Image credits & sources
Every image on this site is a Wikimedia Commons file under a CC or public-domain license, FAA public-domain artwork, an attributed CC figure, or original artwork/renderings made for these pages. Attributions stay in place under each image on its original page; this page collects them in one spot.
Not reproduced: No Boeing maintenance manuals, SRM figures, or proprietary drawings. Embedded YouTube videos are public videos chosen as general orientation. They are not official Boeing, USAF, or USN training.
Credit sections on the original pages
- Structures: image credits & licenses (FAA public domain; Leishman, Introduction to Aerospace Flight Vehicles, Embry-Riddle, CC BY-NC-ND 4.0, shown unmodified)
- Machining reference: sources (Wikimedia Commons tooling and 707/737 photos, credited under each picture)
- CNC mill simulator: catalog reference images are renderings the simulator generates itself
- Outside courses and video pages: link-outs to public FAA, Tooling U, ACRATS, FTI, Quintus, NPTEL, and PRI/NADCAP resources
Every captioned figure (35)
Captions and attributions are reproduced exactly as they appear on each page. Images under CC BY-NC-ND (Leishman) are shown unmodified.
| Page | File | Caption / credit as shown |
|---|---|---|
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | faa-principal-airframe-units.jpg | Principal airframe units. The same groups apply to any fixed-wing airplane, from a trainer to a four-engine jet. Source: FAA Aviation Maintenance Technician Handbook – Airframe (FAA-H-8083-31B), Vol. 1, Ch. 1 “Aircraft Structures”, Figure 1-13. U.S. government work, public domain. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | faa-fuselage-skin-former-bulkhead.jpg | Skin, formers, and bulkhead. Formers hold the cross-section shape; the bulkhead is a heavier, often solid or pressure-carrying frame. Source: FAA Aviation Maintenance Technician Handbook – Airframe (FAA-H-8083-31B), Vol. 1, Ch. 1 “Aircraft Structures”, Figure 1-16 (“An airframe using monocoque construction”). U.S. government work, public domain. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | faa-wing-structure-nomenclature.png | Wing structure nomenclature. Left: nose ribs ahead of the front spar, full ribs between front and rear spars. Right: spanwise stringers stiffening the skin. Source: FAA Aviation Maintenance Technician Handbook – Airframe (FAA-H-8083-31B), Vol. 1, Ch. 1 “Aircraft Structures”, Figure 1-23. U.S. government work, public domain. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | wing-cutaway-stressed-skin.png | Stressed-skin wing cutaway. Rows of rivets fasten the skin to spar caps, stringers, and rib flanges; the ribs carry flanged lightening holes. Source: FAA artwork (credited “wingstructure © FAA, Public Domain”) as labeled in J. Gordon Leishman, Introduction to Aerospace Flight Vehicles, Ch. 10 “Aerospace Structures” (Embry-Riddle Aeronautical University, doi:10.15394/eaglepub.2022.1066). Public domain per the book’s Media Attributions. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | leishman-wing-spar-section.png | Wing section: main spar, rear spar, and the neutral axis. Spar caps sit as far from the neutral bending axis as the airfoil allows, where they do the most good in bending. Source: © J. Gordon Leishman, J. Gordon Leishman, Introduction to Aerospace Flight Vehicles, Ch. 10 “Aerospace Structures” (Embry-Riddle Aeronautical University, doi:10.15394/eaglepub.2022.1066). Licensed CC BY-NC-ND 4.0; reproduced unmodified for non-commercial training use. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | leishman-spar-types.png | Metal spar construction types. Extruded I-beam, built-up box, tubular (welded), and built-up I-beam with web stiffeners and T-section caps. Source: © J. Gordon Leishman, J. Gordon Leishman, Introduction to Aerospace Flight Vehicles, Ch. 10 “Aerospace Structures” (Embry-Riddle Aeronautical University, doi:10.15394/eaglepub.2022.1066). Licensed CC BY-NC-ND 4.0; reproduced unmodified for non-commercial training use. |
| Aircraft Structures — Components, Spars, Ribs & the Five Stresses | leishman-five-stresses.png | The five basic stresses. Compression, tension, shear, torsion, and bending. Real structure almost always sees several at once. Source: © J. Gordon Leishman/ERAU, J. Gordon Leishman, Introduction to Aerospace Flight Vehicles, Ch. 10 “Aerospace Structures” (Embry-Riddle Aeronautical University, doi:10.15394/eaglepub.2022.1066). Licensed CC BY-NC-ND 4.0; reproduced unmodified for non-commercial training use. |
| Machining and GD&T reference | vmc-exploded-labeled.jpg | Exploded view of a typical VMC. Click to open full size. Illustration is AI-generated for teaching and not to scale; labels added by hand-placed overlay. |
| Machining and GD&T reference | vmc-row.jpg | A row of shop VMCs, each with its pendant beside the door. CC BY 2.0, Marcin Wichary. Commons file. |
| Machining and GD&T reference | machining-center-interior.jpg | Inside a vertical machining center during a deep-hole drilling test, with a coolant line aimed at the tool. Public domain, Millermaster. Commons file. |
| Machining and GD&T reference | end-mill-types.jpg | Cobalt high-speed steel end mills: two-flute (top), four-flute (middle), and ball nose (bottom), with end views on the left showing the flute count. These have threaded shanks for a screw-lock chuck. CC BY-SA 2.0, Glenn McKechnie. Commons file. |
| Machining and GD&T reference | ball-end-mills.jpg | Ball end mills (ball nose) in three sizes. CC0, Bricetofly. Commons file. |
| Machining and GD&T reference | roughing-end-mills.jpg | Roughing (corncob) end mills with serrated edges and three different coatings. CC BY-SA 3.0, DieAlraune, edited by RalfR. Commons file. |
| Machining and GD&T reference | end-mills-drill.jpg | Half-inch center-cutting end mill (top), chamfering end mill (left), and drill (bottom). CC BY 4.0, Progress and Poverty. Commons file. |
| Machining and GD&T reference | face-mill-cutting.jpg | Indexable face mill cutting a hardened 4140 steel bar. CC BY 4.0, Progress and Poverty. Commons file. |
| Machining and GD&T reference | face-mill-inserts.jpg | Face mill carrying indexable carbide inserts around its rim. CC BY-SA 3.0, Sevela.p. Commons file. |
| Machining and GD&T reference | t-slot-cutter.jpg | T-slot cutter: a toothed disk on a narrow neck. CC BY-SA 3.0, Taku89. Commons file. |
| Machining and GD&T reference | dovetail-cutter.jpg | Dovetail cutter, widest at the cutting end. CC BY-SA 3.0, Taku89. Commons file. |
| Machining and GD&T reference | center-drills.jpg | Center drills in several sizes: a small pilot tip in front of a 60° cone. CC BY-SA 2.0, Glenn McKechnie. Commons file. |
| Machining and GD&T reference | form-vs-cut-tap.jpg | 5/8-18 taps cut in half: the form tap (left) is nearly solid, the cut tap (right) has deep chip flutes. CC BY 4.0, Progress and Poverty. Commons file. |
| Machining and GD&T reference | form-tap.jpg | 3/4-10 form (cold-forming) tap. No flutes; the faint groove along the thread carries lubricant. CC0, Progress and Poverty. Commons file. |
| Machining and GD&T reference | countersink.jpg | Four-flute countersink. CC BY-SA 2.0, Glenn McKechnie. Commons file. |
| Machining and GD&T reference | machine-reamer.jpg | Machine reamer with spiral flutes. CC BY-SA 2.0, Glenn McKechnie. Commons file. |
| Machining and GD&T reference | boring-head.jpg | Boring head on an R8 (manual-mill) shank. The boring bar clamps in one of the holes, and the adjusting screw slides it off center. CC BY-SA 3.0, Gargoyle888. Commons file. |
| Machining and GD&T reference | carbide-insert.jpg | Used triangular carbide insert with a center screw hole. CC0, Bautsch. Commons file. |
| Machining and GD&T reference | cat40-pull-stud.jpg | Pull stud (retention knob) threaded into the back of a CAT40 holder taper. CC BY 4.0, Progress and Poverty. Commons file. |
| Machining and GD&T reference | er-collet.jpg | ER collet with a 10 to 9 mm clamping range. The slots let it close evenly around a shank. CC BY-SA 4.0, Aweber4418. Commons file. |
| Machining and GD&T reference | vise-parallels.jpg | Vise setup on a mill: the part references the fixed jaw and sits on a ground block. Public domain, Cdang. Commons file. |
| Machining and GD&T reference | edge-finder.jpg | Double-ended mechanical edge finder: a round tip for edges and a pointed tip for lining up on a mark. Commons files it under wigglers. CC BY-SA 2.0, Glenn McKechnie. Commons file. |
| Machining and GD&T reference | dial-test-indicator.jpg | Dial test indicator checking runout of a collet holder in a lathe spindle. CC BY-SA 4.0, David English. Commons file. |
| Machining and GD&T reference | panam-707-side.jpg | Boeing 707, whole-jet side view. Public domain, San Diego Air and Space Museum. Commons file. |
| Machining and GD&T reference | 737-flaps.jpg | Boeing 737, wing with trailing-edge flaps extended. CC BY-SA 3.0, Manic-nirvana. Commons file. |
| Machining and GD&T reference | 737-empennage.jpg | Boeing 737-800, empennage: vertical stabilizer and horizontal tail. CC BY-SA 2.0, Cory W. Watts. Commons file. |
| Machining and GD&T reference | 707-engines.jpg | Boeing 707-338C, engines on pylons under the wing. CC BY-SA 4.0, Wal Nelowkin. Commons file. |
| Machining and GD&T reference | 707-gear.jpg | Boeing 707, main landing gear. CC BY-SA 3.0, Mgw89. Commons file. |
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