Mammoth begins 777-200LRMF test flights, STC eyed by early 2026
Brian McCarthy told The STAT Trade Times that Mammoth has secured 35 firm orders across both aircraft types, with additional negotiations underway pending STC issuance.
Image: Mammoth Freighters / LinkedIn
Mammoth Freighters has announced that its Boeing 777-200LRMF will undergo test flights throughout the month of August.
Brian McCarthy, VP of marketing and sales at Mammoth Freighters, provided an update on the programme to The STAT Trade Times, saying, “We will be conducting 200LR flights throughout August, but I can report that all of our ground smoke flights have been completed with exceptional, successful smoke detection times. We nailed the design, and it works great. All ground smoke detection, smoke penetration, and smoke migration tests are now complete, and we see no issues arising when we take to the air with the same tests.”
Supplemental Type Certificate (STC) approval: what’s next
Speaking on the STC, he explained, “Since the 200LR STC is a prerequisite of the 300ER certification, lots of grease is going to the 200LR. The 300ER STC is dependent on the 200LR being certified because we can’t amend the 200LR STC and certify without the STC issuance for the 200LR.”
According to McCarthy, if Mammoth has the Type Inspection Authorised (TIA) in September, then they expect to complete all the flight testing and data submittals by about November/December for the 300ER.
“This would then suggest that we will be “TIA” by December 2025. Then we would be simply waiting for the Federal Aviation Administration (FAA) to finish up the administrative review of the final reports and data submittals in January after the holidays. The holidays will definitely get in our way,” he added.
This indicates that Mammoth expects to secure the STC for the 777-200LRMF by early 2026.
Why the 300ER STC hinges on the 200LR
McCarthy explained that “Mammoth has one project number with the FAA that covers both 200LR and 300ER model variants. The FAA recognised that both of these aircraft are so close in their design from the systems and structural standpoint that they authorised a master STC issuance as the basis for certification, with the 200LR being the master STC. They further authorised the 300ER to be certified using the amendment process that has already been established for STCs.”
He likened the process to past certifications of closely related aircraft, citing the Boeing 737-200 and -300 as an example.
“The only real difference with these airplanes is 33 feet or about 10 metres, in fuselage length.” He said, noting that while some analysis is required for the longer fuselage, the systems, front and rear fuselage sections, wing, wing box, and landing gear are virtually identical.
McCarthy added that most 300ER tests will be largely academic, as they mirror those already completed for the 200LR.
The B777-200LRMF offers a maximum gross payload capacity of 233,000 lb (105,687 kg) and a maximum take-off weight (MTOW) of 766,000 lb (347,452 kg). In comparison, the B777-300ERMF has a maximum gross payload capacity of 216,000 lb (97,976 kg) and an MTOW of 775,000 lb (351,534 kg).
Current order book
McCarthy mentioned that the company’s order book stands at 35 firm orders, with several additional customers in discussions pending STC issuance. Jetran Ltd., based in Horseshoe Bay, Texas, holds the majority of 777-200LR orders, while Avia Solutions Group accounts for six of the 300ER orders. End operators include Qatar Airways and DHL for many of the 200LRs, and one of Avia Solutions Group’s AOCs, BBN Istanbul, will take the 777-300ERs as they are completed.
