Grumman G-21 Goose - Variants

Variants

G-21

Original production version, powered by two 450 hp (336 kW) Pratt & Whitney Wasp Junior SB engines, 7,500 lb (3,400 kg) gross weight. Six passengers. Twelve built, all converted to G-21A standards.

G-21A

Increased gross weight (8,000 lb (3,636 kg)). Thirty built.

G-21B

Export coastal patrol flying boat. Armed with .30 in machine gun in bow and dorsal hatches and two 100 lb (45 kg) bombs underwing. Twelve built for Portuguese Naval Aviation.

G-21C

Conversion by McKinnon Enterprises, re-engined with four 340 hp (254 kW) Lycoming GSO-480-B2D6 air-cooled, geared, and supercharged flat-six engines and fitted with retractable wing-tip floats, a fiberglass “radar” nose, a one-piece “wrap-around” windshield, and “picture” (enlarged) cabin windows. Gross weight increased to 12,499 lb (5,669 kh) as result of internal structural reinforcements. Two converted as piston-powered models G-21C (serial nos. 1201 and 1202) in 1958-1959. Two other airframes subsequently converted in 1968, but with two 550 shp (579 eshp, 432 kW) Pratt & Whitney Canada PT6A-20 turboprops per STC SA1320WE as G-21C “Hybrids” (serial nos. 1203 and 1204.) The two G-21C “Hybrids” were actually identical to the later 10,500 lb model G-21E, but they were never certified as such.

G-21D

One G-21C further converted by McKinnon with extended bow section marked by two extra windows on each side and accommodating another four passengers (serial no. changed from 1201 to 1251 in conjunction with re-certification as model G-21D in June 1960.) In 1966, it was re-engined with two 550 shp (579 eshp, 432 kW) PT6A-20 turboprops and fitted with revised Alvarez-Calderon electric flaps in accordance with STC SA1320WE, retaining the G-21D designation but subsequently identified as a McKinnon “Turboprop Goose.”

G-21E

Fully-certified new model based on simplified turbine conversion of McKinnon model G-21C, with 550 shp PT6A-20 engines (680 shp Pratt & Whitney Canada PT6A-27 engines optional) and more fuel, but without all of the structural reinforcements of the 12,499 lb model G-21C. 10,500 lb (4,763 kg) gross weight. One converted (serial no. 1211.)

G-21F

Conversion by Fish & Wildlife Service in Alaska (using McKinnon engineering data) with 715 shp (533 kW) Garrett TPE331-2UA-203D turboprops. One converted but the FWS model “G-21F” was never approved by the FAA and the one example that was built was inexplicably re-certified as a supposedly modified McKinnon G-21G in spite of the fact that it was not built by McKinnon nor ever conformed to the model G-21G type design.

G-21G

Final McKinnon conversion also fully certified as a new model with 680 shp (507 kW) PT6A-27 engines, 586 US gal. of fuel, and 12,500 lb gross weight. Two converted (serial nos. 1205 and 1226.)

XJ3F-1

Prototype eight seat utility amphibian for U.S. Navy. One built 1938.

JRF-1

Production version of XJ3F-1. Five built for U.S. Navy.

JRF-1A

Similar to JRF-1, but with target towing gear and camera hatch added. Five built for U.S. Navy.

JRF-2

Version for United States Coast Guard, with provision for carrying stretchers. Seven built.

JRF-3

Similar to JRF-2, but fitted with autopilot and deicing boots on wing leading edge to aid operations in Arctic. Three built for Coast Guard.

JRF-4

Similar to JRF-1A, but could carry two depth bombs under wing. Ten built for U.S. Navy.

JRF-5

Major production version, incorporating bomb racks from JRF-4, target towing and camera gear from JRF-1A and de-icing gear from JRF-3; 184 built. In 1953, a modified JRF-5 was used to test the landing and takeoff characteristics of hydro-skis for the U.S. Navy.

JRF-5G

24 JRF-5 transferred to US Coast Guard.

JRF-6B

Navigation trainer purchased for supply under Lend-Lease. 50 built.

OA-9

Transport and air-sea rescue amphibian for United States Army Air Forces. Twenty-six ordered in 1938, supplemented by five JRF-6Bs carrying the same designation.

OA-13A

Designation given to three G-21As impressed by USAAF.

OA-13B

Two JRF-5s transferred to USAAF.

Goose Mk I

British designation for three JRF-5s supplied to the Fleet Air Arm.

Goose Mk IA

British designation for 44 JRF-6Bs supplied under Lend Lease and used for Observer training by 749 Naval Air Squadron in Trinidad.

Goose Mk II

British designation for two JRF-5s used as staff transports by British Air Commission in United States and Canada.

Grumman LXG

A single Grumman G.21A evaluated by the Imperial Japanese Navy Air Service .