I've been following the development of Jet Thunder for a couple of years now. I'm pleased to see the effort being made with the Harrier Nav / attack system, it looks like a fair number of HUD modes etc are being modeled.
I’m particularly interested in the navigation and attack capabilities of the early Harriers, however research on the net has only led to a partial understanding of this subject. It’s the same story with published works.
I’m aware that some members of the dev group (Dante-JT?) have access to Sea Harrier manuals and I wonder if you or anyone else could fill some of the gaps in my knowledge? Hopefully none of the answers will breach any security concerns etc….

If we start with the Sea Harrier:
The SHAR used the Ferranti 1010? navigation system and Smiths HUDWAC – not a pure inertial system due to ship board use, my questions are;
1) Did the SHAR have CCIP / CCIL modes for bombing? The HUDWAC software provided weapon-aiming cues for Air to Air, but what was available Air to Ground? Both Ward’s and Morgan’s books make reference to depressed sightline attacks (DSL) with pre calculated depression angles for manual bombing. No mention is made of CCIP, which leads you to think it wasn’t available. The question is why? The aircraft had a pretty accurate nav system with Doppler, which could provide data like wind vectors etc needed for CCIP.
2) If it had CCIP, did the system have a Planned Attack / Laydown mode? – Designating a waypoint as the target then carrying out a computer-assisted attack. Ward mentions in his book that 801 sqn SHARs performed laydown attacks at high altitude using a manual pre calculated release distance from the current waypoint – very much an ad hoc technique. So did the SHAR not have a computed planned attack mode?
3) The SHAR defiantly had a LOFT / TOSS capability – mention is made of this in numerous sources. This would have needed a radar lock on, of a surface ship for example, with the HUDWAC providing the required pull up and release cues. This capability was no doubt originally intended for its nuclear strike role – lobbing WE177s at ships. Can anyone confirm this and provide more detail? What did the pull up symbology look like? – Was it similar to the Tornado’s?
4) Other sources I have mention 3 Air to Surface bombing (ASB) modes; ASB1, ASB2 and ASB3;
ASB1 – basic manual bombing with depressed sightline – fine understood
ASB2 – computer assisted bombing, ‘which accounts for height, speed, altitude and wind speed’ – Is this referring to CCIP? This source comes from the mid nineties- was CCIP an upgrade that took place after 1982 maybe– a possible reason for no mention in Wards book????
ASB3 – Computer assisted bombing with radar ranging – using the Blue Fox to radar range the target to provide a more accurate calculated release point. Good, I understand the concept – can anyone confirm and provide details of HUD symbology etc?
I don't imagine there were buttons for ASB1, ASB2 etc in the cockpit - these merely being configurations of the system that required setting up. There were no doubt other reversion modes as well.

Now for the Harrier GR3:
The GR3 used the Ferranti FE 541 inertial attack system – an early (analog?) INS system, which was ahead of its time in 1969 but often said to be too complicated for the aircraft it was put into…. I know CCIP / Planned attack etc is irrelevant for a Falklands sim since it wasn’t available due to problems aligning the FE 541 on board ship.

However the GR3 had a sophisticated system for both planned and target of opportunity attacks. Some of the HUD symbology can be seen here:
http://www.flightglobal.com/pdfarchive/view/1971/1971%20-%200108.html

Clearly the GR3 was capable of computer assisted planned attacks on known locations, but again, was there a CCIP mode? I ask because there seems to be no ‘release cue’ present on the bomb fall line. This was a short little line that would rise up to meet the ‘target bar’ (the one aligned over the target), when the two lines met the bombs would release automatically. The little ‘release cue’ represented I think a CCIP solution – at least it does on the Jaguar for which I have a NAV / ATTACK Brochure produced by British Aerospace. Now the HUD symbology for both the Harrier and Jaguar look very similar (both made by Smiths), so without the ‘release cue’ I ask the question did the Gr3 have CCIP for bombs? Again there seems to be no specific mention of it in my research.
(Since you’ve modeled the GR3 cockpit – can you tell me the labels on the weapons panel to the left of the pylon select switches – this may provide insight)

Does anyone own or has seen this manual:
http://www.flight-manuals-on-cd.com/AV8.html - CD 2 ‘Manufacturers Pilot's Notes for the Harrier GR.Mk.1, HSA Publication No 25 dated 2-12-71 with approx 196 pages.’
Does it contain any further information on the navigation / weapons system?

Sorry, it’s been a longer post then intended but for some reason I’m intrigued by this stuff. Maybe someone can help fill in the gaps……

Adam.

Last edited by Adam106; 08/21/11 02:56 PM.