Bjorn’s Corner: The challenges of airliner development. Part 33. Multi-country Certification

By Bjorn Fehrm, Henry Tam and Andrew Telesca.

December 10, 2021, ©. Leeham News: Our aircraft has now achieved its first deliveries and is Entering Into Service (EIS) with our launch customer. 

This covers one customer and one jurisdiction. As each country is sovereign in Airworthiness certification, we have work to do for each market we want to address.

Figure 1. A new 19 seater design, the Cessna 408 SkyCourier, started life as a cargo aircraft certified to US Part 23 standards. Here, the passenger version. Source: Cessna.

Certification in additional countries:

Our launch country and customer allows that a 14 CFR Part 23 aircraft with 19 seats can operate regular airliner/commuter services. We know from Part 5 and 6 that this can’t be the US market.

The FAA rules clearly state: 

To operate a 19 seater in the USA, an operator needs to operate under 14 CFR Part 121.  But, §121.157 Aircraft Certification and Equipment Requirements then states “(h) Newly type certificated airplanes. No person may operate under this part an airplane for which the application for a type certificate is submitted after March 29, 1995, unless the airplane is type certificated under part 25 of this chapter.” 

So, by certifying to Part 23, the general aircraft certification rules, we have excluded regular passenger service in the US as a market for our aircraft.

The example shows how tricky it is to develop an aircraft in the 9 and 19 seat sizes. Certification rules differ by country and as smaller countries often align their certification rules with larger countries we need to research each market individually.  Are our target markets making their own rules or do they follow the FAA line or the EASA ideas for this size aircraft?

If we lose too much attainable market by this rule difference we should have investigated what it would have cost in time and money to certify to the tougher Part 25 rules. This opens a larger market, where most countries accept the aircraft can operate in regular passenger service. But Part 25 produces a heavier, more expensive aircraft, with more complex systems.

A smart go to market strategy

If we assume we stick to a Part 23 aircraft we address a non-US market. It probably means our design is more utilitarian than fast and smooth for a North American passenger market. 

A smart way of developing an aircraft can be to target a US market cargo role and then make a passenger version for non-US markets. An example of such a project is the Cessna SkyCourier program. Cessna designed the aircraft as a cargo aircraft with US FedEx as launch customer (50 fixed and 50 optional orders) but also markets a 19 seat passenger version for non-US markets (Figure 1).

It’s a clever way to secure a large and predictable base market, at which to align the design, then with modest investments market both the Passenger and Cargo version on a broader world market.

Example of certification differences per country

Luckily for us, the complexity of multinational certification has been recognized for a long time. To try and limit the impacts there are many bilateral treaties between jurisdictions (for example the US and EU, or the EU and Japan) to recognize work done by the original certifying authority.

This means we can take credit for the testing and other accomplished work unless there is an actual regulation difference (sometimes called a significant standards difference) between the countries. For most smaller countries the regulations are very close to either the US or the EU and there are only small additional certification campaigns needed if we have certified with the larger authorities — manageable as long as we plan ahead.

A few examples of differences in airworthiness standards between countries:

  • Canada requires stricter testing standards for cold weather than the US.
  • Russia has more difficult standards for rough runway loads than the EU.
  • The EU requires large airplanes to satisfy more icing conditions than the US
  • The US requires additional compliance work to address uncontained rotor failures relative to the EU

If we determine that we should pursue Part 25 compliance in the US after completing certification in the EU for our passenger version, we need to understand the full list of differences published by the FAA here: https://www.faa.gov/aircraft/air_cert/design_approvals/transport/transport_intl/sd_list/ssd_nonssd_list/

Even when there are no regulation differences a good validation plan is needed to avoid delivery delays and customer penalties:

  • Depending on the country, validation timelines can range from 3-18 months (even if there are no holdups).
  • Different countries will focus on different areas for review. For example, it is common to need a longer flight operations evaluation in the Middle East, which means planning for the cost and asset availability of an extra flight test program. 
  • Japan cares deeply that all the evidence is prepared completely and there are no gaps, so it will often engage in a detailed audit. 
  • China is continuing to grow the capability and influence of their certification authority, and will therefore often require a long technical review to ensure their understanding of the aircraft.

In many cases, we may be able to negotiate that the standards of our original certification authority provide an equivalent level of safety to the validating authority (though this can take a long time), or we can plan our original certification campaign to envelope the stricter requirements to prepare for future validations.

 However, this is only possible with upfront research and planning, and if we ignore it we will find ourselves with significant costs for repeated testing, additional production challenges to manage different configurations for delivery to different countries, and delivery delays as we try to expand outside our original jurisdiction.

7 Comments on “Bjorn’s Corner: The challenges of airliner development. Part 33. Multi-country Certification

  1. Mmmh, I kind of laugh when I see that “Japan cares deeply that all the evidence is prepared completely and there are no gaps, so it will often engage in a detailed audit” when the MRJ certification was such a horror story.
    Was there no learning from the Japanese regulators over the years to help Mitsubishi achieve a relatively painless regulation of the MRJ?
    The FAA and Boeing were too close, was JCAB too far apart from Mitsubishi and has Airbus and EASA got it relatively right?

  2. “If we assume we stick to a Part 23 aircraft we address a non-US market.”
    “full list of differences published by the FAA here:”

    These are the differences between Part 25 and CS-25, but wasn’t the certification basis for the EU passenger version CS-23?

    • yes, we assumed we design to Part 23 rules and therefore market the passenger version ex. the US. But the article series is to show and discuss the consequences of different choices that we make early in the program, thus we also discuss the consequences of a Part 25 route.

  3. How would an aircraft certificated in previous decades but re-winged and re-engined be viewed by certification agencies?

    • Hi Fastship,

      it depends. Traditionally this could be achieved with an Amended Type Certificate, example 737 Classic to 737NG. Today it would very much depend on a number of factors if this requires a new Type Certificate or not.

      • In seeking to develop new types I would claim you are pursuing declining marginal returns. Rather then pursing your putative design for this segment or any other, capital and that even more precious commodity time would be better expended on applying the improvements in new technology to existing designs in which the capital and time costs are sunk costs.

        Certification authorities are largely agencies of protectionism erecting ever higher barriers to entry for new entrants.

        A re-winged and re-engined existing airframe, already certificated would achieve 95% of what a clean sheet design would for 95% less time and cost.

  4. Hi Fastship,

    it depends. Traditionally this could be achieved with an Amended Type Certificate, example 737 Classic to 737NG. Today it would very much depend on a number of factors if this requires a new Type Certificate or not.

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