SRIM'S

Health and Safety was very much an afterthought back in those days. With that follows airworthiness, I guess! I can remember de-greasing motor and generator bearings over a trik bath, in the mid 1970’s, often feeling quite dizzy at times. I can still hear the Chief saying “stand outside and take a few large breaths son and then get back to it”.

Interested to hear EWAD still existed in 2007. I could have sworn it was contractorised whilst at Wyton in 1993 or so. However, its life past, the OSD of the Nimrod R1, in Jul 2011 is non-existent.

Today, config change is by SM or DA mod. The MAA very much encourages the latter. But is not in a position to mandate. Both sides (MOD and the platform DA) have equal responsibility for DA mods and sign up to that fact.

Engineering decision making re different platforms is carried out within the relevant platform Project Team (largely based at MOD Abbey Wood, Bristol). The DA’s have oversight of all the decisions / activities by regular communication and meetings. The actual decision-making engineers AKA Engineering Authority (EA) are individually licenced by the MAA. They must have a good knowledge of their systems, hold an annotation of IEng or CEng. IEng and CEng annotation is a form of licence issued by the Eng Council (UK) – they are seen as “leaders” in engineering experience, knowledge and ability. Additionally, they must also have a very good understanding of the MAA regulations. These individuals are typically RAF Flt Lt / Sqn Ldr or Civil Service equivalent.

SM’s, would be written by EA staff and installed by either industry (working on behalf of the DA) or the RAF itself. The SM process of clearance does not allow industry / DA to make comment or sign up to it. However, out of courtesy a copy of the SM leaflet would be handed to the DA if they have not already seen it.

DA mod’s, on the other hand are drafted by the DA and cleared by a top-level committee called the Mods Committee (MC). The MC is chaired by a MAA licenced senior engineer (typically RAF Group Captain) or Civil Service equivalent. Issues are identified and mitigated before both sides sign up to the change. This is BEFORE any metal is cut. Issues identified during TI or PI are then put back throu’ MC following mitigation the MC documentation is resigned before production is ramped up.

The biggest mod programme I ever had any dealings with was Project JULIUS – the Chinook HC4 programme. This major change was the largest ever seen on the World-wide Chinook Force. The programme ran very smoothly indeed. In the early days a few minor issues occurred. But all were solved, to the satisfaction of both sides, within 24 hours of being notified.

Another example of what would be seen, today, as bad practice – at the time of Project JULIUS (2010) there were 20 different Special Trial Fit’s (STF’s) installed across the fleet. They all disappeared as part of JULIUS but some had been flying around since the mid 1980’s. When does trial become permanent? I had previously forgotten to mention STF’s.

12jaguar – you might like to know the Chinook RWR SRIM was later “cleared” to become SEM 238 and then DA mod 263. All before my time on the Wokka. But a good example of making progress towards best practice, I guess.

Hi all

Interesting discussion. I was on EWAU/EWAD a a Cpl Rigger Wyton from 89 to 95 when I left the mob. EWAD moved to Waddington in late 94 with 51Sqn following on shortly after. I was holding for a time at Wyton apart from a short spell detetch back to EWAD to assist with a SRIM fitting RWR and PWR on a Chinook. Thence back to Wyton for a short time assisting with a structural tear down in CSF on a Canberra PR7, finally leaving in July 95 (blimey 28 years ago!)

SRIMs and TRIMs even to me as a lowly JNCO seemed a bit of a gash way to get things done on aircraft (even worse than SEM/SMs)

EWAD continued for some time at Waddington, and as far as I can recall as late as 2007/2008 when I was working as a Tech Author at Marshalls and occasionally had to converse with the Sqn 

John

hypersonic. I agree with all you say in your posts. SNAFU. 

One of the Jaguar mods required the gun exhausts to be extended rear wards. BAC proved a set of jigs that allowed the precise amount of metal to be removed from the airframe. Unfortunately we lacked the correct cutting tools and follow-up rollers to make use of the jigs. No amount of ‘badgering’ to those upon high to get their fingers out and contact BAC for the required tools ever resolved the situation. 

The outcome was that all the marking up cutting of airframe and new parts took weeks longer than needed. And with many of the airframe fitter new and just out of training the quality of the finished job wasn’t always as good as it could be. If viewers ever encounter any of the early Jags, perhaps up to about XX766, they may see what I mean.

Those were the days when H&S hardly seemed to exist in parts of the RAF. Disposable gloves for PRC application – good luck with that; how to remove the PRC from the hand… MEK; open trik baths, omg! I remember we  once did some prep work for the electricians that required the large forward fuel tank of the PR 7 to be ‘dropped’. The valve above the tank was motored closed and confirmed by the dolls-eye indication. We had the the required cradle in place, and the tank was slowly lowered away from the aircraft. When low enough then access could be made to separate the large rubber hose from the fuel tank and so swing the fuel tank out of the way. In went my Sargent ‘Larry’ Lamb to do the deed. Next moment the entire fuel content of the aircraft started to exit the (apparently) faulty fuel valve! Total panic ensued. Electric power was cut via the emergency lever atop the Dalek, hangar power cut, hangar doors opened, aircraft dropped off jacks, tow-bars attached, tugs pulling aircraft out of the shed, fire engines – didn’t know we had so many! arrived. And all the while Larry (bravely?) remained under the shower of fuel that now covered the hangar floor trying desperately to reattach the fuel  hose to the valve. He was obviously soaked to the skin with fuel, so we needed get him into the shower ASAP. Only, we there was no shower in the hangar. There was of course the post event enquiry that tried its best to attach blame for the incident, but I don’t recall the lack of a shower in the hangar getting a mention.

Trial Fit (now-a-days called Trial Installation / TI) and Proof Fit (now-a-days called Proof Installation / PI) are standard ways of carrying out mods. TI is all about does everything fit where we want it to / IAW the drawings. PI is a test of how long it takes to fit and how many personnel are required along with skill sets and relevant ergonomics.

What you are explaining, Re SRIM 3799, is systematic of a failed process / system. I gave some examples earlier. BAC (the DA) not involved and looking on in dismay. You are trying your best but the shopfloor is not the place to rectify such poor decision making. Issues and possible issues should be managed at the Assessment Stage – Is it possible? What are the risks? What is the Mitigation Action for the risks? How, do we fill the empty rivet holes? Etc, Etc, Etc. These should be managed and developed by the “Seniors” in the office BEFORE any sort of production is attempted. Once you go into production as early as the TI identified issues should be small and as such easily mitigated.

I mean who came up with the idea of sawn-off rivets and araldite – and who signed that idea off? Lets be honest as the wings flexed in flight the rivets would be popping probably followed by panels falling to the ground. No amount of Bob-the-Builder hats would have saved those below.

Further, the use of the DA in config change introduces an extra set of eyes and therefore reduces the risk of issues occurring. Both sides have a responsibility when it comes to signing actions off.

But sometimes it can become frustrating even in more recent times…..

During my time on Chinook, as a Civil Servant, my Boss an RAF Group Captain had been trying to convince Boeing, our DA, that we should be allowed to use Rain-X on our window screens. The product is widely available and used on car window screens up and down the land. The UK Chinook Fleet is unique in that all three window screens have wiper blades. The rest of the World utilises two wiper blades. Our system is operated by two motors with one powering two blades and always under strain. The idea was Rain-X would help to lubricate the screen. Boeing had claimed all along that the screens would not be able to dissipate heat and therefore crack if Rain-X was applied.

We discovered that the Dutch armed forces are cleared, by Boeing, to use a similar product on their CH-47 Fleet. As a result we tasked Boeing to carry out a series of trials. They decided to use a brand-new HC6 which was on pre-delivery flight trials in California. They parked the Chinook nose into the sun and powered up the screen demister, the ambient temperature was more than 35 C. Twenty or so minutes later the screen cracked. Point proven said Boeing. Until we pointed out that we do not use the screen demister in outside temperatures of 35 C. The screen itself would have seen something in excess of 50 C during that short period.

It is all about understanding the issue and managing it correctly as I said above. SRIMS, SEM’s and in most respects, SM’s didn’t identify the risks. An unidentified risk can’t possibly be managed.

My records show that many of the ex TFF Lightnings were SFS during 1974 presumably as part of the draw down programme of 60 MU. F1A XM173, which may well have come from the storage hangar at 60 MU, arrived at RAF Binbrook during 1974 and was used as an “Airfield Decoy”. I got my aircraft tow licence using that aircraft. It is now proudly displayed in the staff dining room of Dyson’s HQ in Wiltshire. Hanging from the roof!

I was at RAF Leconfield, with the Bolt Holed Lightning Force out of RAF Binbrook in 1976, I seem to remember the last few Jaguars still there but 60 MU had closedown. The Airman’s Mess was very good! Considering the site was technically on care and maintenance by then. The Lighting Force was undergoing a paint programme and as a result the Painters set up a temporary spray bay facility in one of the hangars. A recently resprayed Lighting was seen taking off one day and left its coat of paint halfway down the runway. Much to the annoyance of the following Hastings T5 which was sitting patiently awaiting its turn on the runway.

However, I returned in the early 1990’s as an RAF SNCO to complete a specialist driving course at the Army managed Joint Service Driver Training School (can’t remember the exact title). I was learning how to drive and maintain the tracked BV-206 – often referred to as the Snow Cat. Whilst driving throu’ Beverley one morning I shed a “wheel” which rolled down the road and finished up among the pick and mix in Woolworths. “Catering” was somewhat different by then with meals eaten out of mess tins in the dining room. You were then responsible for washing your own tins and cutlery. Glad I joined the RAF and not the Army!

Green Satin, for those who don’t know was a navigation system originally developed for the V-bomber Force in particular the Vulcan. It was also known as ARI 5851 (Airborne Radio Installation). The staff at Leconfield were right to be concerned about design / structure changes on the Canberra PR9 when compared with the PR7. The PR7 was developed from the B6 AKA 2nd generation Canberra. However, the PR9 was developed from the B(I)8 AKA 3rd generation. Certainly, in the case of the PR9 the structure was considerably different from the PR7 to allow for “high level” operations amongst other things. I never worked with the B(I)8 but its structure was probably similar to the PR9. During my time at RAF Wyton, on the Canberra Force, there was still a handful of PR7’s left – operated by 100 Sqn. As well as a small Sqn of PR9’s (39 Sqn / 1 PRU) at different times.

hypersonic. Thank you for adding some depth to the SRIM story. 

As you say, the Leconfield SRIM Squadron was part of 60 MU, however, other than being on the same airbase we had little day-to-day contact with the work going on in the other hangars. Personally, I was posted into the SRIM Squadron from the Lightning major servicing team. I was posted in because I had some specialisation with airframe repairs. After SRIM I then moved briefly onto the Chipmunk refurbishing in hangar 3; then briefly to the Phantom modifications (titanium rivet drilling – yuk!), then some fuel tank sealing back on the Lightning unit; finally to a year doing the early Jaguar mod programme. 60 MU then closed in 1976 and it was off to Abingdon. All of my employment at 60 MU was predominantly airframe repair and modification work. 

RAF Leconfield was a very happy place with a great airman’s mess that was second to none. Millions of pounds had been spent upgrading the hangar facilities, but the savage 1975 Defence cuts put paid to the RAF’s presence there. A great shame it closed!

The SRIM unit (we always knew it as ‘Special Radio Installation and Modification Squadron’) was based in 4 hangar. We had the the northern-half of the hangar, 202 squadron (Whirlwinds) had most of the eastern half for their helicopters, and they also did the refurbishment of other units Whirlwinds’ (lots of magnesium alloy skin replacement at each input). Tucked away in a small area of the hangar was a storage area for the Avon engines destined for the refurbished Lightning – all cosy in their rubber storage bags. A few rooms comprised the ‘build’ unit for making up SRIM metal components. The lower and upper level offices at the airfield side of the hangar was taken up with the unit offices, crew room, design, technical writing, and drawing offices. Almost all the design and drawing team was comprised of civilians. 

[fyi, 5 hangar was full of Lightning F1’s retired from the TTFs, as well as a few F2s. The hangar also stored the Derwent powered runway deicing equipment]

Almost all of the metal work parts for the SRIM mods was made by Station Workshops staff – and they really good at what they did! In the SRIM unit we built up items such as TRU mounts, and installed all manner of items on to the recipient aircraft and vehicles. 

We generally did a trial-fit on one aircraft, followed by a proof-fit on a second aircraft. 

in my short time in 4 hangar we did trial and proof-fit equipment to the Canberra PR 7, Whirlwind, Wessex, the whole Shackleton AEW 2 fleet (MTI gizmos, and dual UHF boxes), Puma, Beaver, Hunter, Argosy, and Land Rover vehicles. 

The most extensive programme was SRIM 3799 for the Canberra PR 7. Major changes and new flying/engine/ navigation panels as well as more TRUs to power ‘stuff’, and several new aerials too. Most significant was the underwing addition of Green Satin panels. Major de-riveting and new external skin strengthening. On the trial fit we had to fill the old countersunk rivet head holes using the heads of new rivets that had cut off using a special tool, and then araldited into position to blank the old countersink holes. About 3,000 holes to fill. All went well until the rivet skimming/shaving tool was brought into level things up; almost all the ‘infills’ fell out – two weeks of work wasted! The solution used to fill the old countersunk holes was a filler paste; much quicker and easier. But the mod was of great concern to BAC. Early Canberra aircraft with underwing (Blue Silk?) fits to early suffered a number of structural failures. It seemed every week we would be asked to add more wing strengthening. 

Lots of worry from the design team when they heard that 3799 was destined for the Shorts build PR 9s. Apparently Shorts built Canberra aircraft would often differ from the standard EE built aircraft. Thankfully, that became the problem of the Canberra major servicing team at St Athan.

Many of our senior NCOs had served in WW 2. They were ‘chilled’ awaited retirement by played a lot of bridge, telling war stories, and taking advantage of Wednesday market day in Beverley. Happy times!