Turbomeca Turmo

The Turbomeca Turmo is a family of French turboshaft engines manufacturered for helicopter use. Developed from the earlier Turbomeca Artouste, later versions delivered up to 1300 kW. A turboprop version was developed for use with the Bréguet 941 transport aircraft.

Current versions are built in partnership with Rolls-Royce, and the engine is produced under licence by the Chinese Changzhou Lan Xiang Machinery Works as the WZ-6 and Romanian Turbomecanica, Bucharest, as the Turmo IV-CA.

Design and development
The Turmo was initially developed with a single-stage centrifugal compressor, annular combustion chamber and single stage turbine. Power output was from a single-stage free power turbine and was initially 270 hp.

During early post-war helicopter development, the use of cold and hot rotor tip-jets was widely investigated. To provide large mass-flow air for efficient operation of the tip-jets, Turbomeca developed a gas turbine driven gas producer, powered by the free power-turbine of the Turmo to deliver the required gas flow.

Variants
Data from:-Jane's all the World's Aircraft 1957–58
 * Turmo I: The initial version of the Turmo; max continuous gearbox output 270 shp at 3,000 rpm, at 33,750 rpm gas generator speed.
 * Turmo II:Developed version of the Turmo I; max continuous gearbox output 320 shp at 34,000 rpm gas generator speed.
 * Turmo III:With 2-stage free power-turbine, pressure ratio 5.7:1 ;Maximum shaft output 750 shp, max continuous 600 shp at 33,400 rpm
 * Turmo IIIB:
 * Turmo IIIC:A 1,200 hp turboshaft powering the Sud-Aviation Frelon prototypes.
 * Turmo IIIC2: Developed from the IIIC delivering 1,300 hp maximum output
 * Turmo IIIC3: Maximum rating 1,500 hp at 33,500 rpm for production Super Frelon helicopters
 * Turmo IIIC4: Military variant.
 * Turmo IIIC5:
 * Turmo IIIC6:
 * Turmo IIIC7:
 * Turmo IIID:Turboprop for the proposed Breguet Br 942 STOL transport, maximum rating 1,225 hp.
 * Turmo IIID2:1,335 hp at 22,460 free turbine rpm
 * Turmo IIID3:1,450 hp at 33,500 rpm
 * Turmo IVB: Military Variant
 * Turmo IVC: Civil Variant
 * Turmo IV-CA:Licence production in Romania
 * Turmo VI:Turboprop engine with two axial stages, one centrifugal compressor stage and two free power turbine stages, rated at 1,800 hp at 32,000 rpm.
 * WZ-6:Licence production at the Changzhou Lan Xiang Machinery Works in the People's Republic of China.

Applications

 * Turboshaft
 * Sud-Est SE.3140 Alouette II
 * Aérospatiale SA 321 Super Frelon
 * Aérospatiale SA 330 Puma
 * Bölkow Bo 46
 * IAR 330
 * SNCASE SE.3200 Frelon
 * Turbotrain
 * SNCF Class T 2000
 * N.300 Naviplane


 * Turboprop
 * Breguet Br 940 Integral
 * Bréguet 941
 * Breguet 941S


 * Automobile
 * Renault Étoile Filante