV-8B can do it........But is RARE.

 

 

Semper Fi!

 

331KillerBee

 

T/AV-8A/B/C Harrier Ordnanceman

 

VMA-231 1979-80

VMAT-203 1980

VMA-542 1981

VMAT-203 1982-84

VX-5 1985

VMA-331 1985-1992

Edited by 331Killerbee
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Number smumbers, 331KB for da win!!!!!!!!!!!!!!!! :lol:

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Xclusiv, do a search for VTOL on the forum, there have been some large discussions about this. The upshot of the discussions, is that its a balancing act between load and range.

 

Also the game doesn't model the "wet" rating of the engine, only dry thrust. In short set the nozzles 60 or 45 and do running jumps, i found it the most realistic.

 

OR you could cheat a little and edit the engine output in the ini ;)

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Since I'm leaving on a long Trip for a couple of Months Friday, I'd thought I share a Story to all of You about the Harrier Hovering that might interest Yall'.

 

 

Being in VMA-331, We were the first Combat Squadron to stand up with the new AV-8B. One of our first Deployments was to MCB 29 Palms, CA. It was for a CAX (Combined Arms Exercise). CAX 2/86. A CAX has all the Elements of a MAGTF (Marine Air Ground Task Force). It has all the Units from Air, Ground and Supporting Arms involved.

 

One Day, durning the Deployment, The Grunt Units assembled at the Flightline at the tempory built Airfield constructed at the Base for Air Operations. They were there to see a Demostration on the New Harrier and it's Capabilities. The Runway is 2500 Feet in Length.

 

For the Hover Demostration for the Grunts, Two Harriers approched the end of the Runway at an Alitutde of about 250 Feet off the Deck and started their Hover. As both had achived Hover, One Aircraft rotated 180 Degrees in the Hover.

 

Now Both Aircraft proceeded to position themselves 10 Feet Nose to Nose at about 250 Feet off the Deck. Then they proceeded to fly Nose to Nose in a Hover the length of the Runway. One Aircraft in foward Hover, One backward.

 

That wasn't the amazing part. The Amazing Part was the fact that both Pilots did this Hover down the Runway with their Hands on the Canopies.........

 

It's one of those Days in which I wish I had a Camera with Me........

 

 

Semper Fi!

 

331KillerBee

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I wish I could of seen that.

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The Harrier is a real special bird. I lived near Yeovilton for about 9 years, i remember a demo done by two of the new FRS2's in i think 93/94 the day before the airshow, side slipping nose to nose down the runway, then rotating about a point between their noses at the end of the runway, then bowing and transitioning to horizontal flight down the runway.

 

I also remember a GR 3 scorching the Conker trees in our street during a combat exercise dodging US F-15's but thats another story... and don't start me on the A-10's!

 

KB, didn't you mention you were stationed at Heron for a while?

Edited by Hokum

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Hokum,

 

I was TAD to Yeovilton in 1982 with RNS 8, 800, 801 and 809 Squadrons. I helped install SEAM Boxes on the Sidewinder Systems prior to the Falklands War.

 

 

331KillerBee

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I think SF2E got water injection (unlimited) with Oct 2009 update.

Symptoms:

1) Engine exchaust goes from clean to smoky when nozzles go down

2) I can hover GR.3 with 4 rocket pods and full fuel. Can fly it backwards, sideways and ahead although helo take off is a bit tricky.

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