Friday, May 15, 2020

IAF Guns The World's Largest Helicopter, It's Mi-26, To The Top

Mil Mi-26 Helicopter - Indian Air Force IAF - 01
Beauty of a product of Soviet Extreme Engineering, a Prima Donna.
Delightful bit of information, demonstrating challenges of Indian Military operation. This video clip, below, provides an enlightening glimpse of a system being pushed to the outer edges of it's capabilities. Watch this Indian Air Force [IAF] Mil Mi-26 Helicopter Halo execute a Maximum Performance Takeoff from a Helipad located high up in the snow-covered Himalayan mountains.
The manoeuvre, that FAA describes as, "taking the helicopter to the edge of the safe operating envelope", and recommends that, "if you are ever in doubt about the outcome of the manoeuvre, abort the mission". No doubts displayed.
Of the manoeuvre, it explains that, "A maximum performance takeoff is used to climb at a steep angle to clear barriers in the flightpath. It can be used when taking off from small areas surrounded by high obstacles."
Helicopter Maximum Performance Takeoff Profile - 01
This video is special for 2 reasons, one, demonstrating difficult manoeuvre under challenging conditions &, two, the clip itself. Not many footage out there of IAF flying the world's largest & heaviest operational helicopter1. These heavyweights are assigned to the Chandigarh-based No. 126 Helicopter Flight, christened, without irony, The Featherweights, of which India acquired 4 Airframes. Since induction, they have been the showstopper of some stellar missions,
"The flight has the unique distinction of operating the world's heaviest helicopter in the highest and coldest battlefield in the world, the Siachen Glacier. The flight has undertaken flood relief operations in different parts of the country as well as relief operations during the Orissa Supercyclone of 1999. The flight played a major role in avoiding a Bhopal like gas tragedy at Paradeep Phosphates Ltd where the Ammonia gas tanks needed to be cooled at the earliest to prevent the gas from leaking out. The flight airlifted heavy duty generators which were used to cool the storage tanks thus avoiding a major disaster. The flight was also actively involved in the Kargil war wherein it performed numerous missions by day and night."
This video, shot in the Himalayas, at elevation of more than 3,500 m, shows the Chopper operating close to it's service ceiling of 4,600 m. Pushing the bird even higher, IAF had been landing them on the 5,500 m Siachen Glacier region, much above their OEM-specified limit. A jaw-dropping sight, these mammoths, with smooth shark-like silhouette, taking to the air, powered by gigantic twin Ivechenko-Lotarev D-126 Turboshaft Engines2, churning out a mind-bending 22,000 HP of raw power. These Titanium-reinforced giants, make for mesmerising visuals, on ground, in air, anywhere.
Helicopter Pilot Profile Poster - 01
Carrying out a maximum performance take-off requires smooth, synchronised inputs provided with the Cyclic & Collective, balanced by the Anti-Torque Pedal, to achieve precise control of Pitch Attitude, Direction and Power, at full Rotor RPM. The complexities of keeping a Helicopter airborne is aptly captured in the poster, above.
Mil Mi-26 Helicopter Size Comparison - 01
Lift is the fundamental characteristic required to keep anything afloat in the air, which is a function of Air Density. Amount of Lift needed is proportional to the weight of the Helicopter. Owing to the rarefied air at high altitudes, generating sufficient lift there, naturally, becomes a challenge. Greater the Take-Off Weight [TOW], greater the lift needed to be generated, leading to greater challenge to flight. Add to that, deficient oxygen in the rarefied high-altitude air degrades engine performance, compounding the difficulties of staying airborne. The clip, thus, shows the Mi-26 performing flight manoeuvre in a double whammy situation - taking-off from an obstacle-ridden path, at a high altitude.

A British RAF Officer, who had an opportunity to fly to Siachen, with the IAF's No. 114 Helicopter Unit, in a Cheetah Helicopter, recently recounted his experience,
"The pilot called "Committed” telling me that he no longer had the ability to overshoot - we had to land now and I still couldn't see…. and with a bump we were down! I never saw it coming. My pilot had executed a flawless zero-zero landing at 22,000ft in a 30-year old single-engined helicopter on a pad I couldn't see until we'd hit it….
….I looked closely: we had landed on a pillar of ice only inches wider than the width of our landing gear. The margin for error was so tiny my incredulity momentarily caused my brain to stop functioning. When I recovered from my shock over the landing site and awe at the pilot's skill….
….I knew I had been witness to extraordinary flying skills. How they did what I'd seen in the region's frequent poor weather was a mystery to me. I was - and still am - filled with admiration for the pilots who fly these missions and for their ground crews who do an incredible job keeping the old SA-315s flying all year round."
As critical as the Mi-26's operations are, PITA has been its serviceability & availability, an oft-suffered angst operating Soviet-origin platforms. An earlier CAG Report about IAF's Mi-series Helicopters noted that, "Serviceability levels were low and fell consistently short of the prescribed 75 per cent. Combined with high Aircraft-on-Ground levels, this was indicative of inefficiency in operations, low utilization of Mi series fleet and poor repair and maintenance activities.". Over the years, improvements have been achieved in these parameters, but reality remains far from satisfactory. At present, none of the 3 remaining Helicopters are in flight-service, awaiting transportation to Russia, as part of a long-pending proposal to perform life-extension upgrades.
Boeing Chinook CH-47F (I) Helicopter - Indian Air Force - 01
To meet expanding requirements, the IAF zeroed-in on the acquisition of Boeing's CH-47F (I)  Chinook Helicopters in 2015, deciding with an initial induction of 15, deliveries of which, also to No. 126, commenced last year. Despite being able to carry much less than the Halo3 at most altitudes, the Chinook trumps the Halo in 1 critical parameter - cost-effective missions. An analysis carried out, comparing performance of the 2 concluded that, at operational altitudes over 7,100 m, the Mi-26's can carry even less than the CH-47F. That being more of an academic observation, the real USP of the Chinook lies in it's fuel economy. Based on the analysis model, the study concluded that at normal operational conditions, the CH-47 consumed around the half the fuel than the Mi-26, to transport the same amount of load. Further, at altitude upwards of 7,100 mm, the Soviet bird guzzles 3 times the fuel as the American. All these fuel savings, in the Chinook's operational life, would cumulatively amount to big savings for the IAF.
Mil Mi-26 Helicopter - Indian Air Force IAF - Z3075 - 01
An Indian Naval Rotary Wing Aviator once flew this Air Force helicopter.  Did some pushing-the-boundaries stuff, when handed its controls of the Mi-26,
"When I fed the lateral pulse-input on cyclic control and our Flight Test Engineer (FTE) directed 'both crew, hands and feet off controls', the giant Mi-26 began an 'elephant dance' seldom seen by anyone other than testers or 'oh, those Russians'! Within few cycles, the helicopter's lateral oscillations increased in amplitude to such an extent that ATC piped up with the customary 'confirm ops normal?' call. It's not a pretty sight to see a helicopter of that size rocking side-to-side, 30 feet over the runway, each oscillation increasing in amplitude, eating distance-to-go markers for breakfast!
Walia decided enough is enough before we hit our 'knock-it-off' criteria. He took over controls (like all good safety pilots must), called off the flight and taxied back to apron with a grim look on his face. His only words - and I still remember it 17 years later - "all this testing vesting is fine yaar, but please respect the machine. I cannot let you do these things to a Mi-26."
The Soviets built one mighty great helicopter, that the IAF uses to reach great heights.
1 = Had it gone into production, the MIL B-12/V-12 Homer would have held that record. This 67 m long beast could carry more than 40 MT of load. Change in circumstances lead to cancellation of the program, after building only 1 prototype.
2 = One amongst the innumerable fallouts of USSR's disintegration - the OKB-478 Design Bureau, that developed the D-126 Engine, and the JSC Motor Sich Company, which manufactured them, both, are situated in the town of Zaporizhia, in present-day Ukraine.
With Russia & Ukraine, today, being not particularly on back-slapping terms, the former had to pursue a development of a homegrown solution. The Aviadvigatel PD-12V Engine now power the helicopter for new Mi-26 customers.
3 = For scale, Chinook Helicopters are often pressed into service, to transport birds that can't be flown.
Chinook CH-47F - Aircraft - 01
The Mi-26 Chopper picks up the Chinook, when it can't fly.
Mil Mi-26 Halo CH-47 Chinook - 01
…and even bigger
Mil Mi-26 Helicopter Tu-134 Aircraft - 001