Overall Dimensions and Wing Geometry

Hangar planning, wingtip clearance and the numbers an examiner expects you to have at hand all come out of one table. Every figure below is stated by the manual to be approximate — they describe the airframe, they are not tolerances.

At a glance

• Wing span13.42 m (44 ft)
• Wing span including ACL13.55 m (44.5 ft)
• Overall length8.56 m (28 ft 1 in)
• Overall height2.49 m (8 ft 2 in)
• Propeller diameter1870 mm (6 ft 2 in)
• Wing area16.29 m² (175.3 sq.ft)
• Mean aerodynamic chord1.271 m (4 ft 2 in)
• Aspect ratio11.06
• Dihedral5°
• Leading edge sweep1°
• AirfoilWortmann FX 63-137/20 - W4

The two span figures

The wing spans 13.42 m, or 44 ft. Measured to include the anti-collision light it spans 13.55 m, or 44.5 ft. Thirteen centimetres separate them, and the larger one is the figure that decides whether the aeroplane fits between two obstacles.

Overall length is 8.56 m (28 ft 1 in) and overall height 2.49 m (8 ft 2 in).

Figure: General arrangement with principal dimensions (redrawn).

The wing itself

The wing uses the Wortmann FX 63-137/20 - W4 airfoil. It covers an area of 16.29 m² (175.3 sq.ft) with a mean aerodynamic chord of 1.271 m (4 ft 2 in), an aspect ratio of 11.06, 5° of dihedral and 1° of sweep at the leading edge.

The propeller diameter is not in the dimensions table

The propeller measures 1870 mm, or 6 ft 2 in, across. That figure is printed on the three-view drawing as a callout struck through the propeller hub — the dimensions table itself does not list it. The approved limitations chapter states the same figure as 187 cm, so the two agree; but if you look only at the dimensions table you will not find it at all.

NOTE — All the dimensions in this lesson are stated by the manual to be approximate.

Reading the drawing against the table

Six of the drawing's dimensions repeat the table exactly: span 13420 mm, span including the anti-collision light 13550 mm, length 8560 mm, height 2490 mm, landing gear track 2950 mm and wheelbase 1735 mm. The drawing is not a pure duplicate of the table, though — it also carries the propeller diameter, and it prints the anti-collision light figure with a decimal comma where the table uses a point.

Check yourself

• What are the two wing span figures, and what distinguishes them?

• What is the propeller diameter, and why will you not find it in the dimensions table?

• What is the wing area, and what is the mean aerodynamic chord?

• Which airfoil does the wing use?

• Are the dimensions in this chapter exact figures or approximate ones — and what does the manual itself say?

Study aid — always fly your aircraft's current AFM/POH.