June 04, 2021, ©. Leeham News: Last week, we examined operating and product certification rules related to 9-seater air taxis and commuters. We took the example of the new Tecnam P2012 Traveller to study the certification rules for a 9-seater. Now we upsize the aircraft to understand the pros and cons of adding extra seats.
If we very roughly scale the P2012’s maximum takeoff weight, we can use it as a “rubber” aircraft to illustrate the pros and cons of a 19-seater.
For a 19-seater, the aircraft needs to accommodate 10 more passengers than the P2012. Assuming each passenger weighs 100 kg, the aircraft would need an extra tonne of payload. An aircraft’s empty weight (including structure and systems) is, historically, somewhere around 50 to 60% of the maximum takeoff weight. The remaining capacity is split between fuel and payload.
As a result, one extra tonne of payload requires an additional tonne of structure and systems to support the payload. This brings the maximum takeoff weight from 3,680kg/8,113lb to 5,680kg/12,522lb. Because the aircraft is heavier, it is likely to consume more fuel. Let’s add, for argument’s sake, 150 kg of fuel and structure to compensate for the higher fuel burn. The resulting maximum takeoff weight would then become 5,830kg/12,853lb.
So, what does an aircraft with a 5,830kg/12,853lb maximum takeoff weight and 19 passenger seats mean to commuter operators?
The good news: it still doesn’t require a flight attendant in many jurisdictions. For example, EASA Part-CAT states that:
“ORO.CC.100 Number and composition of cabin crew
(a) For the operation of aircraft with a MOPSC of more than 19, at least one cabin crew member shall be assigned when carrying one or more passenger(s).”
From an operating economics standpoint, the per-seat cost goes down compared to that of a nine-seater. The operator can now divide crew costs by 19 instead of nine. The maintenance cost could be higher (e.g. bigger engines) but again it would be shared by 19 passengers instead of nine.
And then there’s the bad news:
First, the aircraft needs more equipment. When an aircraft operating under EASA Part-CAT exceeds 5,700 kg/12,566lb, it is required to have two independent static pressure systems, a terrain awareness warning system, a cockpit voice recorder, etc. These are just a few examples and not an exhaustive list.
Second, there are additional training (or type rating) requirements for pilots operating larger or more complex aircraft. For instance, under FAA 14 CFR Part 61 — Certification: Pilots, Flight Instructors, and Ground Instructors, it states:
“§61.31 Type rating requirements, additional training, and authorization requirements.
(a) Type ratings required. A person who acts as a pilot in command of any of the following aircraft must hold a type rating for that aircraft:
(1) Large aircraft (except lighter-than-air). [Large aircraft means aircraft of more than 12,500lb/5,670kg, maximum certificated takeoff weight.]
(2) Turbojet-powered airplanes.
(3) Other aircraft specified by the Administrator through aircraft type certificate procedures.”
Third, under FAA Part 135 (the operating rules for our Traveller), a commuter aircraft can only have up to nine passenger seats. An operator needs to be under Part 121 to take full advantage of all 19 seats. Yet, §121.157 Aircraft Certification and Equipment Requirements clearly 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 for the US market, Part 23 certification for our 19-seater is no longer enough, our aircraft has to be designed to the tougher Part 25 rules.
Why have we not seen a clean-sheet 19-seat commuter in the past decade, or two? There are many plausible reasons. Changes in FAA rules over time could have eroded the demand for 19-seat commuters in the US. It is true that Cessna is currently developing the SkyCourier, a 19-seat turboprop.
Yet, the company is likely targeting FedEx’s cargo missions, as it’s an unpressurized aircraft and would have to fly below 10,000ft when carrying passengers. As a result, the SkyCourier is a cargo aircraft first and a 19-seat commuter second, or perhaps even lower priority.
Price could be another factor that puts 19-seaters at a disadvantage. A Twin Otter 400 costs $6.5M as per Business & Commercial Aviation 2020 Purchase Planning Handbook’s estimate. For those who do not need 19 seats, the cabin volume, or the STOL/floats/skis capabilities, one could get a faster aircraft with better fuel economy, such as PC-12 or HondaJet, for $5.3M.
A nine-seat Cessna Caravan that cruises at a similar speed with a lower fuel burn costs $2.0M. Keep in mind, these are list prices, not actual net prices. Electric aircraft, or other new technologies, may tilt the balance in the future.
There are many 19-seat projects with alternative propulsion systems proposed at the moment. Will these aircraft have a market when the present market seems to sit still and it has not attracted any new OEMs for 20 years? We will need to wait a few years to see whether these new products can deliver on their promises and whether there is a market for them.