UPS and FedEx are scrambling to secure aircraft capacity for the holiday season after their MD-11 freighters were grounded following a deadly crash in Kentucky that killed 14 people, reports the London Independent.

The November 4 accident involved a 34-year-old MD-11 jet whose engine detached during take-off, sending the plane into nearby businesses and killing its crew of three. The grounding of the ageing fleet has created a serious capacity shortage as shipping volumes rise ahead of Christmas.

Derek Lossing of Cirrus Global Advisors told Bloomberg the companies had planned to rely on those aircraft and now face a "real capacity crunch." Shocking footage showed the plane flying low before exploding into a fireball, leaving a long scar visible in satellite images.

The crash could mark the end of the MD-11, with 109 still in service worldwide. UPS operates 26, about nine per cent of its fleet, while FedEx has 28, around 4 per cent. Safety investigators found fatigue cracks in the structure attaching the turbofan engine to the wing.

The Federal Aviation Administration grounded all MD-11s and 10 related DC-10s. The companies may retire the aircraft, which average more than 30 years old, and replace them with newer Boeing and Airbus models, though delivery backlogs mean replacements could take years.

Mary Schiavo, former Department of Transportation Inspector General, said repairs may not be worthwhile given safer alternatives. The FAA is working with NTSB and Boeing, which acquired the MD-11 manufacturer in 1997, to determine next steps.