Transport Aircraft for IAF

[Indranil]

The (amateur, possible under-informed) impression I have gained is that a turbofan is a ducted turboprop in a sense but turbofans spin at higher speeds and the ability to spin at higher speeds gets to be more of an advantage as the altitude increases and air density decreases. I would guess that this would amount to an ability of a turbofan to "rev-up" and produce thrust more rapidly at higher altitudes compared with turboprops. Extrapolating with the guesswork, the need to rev up and produce rapid changes in thrust is not felt in a straight take off or landing, but when an aircraft must maneuver between mountains for a landing approach or on exit from a mountainous region after take off.

Not quite the right deduction Shiv ji ... The equation of thrust is simply:
T = m(c-v) where c is the speed of the air from the engine and v is the speed of the plane.
You can produce equal thrust by pushing more amount of air slowly or less amount of air fast ... The turboprop does the first and the turbofan does the second. That is why a turboprop has a higher efficiency at lower speeds.

The turbofan is not going to be more efficient than a turboprop at low speeds at altitudes ... A turbofan can generate more power than the turboprop at high altitudes only at higher speeds not at approach speeds. ... At high altitudes cruising at nearly supersonic speeds the fan of the turbofan produces less and less percentage of the thrust ... the compressor starts generating a sizable chunk of the thrust (50-60 percent) ... but for this the plane has to be flying fast.

Unless we know the exact details and dynamics of the situation faced by the iAF as well as the typical loads that are required to be carried and where they must be carried from - it would, in my view, be impossible to reach a dogmatic conclusion to say that "Turboprop would be a better choice so why the hell does the MTA have turbofans?" This is as far as my argument goes.

The other point that is that unless we have access to the exact details of what the IAF needs it would be a mistake to say that the An 32 was perfect and the replacement should be exactly in the same weight and power class as the An-32

Again, I am not saying MRTA should have been a turboprop ... As I have said before, MRTA might be just what the doctor ordered (no pun intended ) ... I am also for the RTA having a turbofan variant because it is a going to be stepping stone ... but frankly I feel that a high passenger turboprop would have sold much more (truly low-cost to operate) ... and the military variant of it would have been a good 1:1 replacement for the Hawkers and the AN-32s.

[Philip]

What puzzles me is that why do we often try to reinvent the wheel? The Saras and now RTA display a singularly lack of knowing what is going on in the rest of the world.There are so many manufacturers from west to east who are in the business with decades of experience in designing and manufacturing a wide variety of transports/aircraft.We are ourselves collaboraying withRussia for the MTA.Russia itself is using western engines for its Sukhoi Superjet an 80-100 seater,delivereies have just begun.Europe is together in Airbus-the best example.HAL is manufacturing DO-228s for RUAG,the list can go on.

Given the absence of a continuum of aero-engine and aircraft deisgn in India since Independence-where it has been practised in fits and starts,with the LCA being the best example of delays (at least the HF-24 arrived , but for an undrepowered engine was a beautiful fighter-read the latest VAYU),the shortest way to success would've been to find a collaborator like ATR,CASA,etc.who have been manufacturing such transports to refine the Indian requirement and given the size of the requirement,would've eagerly stepped in.Look at what the Chinese did,buying the rights to produce the A-320 in a dedicated factory.had India seen the light of day,we could've done the very same,as the orders for A-320s from Indian pvt. airlines alone is a staggering 300-400,easily with a potential of 500 of the 320/319 family! From that facility we could've then gone on to manufacturing future follow-on designs.

By the time the first prototype arrives when we are long the tooth,and the dear Lord forbid it suffers a fate such as Saras did, it will be quite outdated and who will buy it then?

[Austin]

By the time the first prototype arrives when we are long the tooth,and the dear Lord forbid it suffers a fate such as Saras did, it will be quite outdated and who will buy it then?

The way it works with commerical players Airbus , Boeing , Bombardier ,Embraer, Sukhoi and other players in the game is they would first scout the market for prospective customers , sell the concept to them sign initial deal for certain number of aircraft to the first launch customer who do get significant discount and then start with the work with some projected inservice schedule for completion of flight test program , certification and delivery dates etc , ofcourse after the initial customer puts into service it would go through its usual pace on how it works and root out any problems that are found in day to day flight regime .

One important thing to note here is all flight test program should be on tight schedule else they would end up paying penalty or worst even loosing customers.

If you look at similar types in operational service like Embrarer , Antanov ,Superjet they are suppose to clock atleast or over 300 flight hours each month for the end operator to make a profit from operations , ofcourse the initial hours can be low as 250 - 270 hours but it has to cross that 300 hours barrier eventually to make it commercially viable and competitive.

After that its really a tough competitive world out there and they would have to compete against the likes of Embraer, Superjet ,Antonov ,Bombardier to cut out a niche for itself.

We can just hope NAL would have worked or would work in similar fashion if not global players then atleast they can rope in big local players like IA or Private Airlines can be counted in to be an initial launch customer and then gradually build up on it.

Ofcourse i am not counting the non-commercial market like our defence service needs

[Austin]

"The Committee has come to a conclusion that the RTA should be a narrow body turbo fan aircraft with a seating capacity for 70-90 persons and stretchable to 80-100 persons," Brahmachari said.

Turbofan or Turboprob , what variant they should build must be based on hard commercial sell which is to say they must build depending on what will sell based in the market based on airliner feedback ,market surveys etc and their own ability to fill in a niche market with a competitive product.

Some committee should not decide what is better a turbofan or turboprob but market factor should sway their decision.

After all the goal of NCA is to build a commerical passenger platform for promoting civil aviation industry in this country.

[Indranil]

As a second exercise related to what you may actually be trying to put across, please show us how the prop versus jet has more significant effect on take-off/landing distance than wing area and weight. I need to know this for my knowledge so if you could help with the equations, it would be very much appreciated.

It would be an interesting exercise and you could actually prove your point about take-off/landing distance with equations no one could dispute.

PS: as an input from me - consider the interaction of prop wash and laminar flow. There is no coanda effect from turbo-props, rather the prop-wash is the most significant factor effecting laminar flow behind the engine nacelles. Hence the effort to put props as far ahead of the wing leading edge as possible, and the interest in pusher type props.

I stand corrected:
2. I said ... prop-wash increases lift ... it doesn't ... you made me read more on this ... thank you!

Actually Shalav, I was initially right.

The slipstream from the props actually increase lift over the wing.

It is not that much at cruising speeds but while at standstill and low speeds, it does increase lift.

In the postfix, I have posted links of some detailed studies ... it is very complex to write an equation and hence the safety regulations asks for specifying "unpowered stall speed" ... there are a lot of wind tunnel studies though.

To simply understand the effects read Airplane Flying Handbook By Federal Aviation Administration,

A propeller produces thrust by accelerating a large mass of air rearwards, and (especially with wing mounted engines) this air passes over a comparatively large percentage of the wing area. On a propeller driven airplane, the lift that the wing develops is the sum of the lift generated by the wing area not in the wake of the propeller (as a result of airplane speed) and the lift generated by the wing area influenced by the propeller slipstream. By increasing or decreasing the Speed of the slipstream air, therefore, it is possible to increase or decrease the total lift on the wing without changing airspeed.

For example, a propeller driven airplane that is allowed to become too low and too slow on an approach is very responsive to a quick blast of power to salvage the situation. In addition to increasing lift at a constant airspeed, stalling speed is reduced with power on. Ajet engine, on the other hand, also produces thrust by accelerating a mass of air rearward, but this air does not pass over the wings. There is therefore no lift bonus at increased power at constant airspeed, and no significant lowering of power-on stall speed.

In not having propellers, the jet powered airplane is minus two assets.

• It is not possible to produce increased lift instantly by simply increasing power.
• It is not possible to lower stall speed by simply increasing power. The 10-knot margin (roughly the difference between power-off and power-on stall speed on a propeller driven airplane for a given configuration) is lost.

Add the poor acceleration response of the jet engine and it becomes apparent that there are three ways in which the jet pilot is worse off than the propeller pilot. For these reasons, there is a marked difference between the approach qualities of a piston engine airplane and a jet. In a piston engine airplane, there is some room for error. Speed is not too critical and a burst of power will salvage an increasing sink rate. In a jet, however, there is little room for error.

You might also want to read about the DBE (Down Between Engines) used to increase lift through using slipstream between the engines by using counter rotating props.

Another read is handling a plane where one of the engines (prop engine) has failed ... the wing with the working engine creates more lift and this induces a rolling effect.

For more detailed analysis read:
Longitudinal Aerodynamic characteristics of light twin engine propeller-driven airplanes
Aerodynamic Characteristics of a Propeller-Powered High-Lift Semispan.

[negi]

^ Yeah nice point about the effect of prop wash on the stall speed and moreover combined with the fact that a turboprop powered plane has high aspect ratio wing the stall speed should be as low as one can hope to achieve for the AC of given size.

[Katare]

Interesting chart of operational cost per flight hour for different aircraft in the USAF fleet.

http://www.flightglobal.com/blogs/the-d ... ombat.html

Of particular note is that the C-17 actually costs less to operate than the C-130H and only a hair more than the C-130J, even with the difference in fuel burn. I'm not sure how it's possible, but there it is.

Because of the small number of cycles they put on the airframes. They are used for long haul to support the deployments in Iraq and Afghanistan. If all an aircraft does is 10 hour flights, by the time it has 30,000 hours, its only landed and taken off 3000 times (3000 cycles), which puts very little maintenance strain on the aircraft. If that same aircraft, for lack of a war, did only short training missions or even did touch and goes, it could end its career with 30,000 hours flight time, but with 60,000 cycles, which would have increased its maintenance cost 10 fold. Its like having a car which is only used on highways on cruise control, and another identical car which is always used in low gear, in city traffic, as its used to teach new drivers how to drive.

This was explained in the quoted article very clearly so what is the need for making a post on the "size of trasporter 101" again?

Large size allows certain low cost transport in certain systems/routes at the cost of loss of flexibility and verstality is a basic concept for any form of transport, nothing specific to C17 or air-transport.

[chackojoseph]

Fifth Indian C-130J Super Hercules departs Lockheed Martin facility in Marietta

[manum]

moved...

[vic]

India is nation with relatively shorter distances. Hence Turboprops are better for Military lift requirements. Benefits are:-

Shorter take off and landing Run
Slower take off and landing run
Better tolerance to Rougher airstrip
Lower fuel consumption
less prone to dirt ingestion
Easier to reverse on own power etc

MRTA is basically a Russian requirements to deal with long distances, cold climate and concrete airstrips. The MTOW is being under stated to make it look like a An-32 replacement. Anyway we should further develop MRTA into 100 ton MTOW aircraft rather then trying to make it An-32 replacement which it is not.

Anyway, India even if MRTA goes ahead we can learn from it. India needs:-

1. C-27 or Il-112 type aircraft for replacement of An-32
2. ATR-42/72 or turboprop RTA (which has been dropped) type aircraft for Civilian needs and for replacement of Avros

3. Turoprop variant of MRTA equivalent to C-130s, AN-70 & A400
4. 70-100 seater NCA (planned)

5. 200 seater Civilan airliner as proposed by Kalam
6. Replacement of Il-76 category (may not be viable so license production of C-17 may make more sense)

[Indranil]

My views in blue.

MRTA is basically a Russian requirements to deal with long distances, cold climate and concrete airstrips. The MTOW is being under stated to make it look like a An-32 replacement. Anyway we should further develop MRTA into 100 ton MTOW aircraft rather then trying to make it An-32 replacement which it is not.
You already know that I would have been very happy to see a turboprop variant of the RTA which would have sufficed your points 1 and 2. However, I don't know whether the An-32s where the ideal fit in first place ... may be 20 Tons is the sweet spot. We were just making more trips with the An-32 for want of an aircraft in the 20T category! If you really have to make the case for a 7-10T category, you will have to provide logistical details like here are so and so airfields which can handle a 10-tonner but not a 20 tonner, and that the rations and equipment needed by my assets there for a size-able amount of time is only 10T and not any more! Otherwise it is only favouritism to an end.
Anyway, India even if MRTA goes ahead we can learn from it. India needs:-

1. C-27 or Il-112 type aircraft for replacement of An-32
2. ATR-42/72 or turboprop RTA (which has been dropped) type aircraft for Civilian needs and for replacement of Avros

3. Turoprop variant of MRTA equivalent to C-130s, AN-70 & A400
I don't understand. Why turboprop in that category? First of all what is the category C-130 and An-70/A400 don't seem to be in the same category. Building the later category is not easy either. Both Antonov and Airbus are struggling.
4. 70-100 seater NCA (planned)

5. 200 seater Civilan airliner as proposed by Kalam
This cannot done till point 4 is covered. So we are on the right track.
6. Replacement of Il-76 category (may not be viable so license production of C-17 may make more sense)
License producing C-17 doesn't make any sense at all! For 40 aircrafts, you want to set up an assembly line of C-17 class of aircraft?! If it is going to be the C-17s, FMS is way better.

[Philip]

I always thought that the AN-32,which was derived from the AN-26 wa sspecifically developed for India to meet our unique "hot and high" requirements.The entire lot of 100 or threabouts are being upgraded, meaning that they suit our needs almost perfectly.What we need as suggested by many here is a family of smaller transports below and above the AN-32 upto the C-130Js.The fact that in the subcontinent distances are shorter is quite right.Some of our high alt. landing strips are also unable to operate the larger heavy-lifters like the C-17s and IL-76s.The urgent task is to facilitate supply and support of the troops in the High Himalayas using light aircraft that can land on small airstrips.

Apart from such aircraft,we also need a large number of medium and heavy helos which do not need airstrips but helo landing grounds.The road infrastructure planned is way behind schedule and will take many more years before it meets current requirements.Airstrips close to the border can be easily targeted by PLA missiles launched from Tibet.It would be far easier to construct a large number of helipads,our "string of pearls" in the ice and snow,located at regular intervals at key points all along the northern and eastern borders with Tibet and China.These helipads should also be accompanied with nearby large secure depots,preferably underground,able to withstand missile attacks,large enough to accomodate emergency supplies,munitions and other eqpt. for troops for months without resupply if need be.
"Helo-hopping" would provide the IA with a ready means to maintain our forward positions.This need is perhaps more urgnt and important than the transports .There was also a report not too long ago saying that the absence of heavy-lift helos hampered the infrastructure projects becasue only they could airlift the heavy eqpt. needed for roadbuilding,etc.

For the record,latest AWST says that the IL-476 will arrive in 2013,but the Russians want it to arrive faster.$100 billion is being pumped into the Russian aviation industry for orders and R&D.The IAF should upgrade Il-76s which have substantial life left in them and order more Il-476s to augmnennt and complement the C-17s on order.They would be far cheaper to acquire and operate,negating another further order of C-17s which only fattens Boeing's purse.The CAG report on the controversial order of Boeing aircraft for Air India in similar indecent haste,must also be examined for "irregularities".

[Gilles]

This was explained in the quoted article very clearly so what is the need for making a post on the "size of trasporter 101" again?

Large size allows certain low cost transport in certain systems/routes at the cost of loss of flexibility and verstality is a basic concept for any form of transport, nothing specific to C17 or air-transport.

My apologies, but I don't understand what you are talking about.

[shiv]

India is nation with relatively shorter distances. Hence Turboprops are better for Military lift requirements.

Since I have a fundamental question about the above assumption - the rest of the post means nothing to me.

If India's strategic air bases are hot and high and there is a requirement for single engine takeoff, landing and single engine flight over mountains - the assertion that "this is better" or "that is better", and why is something that no one has actually provided any information on here and no such information has been located by me on the net.

I would be happy to be corrected - but someone needs to cough up the info/link to show that the above information is correct

The UK is a small country - but the vast majority of inter-city flights are jets.

[geeth]

The UK is a small country - but the vast majority of inter-city flights are jets.

It is the colonial hangover still...

For a very looong time after independence, the LTC for the armed forces used to be free warrant (railway) for any distance and upto 895 Kms in alternate years. Nobody questioned it, till one Kuppusamy in Ministry of Defence got curious and wanted to find out what that 895 number represent.

After some search, he figured out that the number represents the distance from one end to the other of the British Islands.....May be we are trying to apply same "slide rules"

(What I said is a legend and never bothered to check the veracity of the distance. If some one finds a difference of few mm here and there, pardon me for the ignorance)

[shiv]

(What I said is a legend and never bothered to check the veracity of the distance. If some one finds a difference of few mm here and there, pardon me for the ignorance)

All the major cities of the UK are more or less situated between London and Edinburgh. 895 Km in UK is like from Siachen to Andamans.

The Main "cities" are Glasgow/Edinburgh (North)

Manchester/Leeds/Birmingham - Middle

London - South-ish

Edinburgh to London is about 550 km and I have driven that distance several times - each time in about 6 hours or so. So the distances between the "Middle cities" and the ones up North and South is less than 300 km.

OT joke about UK distances being 895 km

An Indian and Pakistani soldier were comparing their respective male organ lengths.
The Indian said 6 inches and the Pakistan asked "How did you measure it?
Indian: "From tip to balls"
Paki:" Then mine is 100 km long"
Indian "How is that possible?"
Paki: "I left my balls on a mountaintop in Kargil"

[negi]

The UK is a small country - but the vast majority of inter-city flights are jets.

Shiv for civil flights Turbofans are the platform of choice because of strict regulations in place as far as the noise from flights is concerned. Turboprops are notoriously noisy , but in military applications noise is not necessarily an issue.

[Victor]

There seems to be little real discussion in this thread so far about why the IAF may have chosen the C-17 and is thinking of getting more. This is a lot more interesting IMO than discussions about why the IAF should not have bought it. IMO, there is no alternative given our requirements and I am certain that the IAF chose the C-17 for its STOL ability to operate in our ALGs (and PoK and Tibet if needed) with huge size and volume loads in mind and not for its long-range capability. This makes perfect sense given the huge disparity in infrastructure in the border areas. What NRao has said on the previous page is true--the C-17 is both a strategic and tactical 'very heavy lift' STOL transport. In fact, it is the ONLY such aircraft in the world today that can do all of the following:

* Fly from Kanyakumari to the Tibet border at jet speed.
* Land in a short semi-prepared ALG.
* Takeoff from a short semi-prepared ALG.
* Land, unload and takeoff in less time than an AN-32.

As a long-range transport, it outclasses the IL-76 in load, range, speed and fuel efficiency. In normal circumstances, it can land in less than 3,000 ft and takeoff in less than 3,000 ft. It is frequently mentioned (though not 'officially') that in 'assault mode' (max performance combat ops), landing and takeoff are each routinely done in 1,400 ft or less which is unthinkable for anything in its class. The best 'assault' transport is the C-130 and the C-17 can be described as a big brother 4xC-130. So far there are no reports of JATO C-17s (like JATO C-130s) but it is reasonable to assume that this is a possibility which would make it an even more impressive performer.

While being a transcontinental jet transport holding several range, load and speed records, the C-17 is optimized for close support combat operations in small, semi-prepared airfields. Using its 'blown flaps' design (also used in C-130, 747 and other transports but not in the same way), the C-17 uses jetblast directed over its STOL-optimized flap system and then downwards to provide significant extra lift. As a result, it can approach an airstrip slowly at a steeper-than-normal angle to make a 3-point landing with minimum roll. After landing, full reverse thrust, wheel brakes and overwing brake flaps bring it to a stop quickly which can be helped with variable pressure tires, specially on rough airstrips. It can then back up in reverse gear to the start of the runway if needed. This is perfect for our tightly situated ALGs which are surrounded by high peaks and extremely difficult if not impossible for IL-76s to use. Taking the length of a typical ALG, the C-17 can under optimal circumstances, land, unload and takeoff without needing to turn around or reverse, providing the fastest possible cycles. So to move the maximum loads closest to the combat zone in the shortest time, nothing else comes close.

[shiv]

The UK is a small country - but the vast majority of inter-city flights are jets.

Shiv for civil flights Turbofans are the platform of choice because of strict regulations in place as far as the noise from flights is concerned. Turboprops are notoriously noisy , but in military applications noise is not necessarily an issue.

Negi I am sure this is true for some airports. Huge numbers of modern airports don't need this regulation because of their location and the fact is turbofans are operating merrily. So the "distance between cities should rule out turbofans" is a bogey. One argument I have heard for turboprops is simple. When the distance between two destinations is small a jet does not even have time to climb to its optimum cruising altitude before it has to start descending for touchdown. In such cases turboprops would certainly be preferable - they could actually reach their optimum efficient cruising altitude, cruise efficiently for a few minutes and then descend.

The choice between turbofan fan and prop would lie in a real life analysis of exactly what proportion of tonnage is going between what class of airfield. Short runway, long runway, long haul, medium haul, short haul, high altitude, sea level, medium altitude high temperature, total fuel consumption from various profiles, safety requirements for runway overshoot, bird ingestion and single engine take off etc. Once this data is examined a much better picture of "requirements" emerges which can then be compared against the aircraft available for that role and the final call of jet or prop should be made on that. Not on generalizations like "X is better in L condition. I think India has more of L so IAF needs X"

When you have an entire fleet to maintain your choice may be guided by where the maximum efficiency is required along with maximum safety. Safety gets a slightly higher rank than efficiency or noise. When it comes to civil flights - in India - airlines that do mainly short haul flights have gone in for fleets of turboprops. Airlines that do mainly long haul use their existing turbofans for the same short haul flights.

[shiv]

While being a transcontinental jet transport holding several range, load and speed records, the C-17 is optimized for close support combat operations in small, semi-prepared airfields. Using its 'blown flaps' design (also used in C-130, 747 and other transports but not in the same way), the C-17 uses jetblast directed over its STOL-optimized flap system and then downwards to provide significant extra lift. As a result, it can approach an airstrip slowly at a steeper-than-normal angle to make a 3-point landing with minimum roll.

The C-17 is spectacular to watch when its huge flaps are down and it seems to float above the runway in airshow demos of slow speed flight. I have two videos of this on YouTube but they do not do justice. You need to have that huge airliner in front of you to really feel it.

[NRao]

landing strips are also unable to operate the larger heavy-lifters like the C-17s and IL-76s.

Perhaps the IL-76 cannot.

The C-17 is designed for that. Thumb-rule: IF the C-130J can, so can the C-17, which carries 3X the C-130!!

The IAF should upgrade Il-76s .....................

My recollection is that Ex-CAS Naik stated that as the C-17 come in, the IL-76 will go out - perfect timing..

.....and order more Il-476s .....

Has IAF ordered ANY IL-476s? Are they even thinking about it? Do not see much chatter on the net about IAF and IL-476. Can someone throw more (not speculative) light on this? TIA.

BTW, the newer C-17s are much quieter.

On:

The entire lot of 100 or threabouts are being upgraded, meaning that they suit our needs almost perfectly

From Aug, 2011 :: India-Russia accelerate Multi Role Transport Aircraft Project

this .....

The project envisages production of a 20 tonne cargo plane for both military and civilian applications with low gross take off weight and capable of landing/take off from poorly surfaced runways. It is intended to replace the AN-32s in the Indian Air Force and equip the Russian Air Force as well.

[Indranil]

landing strips are also unable to operate the larger heavy-lifters like the C-17s and IL-76s.

Perhaps the IL-76 cannot.

The C-17 is designed for that. Thumb-rule: IF the C-130J can, so can the C-17, which carries 3X the C-130!!

Really ... what is so special about the C-17s ?... I am quite sure the C-17s will be used primarily to ferry goods to and fro big hubs ... It would be largely impractical to use the C-17s to do the donkey's job.

[Sanku]

There seems to be little real discussion in this thread so far about why the IAF may have chosen the C-17 and is thinking of getting more.

Because there are no real reasons so far, you have posted some reasons but its very difficult to understand most of them.

* Fly from Kanyakumari to the Tibet border at jet speed.

What does flying at jet speed mean? What speed is jet speed. How does it compare to to other large transporters. What is the range of other transport options?

And pray why will we be flying from Kanyakumari to Tibet border in the first place? How often will that be?

(hint this has all been discussed before)

* Land in a short semi-prepared ALG.
* Takeoff from a short semi-prepared ALG.

No it cant. It has never done so. This has been discussed at length before. No ALGs can take a C-17. Only An-32s class is capable of landing on ALGs. Anything heavier and the ALG gets torn to pieces even if the a/c can some how land.

In fact even Il 76s which regularly land on tougher terrain than C 17s dont use ALGs

* Land, unload and takeoff in less time than an AN-32.

C 17 is not a replacement for An 32. An 32 is a different class altogether. A much smaller and cheaper a/c.

As a long-range transport, it outclasses the IL-76 in load, range, speed and fuel efficiency.

It should, it is twice as large, there fore it would be tragic if it did not outclass it in range and speed. Fuel efficiency is not given. If you calculate fuel efficiency per km or per km/per kg of load?

Also Il 76s come with various different engines now. Newer ones are comparable to anything on a western a/c.

In normal circumstances, it can land in less than 3,000 ft and takeoff in less than 3,000 ft. It is frequently mentioned (though not 'officially') that in 'assault mode' (max performance combat ops), landing and takeoff are each routinely done in 1,400 ft or less which is unthinkable for anything in its class. The best 'assault' transport is the C-130 and the C-17 can be described as a big brother 4xC-130. So far there are no reports of JATO C-17s (like JATO C-130s) but it is reasonable to assume that this is a possibility which would make it an even more impressive performer.

There is pure fiction. There is no assault mode in a C 17 type of heavy lifter. Its a truck not a IFV. All this is broucher stuff, no C 17 has ever done any of it.

C 17s have been brought for quid pro quo for the favor extended to the Manmohan govt by Americans. They also gave Boeing a 100 a/c order from AI which bankrupted it.

Lets hope IAF has better luck with these overpriced white elephants.

[Viv S]

C 17s have been brought for quid pro quo for the favor extended to the Manmohan govt by Americans. They also gave Boeing a 100 a/c order from AI which bankrupted it.

Lets hope IAF has better luck with these overpriced white elephants.

Trouble is that you'd like to blame the MoD for a unwise purchase while at the same time absolve the IAF of all culpability for the affair. Doesn't work like that. We know for a fact is that the IAF did study all the options available to it including the IL-476 and An-124 and found the C-17 was the only viable option.

Its debatable whether that was because of the IL-76's body width limitations, its uncertain production schedule, its doubtful after-sales support, or its inevitable cost escalation, but what's not debatable is that its selection was the IAF's doing, albeit one that the MoD and MoF exercised veto over.

[Victor]

Lets hope IAF has better luck with these overpriced white elephants.

Thankfully 'hope' is not a strategy for the IAF which is why it is thinking of doubling the order for C-17s.

[NRao]

Really ... what is so special about the C-17s ?... I am quite sure the C-17s will be used primarily to ferry goods to and fro big hubs ... It would be largely impractical to use the C-17s to do the donkey's job.

Good question. Both the previous and the current CAS have answered that question. (Current CAS is on record that the C-130 and the C-17 can use two ALGs.)

I too am sure that it will be used for hub-to-hub.

All transports do is donkey work.

But, in addition the C-17 is able to do much more - that other transports cannot do. Per CAS Naik to be sure. Supposedly.

BTW, what is so great about the Rafale/EF that India should buy it?

[Indranil]

NRao ji,

Whatever ALG C-17s can operate from would be do-able with an IL-76 as well, especially if they are re-engined.

IAF has lot of things to move and C-17 is a step in that direction ... I can imagine that the IL-76s must have been difficult to keep in the air ... To expect that C-17s is going to carry Arjuns or 60Tons of cargo to ALGs with unpaved runways is a little far fetched ... It may be done only if push comes to shove, not otherwise.

[Manish_Sharma]

Regret to inform MoD that I am taking back my support to C 17 purchase, as I was fooled into believing they were bought to boost up defence against chipandas. Obviously sending back IA's need to raise Mountain Brigades as too expensive has shown that GoI, MoD are more interested in creating 45,000 jobs for boeing/US than beefing up Indian Army.

[Singha]

I think all a/c will suffer a payload penalty from ALGs. in that sense if this penalty is same for both IL76 and C17 in %, we'd still get more onsite from a successful c17 sortie to the ALG.

[Indranil]

^^^ I will never contest that ... in fact I have always said that India is doing the right thing by acquiring C-17s ... for me it is simple ... if we can get the fleet on time (or before), if there is no (300-400 percent) cost escalation ... if I don't have to wait for spares to keep 80 percent of my fleet up in the air ... then I am ready to pay a premium ...

Also as much as I like the IL-476s, I have no reason to believe why the service quality of the IL-476 will be any different than the IL-76s which have been flying in numbers and yet EVERYBODY struggles to get parts.

But to think that C-17s can go to places where other planes can't is an over statement ... C-17s are newer planes than IL-76s and obviously have an edge ... but it will require the same grade, and the same length of runway as the IL-76s to regularly operate on ... On that I harbor no illusions

[Victor]

..to think that C-17s can go to places where other planes can't is an over statement..
..it will require the same grade, and the same length of runway as the IL-76s to regularly operate on..

The C-17 was designed to be a close support STOL unlike the IL-76. It has twice the lift coefficient which, besides giving the capacity to carry more per sq in of wing area, gives it the ability to touch down precisely on the spot required on an airstrip, something that other heavy lifters cannot do well. By itself, this is not a big deal except when it is crucial to land at the very beginning of a very short runway of say 3,000 ft. Now both planes can land within 3,000 ft on a longer airstrip but the IL-76 will not attempt the feat when that is all that is available because it cannot control its touch down as precisely as the C-17 or control its braking as well. The chances of it undershooting or overshooting the landing are very high.

A close support STOL 'assault landing' is normally carried out on a rough airstrip that has just been made and secured by clearing shrubs, large rocks and trees, perhaps by an advance drop of special operations troops, sappers and bulldozers. It is the inland equivalent of a beach landing and is normally carried out by the C-130 class of transport but the C-17 is the first heavy lifter to be designed for it and most likely why we bought it IMO.

Nothing against the IL-76. We'll be happy to have both I'm sure.

[Indranil]

^^^ I know what you are talking about ... that is exactly what I meant when I said the C-17s will be used in that role only if push comes to shove.

But being able to land and being able to land over and over again are very different ... nobody will abuse such important assets in that manner.

For example is there any airfield where where the C-17s can be (is) regularly used while the IL-76 cannot.

[NRao]

^^^^

I see where you are going with this.

To answer your question, there is perhaps very little difference between the two - load being the major one.

However, the issue was never IL-76 vs. C-17. It was if the C-17 is capable of what it claims it can do, such as land at an ALG, short unprepared strips, etc.

Which you seem to agree it can. IF the IL-76 can, so can the C-17. Which is why you asked, what is so great about the C-17 - from that PoV agreed.

?????

[Indranil]

It is exactly my point ... The C-17 is a huge cargo plane and we have a requirement for such planes ... we should accept and welcome it as such.

But to think that it will take Arjuns to ALGs or operate from unpaved ALGs regularly is frankly asking too much ... All I am asking is that we should set our expectations right.

[Indranil]

It is exactly my point ... The C-17 is a huge cargo plane and we have a requirement for such planes ... we should accept and welcome it as such.

But to think that it will take Arjuns to ALGs or operate from unpaved ALGs regularly is frankly asking too much ... All I am asking is that we should set our expectations right.

[Victor]

..to think that it will take Arjuns to ALGs or operate from unpaved ALGs regularly is frankly asking too much..

I don't expect we will be transporting Arjuns to ALGs or otherwise punishing the C-17 on a regular basis but actually yes, what you wrote is exactly what the C-17 is designed to do. You seem to have missed the "close support STOL" part. This does not mean Hindon or Palam. It means the ALGs and worse.

[vaibhav.n]

I had thought we had acquired the C-130J-30 however the Defence Industry Daily lists India as the launch customer for the MC-130J Combat Shadow 2.

Let the games begin!!

Would also make sense of it's high acquisition costs compared to standard C-130J models. Are we not allowed to use the Amerikhan designation?

C-130J aircraft are now flown by and/or under contract for the USAF and Air National Guard, US Marines, and US Coast Guard; and by Australia, Britain, Canada, Denmark, India (MC-130J launch customer), Italy, Iraq, Norway, Oman, Qatar, and the USA. The Israeli Air Force also placed a formal request, with a contract expected soon.

Interesting Facts:

In practice, maximum normal C-130J-30 payload is 2,000 pounds higher than the C-130J, but 500 pounds lower than the C-130H’s 36,500 pounds. Even so, the extra space comes in handy. C-130J-30s can carry 33% more pallets of equipment or supplies, 39% more combat troops, 31% more paratroopers, or 44% more aeromedical evacuation litters than previous unstretched Hercules versions. The stretched C-130J-30 also shares the C-130J’s ability to use much more of its theoretical cargo capacity in hot or high altitude environments than previous C-130 versions.

In exchange, the stretched C-130J-30 suffers a speed drop of 7 mph (410 mph at 22,000 feet) vs. the C-130J, a 2,000 foot lower ceiling (26,000 feet with full payload), and maximum range at full payload that falls by 115 miles to 1,956 miles. It does outshine the smaller C-130J when carrying only 35,000 pounds of cargo, however: its 2,417 miles is a 576 mile increase over the C-130J, and a 921 mile increase over the C-130H.

Note that except for maximum normal payload, all of the C-130J’s figures remain significantly better than the C-130H, with statistics of 366 mph at 22,000 feet, a 23,000 foot ceiling, and range at maximum normal payload of 1,208 miles.

Link: http://www.defenseindustrydaily.com/the ... cks-03582/

[Sanku]

No ALG is going to take the ground pressure of a C 17 even loaded with Moongfali and survive.

We should cut out all this pointless broucherities and day dreaming.

C 17 will be a expensive option to move stuff from airport A to airport B.

Nothing more -- it has done nothing else in its entire life because it can not do anything else.

[Victor]

I had thought we had acquired the C-130J-30 however the Defence Industry Daily lists India as the launch customer for the MC-130J Combat Shadow 2.

Yow! Now this makes sense. Our Hercules were always referred to as "special operations" aircraft but the C-130J -30 isn't one unless it contains some special sauce. If this is true, maybe a couple are Combat Shadow and have been kept under wraps. It's CV is indeed intriguing: "..low-level aerial refueling missions as well as infiltration, exfiltration and resupply..". Perfect match for the C-17.

..No ALG is going to take the ground pressure of a C 17..

Don't tell this to the Americans because they are using it to land supplies on Afghan ALGs daily.

[Anant]

Sanku,

Take a look at this video and there is plenty of open source material to add to this on the C-17 and ALG. It might make more sense before you post something.

http://www.youtube.com/watch?v=nfI4gSz4RJk

Let me add:

http://www.youtube.com/watch?v=BXnc_w2X ... re=related

The IAF is not run by a bunch of idiots. There is a reason why this plane was purchased and no matter the arm chair analysis that goes on this forum, ultimately, they know what they are doing.