This article first appeared in the November 2017 edition of our free newsletter, to subscribe click here

We have had the good fortune to work on many programs when they are in the early stages of development. This involves working on the prototype design and build. I have touched on this subject in previous articles but it deserves an article all of its own.

Put simply, the sole function of a prototype is risk reduction, or conversely, confidence building.

Both investors and engineers fail to understand the function of a prototype and how that plays out in the implementation and testing of the prototype and how that integrates into the larger development program.

The prototype exists to reduce risk in a number of ways

  • Evaluate a new material
  • Evaluate a new process (manufacturing, inspection, maintenance, etc)
  • Evaluate a new feature or design characteristic

Many types of evaluations are possible and as many as are useful should be done: performance, strength, aesthetic, customer satisfaction, maintainability, inspectability, etc

The results of these evaluations can drive improvements, to the archetype or production design.

The first prototyping mistake:

Fly, Fly Fly!

Many programs feel compelled, often by the investors, to have a visible measure of the value of their investment. This comes in the form of the desire to fly the prototype for an extended period during which it represents little real development value. Hell. You are an aircraft company and you have an aircraft. Whaddaya gonna do?

A prototype only has to function as far as the risk reduction exercise requires and should only be operated until the development risks are understood. Prototypes are rarely designed for extensive flying and every flight of the prototype represents a risk to the program – the prototype has, by definition, unique or new features that are not fully understood. Once the prototype has served its primary purpose it best serves the project as an impressive lawn ornament. i.e. used in a positive way that represents no risk to the program.

The second mistake:

Making production design decisions before the prototype has been fully evaluated.

This is most common amongst startups and is for a very understandable reason

When a project finishes the engineering for the prototype, they have a team of engineers with nothing to do. Most companies start on the production design. This is also driven by the need to keep manufacturing busy.

A lot of startup companies understandably want to build in-house capability during the prototype stage. This includes manufacturing capability.

Once the prototype has been built and is in an evaluation phase the manufacturing workload drops to a fraction of what it was during the prototype build phase.

For a startup company this represents a real problem – do you furlough the manufacturing staff and risk losing the in house capability, tribal knowledge and team synergy that was created during the prototype build? Or do you find a way to keep manufacturing busy in a meaningful way while the prototype aircraft is stepped through the cautious and sometimes painfully slow path to safe flight and eventually the performance evaluations it was built for?

Can the company afford to keep their team together doing ‘busy work’ until they have something meaningful to do?

What often happens is that production design is started early, driven largely by the perceived need to keep the manufacturing team busy.

This approach is not necessarily problematic as long as you make all the right guesses about the prototype performance evaluations and the prototype later goes on to prove you right.

However, even if you make the right guesses about your product the prototype can still reveal critical issues that you did not anticipate that will change your production design.

Should you wait until the very end of the prototype evaluation before starting production design and manufacture?

These questions are faced by every aircraft startup and there is no right answer. However, it may be worth bearing in mind that most aerospace startups fail because they run out of money.

If there is a choice you can make early on in the program that preserves cash, that is a choice you will not regret later.

The Third Prototyping Mistake:

Change for the sake of Change

Once you have a prototype you have a set of prototype tools and a set of engineering that puts you some way along the route towards selling a certified product in the market.

The least change between the prototype and the archetype represents the greatest value possible out of the prototype program.

There is a strong temptation, during the process of changing to the development of the production design, to start over. To take all the lessons learned and start the development of a brand new aircraft is very tempting.

It is better to make the archetype as close as possible to the prototype. Certify the archetype and then further changes can be introduced as supplemental type certificates once you have your type certificate and are making revenue.

If the production design has many significant differences to the prototype it becomes a new design and whether you like it or not, your first production airframe ends up being another prototype.

In the words of somebody wise: “Sales solve everything”. Perfect products never make it to market.

To summarize:

  • Do not fly the prototype for longer than you absolutely need to
  • Wait until you have learned your lessons from the prototype before making decisions on production design
  • Keep the archetype as close as possible to prototype. If you start over, the first production aircraft will be another prototype

It is best to plot the quickest time to market with a ‘compromise’ product that still gives a significant advantage over the competition. Worry about introducing perfection in your STC’s. High value options and upgrades are great ways to generate additional revenue once you have a few hundred aircraft sales under your belt.