Harrier T-bird vertical fins

[Doug]

Hi all, Now it was always my understanding that all 2-seat T-birds had the enlarged (taller) rear vertical fins. On the front page of the instructions, Kinetic list all the versions that can be constructed from the kit. In the T-4 description in the type list you will notice that the T-4 is listed as a 2-seat version of the GR.3, with radar nose, and forward and rear PWR, one on the vertical fin leading edge and one at the end of the tail cone. Now this is where It get's confusing, well to me anyway, it then states that the T-4 had the standard single seat tail installed, is this true? And secondly did this also include the T-4N/T-8 variants?

[Graham Boak]

The early T.Mk.2s had a slightly smaller taller fin, but this was replaced early on.  My understanding was that the T.Mk.4 was simply a T Mk.2 with the uprated Pegasus of the GR Mk.3.  Yes to the PWR, no to the nose sensor (but was this radar - more likely infra-red?).  It is always possible that the RAF modified these aircraft after I left the company and stopped tracking it closely.

[Doug]

My mistake Graham, I was referring to the laser range finder in the GR.3 

/T4 nose, but for some reason wrote radar, my mistake sorry about that. I was aware that the original T.2 had a shorter tail, quickly upgraded to the taller variant, which is why I was querying the Kinetic statement regarding the use of the single seat GR.3 fin on the T.4.

[Graham Boak]

Well, it wasn't IR either!  I still a waiting to discover that they ended up with the LRT.

[scotthldr]

My understanding is that the T-4/N and T-8 all had an enlarged fin over the GR3, however some T-2’s had the same fin as that found on the TAV-8A which was even taller and had no RWR installed on it, was this fleet wide? Dates would suggest that the tall fin was retrofitted with what became  the standard T-bird fin towards the end of the 70’s.

 

From looking at pics on line it looks like the kit comes with two fins, one small and one large? I think Kinetic have got confused a bit here and meant to say something along the lines of that the smaller of the kit fins is installed on the T-4????

[Doug]

That makes more sense, just thought I would ask in case my books had missed this new fact. I must say I am relieved it was a mistake by Kinetic and not a fact we all missed. 

[NG899]

Ah-ha! The old Harrier "shape equals mark" trap has caught you out again!

 

The mark of a Harrier was determined by the type of Pegasus engine fitted:

GR.1 / T.2 - Mk.101; GR.1A / T.2A - Mk.102; GR.3 / T.4 - Mk.103.

 

It had nothing to do with the shape of the nose, fin or tail cone but was complicated by those changes.

SIngle-Seaters

Early GR.3s had the original nose, fine and tail, but did not have the electrical system vents on the engine covers of the GR.1/1A; the GR.3's different electrical system did not need them. On GR.3s you can see where plates have been fitted over the hole left by the vents removal. Early GR.3s also had mesh covered vents in the bullet-shaped tail fairing and did not have the smaller vent added subsequently ahead of the mesh-covered GTS/APU intake. The GR.3 Phase 4 Modifications added the LRMTS nose, RWR to fin (increased in height by 5-inches) and RWR to the tail fairing.

 

Two-Seaters

T.2 - Had the original nose, short fin and tapered tail sting. (XW174, XW175, XW264-XW272, XW925.)

T.2A - The last two of the first twelve T-birds were built as T.2A with the Mk.102 Pegasus; that engine was retrofitted to the other 10 T.2s. (XW175, XW264-XW272, XW925-XW934.)

T.4 -  Fourteen were new-builds: > XZ145-XZ146, XZ445, ZB600-ZB603, ZD991-ZD993. Three - XZ145-147 - were built as original nose-shaped T.4s with the tall fin and original tail sting. The other new builds were, I believe, fitted with raised GR.3 type standard fins including the RWR fairing, RWR on the tail sting and the LRMTS nose. Many of the T.2s upgraded to T.4 had the original nose, low fin and tail sting shapes. All had the GR.1/3 type airbrake. Many aircraft had the shorter Sea Harrier type airbrake fitted at some date. Photos of the same airframe can show it with both airbrake styles, irrespective of fin heights! Port wing leading edge root light fitted to T.4s XW267, XW269 and XW934 - not sure when. Photos indicate that some aircraft had their lower UHF aerial later offset to starboard, which could indicate that these aircraft had also been fitted with the twin radar altimeter aerials. (XW175, XW265-XW272, XW925-XW934, XZ145-XZ147, XZ445, ZB600-ZB603, ZD990-ZD993.)

 

Thus, you could have three types of plain T.4:
1. T.2/T.2A airframe with Mk.103 engine = pointed nose, tapered tail sting, low GR.1 type fin, long airbrake.
2. T.4 new build airframe with Mk.103 engine = pointed nose, tapered tail sting, tall fin, long airbrake.
3. T.4 new build airframe with Mk.103 engine = LRMTS nose, RWR tail sting GR.3-type fin with RWR, long (later in life or short) airbrake.

My big tip on this... refer to photographs fo the aircraft you wish to build!

 

Then there's the...

T.4A - Original nose and tail sting shapes retained on the T4As but they had the RWR fin with (empty) RWR fairing fitted.  These lighter T-birds were used for flying training only, as they were more responsive than the LRMTS and full RWR fitted airframes. T.4A XZ445 - short airbrake; T.4A ZB604 long airbrake and UHF aerial to port; T.4 ZD990 short airbrake and lower UHF offset to STARBOARD.(XW175, XW265, XW266, XW268, XZ147, XZ445, ZD990.)

T.4N - ZB604-ZB606 - new built as T.4Ns. XW266-XW268, XW927, ZB601, ZB603, ZD992 upgraded from T.4/ T.4A. Original nose, RWR fin and tail sting. Internally T.4Ns had the Pegasus Mk.104 and SHAR FRS.1 avionics, excluding the radar, fitted. T.4N ZB604 fitted with long airbrake c.1993 until...TBC.  Short Sea Harrier type airbrake fitted later. Radar altimeter aerials fitted into the area behind the airbrake and ahead of the ventral fin on the T.4N and T.8; one next to the lower UHF aerial just off centre to port; the second one, longer and behind it ahead of the ventral fin. Tie down rings fitted to front u/c leg and outriggers - as fitted to the SHARs - of all new build T.4Ns.  Tie down rings only fitted to the outrigger legs of the other T.4Ns; from photographic evidence.

T.8 - Upgraded to T.8 were ZB603-ZB605, ZD990-ZD993. Original nose, RWR fin and tail sting. Doppler Panels fitted in a 'bolt-on' fairing under the nose ahead of the front u/c bay. Internally T.8s had the Pegasus Mk.104 and SHAR FA.2 avionics, excluding the radar, fitted. Short Sea Harrier type airbrake. Lower UHF aerial now offset to starboard - all airframes. Port wing leading edge root light fitted to T.8s ZB603, ZB604, ZB605, ZD990, ZD993; for sure. Tie down rings fitted to front u/c leg and outriggers - as fitted to the SHARs - on all T.8s.

 

Harriers are complex beasts!

 

I hope that something in there helps you out; good luck!

 

All the best

 

Nick