Note: Jon Ostrower at Flight Global has this update.
The underlying cause for the Cargolux rejection (the airline’s word) of the delivery of the first two Boeing 747-8Fs is performance.
Performance is based, generally, on two things: weight of the airplane and specific fuel consumption (SFC). If the airplane is too heavy, it may not meet the payload and/or range guarantees. If SFC is below specifications, range/payload may be affected. If you combine the two issues, a larger problem exists.
It’s been well known for more than a year that the 747-8 was “heavy” and the GEnx engines burned too much fuel. Despite the two year delay, GE hasn’t developed a performance improvement package (PIP) for the 747-8 that will be ready before the end of 2013, according to sources familiar with the situation. GE’s priority has been the 787 program.
We asked Boeing about the weight and SFC issues. Here is its response: