The Aerodynamics of the MiG 21 Accidents

A fighter pilot flies a wing and an Engine. The qualities of the wing like the wing loading, span loading, aspect ratio, section profile of the wing and the qualities of the engine such as power loading and response time determines the flying qualities of a Fighter.

Fighter flying is one of the most hazardous occupations known to man. It is hazardous because the very high speeds, low level flight over inhabited areas in an airspace often attractive to large birds means that both the reaction times and the options available to a pilot in an emergency are often dangerously limited.

This spate of MiG 21 accidents caused much anguish and was widely written about. This paper is an analysis the technical and statistical aspects of the accidents and has some suggestions of future importance.

The MiG 21: a Technical appreciation

It is significant that for 50 years the MiG Design Bureau were at the forefront of fighter design and yet they never used anything but "yesterday's" proven technology to set and maintain the pace ( Note 1).

There is a lesson in that for Indian aircraft designers..

Coming from such a distinguished pedigree it is not surprising that the MiG 21 was remarkable. It combined low cost proven technology with brilliantly innovative and insightful application of the physics to produce at lowest cost the solution of a high altitude bomber interceptor.( Note 2 ) At the time of its induction into the IAF the MiG with its auto stabilization, radio altimeter, fully duplicated controls and general reliability introduced new standards of safety and reliability .Pilots converting to the MiG 21 were universal in their praise for its ease of piloting and safety and the reliability and the functionality its systems. 'Safe as a bullock cart" was how the aeroplane was described in the late '70s.

The Aerodynamics of the MiG 21 in low level flight.  

Unfortunately all fighters are designed primarily for air superiority but end up in the more hazardous low level close support role.

This was also the case with the MiG 21.From the 1980s the MiG switched to the close support role. New upgrades to make the type suitable for close support also meant a steady increase in weight. The aircraft became more sluggish and unwieldy particularly during the landing and take off and in circuit where the aerodynamic control forces decline as a square of the flight velocity but the inertias remain the same. The weight increase affected the wing, power and span loadings (please refer toTable A- for the MIG the figures on the top of each box are for the FL those below are for the Bis).

The span loading increases is a good indication of how much more angle of attack has to be generated at a given speed to maintain height. Increase in the angle of attack in turn means more power to stay aloft.

The wing loading increase shows how much more speed has to be increased to maintain level flight. A doubling of wing loading would mean a 40% increase in flight speed. This also means a doubling of the power required.

The power loading indicates how much power is available to accelerate the aeroplane should the airspeed fall too low. I have computed the figure for max dry thrust as in a crisis there would not be those few seconds available for the afterburner to kick in before the aircraft impacted.

A special mention must be made of the low aspect ratio of the MiG 21. The low aspect ratio makes the aircraft "alpha "sensitive. The CL /Cd curve becomes unfavourable in low aspect ratio wings. In other word unless the pilot gets the angle of attack right he may see a very great increase in the drag of the aircraft without any corresponding increase in lift. His total energy would decay preventing the aircraft from accelerating. Translated into reality it means one of the following scenarios: During take off "over rotation" -too much nose up-would mean poor acceleration due to high induced drag and failure to lift off with the aircraft running into the overshoot area at high speed.

During landing the misjudged alpha would increase the induced drag causing the aircraft to slow down, lose lift and hit the ground before reaching the touch down area.

During turn into the finals ( or during low level aerobatics) the aircraft is pulling more 'G"s with corresponding increase in induced drag slowing down the aircraft which is already side slipping because of the turn and losing height over ground. A combination of side slip during a turn with high induced drag reducing speed caused unforeseen height loss and a "controlled flight into terrain".

Very many of the MiG 21s lost were in these three regimes of flight. Even in civil airliners most accidents occur during these three phases but:

1) The alpha sensitivity of the MiG21 ,because of the low aspect ratio of 2.2, requires much more precision than the same maneuver when executed in an aircraft with a aspect ratio of 5.6 as in a basic trainer.

2) The continual, if inevitable, weight increase in the MiG 21 meant that the approach speed in the later marks had to be made at a higher and higher speed. This reduced the amount of surplus power available to accelerate away from a "coffin corner "situation". In India the hot weather meant the engine was producing about 12%less thrust and the wing was producing about 12% less lift to begin with.

3) In case of an emergency, to gain height, the pilot in a Hunter or a Kiran would open up the throttle and pull back the stick- things which are instinctive even in a rookie pilot. Ina MiG the pilot has to push the stick forward, build up his energy and then after a delay of several seconds, pull back the stick to climb away. He may simply not have the time when flying close to the ground.

4) The CK ejection seat, one of the best for high speed high altitude ejection simply was not good enough for low level by modern standards. One of the clever features of the CK seat was that as the seat left the cockpit the canopy- which was hinged to the front of the windshield in the FL - attached itself to the top of the ejection seat and rotated itself until it covered the entire front of the ejection seat- thus giving unparalled blast protection when ejecting at supersonic speed. I remember a Martin Baker engineer getting very interested in how the thing worked. I had seen the seat but he had not! Unfortunately I was not able to help him. The semi -encapsulation feature delayed ejection in that it took too long to get rid of the canopy after clearing the aircraft and this delayed clear release and deployment of the Parachute. The 300 kmph, 100 meters minimum parameters meant that many low level ejections were unsuccessful.

The span loading, wing loading the power loading and the aspect ratio of a series of aircraft flown by the IAF is tabulated at Table A.

Accident rates in supersonic fighters

The accident rates in supersonic fighters of the same generation as the MiG 21 makes for relevant comparisons.

Starfighters.

The German Luftwaffe flew about 950 F 104s from about 1960 to 1987 and lost about 292 of them during the same period. Average loss rates were thus about 11 per annum though the peak loss rate was 28 aircraft in 1965 and about the same in 66. The ejection seat of the F104 was even worse that the MiG 21 for low altitude flying. The Germans corrected that by switching over to the Martin Baker GQ 7 seat sometime in the mid sixties.

The Canadians lost half of their fleet of 200 CF 104s during a similar period of service. Training was admittedly a problem with the German Luftwaffe which was barely ten years old at the time of the induction of the F104 but the same could hardly be true about the Canadians.

The true master of the F 104 was the Spanish Ejercito d Aire who never lost a single Starfighter in seven years of service. People said it was due to fine weather over Spain! This usually made the Spanish AF indignant! The British RAF lost over a hundred of their 297 Lightnings in about 25 years of service- a number of them to engine fires which was probably due to a flaw in the detail design. Our MiG losses have been at a much lower rate.

Flying fighters is a hazardous business and continual stress and training on flight safety and discipline without killing the spirit of the Fighter Pilot is a difficult and skilled art.

Interestingly the Pakistan Air Fore lost 23 F-7s ( Mig 21 equivalents ) in 10 years which approximates the IAFs loss rates, given their smaller fleet size. It is stated that the PAF possibly reports only those crashes which are in populated areas. In fact the PAF is extremely touchy about anything that shows it in a bad light and it would possibly be that their actual crash rate is higher than the IAFs MiG 21s.

About their image consciousness I remember in the mid 80s there was a review on the PAF in Air International and there were these enormously dirty and dusty MiG 19s with chipped yellow and red paint and oil streaked fuselages and generally looking very neglected though the MiG 19s were right there on the flight line. Someone obviously got (and deserved ! ) a "rocket" because since then I have never seen a PAF aircraft in any magazine that did not look as if it has just come out of the paint booth.

One notes that there are 4 mid air collisions in the 23 PAF losses reported- the MIGs outward view was never its strong selling point. I feel the mid air collisions were more for this type. A switch to a glass cockpit and bulged hood ( to raise the pilot's eye line) may be useful at least in improving forward view.. Another reason could be due to the very small wing span in comparison to the fuselage length. In formation flying the aircraft would be that much closer together. In a turn, with the poorer visibility sometimes the collision was inevitable.

What should be the accident rates? Ideally zero.

However this is not possible in a profession where getting back with a tale to tell or making a hole in the ground can depend on decisions made with a difference of hundredth of a second or a few meters difference in position or height.

The Western world considers acceptable an accident rate of 1 in 10,000 hours as an 'acceptable". If we can accept this figures at a face value then a simple set of "expected number of accidents " could be created by assuming the number of squadrons and assigning a certain percentage of availability and a certain number of flying hours. This would work out to about 7 aircraft per annum in the 80s and thereafter. The fact that in the tropics the aircraft is flying in a non ISA atmosphere means that the engine thrust and the lift available is lower than available to a European pilot. In addition the flying environment- the ratio of open to densely populated areas, the number and size of birds at low level can alter the accident rate in spite of identical standards of training and maintenance.

Table A .

Comparative parameters of IAF aircraft and also the Chinese FC 17

Type	Power Loading N/kg	Wing loading Kg/sq.M	Span Loading Kg/M	Aspect ratio	Aerofoil Thickness	Pitch Inertia Kg.m*mX10e6
Harvard	2.75	93.3	172	6.96	15% (?)
Vampire	3.8	159.8	355	5.51	12% ( ?)
HJT 16	3.71	157	280	6.025	15%	0.309
HJT 36 IJT	4.6	183	324	5.56	15% ( ?)
Hunter	6.0	228	722	3.24	8 %	1.16
MiG 21	5.6/8.2 (with a/b)	279 334	897 1076	2.2 all models	6 %	1.18(FL) 1.39(Bis)
Su 7	7.3/10.5	274	1019	2.65	10.9 %	2.2513
F 104	6.94/10.41	417	1142	2.44	3.5%	2.12
HF 24 Marut	6	256	799	2.89	6 %	1.387
Hawk	5.4	254	458	5.2	10.9 %	0.5359
FC 17	6.6/ 11	319	816	3.52	6 %

Discussions

1. The above table gives a good insight to the problem. In the earlier days the pilot progressed through the HT 2 to the Harvard and Vampire to the Hunter. The critical parameters of Wing, power and span loadings and the aspect ratio progressed gently and even at the then top of the line aircraft the Hunter the aspect ratio was relatively modest.

As long as the Hunter was there in service a kind of de facto advanced trainer available to stream in the pilots to the tricks of "power flying". The pitch inertia figures are approximate but shows why pilots translating from the responsive Kiran would have found the MiG 21 slow to respond in pulling up or down. Criticism of the Marut and the Su-7 in terms of slow pull out after a close support run can also be found in their relatively high pitch inertias.

With the phasing out of the Hunter the pilots translated directly from the HJT 16 Kiran to the MiG 21 where the figures increased several times. The pilot had to be alert to keeping his energy levels within bounds. Whilst this was also generally managed, it meant, in a case of a mistake, the pilot was skating on thin ice.

2. The accidents were evenly distributed between seniors and rookies. Of the100 cases of accidents where the pilot is identified by name we have 36 accidents where the pilots were Squadron Leaders and above and 24 were of the level of Flight Lieutenants. Only 40 of the accident cases were below these ranks and one could ascribe inadequate experience as a cause. To note however is that 60 % of the accidents, in a sample of 100, involved senior pilots.

3 Of the 164 losses between 1962-2004 that is recorded in the Warbird of India records the main categories were:

Cause	Nos Lost
Mid Air Collisions	10
Bird Strikes	10
Take Off or Landing Phase	29
Combat Related	11
No details in Public Domain	rest

The numbers may appear inadequate as a statistical sample. However one has seen or dealt with an infinite sample (so beloved of statisticians!) but in practice the laws work as well for a sample of 50 as for infinity! Even if we take the first three cases ( leaving the combat losses out) it is statistically reliable. It clearly shows that accidents where that low aspect ratio was a factor ( i.e TO & landing ) dominate with 29 cases out of 49 i.e greater than 60%.

Is the general accident level too high? According to the MOD the IAF lost a total of 315 MiG 21 were lost from all causes in 40 years. Taking out the combat losses this is less than 30% of the MiG fleet in 40 years. Compared to the Canadian losses of 50% and the German Losses of 292 out of 915 F104s in a much shorter period of operation and the fact the percentage of Lightning losses for the RAF were just as high would indicate that losses were not unusual.

The figures from Warbirds of India are likely to be incomplete, especially in the pre 90s figures. However there are some statements made by the MoD that might help us. Using the figures the Warbird's loss records can be modified as follows.

The loss as recorded in the Warbirds site:

Financial Year	No of Aircraft Lost
92-93	6
93-94	10
94-95	6
95-96	4
96-97	5
97-98	7
98-99	10
99-00	13
00-01	12
01-02	8

The figures would indicate that the losses from 98 to 01 are "out of control" But if we modify the figures by using some figures later given by Mr. Pillarisetti (Source: the Warbird thread quoted by Mr. Pillarisetti http://www.warbirdsofindia.com/forum/forum_posts.asp?TID=59&PN=1) and the statement by the MOD about the MiG 21s lost during the period we can construct a closer model of the actual aircraft losses .

In this model the numbers "missing " in the Warbirds site with respect to the MOD statement are equally distributed into those years of the Warbirds site which showed a lower number. The actual crash figures would thus be:

Financial Year	No of Aircraft Lost
92-93	11
93-94	10
94-95	11
95-96	9
96-97	10
97-98	7
98-99	10
99-00	13
00-01	12
01-02	8
02-03	11
03-04	5
04-05	2

(Thanks to Jagan Pillarisetti for this table)

Looking at the revised figures we can say that the losses whilst regrettable do not reflect any sudden decrease in quality.

There are many press reports that said that the dip in 1997-98, where only 7 were lost could be because of ACM Sareen's measures of reduced flying efforts, which was the butt of much criticism. 01-02 drop also indicates some kind of "interference". The view was that the high value for 98-99 was due to Kargil which meant extra flying and the state or readiness thereafter.

The sudden decline of crash rate après 2003, is statistically speaking, "out of control" and indicates the presence of a new factor which powerfully reduced the trend.

The reason for the crash rate as also the sudden decline in recent times can only be conjectured. The popular press mentioned everything from inadequate training (which was probably not true) to spurious engine parts from ex- Soviet Republics to combustion cans losing their enameling. None of this can be verified.

According to Western rates the loss rates should have been around 5to 7 aircraft a year but one must remember that they do not have to contend with large birds and high runway temperatures. Pilot attitudes may play a major part in accidents. "Disciplining" pilots may reduce the accident rates but break the spirit of the fighter pilot which is counterproductive. Somehow the RAF manages to maintain a balance in an understated way and one expects the IAF has its own methods.

Thoughts on Future training equipment

4. The induction of the Hawks will be warmly welcomed but judging by the parameters in table A and the above para 2. It would be unwise to expect any dramatic reduction in accident rates because of the introduction of the Hawks per se.

It is interesting to conjecture whether HAL should prepare a few IJT with a thin, low aspect ratio wing as a Mk 2 IJT. This should have a 6% wing and an aspect ratio of around 3.2 and a smaller area which would improve the thrust to weight ratio and push up the wing and span loadings but keep the same basic systems. Pilots qualifying on the IJT could then easily change to the Mk2 to extend their training envelope by flying a relatively more "snappy yet similar" machine before proceeding to the AJT.

The LCA has an unusually low aspect ratio of 1.9. It will inevitably put on weight in mid life. Unless it has been tamed by the FBW software, the LCA , will be requiring much careful handling at low speed low level flight. It is also a single engine machine. Will it repeat the MiG experience? May be but the loss of life will be less as it has a very good ejection seat.

5 The importance of having the best ejection seat possible cannot be overstated. It is noteworthy that the Pakistan Air Force retrofitted their MiG 19s with the Martin Baker MK 10. Such a seat in the MiG 21would have saved many of the 70 pilots killed. Wg.Cdr Gautam, MVC and Bar who died "dead sticking" a MiG 21 FL during take off at Lohegaon is one name, of the many, who come to mind.

6 HAL made many valiant attempts to revive the HF 24 Marut. The table does show what a good potential it has as an advanced trainer. With the same Saturn AL 55 engine possibly with an afterburner and systems aggregates as the HJT 36 and the avionics of the MiG Bison for commonality and a modest use of composites in non critical parts it is almost spot on advanced trainer cum long range strike aircraft. It has a lot of room for modern avionics. .A time to first flight of 36 months and an IOC of 54 months should be achievable. How about involving the private sector? 7. An investigation of the accidents of supersonic fighters shows the need for a twin engine configuration. Almost all the next generation combat aircraft are twins. This is no coincidence. Since fighter engines are "state of the art" ( sales jargon for "doubtful reliability") it is important to have twin engines so that the plane can get back to base. The number of Starfighters which crashed due to engine related problems is shocking to any investigator. The reported engine related failures in the MiG 21 is noteworthy.

Northrop once published a study where it was claimed that the peacetime loss rate of a twin engine fighter was one fifth of a single engine fighter. This would be true only for a very high and rigid standard of flying discipline but no doubt many of the losses are due to pure engine trouble. In the case of the MIG 21 crashes some 40-50 losses would have been avoided had the aircraft been twin engine.

8. The Chinese FC 1/FC 17 is probably the most intelligent development of the MiG 21 The lateral intake allows for a decent size of radar without obstructing forward view - something that declined with each new mark of the MiG -21. The high aspect ratio larger wing of the FC 17/ FC1would improve both low speed and combat handling as t would bleed off less energy and the lower wing loading would mean that the blistering landing speed would have been tamed to a reasonable figure. We should have had an alternative LCA project along similar lines. It is cheaper, more economical and faster to have two competing projects until a clear winner emerged.

Given the expected delay in the LCA induction the IAF could do a serious contingency study about rebuilding their time expired fleet of the MiG 21Ms. Aircraft are not like the fabled "one Horse shay" in that they don't fatigue all over at once. Life expired means usually the wings have no life left in them. Usually some 8 to 10 other components of the air frame suffer the rest are usually quite good for another 3000 hours. This would essentially mean remanufacturing the centre fuselage carry over structure and the wings and some of the empennage fittings. The RAF is "re-winging" its Hawks which is a good precedent.

Conclusions

1) The MiG 21 is a sound and excellently engineered design by one of the most respected design bureaus in the domain of fighter design.

2) The loss rate of the MiG 21 is in no way worse than any similar fighter of its genre and better than most.

Applying western accident rates is also somewhat unrealistic because of significant decay in thrust and lift due to high air temperatures. A 12% decrease in lift or thrust can lead to a 100% difference between crashing or getting back safe. There being no easy mathematical co-relation.

3) The design of fighters for mach 2 flight makes them difficult to handle during take off and landing. This is traditionally the most accident prone regime of flight- even in civil airliners operated by highly seasoned crews under vary benign flying conditions.

4) Statistically at least there is no conclusive evidence that poor training was a major contributor. Highly seasoned aircrews were involved in a significant number of accidents. Fighter flying is a hazardous job.

5) The ejection seat's performance left a lot to be desired. It may well have been worthwhile to develop a specifically tailored seat once the aircraft was switched to a role involving low level flights. Possibly the licensing agreements did not cover such a case.

6) The sudden decline in the crash rate of the MiG 21 après 2002 cannot be explained with the current level of published information.

7) Twin engine equipment and redundancy of systems, despite a higher first cost, may be essential in the future and may actually be economical during the life of the fleet

8) With innovative engineering the MIG 21 M and the Marut can be the basis of future equipment as a low cost supplement.

-Prodyut Das M.Tech M.Ae.S.I

---

Notes:

The MiG philosophy of simple technology and advanced concepts

1. Some schools think of the Fighter as a showcase of technology, others differ.

The MiG Design Bureau, which set the world standard in high performance fighter design, for fifty years belonged to the second. The remarkable fact of the MiG fighters was the stead fast use of only proven ,decade old technology to achieve phenomenal performance which often the rivals equaled only by much more costly unproven and sometimes ineffective technologies.

The MIG 1/ MiG 3 used steel tube and wood structure in 1941. Despite a heavy engine it was the fastest fighter in the world with an unrivalled high altitude performance.

The MiG 15 used a ten year old centrifugal flow engine design copied from the Nene and yet it not only completely outclassed all other opponents ( Meteor, Panther etc ) having similar engines but also was a very worthy foe to the much more advanced F 86 Sabre.

The MiG 25 Foxbat used steel instead of Titanium and a simple engine that could be described as a large version of the Bristol Viper. Yet by clever but simple design of its intake system it was the fastest and highest flying fighter /interceptor/ PR aircraft for a very long time.

The MiG 29 was clearly set the standard in fighter maneuverability when it appeared yet it neither used FBW nor any composites initially.

A comparison of the design approaches of the MiG 21 and the F104

2. Of the five Mach 2 jet fighters - Draken, Lightning, Mirage III, MiG 21and the Starfighter the MiG 21 was the lightest, simplest and the most widely used. It saw combat in the Vietnam, Indo-Pak and Arab Israeli conflicts where it acquitted itself very well against much more sophisticated adversaries. A technical comparison between the MiG 21 with its adversary the Starfighter F104 A is interesting as it shows how superior packaging concepts permitted the avoidance of expensive technology.

In the F104 Starfighter was definitely the more sophisticated Aircraft. The brilliant Clarence Johnson, possibly spoilt by an abundance of technology and resources, used a combination of a 3.5% thick straight wing with a state of the art J 79c engine wit a 17 stage compressor giving a pressure ratio of 12. The 3.5 % thick wing required CNC milling which was cutting edge technology in 1950s. The wing was cutting edge in a literal sense also. On the ground the leading edge had to be capped to prevent damage and injury. Interestingly the intake was fixed geometry which meant that the intake was inefficient at off design conditions. The tyres, which could not be fitted into the thin wings were of extra high pressure and had to be fitted into a narrow track fuselage mounted undercarriage. The ejection seat was of a downward ejection type which must have been unnerving. The fact that the wings were almost solid meant that all the fuel was carried in the fuselage. This must have lengthened the fuselage considerably increasing its pitch inertia.

The MiG 21 team chose the innovative tailed delta concept. Initially derided by the West it was proved to be the best solution for the supersonic combat role. It combined lowest wave drag and yet avoided the problem of high induced drag of the pure delta which had to use "up" elevon" resulting in loss of lift during take off or a turn. Engineering wise the Delta plan form of the tailed delta meant a reasonably thick wing which could be manufactured by traditional sheet and rivet methods.

The engine compressor had only six stages but two spool technology (first used in the Daimler Benz ZKL in 1944 !) allowed a pressure ratio of 9. This combined with a conceptually sophisticated but engineering-wise simple translating intake cone allowed better ram pressure recovery. With typical MiG Bureau simplicity the cone was three position rather than being continuously variable. The overall pressure ratio was thus pretty close to the F104s but the fewer engine stages meant a much cheaper and lighter engine.

The MiG 21 is till date the lowest powered Mach 2 interceptor in service despite a profusion of bulges and scoops and having mushroom head rivets towards the rear.

The undercarriage was a brilliant design which allowed a wide track undercarriage with low pressure tyres for ease of ground handling. The ejection seat not only equaled the performance of the contemporary seat but the semi encapsulating feature gave an outstanding protection for high speed bailout Unlike many of its contemporaries all systems were duplicated.

The MiG 21 went on to successful service with both large and small, relatively obscure and new air forces which speaks well of its serviceability and reliability.

Whenever used in combat (Indo-Pak, Vietnam and Yom Kippur) the MiG 21was a very respected opponents to warplanes several times more expensive. Pakistan lost 3 Starfighters to the MiG 21 in 71 and the Israeli Air Forces had greater respect for the MiG 21 in the Yom Kippur war. The F4s and Mirage 3s usually avoided dog fights with the MiG-21.

Western Industry found the selling price of a MiG 21 unbelievably low and politically motivated but sheer good engineering and ruthless standardization kept prices down. Low prices led to mass production. If prices were indeed subsidized the amount would not be as much as is made out to be.

---

References and acknowledgment;

This is to thank Jagan Pillarisetti of Bharat Rakshak and Warbirds of India for allowing me to use the data on his Warbirds site as well as supplementing the data with further information and comments.

Wg. Cdr. Sekaran ( Retd) of MOFTU for his inputs in discussing the accidents listed in the Warbirds of India site.

The reader is also directed to search the following websites through any search engine. I used Google.

1. Bharat Rakshak
2. Warbirds of India
3. Greg Goebels website on Fighter aircraft
4. www.-916 - Starfighter for Starfighter losses and operational history
5. Encyclopedia of Fighters Gunston for basic details of the Aircraft.
6. Air International
7. Air Forces Monthly
8. http://mod.nic.in/pressreleases/content.asp?id=119 mentions that a total of 315 MiG-21s were lost in about forty years - Oct 63 to end of July 2003 The MOD also stated that between April 1992 to March 2002 , a total of 102 MiG-21s were lost in accidents and 39 Pilots killed. We have records of 81 of these Mig-21 mishaps.

The opinions expressed in this piece are personal and do not reflect the opinion or policies of the organization I am currently employed in.

Prodyut Kumar Das is an Alumnus of St.Xaviers’ Hazaribagh, IIT Kharagpur, and IIM Kolkata. He started his career with Aircraft Design Bureau HAL and for twenty years worked and led various vehicle related Product Development Projects with leading Indian and multi National Companies.

He left Industry to join IIT Kanpur in 1993 as a Professor in the Department of Mechanical Engineering. There he won a prize of the Royal Aeronautical Society of UK for his design of a light sports aeroplane using grants given by ARDB. He also did a project study on “The design of a Light Car costing less than 1 Lakh” which was a Ministry of HRD funded project IDICM 36 and started his research on Stirling Engines in which the IN was keen.

When IIT Kanpur did not renew his 5 year tenure he returned to the  Industry as a Vice President Technical and finally retired as Advisor Aerospace in the e- Engineering Division of a Leading Indian Engineering Company.

He currently teaches Engineering in a Private Engineering College in his hometown and continues his Research as a Consultant. He has been writing on matters related to Defence Engineering since 1990s.

The Kaveri Turbofan Project - an “open source” Assessment

If reports that the Kaveri has reached 90% of its Full Military power are true it represents a considerable achievement for the Engineers concerned. It also indicates no foreign collaboration is required to complete this project. The above numerator is unfortunately tarnished by the denominator of several decades of development with no engine flight cleared and a realistic date of completion is uncertain. Jet Engines development presupposes certain facilities as sine quo non: a) Test rigs for combustion chamber development   b) Test rigs for testing the compressor spools together at rated conditions, c) test rigs for testing the turbine blading for cooling, thermal and mechanical loads simultaneously and finally d) a flight test bed to test the engine in the air. Item d) is still not available in the country and there are reasons to believe that items a), b, c) were not available at the time of taking up the project and may not in fact be satisfactorily available even now. Recall that Egypt, developing the E300 engine under the guidance of Ferdinand Brandner, with much poorer traditions and resources, had a flying test bed , a modified AN12, in 1964,.

The lack of these basic test rigs and their exploitation would have had a significant effect on the programme. The present “problems” with the engine – lack of performance, unreliability and overweight can be traced directly to the lack of the above test rigs and indicates a lack of top leadership at the front line of problems. It was “disconnected thinking”, in 1987, to so confidently say that our engine would be “flat rated”. The basic tools needed for the job was nowhere there. The relatively low total running hours (< 2000hrs for the entire programme spread over about ten engines) would mean that the infantile “measles and mumps” kind of problems have not yet been exposed. If the engine hours are correct, it was surely premature to have air tested the engine in 2003 when it, quite expectedly, failed. “A part of the learning process” is not an adequate explanation for this kind of repeated self induced “failure”. The failure delayed the project and should not have been done at that point of time. I recall a former Director, in discussing the Kaveri pressure ratio, admitting privately “Yes. We did over reach ourselves”. He was being modest! The fault, dear Brutus, is in our stars! Pratt & Whitney (P&W) was not allowed to do Jet Engine work because of the War. GE was clearly ahead. Immediately after, in 1945 itself, P&W set up a Turbine Laboratory (WTL). Note that they named this critical survival asset after their Chief Engineer Andrew Wilgoos and not after Rentschler, their Founder & Chairman!)  WTL was fully integrated into P&Ws mission to be a prime player rivaling GE and had the skill and resources of P&W on tap. We set up GTRE but it was a completely different entity vis a vis HAL in terms of aims, service conditions and critical performance parameters. Yet GTRE was supposed to depend on HAL. We do things right but don’t or cannot do the right things! Even given the best of intentions results would be what they are.

The Good news is that an engine that is giving 90% of its cold thrust cannot be all that bad. The engineers who can achieve that also cannot be bad. What has been lacking has been the leadership over several “generations” of higher management. We will come to this point later. The Kaveri does not want more technology. It needs more care and analysis. Jet engines, though inherently simple, are extremely sensitive to detail as the following examples will illustrate. “Point one millimetre” (‘four thou’ if you are that old!) is the general unspecified tolerance in aerospace machinery. It is the average thickness of human hair. If the gap between the rotating blades and the casing varies by this “point one “ millimeter in a Kaveri sized engine it means a difference in the turbine tip/casing flow area of about the size of a 20mm hole. Imagine the differences in flows if you are dealing with pressures of around 20 bars! If the clearance is that amount too little, you will soon get very expensive sounds, blades being shed and possibly an engine fire. The tip clearance is a decider for TBOs. The current technique is to remotely sense the tip clearance and heat or cool the casing locally to keep the clearance constant. No wonder the grudgingly respected Chinese engineers still manage to stir fry their new engines with some regularity! The same “thickness” or (thinness, if you will!) in the engine casing will vary the weight of the engine by approximately 5-8 kg and an increase or decrease in engine length by about ten millimeter will affect engine weight by about 4 to 5 kgs due to casing and shaft weights. Of course a 0.1 mm variation in blade profile is unthinkable.  I cite these figures to show the “gearing” between cause and effect in Jet engine development and the need to go over details, components and results with a fine comb -and an engineering Sherlock Holmes by your side!

However creditable the performance of the “troops” the present situation reflects on the higher direction of the programme.  There are two management issues involved. The first was to undertake the project without having the physical resources ready. Everything is always wanted yesterday. It appears the then leaders, (assuming they knew clearly what was involved) either wanted to “make someone happy” or wanted the project “at any cost”. Honesty about the situation-so disdained by the “clever”-   is an essential requirement –and a mark of leadership. In 1962 Lt. Gen Kaul, by acceding to political pressure gave us the Himalayan Blunder .Nine years later Sam Manekshaw by stubbornly (but charmingly!) refusing to move until he was ready, delivered Bangladesh! The second area of failure of Leadership was a failure of knowledge. There was a lack perhaps of a holistic view of what the engine was supposed to do. They apparently wanted an engine “just like the F404” rather than thinking more systemically about an adequate engine which would do the job. By these two fatal lacunae-one physical and the other mental- GTRE fell into “mission impossible” mode.

Rebooting our mindset

Let us look at the above in a bit more detail. Modern Western Military engines are, perhaps surprisingly, strongly injected with technologies developed for competing in the civilian markets. It makes sense for the West to use these thoroughly proven technologies in their military programmes- it helps to amortize costs! An opposite corollary was the USSR where Technology Development was always led by Military requirements and USSR civil engines were the dregs in terms of Sfc and TBO!  For a civilian engine a TBO of 4000 hrs is “essential”. The plane flies fourteen hours per day. One cannot yank the engine off the pylon every 6 weeks as a R29B style of 550 hour TBO would entail. Every gram of fuel saved per hour is of consequence given the huge number of hours flown per year. This entails engines having compression ratio s of 20:1 to 30:1 with current research exploring 70:1. (Want to play catch up with the Technology, any one!) One could go on but the drift is that before we follow someone’s lead we have to stop and think of our task and the cloth we have for our coat. What are these?

a)    Slash the engine ‘to begin with’ TBO to around 400-500 hours .Insist the Air Force declare what is their attrition rate for single engine close support fighters. I know we lost about 30 Hunters out of 96 active in the six squadrons in the nine years between inductions to just before the ’65 war. Very few if any of these could have approached 1000 hours. It would be interesting to have a histogram of the number of engine hours of all the MiG 21s at the time of their write off. If this figure is pretty low as I suspect it to be, there is no need to make a 2000 TBO or 4000hr technical life an immediate target. A 250 hrs TB0 (Incoming! Incoming! Duck! Duck!) would last a couple of years on a fighter airframe. Reduction of TBO time will significantly reduce the development task without affecting the operational efficiency. The ‘problem” of low TBO-replacing engines- can be ameliorated by designing for easy installation and removal. In the Mig 15 two men could do it in one hour!  Engines are more “plumbed” nowadays but that is where the challenge of good engineering comes in! Incidentally, an Indian Engine built with Indian materials in Indian factories would be formidably competitive against all comers even with these low TBOs and TTLs.

b)    Do we really need 20:1 CRs (compression ratio) given the engine becomes heavier and more surge prone as we jack up the CR? Higher CRs mean more stages and the compressor and combustor casings being open ended pressure vessels, mostly in heavy alloys add much to the weight. Remember that a 0.1 mm thicker casing will add 8 kg to the weight! We know the benefits of high compression ratios are subjected to diminishing returns. The Orpheus with a CR of 6:1had a sfc  1.03, the R 25 had a CR of 12:1 and had a sfc of 0.9 and an engine with 20:1 CR will have an sfc of around 0.8. This “high compression ratio” led improvement in sfc does not pay in our typical low duration sorties. For an IAF standard fighter sortie the weight of engine plus fuel required (for the same level of technology in other areas) disfavours the high compression engine. Also because the compressor passage areas are fixed, the resistance to compressor flows at part throttle (where the wretched engine will be spending most of its life, anyway!) the proneness to surging will cause problems. Finally to remember is that high CRs in themselves are a partial contributor to the sfc figures. Burners, combustor and turbine blade technology being the others.

c)      Are we worrying too much about smoke and NOx? Western “standards” are again derived from already existing and already proven and available low risk “Civilian” technology which we do not have. A short combustor means a lighter engine because the shaft and casing becomes shorter. Shorter combustors will require focused research on getting the spray pattern “tighter” in the spread of droplet size. How much work has been done in this area before we set our targets?

d)      Western aircraft design philosophy believes that VG intakes don’t make sense below M1.3. Our designers follow the same track. This, I believe, is a “frozen” thought from the ‘60s and the days of electromechanical sensors and actuators. Given developments in sensor technology  and computer controls we should look at new variable geometry intake configurations to maximize pressure recovery. Even if we can save the equivalent of one or two stages on the compressor it would help in reducing the length of compressor, ergo a lighter engine.

e)      Also to be examined is the total thrust /fuel flow requirement profile and optimize the engine’s weight and fuel consumption in relation to the task. A typical LCA type engine will have the following profile. A/B thrust approx 2⅟2-3 minutes, Full military 6 minutes, 60% thrust 20 minutes, 45% thrust 25 minutes, and flight idle about 5 minutes. The figures are illustrative but the idea that we must reduce the Total fuel burn/sortie rather than optimize for a rarely used “best” figure. The intake, the engine and the afterburner   together have to be seen as a system which will give optimum performance in the 0.6-o.8M at low level with all other conditions being seen as “special” cases for the system.

f)       A consequent question to the point made above is given that relatively small duration of operation of the max. Installed thrust how much of the thrust should come from the engine and how much from the A/B? The Tyumanskii/Gavrilov R 25  of the MiG 21bis is an example of alternative thinking. The dry thrust is 59kN, with A/b it is 69kN but with a “boosted” a/b it gives 97kN (from Russian sources!) which thrust wise would be ample even for the LCA! The use of the boosted A/b reduced engine life at the rate of one hour per three minutes but it works! Anyway as said before a “totally Indian engine” will be cheaper.

There are several more such issues but the point I am trying to make is that we have to see the task not as an engine “just like” something else, as I suspect, had been done. Let us move from mere Information to Knowledge and, hopefully, from Knowledge to Wisdom! GTRE   hamstrung itself by trying a “drop fit” replacement for the F404. The saner approach would have been to have a dialogue with ADA so that ADA would be prepared to “rebore” (Not, please, literally as one irate reader seemed to think!) the LCA airframe to accept the slightly different engine.  We must therefore come to a state of mind where we read the book and then throw it away to chart our own course. So what needs to be done?

If you have ten hours to chop a tree…

Spend nine sharpening your axe! Build up and “sophisticate” our test rigs so that the key problems can be solved in detail. For example the test rig for the turbine blade should not only be able to handle a mass flow of around  5kg/sec @ 1400⁰ C- for a cascade of four or five blades but also will be able to simulate the creep loads on the blade whilst a separate air source will  supply cooling air through the internal passages. Similarly for the compressor test rigs it is necessary to have rigs powerful enough to test the two spools together irrespective of what may be the practice in other countries. A short combustion chamber will need research on droplet uniformity, spray pattern, burner types and configurations. Turbulence and uniformity of temperature at Turbine entry are other areas to study. The test rigs help to break down the problem before synthesizing the solution. These test rigs are the axes for the problem and in future we must emphasize test rigs and their roles in any project. Normally the evolution, design, fabrication, and operation of productive test rigs will require the same quality of ingenuity and good engineering as the engine itself.

The obvious thing to do-don’t!
Perhaps there is a need to review the Jet engine programme as a “National” programme rather than a DRDO baby. No single organization can do the job alone. In England Bristol Engines starting Jet development from scratch but let Lucas focus on the critical fuel systems and combustion. Team work has to be enforced by getting GTRE back to what it really was set up to do and HAL has to be forced to pick up “GTRE’s baby” and bring it up to some state of civil behaviour. It is possible that a team of HAL ‘s best designers and fitters from Koraput and Engine Division are transferred to lead the Kaveri programme. Unfortunately, whilst administratively such action is possible it won’t work in peacetime. Internal priorities would change; the organizations concerned would become creative. We would see tribal warfare the Pathans would relish! As things stand GTRE must find a way out from the difficulties it has created for itself!

What ails thee Knight?

Over the decades our betters have replaced in our Engineering colleges “practice based” engineering with “science based” engineering-even at the undergraduate level!  Consequently GTRE, as with other scientific research establishments in India, has unquestioningly adopted the rather large assumption that possession of an engineering degree confers the abilities of an engineer to the holder. The natural consequence of this assumption is that the more the degree the more the “qualification” of the person to take engineering decisions -never mind that one of the most esteemed and successful engineering leaders in the country, who has unfailingly delivered, Mr. E Sreedharan of Pamban Bridge, Delhi Metro et al ( the list be long!) is a “mere” B.E. The reality is that Engineering is a practioner’s   art and the “qualification”- irrespective of its degree -is merely a license to enter the area.  Possibly, as in education, in selecting “leaders”, possessions of qualifications have outweighed other parameters. The result is a lack of engineering leaders who enjoy being “at the front”.  I could cite several examples (looking back, quite amusing!) of the effect of lack senior “engineering leadership at the “frontline” .That will have to wait. However I will give an “unrelated” example. Rommel won his battles often with inferior forces, because he had much more direct knowledge of the tactical situation “real time” and was personally judging the situation with his great experience and technical skills-apparently he was an IC engine “nut”-rather than relying on what some inexperienced Feldwebel thought of the situation. This undistorted, experienced, assessment of realties came from being right at the front when his opponents were at their HQ way back from the action. How many “Top” Scientist work side by side with the fitters? The administrative problem is that passionate engineers often tend to be “enfants terrible” of the organization and are often ACR’d  ( quite validly, depending on your priorities!) “Not quite mature” or “good but simple minded”! The net result of all this is that GTRE probably has excellent administrators- and they are also needed -but it does not have excellent practical engineers who can calmly “think things through” and yet have the authority to get thing s done.

There be hope yet…

Despite the clouds above the situation is ripe for rapid rectification which should enable us to have- without foreign collaboration- a flight cleared engine within a predictable and short time scale Foreign collaboration, if available, may not hurt but I believe the here the demand for collaboration is a  bureaucratic “failsafe” decision; no one can be blamed. It is this lack of “the right stuff” – people who will work on the engine rather than eat their dinner-which is why we are where we are at present. Instead of commercial collaboration what we can do is however is to get retired engine designers over as a Teacher or a guide. The Chinese not only regularly had Hooker over as an honoured Guest they also had Ferdinand Brandner over as a Professor in their top University.  I don’t think Brandner simply taught the prescribed course! The other reason for rejecting foreign collaboration for the Kaveri is the nature of the present need. The answer to the Kaveri’s performance problems cannot be yet more technology-there is no magic in Technology- but more care and thought and listening to what the engine is trying to tell us- yes it talks! Assuming the basic design (barring, apparently the A/B) was sound, what is needed is a hundred small improvements - improving the surface finish of the compressor casing bore or the blades, working on cleaning up flows near the roots, stressing the components down to closer margins, tightening technology processes and so on rather than introducing “blisks” or “shrouded blading” or SCBs which everyone seems to talk about. We put in certain Technology. It was put in to do a job. Why is it not then doing it? It is here that GTRE is, by its charter, subtly handicapped. Being a R&D set up it does not have those seasoned practiced people whose hands can “read “the engine even with their eyes closed. A R&D organization, anywhere on the Globe will not have the skills common in a production unit. 

Cutting your coat

We need to:

i)                    Enter into a dialogue with the customer about TBO, engine change procedures, TTL et al.
ii)                   Back off from trying to build something “same as the GE F XYZ”. It is not necessary or even the best solution.  The Airframe boys should be ready to rebore their fuselage. Everyone does it all the time.
iii)                 Flog the engines on the test beds even if they are developing no more thrust than kerosene stove. If 550 hrs TBO is technical target one would expect 5500 hours on a batch of ten engines anyway. That way at least the infantile mechanical problems are exposed and can be corrected.
iv)      Prioritize the acquisition of more than one flying test bed. Do you know Harry Folland’s last design was a large test bed to test the 2000 hp class Bristol engines that were supposed to be coming up in the 40s. A large simple multi engine aircraft an enlarged Canberra using the AL31 would be a lovely project for “people building”.

If we were to do it again
In future the task has to be bifurcated with GTRE contributing by providing experimental data and HAL Engine plant doing all the nitty gritty mechanical detail design stuff in which HAL is arguably, by far and away is better placed to do. Let me illustrate by one example: The Kaveri accessories drives gear box. HAL Helicopter Division has years of experience designing and making lightweight gear boxes for helicopters. For reasons possibly of “unease with HAL”, ADA gave the contract to CVRDE, a sister organization but with no aerospace collaboration and no direct access to the technology. My bet is that HAL Helicopter Division would have given a better gearbox in shorter time simply because the HAL’s supply chains of know how, information, machinery and process technology  and human resources were shorter than CVRDE. With every “license manufacture” agreement comes  a wealth of information- materials, processes, heat treatments, machining methods, testing methods and parameters, even how and where to mark the part no and how to store the part. Over the years, at HAL this “know how” has been subconsciously processed into Know why. To CVRDE it would be new territory.  The difference may or may not have been much but “look after the days and the years will look after themselves”.  This is why RAE and it’s cousins at AMES or Zhukovsky do not design engines and aircraft.

What are the areas on which DRDO/GTRE is particularly well equipped to focus on and what will be necessary for us to develop for a future Indian Engine programme?

1)      Carbon fibre fan casings: TETs, engine efficiencies and thrust are in symbiosis. Given modern TETs a pure jet is no longer efficient and some degree of bypass is inescapable. The fan shroud operating at relatively low pressures and temperatures is an ideal case for (carbon) composites. DRDOs appropriate unit should develop expertise on fabricating and proving fan shrouds of approximate 900mm dia. and capable of handling pressures of 2-5 bars.

2)      Short Length combustors: Excellence in combustion is a key to fuel efficiencies and light weights. GTRE must focus on a target of the shortest combustor length. Dual spray nozzles optimized for cruise and max thrust as used in modern civilian engines may be explored if found imperative.

3)      Compressor Aerofoils: The R11 achieved a 9:1 compression ratio using just six stages with consequent savings in weight. Could this be “the starting block” for a new development programme aimed at high pr. rise per stage with stable operations?

4)      Carbon fibre fans capable of sustaining bird hits.

5)      Turbine cooling technology: GTRE must further improve its capability to simulate actual working conditions faced by turbine blades.

6)      Production technology for precision cast “ready to use” turbine blades.

7)      Expansible thermal coatings to minimize “heat losses” through compressor casings.

8)      Technology for “milling” combustor surfaces to very close limits.

9)      Fan gearing systems. The future engines will all be geared so that the fan drive turbine can run at its happiest speed. This will give us useful freedom in fan design.

10)   Blisks. The Centrifugal Compressors, carved from an aluminum “cheese”, was an early form of Blisk. If HAL has the Goblin compressors process sheets these could be the starting point for our “Blisk” programme. Why not give HAL the contract?

It is tempting to suggest that the actual bench testing should be done by a different and independent group. Honda used to test all their engines at a different and independent test site. This is merely good Industrial practice and should be worth replicating here.

The flying test bed is of course an imperative. “Outsourcing” this function is simply not on. Apart from the problem of logistics there is also the subtle question of security of the engine itself when abroad. Countries adopt or build their own special aircraft for acting as a flying test bed. It is just a pipedream that if a few airworthy C119G airframes were available today one could toy with the idea of an interim test bed for the Kaveri! The old thing was configurationally ideal for a test bed. Of course an “enlarged” Canberra (ref “The Haft of the Spear” Vayu) would be another option. These would be simple aeroplanes capable of being designed, built and maintained by simple people and would need a simple budget!

With such a list of activities to do GTRE would be busy and happy. I am reminded of the fact that TsAGI “discovered” that the tailed delta configuration was the best layout for the supersonic combat role and such was the quality and reliability of its findings that both Mikoyan and Sukhoi   OKBs were not too proud to rely on Ts AGI data for the MiG 21 and Su9 aircraft plan forms. Perhaps the proud traditions of high quality fundamental research continue till today; the similarity of aerodynamic layout of the Su 27 and the MiG 29 is no coincidence.

Give unto Caesar….

We must give unto HAL that the logical house for development of actual engines is HAL Engine Division. The reason is that they are organized, experienced and their supply chains are shorter. What then will they do? For my money they should engage in the development of three “core” engines using not tomorrow’s technology, not today’s technology but yesterday’s technology. By yesterday’s technology I mean technology that has been in production at HAL BLR or KPT for the last five years at least and we are all exposed to it thoroughly. The three cores will be of sizes 10kN, 25 kN and 60kN. They should all be single shaft turbojets and the stress will be on timeliness, reliability and technology security above all the other necessary aims. It is a sedulous myth that advanced features “teach”. If advanced features are a cause of such delay as enabling the proposer (s) to retire without delivering, then “advanced features” is de facto an accessory to a swindle. Maximum stress will be put on using  Midhani materials. The Orpheus, the work of a Master, has a few interesting features which could be replicated. The shaft is a thin walled large diameter tube; it easily permits the insertion of the second spool’s shaft as was done in the case of the Pegasus which gave three times the thrust even in its earliest version (despite VTOL configuration!). We can expect more. The second Orpheus feature I find desirable is that it has a limited number of stages (7+1) on a short shaft and so can use just two bearings thus avoiding the third bearing and jointed shaft with its attendant proneness to whirling vibrations and ,who knows,  blade shedding. In fact starting point for the 25 kN could well be the Orpheus since large quantities of partly used engines must be with ED Sulur (?) following the retirement of the Kiran! The purpose of these core engines is they will over time form a family of fan and “leaky” engines for a variety of military and civil applications ranging from 10kN to 250 kN. They will incorporate the certificated advanced technology GTRE will no doubt develop. In fact GTRE’s contribution will be essential to the success of the programme. A side effect of the development of these small  “cores” is that any of the Embraer’s can be rigged up as a 3 engine flying test bed either DC10 or Lockheed Tri star style or even in place of the AEW pack and the tail arrangement changed to a twin fin arrangement-good project with a “bite” for our young engineers in collaboration with Embraer.

In a lighter vein, GTRE should quietly examine its press statements carefully before clutching in the “tongue”. Talks about Marine Kaveri are allowable but to talk of a Kaveri powered locomotive is to betray “Ivory Tower” disconnection. Not only will the engine choke in the Indian dust but also the power would be so enormous the train length would exceed the loop line (siding!) length used by the Railways. Marine and Power versions are completely different animals using different materials and operating in different ambient conditions. These derivatives will in no way help the Aircraft Engine programme and recalls Northkote  Parkinsons’s story about how a big Government funded project  to make a hyper rocket fuel failed miserably but said the Chief of the project at a press conference “I am afraid we have failed to have a useful rocket fuel but fortunately we find it is an excellent paint remover!” The UACV Kaveri idea is much better and on the right track.

Nil desperandum!

The Kaveri is in no way worse off than the LCA programme. What is needed, as with the LCA, is not more technology but more care and attention to detail. That will transform both projects if not into outstanding stupor mundi (wonder of the world) products as so tiresomely claimed but at least in to serviceable and affordable equipment.  I take this opportunity to thank Shri Ashok Baweja, (Chairman HAL2004-2009)  for suggesting during a casual conversation why I did not do a piece on the Kaveri. This piece had its genesis in his suggestion and is by way of thanks for the same.

Prodyut Kumar Das is an Alumnus of St.Xaviers’ Hazaribagh, IIT Kharagpur, and IIM Kolkata. He started his career with Aircraft Design Bureau HAL and for twenty years worked and led various vehicle related Product Development Projects with leading Indian and multi National Companies.

He left Industry to join IIT Kanpur in 1993 as a Professor in the Department of Mechanical Engineering. There he won a prize of the Royal Aeronautical Society of UK for his design of a light sports aeroplane using grants given by ARDB. He also did a project study on “The design of a Light Car costing less than 1 Lakh” which was a Ministry of HRD funded project IDICM 36 and started his research on Stirling Engines in which the IN was keen.

When IIT Kanpur did not renew his 5 year tenure he returned to the  Industry as a Vice President Technical and finally retired as Advisor Aerospace in the e- Engineering Division of a Leading Indian Engineering Company.

He currently teaches Engineering in a Private Engineering College in his hometown and continues his Research as a Consultant. He has been writing on matters related to Defence Engineering since 1990s.