By Bjorn Fehrm, Henry Tam, and Andrew Telesca.

December 17, 2021, ©. Leeham News: As we wrap up the series where we look at the monumental work you have to do to get a new aircraft type certified, we will discuss how we need several aircraft variants, addressing different markets, if we shall survive as an aircraft manufacturer.

All successful aircraft manufacturers produce and market a family of aircraft. If you stay with only one variant, you will find it hard to keep good people as the development work ends.

Figure 1. Beech 1900, a 19 seater aircraft developed from the Super King Air 200 with 9 seats. Source: Textron Aviation.

The need for more variants

As a new OEM, our focus has been to get our first aircraft out the door and to start getting money back into the company. Although it takes quite some time before we are cash positive on aircraft deliveries (Figure 2), we should have planned our future steps in development from the beginning of the project.

Figure 2. It takes until we have produced around 100 aircraft before we earn money on delivered aircraft, ref. Part 30. Source: Leeham Co.

There are many reasons we need to produce and sell more than one aircraft variant:

• We’ve had to build very comprehensive intellectual assets in the course of our development that are usable in future programs. This isn’t just our design data and people, it’s tool suites for design, analysis models, test plans we can reuse, safety analysis, certification plans, safety of flight processes, standards for Prelminary Design Reviews (PDRs), and lessons about activity sequencing for things like loads loop analysis and test system builds. Many expensive lessons have been learned along the way that will be forgotten if we don’t continue developing aircraft.
• We have also built a supplier base that has engaged their engineering capabilities to develop and adapt their products to our needs. Do we only use this capability to have these supply one product to us? Is this in the long term an interesting business for these suppliers? An aircraft manufacturer is uniquely dependent on its supplier partners, not only for their continued production of the adopted parts but also for developing improved variants to lower maintenance costs and to serve future aircraft variants.
• We need profitable sales as we get past initial production to pay back ourselves and our investors for the program, but we also need this money to grow our business, continued improvements, and implementation of airworthiness directives – and in all probability accident investigation and the resulting liability costs. We also need to use our developers for certification of product improvements to bring down cost or recover performance we didn’t hit for the initial EIS. These also need to work on new variants of buyer furnished equipment such as cabin items, customized variants, etc.
• An important part of being an airliner OEM is the support network we build to make sure our customer’s aircraft stay in the air. As we recruit Maintenance, Repair, and Overhaul (MRO) partners to keep our customer’s aircraft flying, we need to give them an outlook that contains more than us addressing just one market with one variant. The 19 seat airliner market is a rather small market. Figure 3 was part of our Part 10 article that discussed the market for 19 seaters. We see that over the next 20 years there is a market for 632 new aircraft, or 32 aircraft per year. As described we have two active OEMs sharing that market with us, Viking with Twin Otter and Do228 produced by the part of RUAG now owned by General Atomics European division.

Figure 3. JADC 2019 to 2040 turboprop market segment forecast. Source: JADC.

Successful programs have many variants

So there are a number of reasons we need to develop variants of our base aircraft. If we manage to design a good, flexible base aircraft there is potential to develop the base design into many variants, over many years. 

The record for variants of a commuter has perhaps the Beech Super King Air series, Figure 4.

Figure 4. Revision 125!! of the TCDS for Beech Super King Air series. Source: FAA.

The FAA Type Certificate Data Sheet, TCDS, is published in its 125th revision in September this year. Together with the original King Air (the non-T-tail variant) about 7,500 King Airs are built to date in over 40 variants.

A large reason for this type still being in production with about 50 deliveries per year is the installed base of over 7,000 aircraft worldwide and the support network this can allow.

An airliner’s job is to be in the air. It has to fly every day and if there is a problem in the jungle of Borneo, it shall be fixed with local knowledge fast. 

Only a large family of aircraft can support such a support network. This is often forgotten when plans are made for a new aircraft OEM with its products.

It doesn’t matter if our product is x% better than the incumbent market leader such as the Super King Air.  The operators go by what they can operate with the smallest possible headache. Their customers need them to fly the passengers or the goods when planned. If the aircraft is unserviceable, then the customer changes carriers pretty fast.

So what variants can we plan around as we develop our base aircraft? Our base aircraft is an unpressurized utility-oriented aircraft. Executives don’t like to fly in weather at 10,000ft (the maximum altitude without passengers wearing an oxygen mask in an unpressurized aircraft) so an executive version is probably not smart.

On the other hand, different utility versions like a dedicated freighter with a big cargo door, a military version of this freighter as a combined transport and freighter variant, a medivac version or Intelligence, Surveillance and Reconnaissance (ISR) version are all variants that can clinch niche markets, where volumes are low but margins are healthy.

There is often the possibility to stretch the aircraft, but with our aircraft placed at 19 seats, the next natural size is 39 to 48 seats and this is a too large stretch. It requires a total redesign to compete with the incumbent 39 to 48 seaters.

Depending on the development of low emission propulsion systems and investor interest or government grants for sustainability projects we might want to develop a more sustainable variant of the aircraft. How this can look will be part of a new Corner series on the New Year.

As we wrap up, a big thanks to our experts

As we wind down this rather unique series, I would like to thank the two industry experts that helped me with knowledge and ideas, without whom this series hadn’t been possible.

I had the pleasure with work with Henry Tam, who was Head of Mitsubishi’s SpaceJet 100 program, now a fellow Mentor at Sustainable Aero Lab, and Andrew Telesca, who Headed Mitsubishi’s Certification Management Office, now at MagniX.