av8b n/a and harrier gr7 differences

[Dave317]

I know there are loads of people on here who would love a British harrier over the av8b. I also know it may be coming in the future but what are the differences between the 2?

[Tirak]

I know there are loads of people on here who would love a British harrier over the av8b. I also know it may be coming in the future but what are the differences between the 2?

 

Kind of late to the party mate. A few months back RAZBAM put together a poll asking which Harrier the community would prefer, the AV-8B(NA)\Plus or the GR.7/9. The GR harriers won by a respectable amount so that is what was decided to be done. However shortly after RAZBAM ran into trouble with the module. Classified material meant they couldn't have access to too many systems, they specifically mentioned the Targeting Pod was a point of contention, though hardly the only one. On the reverse side of that, they found that they had much more detailed information available to them to do an AV-8B Harrier, and so after apologizing to the community they switched over, thus putting ourselves in this position today.

 

They have not ruled out a GR.7/9 Harrier, however barring the sudden declassification of a number of systems by the MoD, I wouldn't hold my breath for it.

[Automan]

The engine have a different designation but it's the same.(except for gr7A with uprated engine)

Externally you can see 2 small budges under the nose and on the rear: this contains the Marconi Zeus ECM antenna

FRONT

REAR

 

Different profile for leading edge of the wing, reinforced for sustaining severe bird strike, and one pylon more under each wing.

 

Cockpit use U.K. avionics, Marconi moving map, wide angle HUD and an improve MBB MK12 typ 2 ejection seat.

Obviously armament have some differences

[Buzzles]

Also, no guns on the G7/9 :(

[Automan]

Yes, no cannon: initially was planned the ADEN 25 pod (same ammonition of the Equalizer) but later was cancelled.

Anyway, the Gr.7 usually have the empty gunpods, not much different from AV-8b variant gunpods

[comie1]

empty gunpods

 

Why did they do that?

[Automan]

They were retained to prevent exhaust gas recirculation in vertical landings (which causes loss of control). When the pods aren’t fitted, you’ll see strakes there instead to do this job.

[comie1]

you’ll see strakes there instead to do this job.

 

That's what I was wondering... Why use empty gunpods (must be heavier) over strakes?

[Vampyre]

Why did they do that?

 

Evidently, the pods were paid for but the guns never materialized... might as well use them for something, right?

[Automan]

The empty gunpods were replaced with the strakes when the program to fit in the Aden 25 was cancelled

[comie1]

Ah now I see thanks guys!

[joey45]

All the subsystems still stayed in place for the boom boom sticks.. So in theory the GR-7/9 can use the same pods as the AV8 version.

[Zeus67]

Why did they do that?

 

They were retained to prevent exhaust gas recirculation in vertical landings (which causes loss of control). When the pods aren’t fitted, you’ll see strakes there instead to do this job.

 

Actually the main problem is that the aircraft cannot fly without them.

 

The gunpods or the strakes are required, not to prevent smoke ingestion in the engine, but to maintain the aircraft's aerdynamic profile. Without either the gunpods or the strakes the aircraft will become uncontrollable.

 

We are going to model damage to strakes/gunpods so prepare yourselves to fly one of these:

 

[comie1]

I just thought it was strange that they used empty gunpods over Strakes but the lads explained it well :thumbup:

Zeus I think at this point you'd be quicker to list what you're not doing lol :book:

So Looking Forward to this..

[Automan]

Actually the main problem is that the aircraft cannot fly without them.

 

The gunpods or the strakes are required, not to prevent smoke ingestion in the engine, but to maintain the aircraft's aerdynamic profile. Without either the gunpods or the strakes the aircraft will become uncontrollable.

Hi Zeus, just to clarify, the strakes under the fuselage have a proper name: are the LIDs=Lift Improvement Devices.

The LIDs were studied by NASA during the test on wind tunnel of a STOVL plane (the model 279-3C built by MDD) for Hot Gas Ingestion (HGI) Control Technology.

Read here about STOVL Hot Gas Ingestion Control Technology

Just some extract of this doc

here at page 3

[i]The LIDs perform two main functions, 1) vertical
lift improvement, and 2) HGI reduction, as demonstrated
on the currently operational AV-8B Harrier VSTOL
aircraft. These benefits result from the LIDs
capturing the fountain upwash and redirecting it away
from the aircraft. Improved lift performance is
obtained from the upward force which is created by
reversing the fountain upwash momentum. Hot gas
ingestion is reduced because the LIDs prevent the
fountain upwash from flowing along the undersurface to
the inlet.
[/i]

 

and here at page 8

[i]LIDs were found to be very effective in reducing
inlet temperature distortion. They minimize near field
HGI by inhibiting the forward movement of the upwash
along the fuselage. When LIDs were added, the
temperature distortion at the engine face was
significantly reduced, (right side of Figure 19), due
to elimination of near field HGI. This causes the far
field HGI to dominate and since it is better mixed with
the ambient air, engine face temperature distortion is
essentially eliminated.[/i]

So what you wrote about the strakes is partially correct, yes the strakes/gunpods may have an aerodynamic involvment, but the plane will become uncontrollable basically cause of hot gas ingestion in the engine that lowered the thrust rising the inlet temperature;)

[1stBEAST]

if RAZBAM do the GR variants of the Harrier sometime(if possible) would be nice to have the Gunpods included^^ even if the nevery materialized for the Real RAF they would be nice to have :-)

 

but for now, i wait eagerly to get my hands on the AV-8B N/A :-)

[whiteladder]

So what you wrote about the strakes is partially correct, yes the strakes/gunpods may have an aerodynamic involvment, but the plane will become uncontrollable basically cause of hot gas ingestion in the engine that lowered the thrust rising the inlet temperature

I agree the main reason for the strakes/pod is Lift improvement/HGI, without them in place the front air dam flap has no effect.

The GR7/9 routinely flew with an asymmetric pod configuration, not sure this would be possible if the were play such an important role in aerodynamic stability. The previous generation harriers also flew without any pod routinely.

 

 

 

[Prowler111]

Externally you can see 2 small budges under the nose and on the rear: this contains the Marconi Zeus ECM antenna

And that´s exactly where all the issues start, in developing this aircraft..

[Harry.R]

We used to called them tusks back in the day..:music_whistling:

[robmlufc]

Hi Zeus, just to clarify, the strakes under the fuselage have a proper name: are the LIDs=Lift Improvement Devices.

The LIDs were studied by NASA during the test on wind tunnel of a STOVL plane (the model 279-3C built by MDD) for Hot Gas Ingestion (HGI) Control Technology.

Read here about STOVL Hot Gas Ingestion Control Technology

Just some extract of this doc

here at page 3

 

So what you wrote about the strakes is partially correct, yes the strakes/gunpods may have an aerodynamic involvment, but the plane will become uncontrollable basically cause of hot gas ingestion in the engine that lowered the thrust rising the inlet temperature;)

 

On the Harrier, the LIDS fence and strakes are different components. The strakes are interchangeable with the gun pods. We used to sometimes fit gunpods because there wasn't enough strakes for the entire fleet.

 

The LIDS fence sits just behind the nose leg and opens in certain configurations. U/C down and nozzles and/or flaps in a certain position. I'll have to check.

 

Tusks were great for hanging your hivis/coat/bump cap/ear defenders on!

 

The AV8B also flare launchers on the top of the rear fuselage, between the wing and the fin. As opposed to the GR7/9 which has a flare launcher underneath, just next to the airbrake.

 

 

Edited August 16, 2017 by robmlufc

[Automan]

I have an official cutaway of the harrier, what you call LIDS fence is the Lift Augmentation retractable cross-dam.

LIDs are the assembly of the strakes and the retractable cross-dam

[robmlufc]

I have an official cutaway of the harrier, what you call LIDS fence is the Lift Augmentation retractable cross-dam.

LIDs are the assembly of the strakes and the retractable cross-dam

 

I've never heard or seen it called that! I can guess you can call it whatever though. The LIDS switch in the cockpit retracts the LIDS fence.

[Automan]

I’m not saying you’re wrong, the switch will retract the mobile part of the LIDs, the strakes( or gunpods) are fixed. Sometimes in operational use some terms become standards and differs from what the designers and engineers have defined;)

[robmlufc]

Maybe so! It's definitely a LIDS fence though, the engineers said so ;)

[Cool Breeze]

av8b n/a and harrier gr7 differences

 

While the strakes may work with the LIDS to prevent HGI and improve the lift generated while in or near the hover. The strakes or the gun-pods played a large roll improving the lateral stability of the Harrier. Losing one or having them damaged will be interesting. Thanks for the attention to detail here Zeus!