Team-BHP - Combat Aircraft of the Indian Air Force

Tejas does a dry mid air refueling and takes a significant step towards FOC

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In a big step in its development cycle, a made-in-India Tejas fighter jet today refueled mid-air from an Indian Air Force tanker aircraft for the first time.

The sortie, flown by test pilot Group Captain Rajeev Joshi of the National Flight Test Centre, is a key step in expanding the range of the single engine fighter for it to receive its Final Operational Clearance (FOC) certificate.

The test conducted on Tuesday, shortly after 1 pm, involved a 'dry' link up. In other words, there was no fuel which was actually exchanged between the Indian Air Force Il-78 tanker and the Tejas fighter through its air-to-air refuelling probe. Nine further tests will be conducted to validate this capability including 'wet' tests when fuel is transferred from the tanker to the fighter. The air-to-air refuelling probe of the Tejas has been designed by the international aerospace systems major Cobham.

According to sources, the Tejas fighter perfectly replicated computer simulations of mid-air refueling which have been carried out on the ground by engineers associated with the Tejas programme.

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Originally Posted by Sutripta (Post 4455508)

Was wondering if it is possible to do a back of envelope calculation.
What was the weight of the Marut, and the flame out - did it occur only at a certain speed band, or anywhere in its envelope?

My knowledge falls far short.

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The Gnat also had Adens (2 I think). And was small and light. Any problem there?

Gnat did not have flame out problems but did have ammo chain jamming problems. Only two aircraft that carried four 30mm's were Hawker Hunter and Marut. The Hunters RR Avons stayed burning through the firing recoil.

@Narayanan Sir, I wish your words could magically come true. I am a WOMBAT qualified but medical reject. My connection to the uniformed service goes back to my time in Air NCC and ever present aspiration to wear the coveted wings to touch the sky with glory. With some friends and family in the Uniformed service and by talking and reading to experts here and elsewhere, I gain my knowledge. The technological aspect is because of my educational background in this very field. :)

Well, as mentioned by you, I believe the sudden loss of Gp. Cpt. Das was the last nail in the coffin of the development of HF Marut. What is astonishing to me is that the HAL has moved on from its setback during Marut and has successfully (?) developed a state of the art Tejas but the GTRE seems have been stuck in the 60's. My last info on the Kaveri was the non-availability of technology and know-how to manufacture/fabricate the single-piece blade technology of the high temperature turbine. Also the inability to uptune the engine to meet the 100kN thrust requirement of the Tejas. Can we say GTRE played a significant role in the "failure" of Marut? Failure in the sense of not have made further developments with its airframe and scrapping of the whole project.

Is there any report for us mango people to read on why the Marut was cancelled and started from scratch with Tejas? Now that we are contemplating on building a Medium role fighter, the Marut (or its further developed blocks) would have been (had it existed) a perfect fit for the MMRCA deal, don't you experts think so?

Seems like IAF does not use the "Empty to Empty" lol: method to calculate the mileage. They should recruit some maruti engineers in their operations/engine division. The total fuel capacity (internal only) is around 2400 Kg and with the external tanks of (minimum) 800 Kg (outer hardpoints) each or 750 Kg (belly) tank, the total fuel carrying capacity could be quite high but they took in only 1900 Kg of fuel.

Does anyone have any info on how long this transfer took? Would be from the operational point of view interesting to compare with the US/EU based transfer systems. I found none so far.

The newest buddy refuelling mechanism by US jets have a rigid arm and the refuelling probe (at the intake end) is a port and have come across some papers that show that this technology is far more safe and quicker as the pumping rates can be quite high. Also, the aerial stability of both the tanker and the fuelled a/c is quite high even under bad weather conditions.

I am sure it is the newest version, but the refuelling by means of reeling out these hoses with baskets is one of the oldest in the book. So called probe and drogue system. It is a relative simple system.

This type of system was already deployed on the very early tankers such as the British Victor, now to be seen at Imperial War Museum at Duxford. I just happened to come across this last week during my trip in the UK

Combat Aircraft of the Indian Air Force-p9046677.jpg

Here you can see the pods with the hoses / reel / basket:

Combat Aircraft of the Indian Air Force-p9046678.jpg

The boom systems are much more safe, less prone to failure, more robust in handing and allow for higher fuel transfer rate. It does require a skilled operator and a more advanced type of tanker plane.

Of course, there are still tankers around that have both a boom as well as two probe and drogue system. They all come with their own pro’s and con’s.

I had the pleasure of having some discussions with the design team of one of these things and they showed me the real thing as well. Although it looks like a relative simple bit of kit it is actually quite a complex design and fabrication process. A lot rides on these system working well of course!

Jeroen

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Originally Posted by Jeroen (Post 4459897)

I am sure it is the newest version, but the refuelling by means of reeling out these hoses with baskets is one of the oldest in the book (I believe late 1940’s saw the first attempts. So called probe and drogue system. It is a relative simple system.

The boom systems are much more safe, less prone to failure, more robust in handing and allow for higher fuel transfer rate. It does require a skilled operator and a more advanced type of tanker plane.

Of course, there are still tankers around that have both a boom as well as two probe and drogue system. (The Dutch/Beglium airforce springs to mind :) ) At the end of the day different systems come with their own pro’s and con’s.

I had the pleasure of having some discussions with the design team of one of these things and they showed me the real McCoy as well. Sat in on a simulator training as well. Very interesting. Although it looks like a relative simple bit of kit it is actually quite a complex design and fabrication process. A lot rides on these system working well of course!

Jeroen

Jeroen is indeed right. Probe and drogue is probably the simplest refuelling system and hence the cheapest.

However boom refuelling like you see from many tankers is better in a combat environment because time is of essence. You can tank up a lot quicker. In fact the entire USAF operational doctrine could be simplified as having the AEW and tanker assets as the real lynchpin given their short ranged high performance jets need regular topping up.

Till now booms were operated using a manually controlled boom that foudn the receptacle. For this you'd have a boom operator in the tail of the plane whose job is to do so. For their newest tanker the KC-46, the Americans have run into a whole host of problems, one of the key ones being related to making the boom operation controlled remotely using a number of cameras rather than having an actual person in the boot so to speak pointing it about.
[See: http://www.thedrive.com/the-war-zone...elivery-looms]

And again, boom equipped tankers can still run probe and drogue. Hypothetically the KC-46 can top up 3 aircraft simultaneously. 1 by boom and 2 by probe! It's a nice capability to have but given India's budget restrictions I think our current system is adequate for our needs. What is needed more than anything are the new tankers. Last I heard the Airbus MRTT had won the contract but in India that counts for little..

I might be wary of the buzzwords but I'm glad with the Tejas news. Darned thing needs every little win it can. C'mon now, keep chugging along and start getting inducted into squadrons!

Quick question - the test jet was a Mk1A?

Also the buddy refuelling pods are Cobham's AFAIK. Even have what look like IAF jets on their website
https://www.cobham.com/mission-syste...fuelling-pods/