D class blimp

D class
Role	Patrol airship
Manufacturer	Various (Goodyear-Zeppelin Corporation, Goodrich)
First flight	13 July 1920 at Wingfoot Lake
Retired	1924
Primary user	United States Navy
Number built	6

The D class blimp was a patrol airship designed by the US Navy^[1] in the early 1920s. The D-type blimps were slightly larger than the C-type and had many detail improvements. The Navy continued the practice of dividing the envelop production between Goodyear and Goodrich. The control cars were manufactured by the Naval Aircraft Factory. The major improvements were a better control car design. The engines were moved to the rear to reduce noise and allow better communications between crew members. The fuel tanks were suspended from the sides of the envelope. The envelope was identical to the C-type, except an additional six foot panel was inserted for a total length of 198 feet (60 m) and a volume of 190,000 cubic feet (5,400 m³).

Operational history

Aerial view of NAS Rockaway in 1919 looking eastward with view of airship hangar.

The D-1 burned the day of its first flight in the Goodyear hangar^[2] at Wingfoot Lake, Ohio. The D-2,^[3] D-3, D-4 and D-5 were transferred to the United States Army which the Air Ship Board had given the primary role of operating non-rigid airships after World War I. D-1 participated as an observation and photography aircraft at the famed "Mitchell" bombing test of 1921. D-3 also participated in the Mitchell bombing trials, tested experimental mooring masts, D-3 also participated in early "hook-on" experiments to see if it was possible for an airplane to fly up to and hook onto a trapeze hanging from an airship. No actual hook-ons were achieved, but approaches were practiced. D-4 also participated in the Mitchell trials, and in observation jobs. The D-5 was never operated by the Army with that designation. After the loss of D-2, the D-5 was erected with more powerful 180 hp Wright V engines and flown as the D-2-2.

The Navy retained one additional D-type, the D-6.^[4] The D-6 was built by the Naval Aircraft Factory, Philadelphia, Pennsylvania, but her design was sufficiently different to separate her from the other five D-class airships. It featured a further improved control car (the "D-1 Enclosed Cabin Car) which had a water tight bottom for landings on water and internal fuel tanks. The D-6^[4] was burned in the Naval Air Station Rockaway hangar fire^[5] of 31 August 1921 along with two small dirigibles, the C-10 and the H-1 and the kite balloon A-P.

The last operational D-type, the D-3 was apparently deflated by the Army in early 1924.

Operators

 United States

• United States Navy

Specifications (typical)

General characteristics

• Crew: Four
• Length: 198 ft 0 in (60.37 m)
• Diameter: 42 ft 0 in (12.80 m)
• Height: 58 ft 0 in (17.68 m)
• Volume: 190,000 ft³ (5,380 m³)
• Useful lift: 4,340 lb (1,969 kg)
• Powerplant: 2 × Union, 125 hp (93 kW) each

Performance

• Maximum speed: 58 mph (93 km/h)
• Cruise speed: 40 mph (64 km/h)
• Range: 1,480 miles (2,380 km)
• Endurance: 37 hours

Armament

• 1 × .303 Lewis gun
• 4 × 270 lb (122 kg) bombs

See also

• List of airships of the United States Navy

References

1. ^ Kite Balloons to Airships...the Navy's Lighter-than-Air Experience
2. ^ The Goodyear Blimp: History of Wingfoot Lake Hangar
3. ^ U.S. Navy Goodrich Airship D-2 1920^{[dead link]}
4. ^ ^{a b} U.S. Navy Goodyear Airship D-6 1921^{[dead link]}
5. ^ NY Times Sept. 1, 1921, Page 2, Biggest Navy Blimp Burns with 3 More