The combi-aircraft is the centaur of aviation. Like the mythological figure it’s a rare find, but it still serves a purpose in certain parts of the world.
Now Pemco Conversions, a subsidiary of aircraft leasing and cargo transport provider Air Transport Services Group (NASDAQ: ATSG), is taking the half-passenger, half-cargo concept to the next level.
The dual-use plane is called a FlexCombi — the ultimate in flexibility.
It’s a Boeing 737-700 passenger plane converted to a cargo configuration, but it has a sliding bulkhead that gives an operator three options: a 24-seat cabin with room for six pallet positions; a 12-seat cabin with a seven-pallet payload; and a full freighter mode with eight container positions, two of them smaller variants. Pallets are loaded through an oversize cargo door. Loose cargo and baggage go in the lower hold, which is too small in narrow-body planes for containers.
The U.S. Federal Aviation Administration this month issued Pemco a supplemental type certificate for the unique conversion design.
Pemco, based in Tampa, Florida, has been producing converted 737-300 and 737-400 full freighters for years. It even offers a “Quick Change” version in the -300 series that can go back and forth between a freighter and full passenger plane with 147 seats. The changeover takes 30 minutes because the seats are on pallets anchored to the floor and are simply rolled in or out on built-in tracks.
The combination – hence “combi” – aircraft has always been a niche market but previously had some mainstream use.
KLM recently got rid of its last 747-400 combi aircraft. British Airways, Iberian and Asiana also operated 747 hybrid aircraft. Icelandair and the former Braniff International operated some 737 versions.
Alaska Airlines retired its 737 cargo-passenger planes in late 2017, replacing them with three dedicated 737-700 freighters. The combis served as a crucial link for small, isolated communities across the state. The combis enabled Alaska to provide daily cargo service versus a couple of times per week.
Industry officials say the dual-use planes are useful in remote areas because they allow airlines to split flights with freight and people for locations where there is not huge demand for either. The configuration can cause operational challenges trying to balance whether to take a larger load of cargo or more people.
“We have a lot of customers in Canada that use the 737-400 combis because it’s a vast area. They fly freight and passengers up to camps, and a lot of these companies shuttle high school sports teams around,” Mike Andrews, director of conversion programs at Pemco, said in an interview.
Andrews said South American governments also buy combis to ferry troops and cargo at the same time.
Pemco has completed the first 737-700 FlexCombi for Bahrain-based Chisholm Enterprises and its subsidiary, Texel Air, a nonscheduled cargo airline, ATSG said in a news release announcing the FAA approval. Texel will operate the hybrid aircraft from Bahrain International Airport.
The company was able to get the plane to delivery already because under the FAA’s certification program it could simultaneously work on the conversion and share data with regulators who signed off on each stage and then did a final review, Andrews explained. In the past, aviation companies had to wait until the FAA completed its analysis before starting any aircraft redesign.
Pemco, which is licensed by Boeing to do the conversions, said it plans to seek certification from the European Aviation Safety Agency and the Civil Aviation Administration of China.
The conversion house is also developing a 737-700 full freighter, which will feature nine pallet positions and a payload of up to 45,000 pounds.
ATSG, better known for operating cargo fleets for Amazon Air and express carrier DHL, and leasing planes to UPS and other clients, acquired Pemco in 2017. Subsidiary Air Transport International has four Boeing 757-200s combis under an operating agreement with the U.S. military, according to the company’s website.
Another subsidiary, Cargo Aircraft Management, landed its first dry lease (aircraft-only) customer in Mexico this week. ATSG said MasAir (Aerotransportes Mas de Carga, S.A. de C.V.) is renting a 767-300 converted freighter for five years to help with its expansion in Latin America and the U.S.
ATSG reports second-quarter earnings on Wednesday.