Manufacturer test registrations: F-W, D-A and N-numbers explained

At the fence in Finkenwerder, a brand-new A321neo rolls past, the livery of an Asian airline already complete – but at the tail there is a German registration. In Toulouse, meanwhile, jets in customer colors wear a French F-WW… that appears in no airline fleet list. These are test registrations: provisional registrations under which a manufacturer operates its aircraft before the customer takes it over. This article explains how the French F-W series, Hamburg’s D-A registrations and Boeing’s N-numbers work, why the switch to the final registration matters so much to spotters and how to record such sightings cleanly.

Test registrations: the short answer

A newly built airliner initially belongs to the manufacturer. Before it goes to an airline, it has to fly: first flight, factory flights to check the systems, acceptance flights with the customer on board. All of that requires a valid registration – and because the airline is not yet the operator at this point, the jet flies with a provisional registration from the country where it was assembled. At handover it is then re-registered to its final registration.

What these provisional registrations look like depends on the register of the country in question:

• France explicitly reserves the F-W… series for provisional registrations that manufacturers use for flight tests. Airbus in Toulouse uses it intensively, especially the F-WW… subgroup.
• Germany has no dedicated test letter series in this form. In Hamburg-Finkenwerder, Airbus flies with German registrations of the D-A class, which applies to aircraft over 20 tonnes maximum takeoff weight.
• USA: Boeing uses regular N-numbers from the US register – sometimes chosen to be meaningful, sometimes unremarkable.

How registrations are built in general and which prefix belongs to which country is explained in the basics article Understanding aircraft registrations.

Why manufacturers need their own registrations

An aircraft without a registration may not fly. At the same time, a new jet is in an in-between state from the moment it leaves the final assembly line until handover: it is built but not yet accepted; it often already wears the customer’s colors but does not belong to the customer. A whole series of flights takes place during this phase:

• First flight – for a production aircraft, the first flight of that individual airframe; for a prototype, the first flight of an entire type.
• Factory or production flights – test flights in which manufacturer crews check systems, engines and flight characteristics.
• Acceptance flights – flights with customer representatives who inspect the aircraft before taking it over.
• Flight test campaigns – for new types or variants over months or years, often with instrumentation on board.

How to recognize such flights on flight radar services is shown in the guide Tracking test flights, factory flights and first flights. As for the registration, as long as the manufacturer operates the aircraft it is listed in the manufacturer’s register – and that is exactly what makes test registrations so appealing to spotters. They often exist for only a few days.

France: the F-W series from Toulouse

The French register is the easiest to follow for spotters. Registrations begin with the nationality mark F, followed by four letters. Regular airliners wear, for instance, F-G…, like the A321 F-GTAJ of Air France. The F-W… series, by contrast, is reserved for provisional registrations that manufacturers use for flight tests.

At Toulouse-Blagnac Airport, the home base of Airbus, you come across these registrations all the time. The F-WW… subgroup is especially common and has been assigned to countless production aircraft over the years. Airbus also uses other F-W combinations – particularly for prototypes, where the registration likes to carry a message.

Registration	Aircraft	What it shows
F-WWOW	first A380, first flight April 27, 2005 in Toulouse	classic F-WW…, chosen with a wink
F-WXWB	first A350-900 (XWB), first flight June 14, 2013	type designation hidden in the registration
F-WWCF	A350-900 MSN 002	test aircraft from the F-WW group
F-WZGG	A350-900 MSN 003	F-W, but outside F-WW
F-WTTN	first A330-900, first flight October 19, 2017	prototype of a new variant
F-WBXL	first BelugaXL (MSN 1824), first flight July 19, 2018	later in regular service as F-G…

The BelugaXL shows the transition especially nicely: as a test aircraft it carried the W in its registration, while the BelugaXLs in airline-style service for Airbus fly with regular F-G registrations. More on the type is in the profile Airbus BelugaXL.

If you want to see the test jets in Toulouse, it is worth a look at the area around the Aeroscopia museum at Toulouse-Blagnac. How spotting works there overall is described in the guide Plane spotting at Toulouse-Blagnac; the rules that apply at French airports are summarized in Photography at French airports.

Germany: D-A registrations from Finkenwerder

In Hamburg-Finkenwerder, Airbus assembles aircraft of the A320 family and flight-tests them from there. The factory airfield with the IATA code XFW and the ICAO code EDHI has no public scheduled traffic; its runway 05/23 is 3,183 meters long and serves factory, cargo, test and delivery flights.

German registrations work differently from French ones: the first letter after the D stands for the weight class. D-A is the class of aircraft with more than 20 tonnes maximum takeoff weight – and that is exactly where the Airbus jets built in Hamburg end up before delivery. The system is explained in detail in the article German aircraft registrations.

The best-known example is the A321neo prototype. It flew for the first time in Hamburg on February 9, 2016, as D-AVXB. The A321XLR also took off on its first flight in Hamburg, on June 15, 2022. Production looks similar: at the fence in Finkenwerder, jets in the colors of airlines from all over the world regularly stand with a D-A… at the tail that disappears after handover.

For spotters in Germany this is a real advantage: factory-fresh A320neos and A321neos with test registrations are right on your doorstep. Where to stand best at the factory airport is in the guide Spotting at Airbus Finkenwerder.

USA: Boeing and N-numbers

The US register has no reserved test series like the French F-W…. Boeing therefore flies its prototypes and test aircraft with regular N-numbers, which can be reserved as vanity registrations with the US aviation authority, the FAA. This leads to two patterns:

• Meaningful registrations for prototypes. The first 787 wore N787BA when Boeing presented it on July 8, 2007. Its first flight followed on December 15, 2009 from Paine Field in Everett.
• Internal numbers alongside the registration. Boeing internally referred to the six aircraft of the 787 test program as ZA001 to ZA006, and for the 747-8 designations like RC503 appear. In media and press texts you therefore often read these factory numbers instead of the registration.

A special case is test aircraft that already fly in customer colors. On the 747-8, the fourth aircraft in the test program, RC503, already wore the Cargolux livery when it first took off on July 23, 2010. Testing of the freighter version had begun on February 8, 2010 with the first flight from Paine Field.

The Boeing 777-9 also took off on its first flight from Paine Field on January 25, 2020, with two more test aircraft following in April and August 2020. Production aircraft for US airlines often already fly with their final N-registration; for foreign customers, depending on the case, temporary US registrations or the destination registration are used. There is no uniform rule here – in the end, a look in a fleet database decides.

If you want to experience the Boeing world on site, Boeing Future of Flight in Everett and the Museum of Flight at Boeing Field are two good destinations.

Other countries, other systems

Every country regulates provisional registrations in its own way. Two examples from the German-speaking region:

• Austria reserves the OE-V… group for test registrations. More on the system is in the article Austrian OE registrations.
• Switzerland: Here HB-Y… stands for experimental aircraft. Details are explained in the post Swiss HB registrations.

As a rule, a manufacturer flies its new aircraft in the register of the country where they are assembled. If it operates several final assembly lines, the same type can wear very different test registrations depending on the plant. Before you classify an unfamiliar combination, it therefore always helps to ask: where was this aircraft built?

The switch to the final registration

Shortly before handover, the aircraft is deleted from the manufacturer’s register and entered in the register of the customer or lessor. On the fuselage the test registration is replaced by the final registration – sometimes the latter is already on the aircraft beforehand, and the test registration is just stuck on. For you as a spotter, the switch has three consequences:

1. The registration is not permanent. A photo with F-WW… or D-A… shows an interim state that no longer exists after delivery.
2. The hex code usually changes too. The ICAO 24-bit address in the transponder is tied to the state of registry. When the jet changes country, the address usually changes as well – on flight radar maps it then appears like a new aircraft.
3. The serial number stays. The MSN is the only constant between the factory photo and the later airline career. How to look it up is shown in the overview Fleet databases compared.

The ferry flight to the airline often follows – a spotting topic of its own, covered by the guide Tracking delivery and ferry flights. If an aircraft later changes owner again, the game starts over; more on this in the article Re-registrations.

Documenting test registrations cleanly

Precisely because test registrations are reused, a sighting without extra information quickly becomes worthless. An F-WW… from 2015 and the same F-WW… from 2024 can be two completely different aircraft. Here is how to record such sightings unambiguously:

If you collect registrations on purpose, you will find more ideas in the post Collecting registrations. Test registrations are a category of their own there: they can’t be planned, are tied to a few places and disappear again quickly. They often come along with another rarity – the house liveries of Airbus, Boeing and Embraer in which many test aircraft fly.

What to keep in mind

• Not every F-W… is an Airbus. The French series is open to all manufacturers for flight tests. Type and location decide who owns the aircraft.
• Test registrations are recycled. Without a date and serial number, you can hardly match a sighting later.
• Flight radar data is a snapshot. After the registration change, the flight history shows a fresh record under the new hex code. How you can still find individual aircraft is explained in Tracking an aircraft by registration.
• Factory grounds are not public space. At factory airfields, stay on public paths and at designated spots. What is allowed is covered in the article Is plane spotting allowed?.

Conclusion

Test registrations are an aircraft’s registration before it becomes an airline aircraft. In Toulouse the French F-W series serves this purpose, in Hamburg-Finkenwerder the jets fly with German D-A registrations, and Boeing uses regular N-numbers – with prototypes happily using a meaningful letter sequence like N787BA. For spotters, all three systems have one thing in common: the registration is fleeting, the serial number is not. If you note both, your factory photo is a piece of aviation history that can still be matched unambiguously years later.