Selecting a Hangar Door Type

Small vs large aircraft hangar

For a single small plane, it’s easy to design a small building and door combination that works without breaking the bank, you can use low cost bifold or hydraulic tilt-up doors. Simple square building design typically requires little consideration of door loading or space requirements.

However, for hangars with larger openings (80 ft. or more) that can accommodate multiple nested aircraft, the typical bifold and tilt-up small door design doesn’t scale and larger more flexible sliding doors are required. In larger hangars the oversized door frames, hinges, and lifting mechanisms have forces that grow exponentially with size – raising costs and engineering complexity not just for the door but for the entire building envelope.

And for multi-aircraft hangars where daily operations are more intensive and complex, metal sliding or sectional doors are generally preferred. They span greater widths and when designed properly, allow for highly efficient operations – enabling individual aircraft to move in or out without requiring every door section to open. (For the record, fabric doors can usually do the job, but they are generally more expensive.)

Multi-aircraft hangar design is both an architectural and an engineering challenge

At Spec-Dor, we specialize in the five key areas that make these large door systems possible:

Segmented Door Panels

  • Doors are divided into multiple panels or modules, each aligned to a bay.
  • Only the section in front of the aircraft being moved needs to open.

Independent Drive Systems

  • Each door section has its own motor or drive.
  • Separate control panels per section with interlinked safeties.
  • Modern systems use motorized trolleys or dedicated operators for each panel.

Track & Guide Infrastructure

  • Robust overhead and floor tracks with precision rollers ensure smooth movement.
  • Tracks are engineered to support wide spans and remain aligned under wind and snow loads.

Control & Safety Systems

  • Programmable controls allow targeted opening of specific panels.
  • Safety interlocks, sensors, and limit switches prevent collisions with aircraft or other panels.

Structural Reinforcement

  • The hangar frame is engineered to handle concentrated loads where doors stack or nest.
  • Door weight sits on bottom track concrete, reducing building loads.
  • Rigid lintels or trusses prevent sagging across large spans.
Hangar door opening stages diagram

Here’s an example of a Spec-Dor hangar door solution that was specifically designed for optimal efficiency. The original proposal (not from Spec-Dor) had an expensive ten section design with motors on the sections at opposite ends. Getting the maximum opening was a complicated affair that required stacking the door sections in the middle and then shifting them to one side. Spec-Dor proposed half the number of sections, making them all motorized and controllable for a final cost that was less than the original 10 section design.

A Simple Size-Based Rule

Up to ~48 feet wide: Bifold doors are typically a practical, efficient solution.

80 feet wide or more: Bottom rolling (sliding) doors are generally the better choice, especially in professional, high-cycle operating environments.

Between these ranges, factors such as climate, building structure, and usage frequency become decisive.

Bottom Rolling (Sliding) Hangar Doors

Wide-span bottom-rolling hangar door

For wide openings and frequent operations, bottom rolling doors are the industry standard.

Pros

  • Scales easily for wide hangars: Ideal for 80-foot-plus openings common to commercial, MRO, and corporate aviation facilities.
  • No dead load on the header: Door weight transfers to the slab, simplifying steel design and reducing building structural loads.
  • Full vertical clearance: Essential for tall tails, maintenance access, and future aircraft flexibility.
  • Low maintenance: Reliable daily operations and minimal downtime.

Con

  • Track cleaning required: Ground tracks must be kept clear of ice, snow, and debris to ensure reliable operation. (Spec-Dor has bottom track heating options)

Bifold Hangar Doors

Bi-fold hangar door

Bifold doors remain effective within defined size limits.

Pros

  • Compact footprint: No side pockets required, useful on constrained sites.
  • Simple operation: Well suited for lower-cycle use and smaller commercial or private aircraft.

Cons

  • Headroom requirements: 20% of the opening height requiring adding more height to the building.
  • Frequent maintenance: to ensure safe lifting operation.
  • Dead weight of door: supported by the header structure.

Conclusion

As a general rule, bifold doors work well for hangars up to 48 feet wide, while bottom rolling doors dominate at 80 feet and beyond—particularly where high-frequency, professional operations demand reliability and scalability.