120x200 Steel Aircraft Hangar

This page is ordered around vehicle bay, because that is the decision this footprint settles first and every later choice follows from it.

The footprint holds 6 functional zones — 2 across by 3 deep — and leaves 20 feet of depth for an enclosed office and crew wing along one wall, keeping the clear aircraft floor rectangular and undivided.

Efficiency is the useful number here: 4,000 square feet of enclosed floor per functional zone, against a 2592-square-foot module. That leaves working slack around each position. The corner nobody plans for is the one that fills first, which is an argument for planning it.

A 120 by 200 footprint is a clearly directional plan: 24,000 sq ft enclosed by 640 ft of wall, at a 1.7:1 length-to-width proportion. Along its 200 ft dimension it takes 3 runs of functional zones at 54 ft, leaving 38 ft over — the 38 ft is where the argument about this size actually happens. Taken purely as arithmetic, 120 by 200 gives 2 functional zones across the 120 ft dimension once 18 ft is reserved for movement, and 3 deep along the 200 ft dimension. Run as a a based-operations hangar combining aircraft floor with office and crew functions, 6 ft across is below the 16 ft this use needs to be worth planning, so there is no enclosed wing, so office and crew functions occupy corners of the clear floor and reduce it to less than a full rectangle The main door and its supporting framing are typically the single largest cost driver relative to a hangar's overall size.

At 120x200 the operating question is a specific one: do office and crew functions live in a defined wing along one wall, or have they taken corners out of the aircraft floor one at a time? That is a different question from the one a aircraft hangar of another shape has to answer, and it is why this footprint is planned as a based-operations hangar combining aircraft floor with office and crew functions rather than as generic covered area.

Span drives headroom at 120x200: 120 feet of width on a 3:12 pitch puts 29 feet over the middle and 14 feet at the walls, so where a tall item stands matters as much as how tall it is. Insulating later is possible; framing for insulation later is much harder.

Height on a 120 ft span is a separate decision from the 200 ft length, and it is the span that sets the frame's behavior. Raising the eave over 24,000 sq ft affects every bay along the 200 ft dimension, so the test is whether based aircraft operations layout genuinely needs the extra clear height or only the floor area.

Nominal bay division computes to 8 bays at about 25 feet, narrower than the 48-foot module — so frame lines land inside positions and the interior has to be set out from the columns. Interior divisions are the last decision that should be fixed, because they are the first one that usually changes.

With 3 rows deep, the rear row is behind the front one. Without a route past it, those functional zones become storage positions rather than working ones — the real cost of depth at this width. Utilities entering on the wrong elevation quietly rewrite the interior layout.

The office and crew wing is the natural place to add capacity, since the aircraft floor is normally sized with margin and staff functions are what tend to outgrow their space first.

Configured as a based-operations hangar combining aircraft floor with office and crew functions, 120x200 is judged on whether the 6 functional zones it holds match the operation, and on whether the 24 feet of spare width leaves the route this mode depends on.

• Does the work need an interior street with independent zones on both sides and turning room at each end, or does it need a second lane that this 120-foot span cannot give?
• Is the 200-foot length being bought for depth, or for the repeated bays — a long uninterrupted bay sequence that suits repetitive layouts and continuous processes?
• Which aircraft dimension governs — wingspan at the opening or tail height?
• Which door system suits the operation, and has the end frame been designed for it?

The 120-foot gable can carry 2 openings, one per functional zone, with 24 feet of wall left for piers between and beside them — the arrangement that keeps each position independently reachable. Long spans buy flexibility that is only worth paying for if the operation actually changes shape.

A dedicated personnel entrance into the office wing, distinct from the main aircraft door, keeps daily staff arrival from requiring the large door to be opened.

The operation this hangar floor could equally be run as is a private hangar built around one owner's aircraft and personal storage: there is no side bay, so personal storage lines the same walls the aircraft has to clear on its way in and out. The aircraft floor stays open and rectangular, and office, crew rest, briefing and any administrative space are consolidated into a single enclosed band along one wall rather than distributed piecemeal.

Depth arithmetic leaves a working end zone here. 2,400 square feet sits past the last row, which is why 120x200 tends to be planned with an enclosed office and crew wing along one wall, keeping the clear aircraft floor rectangular and undivided designed in rather than added later. What the building holds in its busiest week is the honest brief; the rest of the year is slack.

Spare width is the more valuable of the two leftovers here: a continuous 24-foot strip beats the same area stranded at the end of the run, because it touches every position along the way. Plan the exit as carefully as the entrance; buildings are emptied under more time pressure than they are filled.

Spent as a square 155 by 155 instead, the same 24,000 sq ft would stand 2 functional zones across rather than 2, and would trade this plan's length for parallel access. That is the width-against-depth decision this footprint has already made. Compared with a 120 by 150 of the same width, the extra depth here adds run rather than reach: it buys about 3 functional zones in line, and every position past the second is retrieved by moving what stands in front of it. At this scale the building is infrastructure rather than a shed; scheduling, traffic direction and separation of activities matter more than any single dimension. The longest internal travel on a 120 by 200 plan is about 233 ft corner to corner, and the shortest useful one is the 120 ft cross-run. For a a based-operations hangar combining aircraft floor with office and crew functions that matters where based aircraft operations layout sits, because shortening the 120 ft run to serve it lengthens every trip along the 200 ft dimension. Office, crew or administrative functions attached to a hangar are best consolidated into one enclosed wing rather than distributed across corners of the clear floor. That movement pattern, not the 24,000-square-foot total, is what decides whether the leftover 20 feet is useful here.

• 80x120 moves the count from 6 to 4 functional zones (2 across by 2 deep), which is the reason to choose between them.
• 100x100 moves the count from 6 to 2 functional zones (2 across by 1 deep), which is the reason to choose between them.
• 100x120 moves the count from 6 to 2 functional zones (2 across by 1 deep), which is the reason to choose between them.

Because this footprint is planned as a based-operations hangar combining aircraft floor with office and crew functions, the useful next reads are different from the ones a differently shaped aircraft hangar suggests: based aircraft operations layout, hangar office and crew wing, functional zone planning for hangars.

Quantities, not prices, are publishable here: roof cladding runs 24,739 square feet — 3% above the 24,000-square-foot floor at a 3:12 pitch — with 296.3 cubic yards of nominal slab beneath it. Depth is bought cheaply and width expensively, which is why this proportion tends to be argued about before anything else.

Finished office space, crew amenities and any conditioning for those areas carry a disproportionate share of the project relative to the unfinished aircraft floor beside them.

• the door system type, which drives the end-frame design
• the clear opening width and height the aircraft requires
• the eave height the door opening forces across the frame
• the apron outside the opening