Boeing 777-300ERSF

Updated: October 2026 – An endlessly long twinjet rolls to the runway, raked wingtips, two gigantic GE90s – but not a single row of windows. If that happens to you, you’re very likely looking at a Boeing 777-300ERSF: a former passenger 777-300ER that has been converted into a freighter. Here you’ll learn who is behind the conversion, who flies the type and how to tell it from the factory-built 777F.

What is the Boeing 777-300ERSF?

The 777-300ERSF is a converted Boeing 777-300ER. When a 777-300ER leaves an airline’s fleet after many years of passenger service, it can begin a second life as a freighter. For that, the seats, cabin fittings and overhead bins are removed, the windows plugged, a large cargo door cut into the fuselage, the cabin floor reinforced and a loading system for pallets and containers installed. The abbreviation SF stands for “Special Freighter” – that’s what Israel Aerospace Industries (IAI) calls its converted freighters.

The conversion was developed by the Bedek Aviation Group, IAI’s maintenance and conversion division. Its name goes back to the Bedek Aviation Company, from which IAI emerged in the 1950s. IAI also offers converted freighters for the 737, 767 and 747; the 777 conversion, however, is the largest project of its kind. Work on the prototype began in Israel, near Tel Aviv Ben Gurion Airport, where IAI has its headquarters.

From Boeing’s point of view, by the way, the 777-300ERSF is not a model of its own: Boeing built the airframe, and IAI is responsible for the conversion through a Supplemental Type Certificate (STC). That’s why the aircraft generally keeps its old ICAO type code B77W.

The history of the program

The thinking behind it is simple: the 777-300ER was the backbone of many long-haul fleets for years, and over time more and more of these aircraft are coming onto the used market. At the same time, there is no factory-built freighter of this size with two engines. A conversion promises a lot of volume at much lower cost than a new aircraft.

IAI had originally targeted certification and entry into service for the end of 2022. Why it took so much longer is not public in detail. What’s clear: cutting a large cargo door into a fuselage of this length and reinforcing the structure for heavy pallets is one of the most demanding conversion tasks in civil aviation.

Technology and capacity

On the outside, the 777-300ERSF remains a 777-300ER: same length, same wings, same GE90-115B engines from GE Aerospace. On the inside, by contrast, almost everything changes. The main deck becomes a continuous cargo hold, and the lower-deck holds for containers are retained.

The figures differ slightly depending on the source, because manufacturers and operators calculate differently. IAI quotes a maximum payload of around 101.6 tonnes, a total volume of a good 819 cubic meters and 47 loading positions; the range with full payload is, according to the program, about 4,500 nautical miles. Kalitta Air quotes around 102 tonnes of payload and a total volume of about 854 cubic meters for its own aircraft, of which around 640 cubic meters is on the main deck.

Feature	777-300ERSF (IAI)	777F (Boeing, factory-built)
Basis	used 777-300ER	newly built, derived from the 777-200LR
ICAO type code	B77W	B77L
Length	73.9 m	63.7 m
Wingspan	64.8 m	64.8 m
Max. payload	approx. 102 t	102 t net (Boeing)
Volume	significantly larger, according to IAI around 25% more than the 777F	reference value
Main-deck cargo door	left, behind the wing	left, behind the wing
Range with full payload	approx. 4,500 nm (program figure)	around 9,200 km (Boeing)

Bottom line: the 777-300ERSF is a volume freighter. It’s particularly suited to light, bulky cargo, such as e-commerce shipments, where space runs out faster than the permitted load. The 777F plays to its strength with heavy cargo over very long distances.

The competitor: Mammoth Freighters

IAI is not alone. The US company Mammoth Freighters announced its own conversion programs for the 777-200LR and 777-300ER in September 2021. The variants are called 777-200LRMF and 777-300ERMF – the “MF” stands for Mammoth Freighter. So it is not a 777-300ERSF but a separate conversion with its own certification.

For the smaller 777-200LRMF, Qatar Airways Cargo is the launch customer. Its prototype first flew on May 1, 2025, and the FAA granted the Supplemental Type Certificate on April 6, 2026. The larger 777-300ERMF has AviaAM Leasing as launch customer; Mammoth quotes a maximum payload of around 98 tonnes, a good 819 cubic meters of volume and a range of about 4,800 nautical miles with full payload for it. According to information from summer 2025, the prototype of the 300ER version was due to be ready by the end of 2025. We had no reliable information on the current status of certification and delivery of the 777-300ERMF at press time.

In addition, the Kansas Modification Center, together with Wichita State University, announced a third 777-300ER conversion in September 2020, the 777-300ERCF with a cargo door ahead of the wing. The launch customer was Backbone Freighter Leasing. There is so far no reliable information on certification or deliveries.

Program	Designation	Launch customer	Status
IAI (Bedek)	777-300ERSF	GECAS (now AerCap)	certified since September 2025, in service
Mammoth Freighters	777-300ERMF	AviaAM Leasing	in development or testing, check current status
Kansas Modification Center	777-300ERCF	Backbone Freighter Leasing	announced in 2020, no reliable reports on certification

First operator and importance in the cargo market

The worldwide first operator is Kalitta Air from Ypsilanti in the US state of Michigan. Besides the 777-300ERSF, the airline flies the factory-built 777F and the Boeing 747-400F. For its own 777-300ERSFs, Kalitta quotes around 102 tonnes of payload.

The type is also in service with Air Atlanta Icelandic: the Icelandic ACMI and charter airline was named in industry reports in September 2026 together with Kalitta as an operator of the new 777-300ERSF. How many aircraft each operator flies exactly changes with every delivery – you’ll most likely find reliable fleet numbers in current databases.

Why is the type so important? Many large freighters of the older generation – especially the Boeing 747-400F and the McDonnell Douglas MD-11 – are getting on in years. The new factory-built widebody freighters, the Boeing 777-8F and the Airbus A350F, are not yet in scheduled service. The Boeing 747-8F is no longer being built. The 777-300ERSF steps into this gap: a modern, twin-engine widebody freighter with a lot of volume, built from aircraft that are becoming available anyway.

You may know a similar principle from smaller types: with the A330P2F, used A330s get a second life, and with the 767-300F and 767-300BCF, the converted freighter has long been standard. The 777-300ERSF carries this idea over to the next size class.

How to recognize the 777-300ERSF

Basically, you identify a 777-300ERSF in two steps: first you establish that it’s a 777-300ER, then that it has no windows.

There is one trap: during the pandemic, some airlines used 777-300ERs with seats removed on cargo-only flights, Emirates for example. But such “preighters” still have their windows and no main-deck cargo door. If the windows aren’t missing, it’s not a converted freighter.

Where to find the 777-300ERSF

The 777-300ERSF is still a rare type. Fleets have only been growing since certification in autumn 2025, and the aircraft mainly fly long cargo routes across the Pacific and Atlantic. So a catch in German-speaking countries can’t be planned – but there are places with better chances than others.

Location	Chance of success	Why
Leipzig/Halle	low to medium	Major cargo hub with a lot of long-haul and charter cargo
Frankfurt	low	Germany’s largest cargo volume, many ACMI and charter freighters
Liège	low to medium	Pure cargo focus, frequent charter and long-haul freighters
Passenger airports without cargo traffic	very low	At most diversions or special flights

At Leipzig/Halle Airport, cargo traffic runs mostly at night. From the observation deck and other locations, you can catch the long-haul freighters at the edges of the day; tips on this are in the Leipzig/Halle spotting guide. At Frankfurt Airport, the Zeppelinheim viewing platform gives you a good view of landings. And at Liège Airport, almost everything revolves around cargo – the Liège spotting area is a must for freighter fans anyway.

Photo tips for the long freighter

A fuselage without windows quickly looks monotonous in photos. With a few tricks, you can still get a strong shot.

When the light is right at your spot, you can work out in advance with the guide Planning sun position for your photo spot. Since many freighters fly at the edges of the day, that’s especially important for this type. General features of freighters and other types you’ll meet at cargo hubs can be found in the article How to recognize freighter aircraft.

Common mix-ups and how to rule them out

Conclusion

The 777-300ERSF is one of the most exciting new arrivals in the cargo market: long, modern, twin-engine and built from aircraft that would otherwise end up in the desert. After a long development phase, it has been in service since certification in September 2025 – with Kalitta Air as first operator and Air Atlanta Icelandic as an additional user. If you want it in your logbook, you mainly need patience and an eye on the schedules of the cargo hubs.