Cheetal is re-engined version of Cheeta with M333 engine. Only engine is changed.
But this Chetan has everything changed except the airframe.
Deccan Herald: Chetan set to take off at Aero-India 2005
The new helicopter Chetan, an upgraded version of Chetak and designed by HAL, consumes less fuel thereby increasing its range and endurance.
DH NEWS SERVICE BANGALORE:
‘Chetan’, the new helicopter of the Hindustan Aeronautics Limited (HAL) that made its first ground run on Monday, is all set to take part in Aero-India 2005 to be held from February 9 to 13.
The helicopter is said to be a “re-engined and upgraded” version of Chetak and the only thing it retains from the original is the frame. Everything else is new. Its engine is changed - the same as the one that the Advanced Light Helicopter (ALH) uses. So the control systems are also new, as will be the rotor blades.
According to a senior officer at the HAL the helicopter which will make its maiden flight within a few days will perform at the aero show after a few test flights. The Chetan project is entirely funded by HAL with a mission to evacuate causalities from high-altitude (above 10,000 ft), he added.
The project was started six months ago and received its impetus after HAL’s Cheetal created a world record by landing 25,150 feet on Saser Kangi peak, next to Siachen Glacier, said the officer.
The power plant for Chetan is the same as used in the ALH Dhruv (TM 333 2B2). The Chetans will sport glass cockpit in future giving the pilot versatility in monitoring onboard systems.
Speaking to Deccan Herald HAL Chairman A K Baweja said, “The modern engine will make Chetan a highly reliable helicopter with far less fuel consumption which will increase its range, endurance and useful load. HAL is also involving DGCA officials in the flight-testing process to get the civil certification for Chetan,”
The new helicopter will widen HAL’s export market with many countries already flying Chetaks. “Chetans will encourage many states to go in for life-extension of the their existing fleet of Chetaks,” Wg Cdr (Retd) C D Upadhyay, HAL’s Chief Test Pilot (RW) said.
Chetan’s first flight will take place by January end. It will be flown at Aero India 2005 by Wg Cdr P S Rao and Sqn Ldr S Jain, who are the project test pilot and test engineers respectively.
What that means to me is that the whole propulsition and control is changed. Along with the engine the rotor and gearbox are changed. This is significant since the Cheetal uses the original rotor and gearbox but the engine shaft is rotates in opposite direction, so an external appendage was added to drive the rotor is correct direction. So this new helicoptor with blades and transmission matched to new & more powerful engine means better performance overall, and greater range due to more efficient engine as well as not needing those tens of kilo of gear train to invert the direction of engine drive train. Hopefully they have also put in a better Gearbox to match greater stress arising out of powerful engine and high altitude gust.
As for glass control that is very good news also. Mountain operations need GPS and precision nav aids, something sorely missing in Cheetha.
The key data to lookout for is how much fuel+payload it can lift at 25,000 ft?