Tuesday, June 30, 2020

Watching These IAF HF-24 Marut Fighters Taxiing & Taking To The Air Is A Sight Just As Contemporary

HF-24 Marut Aircraft Indian Air Force IAF - 001 - TN
The sleek, pencil-slim contours of the HF-24 Marut, developed in the 50s India, with it's elegant, swept-wing & tail configuration, attached to a perfect Area-ruled fuselage, would have been totally at home in a line-up of current, operational aircraft - the JAS 39 Gripen, MiG-29, J-10, F/A-18. In fact, at the risk of losing sight of objectivity, it could be argued that the Marut's appearance exuded certain futuristic vibe, amplified by the gleam off it's naked, unpainted airframe. This rare video footage, shot on May 10, 1964, when the Indian Air Force [IAF] received it's first 4 Marut, showcases the HF-24 in it's pristine glory.
As the four HF-24 fighters lumber down the runway, performing a budget 'Elephant Walk', taking-off in tandem, flying in a tight formation, we are treated to a glimpse of it's weapon load-out. The Marut could be laden with a multitude of ordnance - free-fall bombs, rockets & 30 mm bullets that it's 4 Aden Mk. II Cannon would pump out to "de-materialise" target upon impact. Vibrations generated while firing all 4 cannons simultaneously, though, was so intense that "the entire instrument panel fell into the pilot’s lap as soon as he pressed the trigger!!". This caused severe stability issues during flight, which eventually caused the tragic loss of life of an IAF Test Pilot during it's 4-Gun trials. Subsequently, HAL removed 2 Guns.
IAF HF-24 Marut Aircraft Weapon Loadout - 01 IAF HF-24 Marut Aircraft Weapon Loadout - 02
IAF HF-24 Marut Aircraft Weapon Loadout - 03 IAF HF-24 Marut Aircraft Weapon Loadout - 04
  1. Aden Mk. II 30 mm Cannon Gun
  2. Retractable Matra Type 103 Rocket Pack
  3. SNEB Unguided Air-To-Ground 68 mm Rocket
  4. Matra Type 116 Launcher
  5. .
  6. 1000lb Dumb Bomb
  7. .
  8. .
A notable feature omission was missile-firing capability. A perfectly understandable decision. A country had no Aeronautical legacy was developing Asia's first Jet-powered aircraft. Missile-firing was a feature that itself was in the early stages of introduction in aircraft that the established Aeronautical powers were building. There is, however, nothing to state that, had Marut's development proceeded organically, future variants wouldn't have been upgraded to such capability.
HF-24 Marut Aircraft Indian Air Force IAF - 002 - TN
Adoption of certain design elements were indicative of the boldness of approach. It's bubble Cockpit canopy, for example, significantly improved the pilot's field of vision, & whose fabrication was a testament to technical acumen of tradesmen involved. Another stand-out feature of the Marut was it's retractable, hydraulically-actuated Rocket Pack. Housed within the aircraft's belly, it could fire 50 Matra Type 103 rocket. Internal weapon bay - defining feature of current 5th generation fighters. Though neither were pioneering concept, per se. Bubble Canopy & Retractable Rocket Pods were features seen in other aircraft like the French Dassault M.D.450 Ouragan, the American Vought F-8 Crusader, the British de Havilland DH. 110 Sea Vixen. It, nevertheless, demonstrated intent to challenge capabilities, expanding them, rather than play fully safe.
X-241 Wooden Glider - HF-24 Marut Aircraft Indian Air Force IAF - 001 - TN
Full-scale Glider Mock-up of the Marut Aircraft - X-241
At the heart of the Marut's inability to hit home run lay it's twin Powerplant - the Rolls-Royce [Bristol] Orpheus Mk. 703 Turbojet, seen being overhauled in the workshop at around 1 min 16 seconds in the video. Chosen just as an interim measure, in part due to the fact that a variant, the Orpheus 701, was already in license production in India for it's Gnat aircraft, the Engine was not catered to take the Marut to designed Mach 2 speeds in level flight. When development of it's intended Powerplant, the Bristol Siddeley Orpheus 12 Simplified Reheat [BOR.12 SR] Turbojet Engine, came to a premature halt in the UK, India refused to bankroll the further work needed - an amount of £1,500,000, further reduced to £300,000, reasonable by Indian standards, even then - Big Mistake!
Bristol Siddeley Orpheus 12 Simply Reheated [BOR.12 SR] Turbojet Engine - 01 - TN
From then on, the quest to find a compatible Engine became the over-arching priority, eventually preventing the Aircraft from ever realising it's full potential. The search took India on a trip around the world, with Pit stops in the USSR [VK-7, RD-9F], Germany [RB153], France [Atar 09K-53, Super Atar M-53], UK again [RB199] & Egypt [E-300]. Their quests to the Soviet Union & Egypt went beyond mere air kissing, ones that we will explore a bit more.
With the Engine now in the centre-stage, the role that the, then, recently established Gas Turbine Research Establishment [GTRE] played became vital. Need for tighter editing & proof-reading aside, in his memoir, 'Restoration of Split Milk' [affiliate URL], Air Vice-Marshal [Retd.] Sailendra Nath Roy Chaudhury, who was the GTRE's Founder Director, lets us in on some dynamics at play during programme.
HF-24 Marut Aircraft Indian Air Force IAF - 012
For one, he wasn't too appreciative of the appointment of the German Dr. Kurt Tank to head the programme, citing his portfolio lacking a prior Jet-engine aircraft. This, though, wasn't completely true, as he had built the IAe Pulqui II aircraft, while in Argentinian self-exile. Subsequently, he also began work on a follow-on, the Supersonic IAe.43 Pulqui III, whose profile bore an uncanny resemblance to the Marut.
HF-24 Marut Aircraft Indian Air Force IAF - 003 - TN
HF-24 Marut Aircraft Indian Air Force IAF - 004 - TN
The Director, instead, expressed preference for the British Dr. W.E.W. "Teddy" Petter, who was also in contention for the position. Most famous for designing the 'Sabre Slayer' Gnat, Dr. Petter also designed the Jet-powered Hunter & Canberra, & initiated development of the Supersonic English Electric Lightning. Another Petter-designed aircraft the IAF was familiar with was the Westland Lysander, that it's pilots flew during World War II.
HF-24 Marut Aircraft Indian Air Force IAF - 005 - TN
HF-24 Marut Aircraft Indian Air Force IAF - 006 - TN
Second, the HF-24 being a HAL-driven project, with it's own Engine Division, GTRE's involvement in the Programme was not "organic", being onboarded only after UK ceased development of the BOR.12 SR. Even after it made common cause with HAL on the HF-24, the co-operation it extended to GTRE was less than optimal, he felt.

As mentioned before, with the BOR.12 SR door closed, HAL explored other options. One among them was the Ferdinand Brandner-designed E-300 Engine. Both generated comparable thrust.
HF-24 Marut Aircraft Indian Air Force IAF - 007 - TN
Egypt was financing it's design to power it's Helwan HA-300 aircraft, that was getting shape under the leadership of the German Engineer Professor Wilhelm Emil "Willy" Messerschmitt. To that end, a Marut airframe [Mk. IBX] was shipped over for Engine integration. There, the team carried out flight-tests, mounting the E-300 on the HF-24. As a serving officer, IAF Test Pilot, Group Captain [Retd.] Kapil Bhargava, who was deputed to Egypt with the Marut, gives a vivid & candid account of his stint there. It included test-flying the HA-300 prototype, becoming the first pilot in the world to do so.
"The first flight on March 7, 1963 was as much routine as the maiden flight of a fighter aircraft of a revolutionary design can ever be. There was no trouble of any kind in its short duration of 12½ minutes. The excitement came after the flight. When we were sipping champagne, Prof. Messerschmitt shook my hand and held it for a while. He was trembling. I asked him what the matter was and why he was so tense. He replied, "When I think of what could have happened". I told him that we had done all our worrying on the ground with every contingency planned for. The safety of the aircraft was the issue with which we had been struggling for six months. He said that while that was all very well, many of his prototypes had crashed on the first or an early flight. I lightly replied that he should have listened more to his test pilots and not threatened to send them off to the Russian Front if they disagreed with him. He just smiled."
Initially, though, he experienced severe acrimony, bordering on racism, at the hands of it's German development team. Eventually, he earned their unbridled respect, having pointed out severe design flaws in the aircraft. However, that effort too was stillborn, resulting from geopolitics, Egypt's participation in the 6-day War, & subsequent total project abandonment.
X-241 Wooden Glider - HF-24 Marut Aircraft Indian Air Force IAF - 002 - TN
He has also written about the HF-24 development on the Marut Fans blog. The blog hosts an extensive collection of writings, chronicling first person accounts of the IAF Pilots, assigned to Squadrons flying the Marut. A treasure trove of information.
HF-24 Marut Aircraft Indian Air Force IAF - 013 - TN
The prospect of uprating the Orpheus 703 itself, to produce more thrust was taken up. With the OEM, the Bristol Siddeley Co., onboard one approach considered was integrating the Booster Stage of the Klimov VK-7 Turbojet engine with the Orpheus, designating the aircraft powered by this engine as HF-24 Mk. IB. However, the centrifugal flow configuration of the VK-7 was found to be incompatible with the axial flow 703, that would've necessitated extensive redesigning of the Marut to achieve fitment. The plan too got shelved.
Tumansky RD-9F Turbojet Engine GTRE - 001 - TN
The team then gave a look-in to the axial flow RD-9F engine & purchased 6 of these engines, to develop & integrate. This however, posed another set of challenges. As AVM Choudhary noted,
"Unfortunately major problems surfaced after arrival of these engines. It was soon discovered that these engines cannot be fitted in the aircraft! The engine accessories fitted on the top of the engine was not properly assessed when the senior HAL member made the short trip back to India, specifically to cross check with Dr. Tank. The bigger diameter of the reheat pipe could be accommodated within the existing fuselage, but the problem about the rear end was ignored altogether as a minor issue, HAL."
The HF-24 had engine mounts in a manner compatible with the BOR.12 SR's downwards positioned accessories. The RD-9F, however, had it's accessories on top. It was concluded that, "the solution was to convert the RD 9F engine's external feature to be the same as B.Or 12 SR. The design change required was to shift all the accessories from top to bottom.". GTRE was tasked to achieve this, who re-engineered it, making it compatible with designed mounting arrangement, demonstrating operation on the test-bed. In all this, the AVM says, "the HAL's aircraft design team was aloof and kept it's distance from such a proposal".
Soviet consultants brought in to address the dimensional incompatibilities agreed to make suitable changes needed to accommodate the engine in the Fuselage. An agreement to that effect, plus it's license production in India was signed in Moscow. Just as things were getting ready to move forward, roadblocks again. While the Marut was designed to attain Mach 2 speeds, with the RD-9F, it would attain Mach 1.4-1.6, perhaps reaching Mach 1.7. Unacceptable to Dr. Tank, who vetoed the buy, the book states. A tentative step front, a quick step back.
Rolls-Royce [Bristol] Orpheus Mk. 703 Turbojet - 001 - TN
With options knocking down like pinballs, one after the other, it was considered to take up development of an Afterburning [Reheat] solution of the Orpheus 703, operating at 1700o K - the Orpheus 703R-1700 K. Of this effort too, "Dr. Tank could not care less, even when he was nowhere near meeting the initial ASR he was invited for. He had the support of a few qualified Aeronautical Engineers of Indian origin. For them Dr. Tank was an infallible hero….", writes AVM Chaudhury. This was followed by an upgraded Afterburner operating at 2000o K - Orpheus 703R-2000K. Though the Engine got Type-certified, neither solutions could meet set performance target.
As we learn, these GTRE efforts did not receive adequate support needed from Dr. Tank-lead HAL team. The structural changes made at the Tail section, to accommodate the Reheat Engine resulted in the Aircraft experiencing increased Base Drag, hampering Cruise & Dry Climb performance. Combat Radius got curtailed, though the increased Thrust would likely have improved it's combat effectiveness & survivability. The HAL team, one gets a sense, had it's mind firmly set on the BOR.12 SR engine & were unwilling to explore other possibilities.  The opinions expressed & suggestions the GTRE made, especially with regards to the Base Drag, to HAL weren't given full cognisance. Multiple Government committees, in their reports, had also questioned the IAF's own commitment to the programme. Clash of egos, cult of personality & diverging thrusts, all contributed to putting paid to a project of National strategic importance.
Some portion of the book is available as a preview on Google Books. Posting relevant available pages here for parsing. Buy - Restoration of Split Milk [affiliate URL].
All these could have been averted with better Project Management practices & coordination. The endeavour was found lacking on this front. As noted in the SIPRI Report, "India's Ad Hoc Arsenal: Direction or Drift in Defence Policy" [affiliate URL],
"The decision to develop the Marut was a political one and the key decision makers were relatively unconcerned with the technical problems. Furthermore, Kurt Tank was an aircraft designer, not an engineer. Aircraft designers are trained in a systemic fashion and consider that a project is essentially the sum of its component parts. In the absence of strong direction from the MOD, problems of co-ordination and conception arose…..
…...At no point is it possible to identify a well orchestrated attempt to weigh the views of the military, the politicians and industry. Instead, the progress was linear, as the project proceeded it passed from the hands of the politicians, to the military and finally to industry. Or, put another way, the politicians defined the possibilities, the military defined the problem and industry was left to define the answer."
Emerging out of this learning, was the Government's decision to establish the Aeronautical Development Agency [ADA], the nodal authority to manage & coordinate activities pertaining to the Light Combat Aircraft [LCA], Tejas. 28 years after the programme commenced in 1992, the Final Operational Clearance [FOC] variant of the aircraft [SP21], performing it's maiden flight on March 17, 2020. It was to the detriment of this Nation that a yawning gap emerged between the abrupt termination of the HF-24 & commencement of the Tejas effort. This lead to a loss of momentum, degradation of institutional know-how, collapse of the Supply Chain & vendors cultivated. The drain of Aeronautical brain witnessed in the 70s & 80s, due to lack of adequate in-country domain-specific challenges, compounded the challenges faced while taking the LCA project off the ground. The country's Aeronautical expertise took a hit of at least 2 decades, perhaps even 3 due to this.
HF-24 Marut Aircraft Indian Air Force IAF - 008 - TN
One complaint, amongst the many, made of the IAF drafted Air Staff Requirement [ASR] was that it asked of the Moon from the HF-24. This view is expressed again with it's ASR for the LCA, what with it even revising the LCA-specific ASR. This is akin to asking for 2 Moons, when attempts to reach the LEO is proving to be a big ask. Conventional wisdom stipulates that a fighter aircraft be designed to do one job exceedingly well, with another job it can perform moderately acceptable. Prime example of this is the Eurofighter Typhoon. Developed by a consortium of European countries, with a cumulative Aeronautical history spanning centuries, it's executes a primary role of an Air Superiority aircraft. It was only after it achieved it's primary objective that developers, subsequently began expanding it's envelope, refining it's Ground Attack capabilities. The IAF, too, abides by a similar dictum, when it goes shopping overseas for aircraft. The Jaguar, for example, is Ground-attack platform, a bomb truck, flying low-level, carrying plenty of Ordnance, at a time when it is not expected to encounter much aerial opposition. The MiG-21, on the other hand, is a high-speed interdictor, that flies at high altitude to deter opposition fighters from crossing the Rubicon. True multi-role capability in an aircraft is a niche attempted by an elite few, even fewer then, when Indian programmes were in conceptual stage.
HF-24 Marut Aircraft Indian Air Force IAF - 009 - TN
Yet when it came to the Marut, it stipulated outcomes that defy objectivity -  should be able to fly, both on the ground, as well as very high up, carry armaments for either mission, fly in any weather, take-off from any runway, be it on land or water - yes, a Navalised HF-24 was also on the tables.
One is lead to believe that makers of Optimus Prime sought inspiration from IAF's ASR. With an eye on infusing a modicum of realism, even they scaled down Prime's capabilities - the Optimus Prime isn't water-worthy. A similar IAF ASR, the Tejas is currently fulfilling. In the Marut's case, though, Gp. Capt. Bhargava says that these capabilities were promised by Dr. Tank himself, which the IAF merely incorporated into it's document. FWIW.
HF-24 Marut Aircraft Indian Air Force IAF - 010 - TN
HF-24 Marut Aircraft Indian Air Force IAF - 011 - TN
The country is set to embark on a number of Aerial Development programmes in the coming years - TEDBF, ORCA, AMCA, MRTA, MLH, being a few of them. Best practices & lessons learnt from the hurt suffered from previous programmes be incorporated to move forward. The HF-24 was undoubtedly, a colossal lost opportunity. Lot of ground was lost, lot of it recovered, plenty more to cover.