Wednesday, 16 June 2021

The Unsung designers of HAL (1950-1980)

The Unsung designers of HAL (1950-1980)

I have deliberately left out Dr. V M Ghatge. I have confined myself to those whom I knew at least by sight.

Raj Mahindra (1920-1970)

There is little information available now of about the early life of Raj Mahindra but it appears that he had worked in the British Aircraft Industry for ten years before joining HAL in the early ‘fifties. During his stay in Britain during the war years he married a British girl and he himself held a British passport. At that time India was under British rule and there was no special stigma about being a British passport holder. Today, I suppose he would have been a NRI. I mention all this because this fact of having a British wife was used to lever him out of the leadership of the LCA project –with fatal results for the project. At the time of joining Raj Mahindra had specifically asked if his British passport or his wife being British would affect his prospects adversely but he was reportedly assured such would not be the case.

On joining HAL he quickly made his mark on the HT 2, HT 10 (stillborn), HF 24 projects but his magnum opus was the HJT 16. He shared the leadership of the design with Dr. V.M. Ghatge and after the retirement of Dr.Ghatge in 1961 he was solely responsible for the service development of the aircraft of which was built.

People with shallow knowledge of aircraft design usually declare that the HJT16 was a copy of the Jet Provost. How wrong they were! When it first flew-within 36 months of the project being sanctioned -the aircraft was technically in advance of the Provost mainly in account of the fact that the early Provosts (Note )  were not equipped with a pressurized cabin until the Jet Provost Mk7 of 1964.

Raj Mahindra intuitive approach to aerodynamics can be exemplified by his approach to getting the HJT 16 good spin behavior. The side by side seating, square cockpit top and relatively short fuselage and most importantly the mid set –“ëlephant ears” side intakes meant that the fin at high AOA would be immersed in disturbed airflow. This was before CFD and gives us an insight that a good aeronautical engineer should carry a CFD programme in his head! Indeed he must! Raj Mahindra’s solution was increase the height of the fin so that at least some portion of the fin would be in the free stream and therefore retain rudder authority. You can read about it in my blog  :profprodyutdas on the spinning problems of the HJT 36 I wrote some years ago. In the HJT 36 again used the mid set elephant ears intake of the HJT 16 and faces the same problem though again the problem is quite curable – without foreign consultants and huge fees.

I would have preferred if he had taken some more time to “fiddle” around with vortex generators or recontouring the bottom the fuselage and intakes to get the airflow to cling to fuselage until it reached the fin but perhaps “fiddling” and “tinkering” are cultures alien to us. If you look at the fin of the Jet Provost is much smaller thus benefitting weight and thus both acceleration and rate climb. One possible reason for the smaller fin could be that the Jet Provosts inlets are “less obtrusive” and blended quickly into the fuselage and is set lower vis a vis the fin and tailplane. Be that as it may it is without doubt that Raj Mahindra was both experienced and had that elusive “feel” so necessary for creating an aircraft and was one of the fittest men then available to us for leading the LCA project.

This was obviously recognized by the backers of the LCA programme who were mainly in the corridors of the South Block. Along with Dr. SR Valluri as Project Director Raj Mahindra was selected to be the Chief Designer of the LCA. In my idle moments I have wondered whether the project would have been at all sanctioned if Dr. Kota had been presented at the very beginning as the Chief Designer.

What happened was that within a year of the sanctioning pressure was brought on SR Valluri to ease out Raj Mahindra. Reportedly Suresh Kalmadi the Congress MP raised the question in the Parliament about the nationality of Raj Mahindra’s wife and wondered whether a project of national importance such as the LCA could be trusted to a man whose wife was a foreign national and therefore by implication sure to be a highly efficient spy!. Why this aspect was not considered at the time of getting sanction for the project is of course a “sore thumb” question.I believe that the intentions of the South Block were not bonafide to begin with. The upshot was that Dr. Valluri felt that VS Arunachalam was not being energetic enough to defend Raj Mahindra in what were obviously ridiculous charges. Since Dr. Valluri was sure that Raj Mahindra’s leadership was sine qua non and perhaps analyzing other signals from other interactions with South Block , he ,being a man of honour , resigned. The result of these dealings forty years ago is that we have the smallest fighter in the world being also the heaviest. Our problems are NOT of Technology. Unless ADA changes their thinking ADA will next be doing the heavier than air balloon! Having said that I do believe that the LCA cannot be so bad and fairly simple fixes may redeem much or many of its shortcomings.

SC Das

Subodh Chandra Das graduated from Bengal Engineering College circa 1940 and did his Masters from IISc Bangalore before joining HAL along with Dr. V.M. Ghatge. He was the Chief Aerodynamicist from the Indian side for the HF 24 project and after the departure of Dr.KW Tank in 1967 he was the Chief Designer of the project and was responsible for the HF 24 Mk.1T., the Basant and the HPT 32 aircraft of which 120 aircraft were delivered..

I had the pleasure of being interviewed by him at IIT Khargpur in 1972 when he led the team that was looking for people for what he hoped would be the HF 73 project. Even at the interview I was impressed by the obvious keenness to do good for HAL. It sort of came through. But what I want emphasise here is something many may have overlooked.

As a PGET in Bangalore I used to roam around the place from the Overhaul hangars to the scrap yard coming across in the process a lot of interesting aircraft including a HAL copy of the Noordyun Norseman (a what!) to Curtiss Commando to Zlin Akrobat not to mention Hunters, MiG and Alizes (sic!). Then along with Subroto “Butus” Roy Choudhury there would be the animated after dinner discussions our chummery when we would redesign the aircraft!

In one of my ramblings I came across a weird aircraft which I thought no sane man would have even put down on paper. It was obviously an Agricultural aircraft which can be pretty weird looking -think of the Bennet Airtruk -but what an aircraft was this?! It had tricycle undercarriage and a cockpit that looked like a telephone box stuck onto a fairly conventional fuselage. It surely could not have flown though even then I could appreciate the care taken to ensure pilot visibility and ground handling. Of course the aircraft did not fly well and I was told rather gleefully that the aircraft could not fly out of ground effect.

Here came the difference. SC Das quickly salvaged the sub- assemblies and redesigned the aircraft’s fuselage to create the Basant II aircraft of which 31 were built. It was a very maneuverable aircraft and I saw Wg.Cdr “Tilak fly very tight figures of eight within a half wing span of the ground with utter confidence. I was worried a wing tip would dig in but he seemed to have the confidence in the aircraft’s tractability. In service it proved to be a robust aircraft with a larger than average (33 cu.ft.) chemical tank and in Haryana it could fly up to 33 sorties in a day spraying 3360 acres in the process.

What was there to admire in such a “goof”?  The thing to admire is the honesty to acknowledge a mistake and the ability he displayed to quickly absorb the lesson and make the modifications necessary. SC Das was Engineer enough to realize even if gross mistakes are made in the search of a solution  the situation must be salvaged and quickly. In contrast the LCA programme it must have been clear by 1996 that the aircraft was grossly overweight and not able to meet the specifications but instead what we have had from ADA was a series of cover ups that outrage common sense and continue even today.

SC Das was also responsible for the HPT 32 which was one of the lightest aircraft of its class when it appeared. I am sorry to say that he took the easy way out having an oversize fin on the aircraft and some of the cowling and undercarriage details could be neater. This resulted in the aircraft having too much drag and though SC Das had retired out by 1979 HAL did not do a “clean up” and “polish” of the design an aspect almost as important as designing of the aircraft. I had written on the fuel feed problem of this aircraft. The problems were cureable but I think the problem was used to buy the Pilatus.

But SC Das’s real effort –unrewarded- was to doggedly pursue the realization of the potential of the HF 24. ASA/HSS/HF73/HF 25 proposals are testimony to his efforts. The HF 25 was interesting because it proposed to use the MiG 21’s propulsion elements to create a viable aircraft. The assessed project cost was a mere Rs.64 Crores in 1978 money. My only nitpick of the proposal was in trying for the maximum aerodynamic efficiency he changed the rear fuselage contours. My objection is that this would entail considerable fresh test flying particularly for spinning. The flat rear fuselage bottom of the HF 24 is an asset that we must keep trading good handling over aerodynamic efficiency. Knowing SC Das he would have given me an attentive hearing !

I say that because having interviewed me he kept a benign if gruff eye on me. We had even discussed the HF 24s gun firing problem and I remember the interest with which he listened to my then yet unformed exposition of the problem and my disparagement of the HF 73 design! Unfortunately, soon after I took seriously ill with Typhoid which almost killed me off. Whilst the HAL Hospital at Bangalore took good care of me the aftercare was a problem, and my parents who were in Calcutta had difficulty coming to Bangalore . To cut a long story short I transferred to Design Office Lucknow and worked on the Ajeet ECS and the indigenization of the MIG 21. SC Das was quite annoyed but he never took it out one me. Indeed , when I met him, for the last time as it turned out, on the platform of Howrah station after I had paid him the traditional respects I told him that I had left HAL and was now working for an Indo British Engineering Company in Calcutta. He said with vehemence “You did the right thing. The Bastards do not want to make aeroplanes”. In a way he echoed another respected HAL senior, Prof. C.S. Murthy who said “They won’t make aeroplanes; There is too much money to be made.”

I will close with one last anecdote which I heard from Subroto Roy Choudhury who had joined a few months before me. You ask him if it is true. The work load at that time was not too high and it seemed that one of the Draughtsmen had wandered over to another Department to chat. One thing led to another and led to a question of daring from which it transpired that one of them challenged the other to show what I will call here as his “Family Jewels”. The items being displayed there was shock and horror (understandable) and a great storm in a tea cup brewed up. Delegations were formed and there was outrage on one side and enraged sang froid on the other. Finally the crisis and the representatives landed up at the Office of the Chief Designer seeking redress. After keeping them waiting, Dasappa, as he was called behind his back heard both sides patiently, swelled up like a turkey cock and simply said “WHOOF”. The message was understood and the parties returned meekly to their desks. That was Dasappa.

PD Desai

I was known for being an “Äviation Nut” at IIT Kharagpur so much so that I used to get invited to their technical seminars and so forth. Sailesh Buch ( now in America) came back from his summer training at Nashik in 1970 and debriefed me about his training during the course of which he told me this tale. The MiG 21 Fl had some problems of aileron flutter under certain flight conditions. Applications to the Russians were met with evasive responses. It was PD Desai who thought of sticking a small aluminum angle strip in front of the aileron as a turbulator. It worked like a charm but the local Russians were extremely annoyed. The modifications were sent to the MiG OKB in Moscow where after due diligence it came back as a very good “mod”. The same lot of Russians who had been “greeking” now came up with smiles hugs and a bouquet and congratulated PDD! I was therefore surprised to read in Air Marshal Rajkumar’s book where he credits Dr. Kota for the “fix”. If Buch’s account is right Dr. Kota was just about a GET at that time. Perhaps success really has many fathers. PD Desai was at that time Chief Designer Nashik having joined HAL in the ‘fifties and worked on the HF 24 project under the Germans. During a visit to Nashik in the mid ‘seventies I came across the project study of a ground attack fighter by PDD. It was an aircraft in some ways similar to the Lansen.

It is interesting that after thirty years at HAL and having reached the position of Chief Designer PD Desai shifted to IIT Bombay circa 1980 as Professor of Aeronautics. The usual gossip at that time was that this was done to make way so that the next incumbent Dr. Kota could be given the post. Head of Aircraft Design Bureau would have counted for in his selection as Project Director LCA. I do not know how PD Desai fared at IIT but my guess is that it may not have been too happy. By the 1980s the IITs -which had tried to attract Industry men in its early days by giving weightage to their practical experience- had switched to the opposite. Led by the Leftists it was gradually made almost impossible to have academic freedom. Indeed it is now almost impossible for an Industry man to join academics but that is another very serious subject that needs importance on its own.

Baljit Kapoor

Baljit Kapoor was no designer. Baljit Kapoor was the founding GM of Lucknow factory and after a successful went to Bangalore as the Chairman of HAL. His keenness to develop HAL can be seen from the fact that when even after leaving HAL I sent a proposal to improve the Ajeet by re-engineering it with the GE J85-GE21 he arranged for a meeting with senior HAL design people.

However I mention Baljeet Kapoor in another context. He was asked to transfer two hundred HAL designers to the newly formed ADA. He opposed this and was summarily removed and replaced by Air Marshal LM Katre. There is an amusing anecdote that a visiting Russian Delegation, apparently, was confused enough to address the new Chairman also as Mr. Kapoor.

My conclusions from the above are the following.

1.     We have the men to do the job.

2.     It is the thinking at Raisina Hill that is crucial for having an aatmanirvar aeronautical Industry.

3.     If Sir Sydney Camm was alive today and applied for a job in the Govt. Aeronautical Establishments the two outcomes would be:

a)     He would be rejected because he was only a Draughtsman by qualification.

b)     He would be selected with a huge salary because he was a Western Man.

Both would be wrong in approach. We do not need foreign consultants. If BAC advice has taken seven years and counting to correct the spin problem on the sorely needed HJT 36 then we should relook as to where the drain is clogged. Or else reexamine if foreign consultancy is the answer if despite expensive consultancy the desired end result - the avoidance of expensive imports by developing acceptable Indian products - is not being achieved.

The Socialist Pattern of Society type of thinking just will not work for high technology involving mass production and customer support. It is essential to bring in the Private sector Aeronautical and Automotive sectors with their vast pool of Engineering design talent and apply them to the task.

No comments:

Post a Comment