Turbo Union RB199 Mk.106

[Jason Dykstra (Wyvern)]

Hi all,

A few friends were looking for at some documents from Operation Granby and found reference to a variant of the RB199 referred to as the Mk.106, however, there does not seem to be any information about this variant in any of the other sources they've looked at. Are there any further sources on it or is it simply an error? I find it odd that it is only referred to in a single source, but it seems it may have only been a Desert Storm modification, if it existed. I have searched on the forums but it doesn't seem that I can come across any references to it.

What are your thoughts?

Jason

(Mods, if there is a more suitable thread, I ask you merge this topic with it, sorry for the inconvenience)

 

[Apophenia]

Not an error. The RB.199 Mk.106 seems to have been short-lived and limited to Tornado F.3s in Operation Granby.

In effect, the RB.199 Mk.106 combined the fan disc from the Tornado ECR's higher-thrust Mk.105 with the F.3's Mk.104 engine. The object was to produce higher-thrust in Op Granby's hot conditions and at all Turbine Blade Temperature switch settings.

 

[overscan (PaulMM)]

Efforts to improve performance initially focused on the operating parameters of the RB-199 Mk 104 engine. Two changes to the Digital Engine Control Unit schedule were provided to permit the engine to be operated with an increase of either 24ºK or 48ºK Turbine Blade Temperature, which raised the available engine thrust by up to three per cent and seven per cent respectively. However, the cost was a reduction of projected engine life to 150 and 80 hours respectively, whereas the normal forecast was 500 hours. The 24ºK increase was made available to crews via a switchable facility in the cockpit, but its use was restricted to combat scenarios only and there is no documentary evidence that it was ever employed. The 48ºK increase was not embodied.

Otherwise, hopes were pinned on the RB-199 Mk 106 engine, a development of the Mk 104; F3s equipped with the Mk 106 began arriving in Dhahran in February 1991. In-theatre assessments of the engine seem to have varied. One officer from 29 Squadron recorded that the Mk 106 ‘had finally produced a reasonably capable ac when compared to the Z-list F3s originally deployed’. On the other hand, the Post Granby Equipment Working Group argued that this improvement had been achieved only by operating aircraft at the very limits of their parameters, with resulting penalties in fuel consumption. Engineering personnel in Dhahran drew attention to the engine’s high oil consumption. To the OC of the F3 Detachment, ‘the advantages of these new engines appeared to be only marginal.’ Nevertheless, in live combat, the very smallest of margins may be decisive.

https://www.raf.mod.uk/what-we-do/our-history/air-historical-branch/post-coldwar-studies/tornado-f3-operations/

 

[bristovl]

Not an error. The RB.199 Mk.106 seems to have been short-lived and limited to Tornado F.3s in Operation Granby.

In effect, the RB.199 Mk.106 combined the fan disc from the Tornado ECR's higher-thrust Mk.105 with the F.3's Mk.104 engine. The object was to produce higher-thrust in Op Granby's hot conditions and at all Turbine Blade Temperature switch settings.

The 106 used the entire 3 stage fan/LPC module from the 105 (whole module, rotors, stators, casings). This was a higher performance LPC design called 62B (see here: http://tornado-data.com/History/engine/engines.htm). The numbering system was an old throwback for research compressors from 60s/70s Bristol - eg. In Andrew Dow's Pegasus book he mentions an upgrade Pegasus version using a 64B fan. I think the B stands for Bristol, but not 100% sure...

I assume the compressor modules must have been loaned from the Germans, since it's hard to imagine RR could have magicked up a bunch of them that quickly.

 

[Jason Dykstra (Wyvern)]

Thanks guys! Sorry for the late reply