Umbrella Production Contract
The umbrella production contract was signed on 30th January 1998 covering the production investment phase to setup the production lines and establish the supplier base. It also covered long lead time activities in anticipation of an actual production contract for the production and delivery of aircraft. The 4 Core nations firmly commited to the acquisition of 620 aircraft, but ordered none under the umbrella production contract. It was instead planned to split the production into three seperate Tranches which would be contracted individually.
Tranches
The Tranches are mere production contracts for the production and delivery of a defined number of aircraft and engines to the contracting nations over a contractually agreed delivery schedule. It's a wide spread misconception that Tranches translate into capabilities. This is not the case! Tranches are only indirectly related to capabilities as all aicraft are ofcourse build to a specific standard. However the capabilities were layed out in the WSPS and not the Tranche contracts!
Batches
The Tranches are divided into Batches and further broken down into Blocks. The purpose of the Batches was to segregate distinctively different build standards by managing them in Batches. This concept effectively applied only for Tranche 1 and was merely superseded by Tranches 2 & 3A as the aircraft build under the latter Tranches were too similar to each other in contrast to earlier plans. As a consequence there were 4 Batches.
Blocks
The Block represents the exacting build standard of an aircraft. It is possible to link capabilities to the baseline configuration of a particular Block, but that was only valid to a specific point in time. Earlier Blocks have always been upgraded to higher standards equivalent to newer Blocks. The Block numbers haven't changed, however, and unlike in other aircraft programmes Blocks in the Eurofighter programme are not really indicative in terms of capabilities, other than at a particular point in time when these aircraft were build.
SRP/PSP/PSC
The above abbreviations are in fact the more common terminology in the Eurofighter programme describing capabilities.
The Service Release Package (SRP) effectively describes the overall capabilities of the aircraft, including clearance, specific system functionalities etc., but allows for some variations.
The Production Software Packages (PSP) are designators describing the overarching software functionality of the aircraft's three major electronic system constructs, namely the Flight Control System (FCS), the Utility Control System (UCS) and the Avionic System (AVS). This leads to the appropriate software packages FPSP, UPSP and APSP respectively with numbers and letters identifying an exacting package, i.e. APSP3/10/00. A PSP could be understand as the package number for a combination of specific software partnumbers. Note that the Eurofighter features dozens of computers with software. Each computer has its software and the revision of the software has a partnumber. This is similar to any other software, it's like FCS World 2.5.X.
The Production System Configuration (PSC) is the most exacting description of actual capability as it defines the allowable combinations of electronic hardware partnumbers with software partnumbers. Integrating dozens of computers into a working system is challenging and it needs to be ensured that everything fits together. Such a fit is described by the PSC covering effectively all AVS, FCS and UCS equipment, plus the gun and propulsion electronics for control and monitoring. The PSCs comprise up to 6 digits, with the first digit originally based on the PSP number, i.e. PSP2 = PSC 2.XX.XX.
The capabilities
How all of the above fits together is now being described.
Tranche 1
The Tranche 1 contract signed on 18th September 1998 covered the production of 148 aircraft and 363 engines for the four core nations, albeit 15 aircraft were eventually diverted to Austria.
Tranche 1 comprised the Batches 1 & 2.
Under Batch 1 the 5 original Instrumented Production Aircraft (IPA) were build in addition to Block 1, 1B, 1C standard aircraft.
Block 1/1B/1C (2003/2004):
These aircraft are commonly refered to as Batch 1 aircraft. They were all twinseats used for initial operational test and evaluation as well as pilot conversion training. They only provided rudimentary air-to-air capabilities. I'll not discuss in detail the rather minor differences between the Block 1 sub-blocks.
Block 1 = SRP1 (Entry Into Service - standard) = PSP1 software = PSC 1.X configuration
FCS: No Autopilot, limited load authorities, advanced features like disorientation recovery and automatical low speed recovery missing.
Cockpit: No DVI (Direct Voice Input) or HMSS (Helmet Mounted Symbology System = HMD)
NAV: LINS, GPS, RADALT, TACAN (GE & IT only), GPWS initial functionality
COMMS: 2 x V/UHF radios and comms audio management unit
DASS: Only DASS computer (DAC) and chaff/flare dispensers
Attack & Ident: Captor M-Scan radar with initial AA functions and limited AG functions.
Weapons: Gun mounted but not cleared, 2 x AIM-9L Sidewinder, 2 x ASRAAM, 4 x AIM-120A/B AMRAAM
Block 2 (2005):
Block 2 aircraft were the first Tranche 1, Batch 2 built aircraft and included the first single seat series production aircraft. Block 2 introduced the SRP2 Initial Operating Capability standard providing enhanced aircombat capabilities.
Block 2 = SRP2 (IOC) = PSP2 software = PSC 2.0
Additions on top of SRP1:
FCS: Initial Autopilot
Cockpit: Initial DVI
NAV: TACAN in MIDS-LVT, functional enhancements, MLS, DME-P
COMMS: MIDS/LINK16 introduction
DASS: ESM/ECM
A&I: Captor-M enhanced software for AA and AG functions + initial sensor fusion
Weapons: 1 x 1000l tank on centreline station, gun clearance for AA firing, 2 x IRIS-T
Block 2B (2006):
Block 2B were initially almost identical to Block 2, but the final configuration represented the definitive IOC standard (SRP3).
Block 2B = SRP3 = PSP2 = PSC 2.1+
Differences to SRP2:
FCS: DRF, ALSR, clearances
Weapons: 4 x SRAAM, 6 x MRAAM, 3 x 1000l tanks
Block 5 (2007/2008):
Block 5 represented the definitive Tranche 1 build standard and the completion of its development also concluded the Main Development Contract. There were in fact to capability standards SRP 4.0 & SRP 4.1, the latter being the MDC closure FOC (Full Operating Capability) standard. I'll limit the description to the eventual SRP 4.1
Block 5 = SRP 4 = PSP3 = PSC 3.1X
Differences on top of SRP3:
FCS: 9 g clearance, enhanced autopilot and clearances
Cockpit: Full DVI
NAV: MMR incl. ILS/MLS, full GPWS, new GPS and additional nav system functionality
DASS: Towed Decoys and LWR fitted
A&I: Radar full AA and AG, PIRATE IRST/FLIR
Wepons: AIM-120C5, digital ASRAAM, 2 x GBU-10, 4 x GBU-16, 6 x UK PW II, modified tanks, FPR/GPS pods, gun AG.
Note that under the Retrofit 2 programme all Block 1 and 2 aircraft, incl. sub-blocks were brought up to an Block 5 equivalent standard. They were not Block 5 afterwards by identifical from a capability point of view.
SRP 4.2 (PSC 3.2 - 2008):
This capability standard was introduced by the RAF to provide an auster AG capability by adding the Litening 3 LDP, 1000lb FF bombs and Enhanced Paveway II dual mode bombs.
SRP 4.3 (PSC 3.3 - 2010):
First 4-national upgrade after MDC closure. SRP 4.3 can be described as the definitive FOC standard as the MDC was closed with a number of concession and limitations. SRP 4.3 finally matches the requirements specified within the WSPS.
Noteable additions:
- Everything from SRP 4.2
- New GPS, radios, enhanced MIDS, radar software, HMSS, MAWS clearance
Upgrades:
T1 aircraft has received a number of upgrades over the years, most notably new radar and DASS software and partially hardware and the so called Drops adding software enhancements to all major sub-systems and clearing the aircraft for selected Tranche 2 / 3A avionics equipment.
Tranche 2
The Tranche 2 contract was signed on 14th December 2004 covering 236 aircraft and 519 engines for the Core nations. 18 A/C were order by Austria, three of them were cancelled and the rest more or less directly diverted to the Core nations as replacement for the 15 T1 aircraft they diverted to Austria. Saudi-Arabia ordered 72 Tranche 2 Typhoons, but technically spoken received 48, with the remaining 24 being Tranche 3 equivalent.
Tranche 2 covered the largest number of Blocks, but they were to similar to warrent multiple batches and there was subseuqntly only a single Batch 3 with Blocks 8, 8B, 9, 10, 11, 15 and the export equivalents (Block 8A for Austria and above Blocks with a C letter, i.e. Block 9C for Saudi Arabia).
Block 8 represented the T2 entry into service standard featuring SRP 5.0 = PSC 3.6, PSP3. SRP 5.0 was capability wise similar to SRP 4.0 for T1 Block 5 A/C, this was owed to the fact that the mission computer suite on T2 A/C was replaced with more capable hardware neccesiating the software to be converted to run on the new processors. The SRP 4.0 related PSP3 revision was used as a stable baseline to achieve this. Other T2 enhancements comprised some structural enhancements, eletrical system changes and many other design optimisations/modifications.
SRP 5.0 (2008/2009) was similar to the above described SRP 4.1 description minus:
- No AG weapons and no gun AG clearance!
Block 9 (2010) aircraft became the first to introduce SRP 5.1 which was the defintive FOC standard for T2 AND T3A aircraft and largely similar to SRP 4.3 for T1 A/C, but lacking the AG capabilities introduced by SRP 4.2 on T1 A/C.
The T2 Blocks evolved from a hardware perspective and there individual software updates, but nothing that really made a difference from an overall capability perspective. These T2 A/C were operationally inferior to T1 SRP 4.3 A/C at that time!
Tranche 3A
Tranche 3 was planned to comprise 236 A/C and 500 engines, but was split into partial Tranches 3A and 3B for financial reasons.
Only Tranche 3A was contracted on 31st July 2009 covering 112 A/C and 241 engines. T3B was eventually cancelled!
Tranche 3A covers only a single Batch 4 and the Block 20 (2014) & 25 (2016) which differ by their computers. T3A included a massive Common Obsolescence Removal Programme (CORP) replacing in two steps most of the aircraft’s mission computers, but also FCS and UCS equipement.
Other than this T3A aircraft only introduced additional provisions fort he AESA radar, CFTs, fuel dump (UK only) and some others. T3A A/C didn’t add any new capabilities per se over and above the T2 A/C, as the contracted standard was SRP 5.1! Only the concidence of the P1E introduction led to the T3A A/C being delivered at the P1E standard!
PxE
The Phased Enhancement programmes have evolved the T2/3A Eurofighter Typhoon beyond the FOC standard achieved with SRP 4.3 for T1 and SRP 5.1 for T2/3A.
P1E represented the first such upgrade and was contracted in March 2007. P1E was split into P1Ea and P1Eb. A P1Eb Further Work standard followed latter on, mainly to provide compatibility of P1Eb with the T3A aircraft’s hardware configuration (CORP computers).
P1Ea = SRP10 = PSP4 = PSC 10 (2013)
P1Eb = SRP12 = PSP4 = PSC12 (2015)
A generic list of changes for P1E overall:
Multirole MMI incl. Improved DVI and HEA AG capabilities
Enhanced MIDS, navigation functions, T2 radar software, IFF MODE 5
Weapons: 6 x EGBU-16/GBU-48 EPW II, 6 x Paveway IV, full Litening 3 LDP integration, IRIS-T digital integration, full AIM-120C5 integration
The majority of T2/3A aircraft have been upgraded to P1E or latter standards by today.
P2E contracted in 2013/2014 was split into two parts P2Ea & P2Eb.
P2Ea = SRP20 = PSP5 = PSC 20 (2017)
P2Eb = SRP22 = PSP5 = PSC 22 (2018)
P2Ea introduces several avionic system enhancements, including a further improved MMI, MIDS improvements, nav system, DASS, radar software, sensor fusion.
New weapon: Storm Shadow
P2Eb is mainly centred around the introduction of Meteor.
P3Ea was a UK only contract from 2014 building on the outcome of the 4-national P2Eb programme. It primarily adds Brimstone 2 as a weapon and improved integration of existing weapons.
P3Ea = SRP30 = PSP6 = PSC 30 (2018)
Note that the SRP designations are no longer used these days. There have been several national modification programmes ongoing in various nations incl. Enhancements on top of the described standards which I will not further detail here.
P3Eb is the standard for Kuwait incl. The Radar 1+ AESA radar, Sniper LDP, VOR navigation and several other enhancements incl. Ballistic bombs (Mk80 series) and some GBUs. There will be a knock off of P3Eb for the Core nations still with the M-Scan radar. The retrofit of the AESA to German aircraft will build on the P3Eb standard first. Deliveries to Kuwait are scheduled to start this year (2020).
Hope the above sheds some light on the subject and increases your understanding of the Eurofighter Typhoon aircraft and its capabilities. The majority of the changes are software driven with hardware upgrades here and there. The computer suite has seen some repeated refreshes/replacements over the years.