Heinkel HD 21

what is it?

The Heinkel HD 21 was a trainer built in Germany during the 1920s. It was a conventional single-bay biplane with staggered wings braced with N-type interplane struts. The main units of the fixed, tailskid undercarriage were linked by a cross-axle, and the aircraft had three open cockpits in tandem, although one of these was typically faired over.

🔎How to recognise it: 1 engine · 10.6 m wingspan

base stats

• speed 135 km/htop speed
• size 980 kgmax take-off weight
• built 18made in total

Bars compare against all aircraft: 3,500 km/h, 20,000 km, 850 seats; size and number built on a log scale up to 640 t (An-225) and 45,000 built (Cessna 172).

fun facts

• 🎂First flew 102 years ago, in 1924.
• 🚗Wingspan of 10.6 m: about 2 cars parked nose to tail.

spec sheet

first flight

1924

number built

18

role

civil trainer

origin

German Reich

makers

Arado Flugzeugwerke, Heinkel

engines

1× Mercedes D.I

length

7.3 m

wingspan

10.6 m

height

3.1 m

max take-off weight

980 kg

top speed

135 km/h

range

—

Specs are for the version in the Wikipedia article's specification section. Blank means the sources don't say.