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Su-27 Orthographic Drawing: Plan and Side Outlines
Learn to draft a Su-27 in true plan and side orthographic views using grids, labeled axes, and a defined line convention for valid alternatives.
Free lesson
Four exercises
Worked answers
Object Drawing Lessons
Orthographic drawing shows an object from fixed viewing directions without perspective. For the Su-27, the plan view (looking down) and side view (looking horizontally) are the most informative outlines. This lesson defines a simple convention: solid lines for visible edges, dashed lines for hidden edges, and a centerline axis for symmetry. Because aircraft outlines can be simplified differently, the rubric rewards consistent proportions and labeled choices rather than one universal shape. All measurements below are hypothetical examples for practice; measure your own reference or equipment when drafting.
Practice materials: Printable downloads are not available for this lesson yet. Use the instructions and four exercises below.
Set up the orthographic box and axes
Begin with a rectangular drafting area divided into two equal panels: plan view above, side view below. Draw a horizontal centerline through the plan panel and a vertical centerline through the side panel. Label the plan axes X (spanwise, left-right) and Y (chordwise, nose-tail). Label the side axes Y (chordwise) and Z (height). Keep one unit scale, for example 1 grid square equals 1 hypothetical length unit, and write it beside the box.
The plan view is a top-down outline: nose at the left, tail at the right, wings extending symmetrically above and below the centerline. The side view is a horizontal outline: nose at the left, tail at the right, vertical fin rising above the fuselage line. Align the nose and tail positions vertically between panels so the two views share the same chordwise stations.
- Draw the outer rectangle and divide it into two panels of equal height.
- Add the plan centerline and side centerline; label X, Y, Z axes.
- Mark nose station and tail station on both panels at the same horizontal positions.
- Write the scale note: one grid square equals one hypothetical unit.
Draft the plan outline with symmetry
Work from the centerline outward. Mark the nose tip on the centerline, then the cockpit region, wing root leading edge, wing root trailing edge, and tail tip. Because the Su-27 is roughly symmetric in plan, draft one half and mirror key stations across the centerline. Use solid lines for the visible outer edge and dashed lines only where a hidden structural line is intentionally shown, such as an internal spar station if you choose to include it.
Keep wing sweep and tailplane sweep as labeled angles or grid counts. For example, a hypothetical wing leading edge may advance two grid squares chordwise for every five squares spanwise; record that ratio beside the plan. Do not invent manufacturing tolerances; if you measure a printed reference, note the measured value and label it as measured.
- Plot nose tip, cockpit canopy outline, and radome join on the centerline.
- Mark wing root leading and trailing stations on the centerline.
- Draw the half-wing outline outward, then mirror it across the centerline.
- Add horizontal tail outline and label sweep as a grid ratio.
- Check symmetry by folding or measuring equal distances from the centerline.
Draft the side outline and vertical fin
In the side panel, the fuselage appears as a long horizontal shape with a raised cockpit canopy near the nose and a vertical fin near the tail. Mark the same nose and tail stations used in the plan so the views align. Draw the canopy as a simple curved polygon, the fuselage underside as a gently sloping line, and the fin as a trapezoid above the rear fuselage.
Use the side centerline for height reference: the fuselage centerline is horizontal, and the fin top is measured in grid squares above it. Label the fin height and canopy height as hypothetical grid counts. If you include landing gear, show it as a simple vertical line with a wheel circle, and state that the gear is extended for the drawing convention.
- Transfer nose and tail stations from the plan panel to the side panel.
- Draw the fuselage centerline and mark canopy start and end stations.
- Outline the canopy, fuselage top, underside, and tail cone.
- Draw the vertical fin as a trapezoid and label its height in grid squares.
- Add optional landing gear as a labeled convention, not a measured standard.
Apply the line convention and self-check
The convention for this task is explicit: solid lines show visible edges in the chosen view; dashed lines show hidden edges only when you deliberately include them; centerlines are long-dash-short-dash and labeled. Lettering is not graded on style, only on legibility. X-height is defined as baseline to midline, and letter styles may vary, so any clear handwritten or drawn label is acceptable.
Self-check by comparing station alignment between panels, confirming symmetry in plan, and verifying that every labeled dimension matches the grid count. A valid alternative is a simplified outline that omits internal dashed lines, provided the outer silhouette and labeled stations remain consistent.
- Confirm nose and tail stations align vertically across panels.
- Measure plan symmetry left and right of the centerline.
- Verify each labeled grid count against the drawn squares.
- Check that solid and dashed lines follow the stated convention.
- Record any simplification choice beside the drawing.
Worked example
A student drafts a plan view with nose at station 0 and tail at station 20 grid squares. The wing root leading edge is at station 8 and trailing edge at station 14. The half-span is 6 squares. Draft the mirrored wing outline and state one check.
Worked answer
Plot the right half-wing from station 8 to 14 at the centerline, extend outward 6 squares, mirror the same stations to the left half, and label the wing root chord as 6 squares. Check symmetry by measuring 6 squares from the centerline on both sides at the wing tip station.
Why: The plan view is symmetric, so the left half mirrors the right half. Labeling the root chord as the difference between trailing and leading stations (14 minus 8 equals 6) keeps the arithmetic checkable and consistent with the grid.
Check: Measure the distance from the centerline to each wing tip; both should equal 6 grid squares. Confirm the root chord label equals 14 minus 8.
Four practice exercises
Exercise 1
In a plan view, the nose is at station 0 and the tail at station 24 grid squares. The horizontal tail leading edge is at station 18 and trailing edge at station 22. The half-span of the tail is 4 squares. Describe the mirrored tail outline and give one arithmetic check.
Show answer and check
Draw the right tail from station 18 to 22, extend 4 squares outward, mirror to the left, and label the tail root chord as 4 squares. Check that both tail tips are 4 squares from the centerline.
Why: The tail root chord is the trailing station minus the leading station: 22 minus 18 equals 4. Symmetry requires equal half-spans on both sides.
Check: Measure each tail tip distance from the centerline; both should be 4 grid squares. Confirm the chord label equals 22 minus 18.
Exercise 2
In a side view, the fuselage centerline is at height 0. The canopy top is 3 grid squares above the centerline and the fin top is 7 squares above it. The fin leading edge is at station 16 and trailing edge at station 20. Describe the fin trapezoid and state the fin height label.
Show answer and check
Draw the fin from station 16 to 20, rising from the fuselage top to 7 squares above the centerline, and label the fin height as 7 grid squares. The canopy top is labeled 3 squares above the centerline.
Why: Heights are measured from the side centerline, and the fin chord is the difference between trailing and leading stations: 20 minus 16 equals 4 squares.
Check: Count grid squares from the centerline to the fin top; it should be 7. Confirm the fin chord label equals 20 minus 16.
Exercise 3
A student labels a wing sweep as 2 grid squares chordwise for every 5 squares spanwise. The half-span is 10 squares. How many grid squares does the leading edge advance chordwise from root to tip, and what check confirms it?
Show answer and check
The leading edge advances 4 grid squares chordwise, because 10 divided by 5 equals 2, and 2 times 2 equals 4. Check by counting the chordwise shift on the drawing from root to tip.
Why: The ratio is 2 chordwise per 5 spanwise. For a half-span of 10, there are two 5-square intervals, so the chordwise advance is two times 2 equals 4 squares.
Check: Measure the chordwise distance between the root and tip leading edge stations; it should equal 4 grid squares.
Exercise 4
The plan view nose is at station 0 and tail at station 20. The side view uses the same stations. A student places the side-view nose at station 2 and tail at station 22. State the alignment error and the correction.
Show answer and check
The side view is shifted two stations to the right. Move the side-view nose to station 0 and tail to station 20 so both panels share the same chordwise stations.
Why: Orthographic views must align on shared axes. The chordwise stations are the shared reference, so a two-station shift breaks alignment.
Check: Draw a vertical line through the plan nose and confirm it passes through the side nose; repeat for the tail.
Common mistakes
- Drawing the plan and side views at different horizontal scales. Use one grid scale for both panels and align nose and tail stations vertically.
- Treating the centerline as a visible edge and drawing it solid. Use the long-dash-short-dash centerline convention and label it as an axis.
- Inventing a precise wing sweep angle without measuring a reference. Label sweep as a grid ratio or as a measured value from your own reference, and state that numerical examples are hypothetical.
- Making the two wing halves asymmetric in plan. Draft one half, mirror key stations, and measure equal distances from the centerline.
Self-check rubric
- Plan and side panels share one labeled grid scale and aligned nose and tail stations.
- Plan outline is symmetric within one grid square, or asymmetry is labeled as intentional.
- Side outline includes fuselage, canopy, and vertical fin with labeled grid counts.
- Line convention is stated and followed: solid visible edges, optional dashed hidden edges, labeled centerlines.
- Labels are legible; letter style may vary and x-height is baseline to midline.
- Any numerical values are labeled as hypothetical examples or as measured from a stated reference.
- Simplifications are labeled and do not contradict the outer silhouette.
Questions and answers
Do I need to show hidden lines?
No. Hidden dashed lines are optional. If you omit them, state that the drawing shows visible outlines only. The rubric accepts either choice if it is labeled.
Can I simplify the canopy shape?
Yes. A simplified polygon canopy is valid if its start and end stations are labeled and consistent with the side view.
What units should I use?
Use grid squares as hypothetical units. If you measure a real reference, record the unit and label it as measured, not as a standard.
Is a perspective sketch acceptable?
No. This task is limited to orthographic plan and side outlines. Perspective or isometric rendering is outside the boundary.