Boeing 747-400M Combi

Updated: October 2026 – A jumbo with winglets and a long hump rolls past you, and everything looks like a normal 747-400. But behind the left wing a huge rectangle shows in the fuselage, much bigger than any passenger door. Then you are looking at a Boeing 747-400M Combi – or at it in your photo from back then. In this version, passengers and cargo pallets shared the main deck. Here you will learn how the concept worked, why KLM became the face of the Combi, how to recognize it reliably and what became of the 61 aircraft built.

What is the Boeing 747-400M?

The 747-400M is a version of the Boeing 747-400 that carries passengers and cargo at the same time on the main deck. Up front and on the upper deck, passengers sit as in a normal jumbo. The rear part of the main deck, on the other hand, can be used as a cargo compartment. A lockable partition shields the cabin from the loading area. This section is loaded through a large cargo door on the left side of the fuselage, behind the wing.

At its core, then, the Combi is a passenger aircraft with a built-in cargo compartment. Cockpit, wing with winglets, engines and landing gear match the passenger version, and the external dimensions are the same too: about 70.6 meters in length and 64.4 meters of wingspan. Like every 747-400, it is flown by two pilots in a glass cockpit.

The name gives away the idea: the M is usually read as “Mixed,” meaning mixed use. In early documents Boeing still listed the model as the 747-400BC. Among airlines, though, the term “Combi” prevailed, which the predecessors had already carried. Important for spotters: in flight trackers the Combi only shows up as B744, with no code of its own. More on these abbreviations is explained in the article IATA and ICAO codes explained.

Why Combi jumbos existed in the first place

The Combi idea is as old as the jumbo itself. Boeing had already built a 200M version of the 747-200, 78 in total, and 21 Combis followed from the 747-300. The 747-400M continued this line and, at 61 aircraft, became the second-largest Combi series of the jumbo.

The economic thinking behind it is simple: on many long-haul routes, passenger demand is not enough to fill an entire jumbo, while at the same time cargo is waiting to be transported. A Combi aircraft adapts. Depending on the route and season, the airline can set up the cargo section larger or smaller and so trade seats for pallet positions. For airlines with a strong cargo business and a network where passenger and cargo flows do not always match, that was attractive.

KLM was exactly such an airline. Amsterdam is traditionally a large cargo hub, and the Dutch airline had already had good experiences with earlier Combi types. No wonder, then, that KLM ordered the new Combi early – and in the end flew it longer than all the others.

How to recognize the Combi

At first glance, the 747-400M is a perfectly normal 747-400. So first you need the basic look of the type, and then one or two details that only the Combi shows.

Important: the cargo door is only visible from the left side. If you stand to the right of the aircraft, the Combi is practically indistinguishable from a pure passenger 747-400. When planning your spot, it is therefore worth paying attention to which side the aircraft turns toward you while taxiing or on approach. How to read and classify the registration reliably is explained in the article Understanding aircraft registrations.

Combi, passenger aircraft or freighter?

Within the 747-400 family, three versions look very similar. The table shows what to look for.

Feature	747-400 (passenger)	747-400M (Combi)	747-400F (freighter)
Hump	long, with windows	long, with windows	short
Main deck windows	continuous	continuous	none
Side cargo door at rear left	no	yes	yes
Hinged nose	no	no	yes
ICAO code	B744	B744	B744
Aircraft built	442	61	126 (plus 40 × 400ERF)

The greatest risk of confusion is with converted freighters. These are former passenger or Combi jumbos that were later converted to full freighters. They also have the long hump and a side door, but the windows on the main deck are sealed. The factory freighter 747-400F, by contrast, has the short hump of the early jumbos and a nose that can be hinged up for loading. For an overview of all variants from the first 747 to the 747-8, see the article How to tell the Boeing 747 variants apart.

KLM and the Combi

No airline is as closely tied to the 747-400M as KLM. The Dutch put the Combi into service first in September 1989 and also received the last one built in April 2002. With a total of 17 Combis and only five pure passenger versions of the 747-400, the Combi at KLM was not the exception but the rule. As is usual at KLM, the aircraft carried city names.

One of the early KLM Combis made aviation history in its very first year of operation: on December 15, 1989, the 747-406M PH-BFC “City of Calgary,” on its way from Amsterdam to Tokyo, flew into the ash cloud of the Redoubt volcano in Alaska. All four engines failed. After a descent of more than 14,000 feet, the crew managed to restart the engines and land in Anchorage. All 245 people on board were unhurt; the aircraft received four new engines and flew for KLM until 2018.

For spotters in Amsterdam, the Combi was an everyday sight for three decades. From Schiphol Airport it flew long-haul routes, for example to Tokyo. If you browse old photo archives from the Polderbaan spotter spot or the Panorama terrace today, you will find plenty of KLM jumbos with the large door at the rear left.

The end in March 2020

KLM originally wanted to take its Combis out of the fleet by January 1, 2021. The COVID-19 pandemic accelerated everything: because demand collapsed, KLM, part of the Air France-KLM group, retired the Combis as early as March 27, 2020.

It was not entirely over, though. Because cargo capacity was lacking worldwide – many passenger flights with cargo in the belly were canceled – KLM brought three Combis back about a week later and used them for pure cargo flights to Asia. This is exactly where the advantage of the concept showed: the main deck cargo compartment was already there. In the airline’s fleet statistics, the 747-400M therefore only shows up as finally retired in 2021.

KLM nevertheless stayed tied to the 747-400 family: KLM’s subsidiary Martinair still flies 747-400 freighters for the cargo division, which according to current planning will be replaced by Airbus A350F freighters from 2027. That has nothing to do with the Combi anymore, though – those are pure freighters.

The other operators

Besides KLM, other airlines ordered the Combi, mainly in Asia. The table shows a selection of important operators, not a complete list. The details are based on published fleet overviews; individual numbers may differ slightly depending on the source.

Airline	Combis	Period	Fate
KLM	17	1989–2020	Retirement, briefly pure cargo flights
Asiana Airlines	6	1991–2017	Conversion to freighters for Asiana Cargo
EVA Air	5	1993–2015	Conversion to freighters for the cargo division
Air Canada	3	1990–2004	left the fleet
Air France	3	1992–2012	left the fleet
Air China	several	1989–2013	partly converted to freighters for Air China Cargo, one aircraft in a museum

It is striking how many Combis got a second life as full freighters. At EVA Air, the Israeli manufacturer IAI carried out the conversion. For the airframe this was the obvious choice: the large side door in the rear main deck was already there. From the outside, such converted Combis are hardly distinguishable from other converted freighters today. How to tell freighters apart in general is shown in the guide How to identify freighter aircraft.

Where you can still experience the 747-400M

As of October 2026, the 747-400M no longer flies in passenger scheduled service of major airlines. Reference works occasionally still list aircraft with cargo and charter operators, but their use is irregular and hard to plan. For spotters this means: getting a Combi in front of your lens is now a real rarity. How rare a sighting actually is, you can estimate with the tips from How rare is my sighting?.

Place	What you see	Context
Shijingshan Park, Beijing	former Air China 747-400M B-2468	rare example of an exhibited 400M, retired in 2013
Technik Museum Speyer	Lufthansa 747-200 in Combi configuration (D-ABYM)	Combi predecessor you can walk through, ideal for German-speaking countries
Aviodrome Lelystad	former KLM 747-200 PH-BUK	KLM jumbo history, but not a 400M
Large cargo hubs	converted ex-Combis as full freighters	recognizable as a former Combi only through the registration

If you are specifically looking for a former Combi, only the registration helps. Note down the registrations of former Combis, check in a database who flies them today, and then follow the aircraft live. How that works is explained in the article How to track an aircraft by registration.

Spotting and photo tips

Even though the Combi has become rare, it pays to look closely at every jumbo – especially at freighters with a long hump.

• Plan for the left side. The cargo door is the central feature. Find a vantage point where the aircraft shows you its left side while taxiing or landing. The runway direction in use decides which side you get to see.
• Side profile instead of head-on. Only in profile can you see hump length, row of windows and cargo door at the same time. A shot from the front at an angle often does not show the door at all.
• Keep the registration legible. For an ex-Combi, the registration is the only proof of its origin. Choose focal length and framing so that the registration is sharp and legible.
• Dig through archives. A large part of the Combi’s history lies in old photos. If you have pictures from Amsterdam, Taipei or Seoul, a second look is worthwhile.

If you are heading to Amsterdam, the article Plane spotting at Schiphol lists the best places around the airport where the Combi had its most important home. The full development of the jumbo is traced in The history of the Boeing 747, and you can find more on the manufacturer on the page for Boeing.

Common mix-ups and how to rule them out

Conclusion

The Boeing 747-400M Combi was the last big Combi series of the jumbo: 61 aircraft that combined passengers and pallets on one deck. It is recognizable by the large cargo door at the rear left with a continuous row of windows, and confirmed through the registration. KLM made it its long-haul workhorse, flew it for over 30 years and took it out of passenger service in March 2020. Other Combis live on as freighters, but only connoisseurs can still recognize them as former Combis.