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Bombardier Q400 Cargo Shelf Part Redesign


Comtek Case Study: Q400 Forward Cargo Shelf
HORIZON AIR SeaTac, Washington



Project Overview:

Founded in 1981, Horizon Air is the eighth largest regional airline in the USA, serving 52 cities in the United States, Canada and Mexico. Horizon Air and its sister carrier Alaska Airlines are subsidiaries of Alaska Air Group.
In recent years, Horizon Air encountered problems with its Q400 aircraft cargo shelf. The shelf, located in the forward cargo compartment near the front of the plane, is made from HSP (honeycomb sandwich panel) supported approximately 3 feet off the aircraft floor and mounted to the fore and aft bulkheads. It is secured with fasteners that thread into inserts potted in the HSP. The shelf is primarily used by the flight crew who can access the compartment from the cabin.
The original cargo shelf was made of a less robust HSP material resulting in the following damage from regular and repeated use:

  • Worn and/or torn skins on the upper surface of the shelf

  • Crushed core

  • Damaged edge strips

  • Damage to the outboard lip caused by impact from items being loaded onto the shelf

The damage to the shelf became significant with repeated use, until it became unusable. While not a significant airworthiness issue, the maintenance crew would often remove the damaged shelf altogether. This reduces storage capacity and convenience, but the shelf became unserviceable so frequently that it was more cost effective to not use it than to buy a replacement of the same build.

Project Objectives:

The objective of the project was to design, manufacture and install a new PDA component designed specifically to eliminate all of the problems experienced by the operators. Horizon Air looked to Comtek to take on this project because of their significant design and HSP manufacturing experience.



Comtek developed its new PDA shelf using existing, approved HSP materials, thus reducing the amount of time needed for certification. The new shelf consists of thick glass/epoxy face sheets and a Nomex core. The upper face sheets are thicker than the lower skins, to increase both the compressive strength of the shelf in bending and its core crush resistance without adding unnecessary mass.

In addition, a polyester matte overlay material was used on the upper face to further increase the component's damage tolerance. The outboard folded HSP lip was replaced with an aluminum angle to reduce costs while providing the same form, fit and function. The edge strips and forward extrusion were redesigned to sit flush in a recess of the matte overlay material, which minimizes the risk of damage when items are removed from the shelf. 


Results Delivered:

The Q400 Forward Cargo Shelf was redesigned to provide the following improvements for Q400 operators: 

  • Increased wear resistance due to presence of the matte overlay material

  • Increased puncture and core crush resistance due to the heavier glass skins, denser core and the matte overlay material

  • The outboard lip resists damage to cargo impact and handling much better than the folded HSP

  • The inboard edging now sits flush with the panel skin preventing any step which can catch when items are removed from the shelf.

The redesigned shelf is a significantly tougher and more durable than the part it replaces, and at only 7.75 lbs, the weight increase is negligible.  In addition, even though the materials used in the part's construction represent a substantial upgrade, pricing is still lower than the original. Comtek's shelf also comes with a 4 year warranty on material and workmanship.

Like all PDA parts approved by Transport Canada, Comtek's cargo shelf is accepted by both the FAA and EASA as equivalent to a PMA part.


For more information about Comtek's upgraded Q400 Cargo Shelf or to discuss an issue you're having with a component Contact Us >>







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