The Cheetah helicopters:

• First inducted in 1976.
• HAL has been manufacturing these through technology transfer agreements with foreign companies.
• Powered by Artouste-III B turboshaft engine.
• Suitable for commuting, observation, surveillance, logistics support, rescue operations, and high altitude missions.

The Chetak Helicopter:

• Alouette III helicopters.
• HAL, Helicopter Division started manufacturing of helicopters in 1962, by entering an agreement with M/s SUD-AVIATION (Presently M/s AIRBUS (Former EUROCOPTER), France.
• The first Chetak (Alouette III) in ‘Fly Away’ condition delivered in 1965.
• A 2-ton class helicopter.
• The seven-seater helicopter is a versatile, multi-role, multi-purpose, and spacious.
• Powered by Artouste – III B turboshaft engine.

Source: ForumIAS