Mini-Suites with doors in aircrafts: what constraints for airlines?

The last few years have seen the arrival of a new type of product in aircrafts: private suites closed by doors. While from the passenger’s point of view this type of product may seem obvious, it is not from the point of view of seat design or even flight operations.

A brief history of premium seats

Passengers who, quite rightly, were ecstatic about a first or business class cabin in the 90s and even 2000s would be in for a real shock when they see today’s products. In the same way that the contemporary passenger would be strongly disappointed to travel in what were the best cabins 15 years ago.

Old timers will remember Air France’s Espace 127, a business class launched in 1995, which would hardly be acceptable in premium economy today. And what about the Espace 180, ancestor of the current La Première?

And yet they were almost a revolution for the time.

However, the business and first class cabins have always followed the same direction: always more space, always more comfort and always more privacy.

The seats have thus become full flat beds. The 1-2-1 configuration was generalized in order to offer passengers on the window side seats without neighbors. Then the seat became more and more enveloping to isolate the passenger from the rest of the cabin and his neighbors until it became like a small individual suite (on the window side) or, at choice, individual or for two in the center of the cabin with the addition of a removable separation.

View from the business seat of a B787 on Turkish Airlines

Only one thing was missing: real doors to completely transform the seat into a private space.

Logically, this type of product first arrived in first class with the suites on Singapore Airlines’ A380s.

Even Garuda Indonesia is on board.

Air France has chosen an ingenious option: a curtain that offers the advantage of totally isolating the passenger because it goes up to the ceiling.

Then the product infiltrated the business class and the number of airlines that adopted it increased rapidly. We can mention the Qatar Airways Qsuite or the British Airways Club Suite. So much so that we wondered if this kind of business class would not one day make first class obsolete.

An option recently chosen by Air France for its new generation of business class.

Today, the frequent traveler has made the 1-2-1 configuration his standard, and if this is not yet the case, it will only take a year or two for the suite with door to become a must have as well.

And the passenger can say to himself that it is so obvious that it is strange to have waited so long to generalize this type of product.

This is easily explained.

A new seat is expensive to design, so airlines go step by step to avoid accumulating a lot of innovations that are not yet requested by the customer.
The customer likes to be surprised but not too surprised. He appreciates the constant evolutions but wouldn’t the customer of 1995 have found today’s business suites too small and wouldn’t he have had the impression of suffocating if he had been offered this product directly?
The demand for privacy is, culturally, something quite recent. In any case to such an extent.

But there are other explanations that are much more down to earth and that have to do with the regulations and the constraints that this implies on the flight operation.

Regulations for suites with doors in aircraft

The biggest concern in air transport is safety. It is therefore easy to guess that anything that modifies the structure of a seat and therefore of the cabin is looked at carefully.

Here is what the EASA says on the subject (CS25.813(e))(version up to 30/06/2022)

Doors separating occupiable areas of the aeroplane cabin that do not obstruct a possible passenger egress path when closed are not prohibited by CS 25 813(e).

Any such door should be openable from both sides without the use of any tool, which means without the need to use any item; it is not acceptable to require the use of even common items such as coins, credit cards, pens etc.

It is acceptable to have a door between a passenger compartment and a passenger emergency exit in contradiction with the prohibition of CS 25.813(e), provided that this door is secured in the open position by means acceptable to EASA that cannot be overridden except by a maintenance action (i.e. the necessary actions should be such that aeroplane occupants are unlikely to be equipped to perform them).

This of course puts constraints on seat manufacturers, constraints that impact the design and operation of seats by crews. But that’s not all.

That same CS25.813(e) stated in 2007:

No door may be installed in any partition between passenger compartments.

At that time, the only thing discussed was the circulation in the cabin, the idea of suites with doors did not even exist in people’s minds.

And in 2017 what did CS25.813(e) state?

No door may be installed between any passenger seat that is occupiable for take-off and landing and any passenger emergency exit, such that the door crosses any egress path (including aisles, cross-aisles and passageways)

Here we are in a bit of a grey area. It is not explicitly about the seats but not only about the circulation in the cabin.

You have seen that the evolution has been slow and that until recently the concept of a suite with door was in theory strictly prohibited. But how did the forerunners like Singapore Airlines do it?

They have requested waivers for each aircraft.

Here you have for example a document that proposes a waiver for the A380, a customer (anonymous) of Airbus having at the time the project to install a suite for two people.

The same goes for the A350.

In both cases the EASA recognizes in preamble that the installation of suites with doors contravenes the regulations in force but can be possible under certain conditions strictly enumerated and which are more or less the same for each aircraft.

Here are the constraints that weigh on a mini suite in an A380.

1) Only single occupancyof the Mini-suite is allowed during taxi, take-off and landing.
2) Mini-suite entrance can only provide access to the specific mini-suite.
3) Mini-suites cannot provide an egress path for evacuation other than the path out of the mini-suite for its single occupant
4) Installation of the mini-suitesmust not introduce any additional obstructions or diversions to evacuating passengers, even from other parts of the cabin
5) The design of the doors and surrounding “furniture” above the cabin floor in the aisles must be such that each passenger’s actions and demeanour can be readily observed by cabin crew members with stature as low as the 5th percentile female,when walking along the aisle.
6) The mini-suite doors must beopen during taxi, take-off and landing
7) The hold open retention mechanism for mini-suite doors must hold the doors open under
JAR 25.561(b) emergency landing conditions
8) There must be a secondary, backup hold open retention mechanism for the mini-suite doors that can be used to “lock” the doors in the open positionif there is an electrical or mechanical failure of the primary retention mechanism. The secondary retention mechanism
must hold the doors open under JAR 25.561(b) emergency landing conditions
9) There must be a means by which cabin crew can readily check, that all mini-suite doors are in the fully open and in the latched condition.
10) There must be means by which cabin crew can prevent the seated mini-suite occupant from operating the doors. This means is envisaged to be used in particular to secure the
TTOL phases of the flight.
11) Appropriate placards, or other equivalent means must be provided to ensure the mini-suite occupants know that the doors must be in the open position for taxi, take-off and landing
12) Training and operating instruction materials regarding the proper configuration of the minisuite doors for taxi, take-off and landing must be provided to the operator for incorporation
into their cabin crew training programs and associated operational manuals.

Time passed before EASA addressed the subject of the A350, and some new constraints have emerged. For example:

Operating instruction materials necessary to provide adequate compliance with SC 5, 9 and 10, considering also the number of individual mini-suites, shall be discussed and agreed with EASA and shall be provided to the operator for incorporation into their cabin crew training programs and associated operational manuals.
This may affect the minimum acceptable number of cabin crew required to operate the aeroplane.
In the TT&L configuration, the mini-suite must provide an unobstructed access to the main aisle having a width of at least 30 cm (12 inches) at a height lower than 64 cm (25 inches) from the floor, and of at least 38 cm (15 inches) at a height of 64 cm (25 inches) and more from the floor. A narrower width not less than 23 cm (9 inches) at a height below 64 cm (25 inches) from the floor may be approved when substantiated by tests found necessary by the Agency.
If the mini-suite doors are electrically powered, in the event of loss of power to the minisuite with the door(s) open, the door(s) must remain latched in the open position.

With time and feedback, the specifications have become much more precise.

So for a long time the mini suite was prohibited then accepted but with strict conditions. No surprise that even if some had the idea to build them and others to install them in their planes, it was not until the end of the 2010s that the concept became popular because it was clearly defined and framed.

We can say that if Singapore Airlines had not made this exceptional request, which led Airbus to apply to EASA, we would still be in a prohibited zone, or at best a grey zone.

Prohibitions, design constraints but also operational constraints for crews that require specific actions and therefore specific training…

So airlines were far from being able to decide to install mini-suites with a snap of the fingers just because they had the idea.

But the mini-suites come with other constraints.

The operational constraints of the mini suite

As we have seen, these mini-suites impose a special safety protocol for the crews. In some airlines, the adoption of additional measures implies a long discussion with the unions who do not want to see the workload of the crews increase.

In terms of service, this also imposes new constraints. The door may have to be opened and closed each time a dish or drink is served. Who opens and closes it? The passenger or the cabin crew? If it is the cabin crew, it complicates their service.

And then the doors have a weight. A weight that affects the weight of the aircraft and therefore its consumption and ultimatelyits carbon footprint. Again, this can be a matter of debate.

Bottom line

Installing mini-suites in an aircraft has not always been allowed and comes with many technical and operational constraints.

It wasn’t enough to have the idea for it to happen. It was necessary to make the regulations evolve, to manage the operational impact on the crews (even to obtain the buy-in of the crews) and tomorrow it will surely be a question of measuring their environmental impact.