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Managing Flight Simulation Training Device Obsolescence

Updated: May 18, 2021


Obsolescence has been an issue in our industry for some time, as typically Flight Simulation Training Devices (FSTDs) have a service life of around twenty years which is way beyond the lifespan of consumer products. With the constant pressure on prices and increasing availability of high performance Commercial of the Shelf (COTS) we have seen the Training Device Manufacturers (TDM) utilising more COTS items; this is making the issue more acute. This article looks at the topic with regards to hardware.

Obsolescence Vs Obsolete?

These two words can sometimes be used interchangeably but are subtly, and significantly, different. In essence “obsolescence” is the process of where an item is coming to the end of its useful life whereas “obsolete” is the end state when an item is no longer supportable. For our purposes we will consider obsolescence.

System Vs Component Obsolescence

Wrapped up in the topic of obsolescence are two distinct issues, those of the obsolescence of complete systems and that of sub-components. Increasingly FSTDs utilise systems developed by third parties. These include motion systems, visual Image Generators (IG) and control loading systems. Whilst the responsibility of component obsolescence rests with the TDM the obsolescence on these third party systems, out of necessity, has to be managed by the Original Equipment Manufacturer (OEM). For the operator they have the option of maintaining a relationship directly with the system OEMs or of relying upon their TDM to pass on obsolescence information. For operators with multiple FSTDs, particularly when the FSTDs are from different TDMs, it is wise to maintain links directly with the system OEMs.

Active Vs Passive (or re-active) obsolescence Management

This is another definition that is important to cover prior to considering the topic further.

For active management the Bill of Material (BoM) of the FSTD is analysed and items identified that are probable to be subject to obsolescence. This exercise disregards items such as fabricated or machined parts and concentrates on electrical/electronic components. Once the list is established suppliers/manufacturers are contacted on a regular basis, typically six monthly to check on current and future availability. The information received back from the suppliers/manufacturers is then used to address the obsolescence.

However the TDMs almost exclusively undertake passive obsolescence management, they action end of life notices when they receive them but do not actively poll their sub-suppliers. This might seem surprising to some readers but for the TDMs it is an economic decision; the gain simply would not justify the expenditure. The BoM for a Full Flight Simulator (FFS) can run to over ten thousand-line items, many more when sub-components are considered. To carry-out active obsolescence on that scale would require considerable resources that the TDMs just cannot afford, there are third party contractors who provide these services but, outside of the defence sector, these are similarly unaffordable.

So, what can you expect from your TDM?

The first thing to be clear on is that you cannot reasonably expect your TDM to just “make the problem go-away”; whilst it is tempting to add requirements to this end in your Request for Proposal (RFP) when buying a FSTD they have no magic wand to do so (see previous blog on Writing a Request for Proposal). As noted above they will probably not be able to undertake proactive obsolescence management. But they do have as much of an interest as the operators to find solutions; not only for production but to support the in-service fleet, particularly in these days when most of the TDMs also run their own training centres.

However, there are things that you can reasonably expect from a TDM. For example;

  • Field Service Bulletins (FSB) that:

    • notify obsolescence

    • provide solution options

    • advise Form Fit and Function replacements where available

    • provide last time buy notifications/opportunities

  • Maintain safety stocks to allow operators time to implement changes

  • Pass on obsolescence notices from system OEMs

  • Support industry forums

Strategies for managing obsolescence

Let’s look at two extremes.

Example One: Up front purchase for insurance. For this strategy the operator buys spare parts with the device to ensure that they have sufficient spares for the lifespan of the FSTD. In theory this should work well and certain military projects have attempted to do so. The first thing to note about this strategy is that it will be very expensive, unaffordably expensive. The second thing is that it will fail; none of the TDMs carry out a full Integrated Logistic Support (ILS)/ Logistic Support Analysis (LSA) on their commercial products and cannot afford to do so, the likelihood of selecting the correct parts for up-front purchase is extremely low. The net result of this policy will be a warehouse full of expensive parts covered in dust.

Example two: Wait and see, handle obsolescence cases as they happen. At first this seems like advocating a dereliction of duty and a policy that will fail, however there are some positive aspects; particularly when backed up with an obsolescence budget. It certainly avoids a large up-front investment. However, it does mean that you need to be very fast to react as soon as the first indications of obsolescence is apparent.

Of course the majority of operators will adopt a strategy somewhere between these two extremes, we would recommend the strategy takes into consideration the differing lifespans of the systems on the FSTD; for example planning for a mid-life update of the visual system whilst planning for life-time support for the motion system.

There are other practical steps you can adopt, we would always advise operators to engage in industry events, such as the Flight Simulation Engineering and Maintenance Conference (FSEMC) which provide excellent opportunities to network with other operators of the same FSTDs. It is also important to maintain links with your TDM and closely monitor their FSBs which should provide you with advance warning, recommended updates and include last time buy opportunities. Another practical step is to ensure that in your purchase contract you have clauses that ensure that, should the TDM withdraw support for the items that they have designed, you have the rights to the detailed design data and right to have them made by a third party for your use.


Obsolescence in FSTDs is a fact and it won’t go away; in the twenty plus year life of a FSTD it is inevitable that the operator will encounter issues. Operators need to think through their strategy for both their devices and the third party systems fitted to them. There will be a financial impact and that needs to be budgeted for.

How can Sim Ops Help?

At Sim Ops we have the necessary experience to assist operators set their strategies in order to manage obsolescence. During the procurement phase we can assist in selecting your spare parts holdings and during service we can assist in locating difficult to find, obsolescent, spares. Follow these links to read more about our FSTD Assessment and Appraisal and Technical Support services.

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