Mammoth Freighters, a US company developing cargo-converted Boeing 777s, expects to complete its first 777-200LR modification by year-end and to achieve an initial regulatory certification by April 2024.

The company says it now holds orders to modify 35 777s from passenger to cargo configurations, including nine modified 777-200LRs due for delivery to DHL under a newly disclosed deal.

Mammoth is also in “advances stages” of negotiations to sell another 10 of the modified Boeing widebody jets, the Orlando-based company’s vice-president of marketing and sales Brian McCarthy tells FlightGlobal on 20 April.

Mammoth 777-200LR freighter-c-Mammoth Freighters

Source: Mammoth Freighters

A rendering of Mammoth Freighter’s in-development cargo-converted 777-200LRMF

He says Mammoth is on track to complete its first modification – that of a 777-200LR due to Canadian hauler Cargojet – by the end of 2022.

Orlando-based Mammoth previously aimed to have its “777-200LRMF” modification approved by the Federal Aviation Administration with supplemental type certificate (STC) in 2023. But the modification’s expected end-year completion likely means the FAA will grant the STC in 2023 – probably by April, says McCarthy.

Mammoth expects to receive an STC for its 777-300ERMF conversion about six months after that, he adds.

Mammoth’s corporate affiliate Aspire MRO is performing the conversion work in a former American Airlines 777 maintenance site at Fort Worth Alliance airport in Texas. Both Mammoth and Aspire are backed by Fortress Investment Group.

Mammoth is initially setting up three modification lines at the site, and already working on conversions of two 777-200LRs (former Delta Air Lines aircraft due to Cargojet) and one 777-300ER (an aircraft owned by AviaAM Leasing).

Work is humming, with employees installing floor beams and assembling door structures, says McCarthy. “It’s crazy how fast this goes once the parts show up.”

Mammoth plans for the Fort Worth facility to eventually have five modification lines. It also hired UK MRO shop STS Aviation Services to established another modification facility in the city of Manchester.

Mammoth has already acquired 10 777-200LRs from Delta for modification. Of those, four are due for delivery to Canadian freight hauler Cargojet. Mammoth sold the other six to US aviation services and aircraft leasing company Jetran, McCarthy says.

Cirium data shows that Jetran has temporarily leased some of those former Delta 777-200LRs to Air India, which will operate them until Mammoth takes them for conversion for DHL, McCarthy says. Jetran also owns a 777-200LR in service with Qatar Airways.

DHL announced on 20 April that it had ordered nine Mammoth-converted 777-200LRs from Jetran, with deliveries scheduled for between 2024 and 2027.

Mammoth’s 777-200LRMF will have cargo volume of 650cb m (22,960cb ft) and maximum gross payload of 105,687kg (233,000lb). Its 777-300ERMF converted freighter will have 814cb m of cargo volume and ability to carry up to 99,790kg of payload, the company says.

Other companies offering 777 cargo conversions include Israel Aerospace Industries and Kansas Modification Center.