Mammoth Freighters is preparing to complete the final, FAA-witnessed test flights of its Boeing 777-200LR passenger-to-freighter conversion programme in early January, a critical milestone ahead of certification and delivery to launch customer Qatar Airways Cargo.
The Texas-based conversion specialist confirmed that the formal test flights for the first 777-200LRMF aircraft are scheduled to take place between January 6 and 8, with the US Federal Aviation Administration observing the programme. While Supplemental Type Certification (STC) approval will not be achieved before the end of the current year, certification and aircraft delivery are expected to follow shortly after the January test phase.
According to Mammoth, the upcoming flights represent the final step in the certification pathway. The aircraft has already undergone extensive testing under delegated engineering oversight, and the FAA-witnessed flights are intended to formally validate performance and compliance requirements before progressing to Type Inspection Authorization (TIA) and final STC issuance.
Once certification activities are completed, the aircraft is expected to be transferred immediately for repainting in Qatar Airways Cargo livery, with delivery to lessor Jetran and the airline targeted within weeks of STC approval. Qatar Airways Cargo signed an agreement earlier this year for five converted 777-200LR freighters, positioning the type as a key addition to its long-haul cargo fleet.
Certification Timeline and Programme Delays
Mammoth has faced a prolonged certification timeline for the 777-200LRMF programme. The prototype aircraft completed its initial test flight in May, followed by a series of company and formal FAA test flights throughout the summer and early autumn. While final certification flights were initially expected to conclude by October, progress was impacted by external factors, including the US government shutdown, which temporarily slowed regulatory processes.
Despite the delays, the company has maintained that the programme remains technically on track. The January flights are expected to clear the remaining regulatory steps, subject to final FAA audits of compliance documentation, data submissions and inventory checks required for STC approval.
Qatar Airways Cargo had originally anticipated delivery of its first converted aircraft during the fourth quarter, but revised expectations now point to January, aligning with the updated certification schedule.
Growing 777 Conversion Activity
Beyond the launch aircraft, Mammoth currently has seven Boeing 777-200 and 777-300 aircraft in various stages of conversion. Five aircraft are undergoing work at Aspire MRO in Fort Worth, Texas, while two are being converted at STS Aviation Services in Manchester, UK. The company recently confirmed that the large cargo door has been installed on the second 777-200LRMF, marking further progress in the programme.
The 777 freighter conversion market continues to gain momentum, with multiple conversion programmes underway globally. In addition to Mammoth’s 777-200LRMF, three separate 777-300ER conversion programmes are currently being developed by different providers, reflecting strong demand for widebody freighters capable of serving long-haul, high-payload cargo missions.
As the industry closely watches the outcome of the January test flights, the imminent certification of the 777-200LRMF is expected to add a new option to the global freighter fleet, supporting airline capacity growth at a time of continued demand for long-range cargo lift.
