Dornier Do J

https://en.wikipedia.org/wiki/Dornier_Do_J

The Dornier Do J Wal ("whale") is a twin-engine German flying boat of the 1920s
designed by Dornier Flugzeugwerke. The Do J was designated the Do 16 by the
Reich Air Ministry (RLM) under its aircraft designation system of 1933.

The Do J had a high-mounted strut-braced parasol wing with two piston engines
mounted in tandem in a central nacelle above the wing; one engine drove a
tractor and the other drove a pusher propeller. The hull made use of Claudius
Dornier's patented sponsons on the hull's sides, first pioneered with the
earlier, Dornier-designed Zeppelin-Lindau Rs.IV flying boat late in World War I.
The Do J made its maiden flight on 6 November 1922. The flight, as well as most
production until 1932, took place in Italy because of the restrictions on
aviation in Germany after World War I under the terms of the Treaty of
Versailles. Dornier began to produce the Wal in Germany in 1931; production went
on until 1936.

The civil version (Kabinenwal or Verkehrswal) had a cabin in the nose, offering
space for up to 12 passengers, while the open cockpit was moved further aft.
Main users of this version were Germany, Italy, Brazil and Colombia.

Over 250 Wals were built by CMASA and Piaggio in Italy, CASA in Spain, Kawasaki
in Japan, Aviolanda in the Netherlands and Dornier in Germany.

Role
Flying boat

Manufacturer
Dornier Flugzeugwerke

First flight
6 November 1922

Introduction
1923

Retired
1950

Primary user
Spain

Number built
250

Numerous airlines operated Wals on scheduled passenger and mail services with
great success. The source Robert L. Gandt, in 1991, (pages 47–48) lists the
following carriers: SANA and Aero Espresso of Italy; Aero Lloyd and Deutsche
Luft Hansa of Germany; SCADTA of Colombia; Syndicato Condor of Brazil; Nihon
Koku Yuso Kaisha of Japan. According to Nicolaou, 1996 the Dornier Wal was
"easily the greatest commercial success in the history of marine aviation".

The Norwegian polar explorer Roald Amundsen accompanied by Lincoln Ellsworth,
pilot Hjalmar Riiser-Larsen, and three other team members used two Dornier
seaplanes in his unsuccessful attempt to reach the North Pole in 1925. His two
aircraft, N-24 and N-25, landed at 87° 44' north. It was the northernmost
latitude reached by any aircraft up to that time. The planes landed a few miles
apart without radio contact, yet the crews managed to reunite. One of the
aircraft, the N-24, was damaged. Amundsen and his crew worked for over three
weeks to prepare an airstrip to take off from the ice. They shoveled 600 tons of
ice while consuming only one pound (454 g) of daily food rations. In the end,
six crew members were packed into the N-25. Riiser-Larsen took off, and they
barely became airborne over the cracking ice. They returned triumphantly after
widely being presumed dead.

On 18 August 1930, Wolfgang von Gronau started on a transatlantic flight in the
same Dornier Wal (D-1422) Amundsen had flown, establishing the northern air
route over the Atlantic, flying from Sylt
(Germany)-Iceland-Greenland-Labrador-New York 4,670 mi (7,520 km)) in 47 flight
hours. In 1932 von Gronau flew a Dornier Wal (D-2053) called the "Grönland Wal"
(Greenland Whale) on a round-the-world flight.

The biggest and last versions of the Wal, the eight and ten tonne variants (both
versions also known as Katapultwal ), were operated by Lufthansa on their South
Atlantic airmail service from Stuttgart, Germany to Natal, Brazil. On route
proving flights in 1933, and a scheduled service beginning in February 1934,
Wals flew the trans-ocean stage of the route, between Bathurst, the Gambia in
West Africa and Fernando de Noronha, an island group off South America. At
first, there was a refueling stop in mid-ocean.

Wals made over 300 crossings of the South Atlantic in regular mail service
(Gandt, 1991, pages 47–48). The 8-tonne Wal was not a success, only two being
built. The six 10-tonne Wals flew the South Atlantic from 1934 until late 1938,
although aircraft of more recent design began replacing them from 1937.

Specifications (Do J Wal RR Eagle engines)

General characteristics
Crew: Three
Capacity: 8–10 passengers
Length: 17.25 m (56 ft 7 in)
Wingspan: 22 m (72 ft 2 in)
Height: 5.62 m (18 ft 5 in)
Wing area: 96 m2 (1,030 sq ft)
Empty weight: 3,630 kg (8,003 lb)
Max takeoff weight: 7,000 kg (15,432 lb)
Powerplant: 2 × Rolls-Royce Eagle IX V-12 water-cooled piston engines, 265 kW
(355 hp) each

Performance
Maximum speed: 185 km/h (115 mph; 100 kn)
Cruise speed: 145 km/h (90 mph; 78 kn)
Range: 800 km (497 mi; 432 nmi)
Service ceiling: 3,500 m (11,500 ft)
Rate of climb: 1.5 m/s (300 ft/min)
Time to altitude: 3,000 m (9,843 ft) in 33 minutes