Boeing 307 Stratoliner

what is it?

The Boeing Model 307 Stratoliner (or Strato-Clipper in Pan American service, or C-75 in USAAF service) is an American stressed-skin four-engine low-wing tailwheel monoplane airliner derived from the B-17 Flying Fortress bomber, which entered commercial service in July 1940. It was the first airliner in revenue service with a pressurized cabin, which, along with supercharged engines, allowed it to cruise above the weather. As such it represented a major advance over contemporaries, with a cruising speed of 220 mph (350 km/h) at 20,000 ft (6,100 m) compared to the Douglas DC-3's 160 mph (260 km/h), at 8,000 ft (2,400 m) then in service.

🔎How to recognise it: 4 piston engines with propellers · 32.7 m wingspan

base stats

• speed 402 km/htop speed
• range 2,092 kmwithout refuelling
• seats 38passengers
• size 20.4 tmax take-off weight
• built 10made 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 88 years ago, in 1938.
• 🏎️Top speed is 3.1× a car on the Dutch motorway (130 km/h).
• 🚗Wingspan of 32.7 m: about 7 cars parked nose to tail.
• 🐘Fully loaded it can weigh as much as 3 African elephants (~6 t each).
• 🌍Range of 2,092 km: 12× Amsterdam to Brussels.

piston: A car-like piston engine turning a propeller: simple and cheap, the classic small plane.

spec sheet

first flight

1938-12-31

introduced

1940

retired

1975

status

retired

number built

10

role

airliner

origin

🇺🇸 United States

makers

Boeing

engines

4× Wright GR-1820-G105A Cyclone

passengers

38

length

22.7 m

wingspan

32.7 m

height

6.3 m

max take-off weight

20.4 t

top speed

402 km/h

cruise speed

357 km/h

range

2,092 km

ceiling

7,254 m

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