The FAA has accepted Kansas Modification Center’s project specific certification plan for its Boeing 777-300ERCF cargo conversion.
The project specific certification plan (PSCP) document describes Kansas Modification Center’s (KMC) 777-300ER passenger to freighter (P2F) modification and establishes its regulatory requirements and compliance.
“Ultimately the PSCP influences the design because of the design requirements ‘baked’ into it,” explains Eric Kivett, program manager at the National Institute for Aviation Research (NIAR) WERX. NIAR WERX is subcontracted to provide engineering and modification services for the 777-300ERCF.
Establishing the 777-300ERCF’s PSCP required several months of collaboration between the FAA’s Certification Office and the Wichita-based cargo conversion specialist
“If we do not get the certification requirement established early, then from a risk perspective, there will be a danger of ‘rework’ toward the end of the program," says Kivett. "It is possible a conversion program could increase in cost and experience unscheduled delays when PSCP acceptance is not in place."
The 777-300ERCF is one of three 777-300ER P2F conversion programs currently under development. Supplemental type certificate approval for the 777-300ERCF is expected to be granted in 2024.
Kivett says the FAA has accepted and closed the majority of issue papers linked to the 777-300ERCF certification process.
KMC expects to cut a hole in its prototype aircraft later this year before beginning work to install the main deck cargo door modification.
“People ask why you are waiting to cut the hole in the fuselage,” says Kivett. “The quick answer is it is much better to cut a hole in the fuselage after the cargo door and surround structure have been properly engineered and the certification path confirmed.”
To comply with the newer FAA regulations incorporated on the 777 modification programs, KMC anticipates an additional ground test requirement. “We will be conducting the necessary test sequences on the baseline aircraft this fall. If we had cut a hole in the fuselage prematurely, we would now have to find a second aircraft for testing,” says Kivett.
A fully functioning demonstrator cargo door has also been built for engineering and testing purposes. The demonstrator is being used to prove the design of the 777-300ERCF’s main deck cargo door, including its structure and mechanisms. The demonstrator is also being used to evaluate control and hydraulic systems under normal and abnormal operation. Later tests will focus on the door’s operational durability.
“We introduce failures in the system, and we have tested the tolerance of the door to those failures," says Kivett. "The door is one of the later things installed on a freighter conversion and we did not want to discover a problem at a late stage in the game."
KMC is looking to achieve a 93-ton gross payload with its 777-300ERCF. It expects to attain this through a relatively low aircraft operating empty weight and without a need to modify the airplane information management system.
The engineering team is identifying materials required for the modification. KMC's is now outsourcing materials and hardware to mitigate against any potential future shortages.