WesWorld

IMPA (Compania Industria Metalurgica & Plastica S.A.) was originally formed to take over the firm of Lieneu & Cia, former agents for the Fisk Tyre & Rubber Company and Argentine distributors for Chrysler automobiles. It manufactures aluminium, lead and plastic articles and undertakes the production of ammunition for the Argentine Armed Forces. It also possesses the exclusive representation in Argentine for the Continental Motors Corp.
With investment from the Atlantean aircraft company Accrisius IMPA has started an aircraft division to build aircraft under licence.
A joint programme between FMA and Spartan led to the design of several new types and IMPA was given the contracts to licence-build the Vanquish series of bombers although its first product was the I-99 fighter.

The IMPA-99 was a license built design from Spartan designed in mid 1932. It became the main light dogfighting fighter of the FAA until around 1936-37.


Dimensions: span 10.97m; length 7.62; height 3.12m; wing area 192sq ft; wing loading 21.61 lb/sq ft; power loading 0.24 lb/hp
Structure: all-metal monocoque fuselage in two sections with Z section fames and L section stringers with riveted stressed light alloy covering, light alloy used for cantilever tail construction and tailplane covering. Cantilever metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Fixed main undercarriage with single oleo-pneumatic legs with pneumatic brakes and a un-retractable castoring tail wheel
Weights: empty 3.654lbs, maximum take-off 4,150lbs
Powerplant: one 900hp Spartan 900 V-12 inline engine with supercharger, maximum sea level output to 2,500ft
Performance: max speed 301mph; service ceiling 25,000ft; rate of climb 3,091ft per minute at 1,500ft; range 212 miles full fuel load
Capacity: pilot in open cockpit
Armament: four 13mm Browning HMG, two above engine and two in wings
Equipment: full controls and navigation equipment including receiver/transmitter, telescopic sight and basic autopilot

IMPA M.B.1 (Spartan Vanquish)

This was the first variant of the Spartan Vanquish to be built in Argentina from 1934 and 148 were built.
Dimensions: span 20.42m; length 12.19; height 3.5m; wing area 600sq ft; wing loading 24.66 lb/sq ft; power loading 0.297kg/hp 0.13 lb/hp
Structure: all-metal monocoque fuselage in three sections with Z section fames and L section stringers with light alloy covering, light alloy used for cantilever tail construction and tailplane covering. Cantilever metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a non-retractable castoring tail wheel
Weights: empty 9,434lbs, maximum take-off 14,800lbs
Powerplant: two 1000hp Spartan 1000 radial engines un-supercharged
Performance: max speed 256mph; service ceiling 23,200ft; rate of climb 1,481ft per minute at 1,500ft; range 1970 miles with 1,000lbs bomb load
Capacity: pilot in enclosed cockpit with navigator/bomb aimer beside and slightly lower with a nose bomb-aiming position, radio operator/gunner in rear fuselage
Armament: one dorsal turret with two 7.92mm FMG/M32 MG (drum feed), two 13mm Browning HMG in wingroots, bombload 2000lbs in one lower fuselage bomb bay
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set and Sperry autopilot, two cameras can be fitted in cabin floor, one flare chute, one rescue dinghy, simple mechanical bombsight


IMPA SI-21A (Sp-21A Vanquish II)

Further development with better engines and an improved bomb aimer's postiton led to 240 of the Vanquish II being built between 1935 and 1937.
Dimensions: span 20.42m; length 14.63; height 3.84m; wing area 600sq ft; wing loading 31.33 lb/sq ft; power loading 0.234kg/hp 0.10 lb/hp
Structure: all-metal monocoque fuselage in three sections with Z section fames and L section stringers with light alloy covering, light alloy used for tail construction and cantilever tailplane covering. Cantilever all-metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a non-retractable castoring tail wheel
Weights: empty 10,825lbs, maximum take-off 18,800lbs
Powerplant: two 1000hp Spartan 1000 supercharged radial engines
Performance: max speed 262mph; service ceiling 26,500ft; rate of climb 1,078ft per minute at 1,500ft; range 1152 miles with 4,000lbs bomb load
Capacity: pilot in enclosed cockpit, navigator/bomb aimer in nose with a glazed bomb-aiming position, radio operator in rear fuselage compartment with two windows ahead of gunner in a hydraulic-powered dorsal turret
Armament: one dorsal turret with two 7.92mm FMG/M32 MG (drum feed), one 7.92mm FMG/M32 MG (drum feed) on swivel mount in nose, two 7.92mm FMG/M32Ar MG (belt feed) in wingroots, bombload 4000lbs in one lower fuselage bomb bay or one semi-recessed 18in torpedo
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon and Sperry autopilot, two cameras can be fitted in cabin floor, one flare chute, two rescue dinghies and mechanical bombsight


IMPA SI-21B (Vanquish III)
IMPA's own engineers developed this final variant to replace the worn out bombers which had seen war service and to further increase the performance. 164 have been built or ordered to date.
Dimensions: span 20.42m; length 14.63; height 3.84m; wing area 600sq ft; wing loading 32 lb/sq ft; power loading 0.13 lb/hp
Structure: all-metal monocoque fuselage in three sections with Z section fames and L section stringers with light alloy covering, light alloy used for tail construction and cantilever tailplane covering. Behind the pilot is a 5mm thick armoured bulkhead. Cantilever all-metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Self-sealing fuel tanks carried in the wings. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a retractable castoring tail wheel
Weights: empty 11,120lbs, maximum take-off 19,000lbs
Powerplant: two 1200hp Ripon R-1200-010A supercharged radial engines
Performance: max speed 291mph at 15,000 feet; cruising speed 201mph at 15,000 feet; service ceiling 29,500ft; rate of climb 1,562ft per minute at 1,500ft; range 1060 miles with 4,000lbs bomb load
Capacity: pilot in enclosed cockpit, navigator/bomb aimer in nose with a glazed bomb-aiming position, radio operator in rear fuselage compartment with two windows ahead of gunner in a hydraulic-powered dorsal turret
Armament: one dorsal turret with two 13mm Browning MG (belt feed), one 13mm Browning MG (belt feed) on swivel mount in nose; bombload 4000lbs in one lower fuselage bomb bay with hydraulic doors
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon and Sperry autopilot, two cameras can be fitted in cabin floor, one flare chute, two rescue dinghies and mechanical bombsight


IMPA SI-21T (Sp-21M)

The Sp-21M was an export variant intended for Mexico but the FAA was so impressed that it ordered several during the war.
Dimensions: span 20.42m; length 12.19; height 3.84m; wing area 600sq ft; wing loading 31.33 lb/sq ft; power loading 0.234kg/hp 0.10 lb/hp
Structure: all-metal monocoque fuselage in four sections with Z section fames and L section stringers with light alloy covering, light alloy used for tail construction and cantilever tailplane covering. Cantilever all-metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a non-retractable castoring tail wheel
Weights: empty 11,670lbs, maximum take-off 18,800lbs Powerplant: two 1000hp Spartan 1000 supercharged radial engines
Performance: max speed 267mph; service ceiling 26,500ft; rate of climb 1,094ft per minute at 1,500ft; range 1200 miles with 3,000lbs bomb load
Capacity: pilot in enclosed cockpit with bullet-proof windscreen, navigator in rear fuselage cabin with one window and one access door ahead of radio operator/gunner in a hydraulic-powered dorsal turret
Armament: one dorsal turret with two 7.92mm FMG/M32 MG (drum feed), four fixed 13mm Browning HMG in the lower nose under the cockpit, bombload 3000lbs in one lower fuselage bomb bay or one semi-recessed 18-21in torpedo
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon and Sperry autopilot, two cameras can be fitted in cabin floor, one flare chute, two rescue dinghies and mechanical bombsight


IMPA SI-21S

A floatplane equipped Sp-21 variant for the Commando de Aviacion Naval for the reconnaissance role with a secondary attack role. The third pre-production aircraft was fitted with floats at the insistence of the Commando de Aviacion Naval Argentina to fulfill an urgent need for seaplanes. Around 20 were converted on the production line from mid 1935.
Dimensions: span 20.42m; length 12.19; height 3.84m; wing area 600sq ft; wing loading 31.33 lb/sq ft; power loading 0.234kg/hp 0.10 lb/hp
Structure: all-metal monocoque fuselage in four sections with Z section fames and L section stringers with light alloy covering, light alloy used for tail construction and cantilever tailplane covering. Cantilever all-metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Two amphibious watertight floats fixed underwing with optional beaching wheels.
Weights: empty 11,670lbs, maximum take-off 18,800lbs Powerplant: two 1000hp Spartan 1000 supercharged radial engines
Performance: max speed 248mph; service ceiling 25,500ft; rate of climb 1,025ft per minute at 1,500ft; range 957 miles with 3,000lbs bomb load
Capacity: pilot in enclosed cockpit, navigator in rear fuselage cabin with one window and one access door ahead of radio operator/gunner in a hydraulic-powered dorsal turret
Armament: one dorsal turret with two 7.92mm FMG/M32 MG (drum feed), four fixed 13mm Browning HMG in the lower nose under the cockpit, bombload 3000lbs in one lower fuselage bomb bay or one semi-recessed 18-21in torpedo
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon, Sperry autopilot, reflector gun sight with torpedo aiming bar, two cameras fitted in navigator's cabin floor, three flare chutes and two rescue dinghies.

IMPA TB-1 (Spartan TBN-7)
This is the Spartan TBN-7 torpedo bomber built under licence for the Naval Aviation's new carrier fleet.

Dimensions: span 15.2m; length 10.60; height 3.8m (50/35/12.5ft) wing loading 24.7 lb/sq ft; power loading 0.14 lb/hp fully loaded
Structure: all-metal monocoque fuselage in three sections with Z section fames and I section stringers with riveted stressed light alloy covering, light alloy used for cantilever tail construction and tailplane covering. Cantilever metal wing with two steel spars, all-metal split flaps and aluminium framed ailerons with fabric covering. Rudder and elevators aluminium framed with fabric covering. Retractable hydraulically raised main undercarriage with two oleo-pneumatic legs with twin pneumatic brakes and a non-retractable castoring tail wheel and catapult spools and retractable arrestor hook attached to the lower fuselage aft.
Weights: empty 7523lbs, maximum take-off 10500lbs
Powerplant: one 1500hp Spartan Currus XV twin-row radial engine
Performance: max speed 294 mph; service ceiling 31,000ft; range 518 miles fully loaded
Capacity: pilot in enclosed cockpit forward, navigator/gunner behind in fuselage in enclosed cockpit facing aft
Armament: two wing-mounted 13mm Browning MG, one manual dorsal turret with one 13mm Browning MG, bombload 1500lbs on one belly and four wing racks or one 18-21in torpedo on crutches
Equipment: full controls and navigation equipment including receiver/transmitter, HF/DF set, naval co-operation beacon, Sperry autopilot, reflector gun sight with torpedo aiming bar, one camera fitted in navigator’s cabin floor, one flare chute and two rescue dinghies.

RR-11

A low-wing two-seater cabin monoplane, It is powered by a 65hp flat-four Lycoming piston engine which gives it a top speed of 100mph. Cruising speed is 95mph with an endurance of five hours which equals a range of 475 miles.

IMPA NT-2 Alicanto
Licence-built ENAER Alicanto Dive-Torpedo Bomber. 100 built in 1942

General characteristics
Wingspan: 14.5m
Length: 11.5m
Height: 4m
Wing Area: 380 ft²
Empty weight: 8,377 lb (3,800 kg)
Loaded weight: 12,345.8 lb (5,600 kg)
Engine: 1 × Austral Incitatus 2W-11 (1,800hp takeoff; 1,650hp at 16,900ft / 5,150m; 2,030hp with water injection at sea level)
Crew: 2
Armour: 8mm thick armoured bulkhead

Performance
Max speed: 345mph (300 knots)
Range: 2,750 km (1,708 mi); 1,100 miles (1770.3 km) with max payload
Service ceiling: 11,000m (36,000 ft)
Rate of climb: 9.4 m/s (31 f/s)

Armament
- 2 × 13 mm MGs in wings
- 2 × 7.62mm MGs in rear cockpit
- 1 × 1800lbs aerial torpedo or bombs

Notes
The Alicanto, although originating as a torpedo bomber design, is fitted with dive brakes to act as a dive bomber.