How many engines for the MMRCA?

Anytime now, the Indian Air Force (IAF) should be submitting its report on the technical evaluations of six aircraft for its 126 Medium Multi Role Combat Aircraft (MMRCA) tender, indicating its assessment and by extension, preferences, after which the Ministry of Defense (MoD) will open the commercial bids submitted by the six vendors and list them in terms of the best prices offered.

But in this contest, the IAF has to make a comparison of the performances of single-engine aircraft, the Gripen and the F-16, with twin-engine fighters, the MiG-35, F/A-18 Super Hornet, Rafale and Eurofighter Typhoon. Speculative noises over the past year have indicated it to be entirely possible for all these aircraft to make the cut as far as the parameters or Air Staff Qualitative Requirements (ASQRs) laid down by the IAF are concerned.

Indeed, the varied character of the six aircraft taking part in the competition, which also cleared the paper-evaluation of their respective technical abilities last year, indicates that possibly all six aircraft could match these parameters in different ways to, more or less, the same extent.

The IAF has also said over the past year, that no aircraft would get extra credit for exceeding the SQRs. From all accounts, the IAF has been comparing the aircraft with the parameters laid down in the SQRs and not with each other. In such a scenario, the IAF could end up having a difficult time distinctly marking their preferred aircraft from the six in the fray. Three possible scenarios could come up.

The IAF could indicate a preference for either only single-engine or twin-engine aircraft, but questions could be asked as to why the IAF made no prior indication of a preference for either type of aircraft. Or thirdly, the IAF could throw up a mix of both types, if not all the competitors, in its technical report. So if the IAF does clear both, single and twin-engine aircraft, in its report, the MoD could be faced with the task of finally comparing the technical merits of the contenders with respect to their cost.

How do you compare the cost and reliability of a single-engine aircraft with a twin-engine aircraft? It seems obvious that single-engine aircraft would be much cheaper to buy and maintain, especially in terms of life-cycle cost, and that the reliability of twin-engine aircraft would exceed those of single-engine aircraft.

And if the IAF gives no extra points for performance exceeding the ASQR parameters laid down, then a decision on selection could rest solely with the MoD judging the commercial bids, where single-engine fighters would have an edge in terms of pricing.

Or would they?

The Austrian decision on the purchase of fighter aircraft is an interesting study of how a unified measure of the cost of the two types of aircraft with respect to their performance can be quantified.

The Austrian Court of Auditors examined the award of a contract for the supply of 24 Eurofighter Typhoon aircraft to the Österreichische Luftstreitkräfte (Austrian Air Force) in 2004, which had been competing with the Swedish Gripen for the order. The court looked at the process their Austrian Ministry of Defense used to arrive at a cost and utility analysis of the two aircraft on the basis of a mathematical model.

The court scanned the process their MoD used for gauging the operational capabilities of the two aircraft — what the report refers to as ‘the military benefits of an aircraft’ or what it means in a fight. Weightage was given to different criteria of performance (range, payload etc), which were tabulated and summed up out of a maximum cumulative weightage of 1000 points. The Eurofighter Typhoon scored a little higher in terms of the weightage given by the Austrian Air Force for performance with respect to their requirements.

The report says the auditors, evaluating the result of the Austrian Air Force and the MoD, found that weightage given to 35 performance criteria required adjustment, which resulted in a further shift of the cumulative weightage in favor of the Eurofighter Typhoon.

The relationship between the respective costs and the military benefits or operational performance of the two aircraft produced the cost benefit/utility analysis, which was a quantification of military benefits and what they cost. The cost benefit/utility analysis reflects the quantification of benefits with respect to their costs. The Austrian Air Force was looking for the maximum capability at the best price, or the ‘best bidder’.

In case of payment on delivery or in ten equal half-yearly annual installments Gripen offered the better deal. In case payment were made in 18 equal half-yearly installments, the Eurofighter Typhoon offer was better.

But the unit price for the Eurofighter Typhoon wasn’t necessarily lower than that of the Gripen. What the court validated was the judgment of the MoD that the offer for the Eurofighter Typhoon was more attractive, considering the payment model being offered for the performance criteria matched by the aircraft. While the Eurofighter Typhoon offer was higher than that of Gripen if payment were made on delivery or over ten half-yearly installments, the cost and utility analysis of the Eurofighter Typhoon offer was a little less than Gripen’s quote, if payments were made in 18 half-yearly installments.

What’s also interesting is that the offer made by the Eurofighter Typhoon consortium for 24 aircraft by payment on delivery wasn’t all that much higher than the offer made by Gripen (the order was later reduced to 18, and then, 15 aircraft). This, in spite of the fact that the engine in a fighter is often considered to make up around one-third of the value of the aircraft.

But at the same time Jane’s has reported a different scenario in the ongoing Romanian process for acquisition of 24 fighter aircraft, with Saab ready to offer 24 new Gripen aircraft at a cost of EUR 1 billion, against 24 second-hand Eurofighter Typhoon aircraft (and also, 24 second-hand F-16 aircraft) being offered at the same price.

It must be noted the costs considered by the Austrian Air Force and Ministry of Defense were not life-cycle costs, as India is going to adjudge. The costs are the offers made for the aircraft, in addition to weapons systems and other support systems. Nor does the report mention the performance criteria which were weighed in tabulating the cumulative military benefits of both aircraft. Each performance criteria may also be weighed differently and indeed, Indian requirements may well be very different.

But at the stage of consideration of the commercial bids, will the ministry also look at issues such as the opportunity cost in the event of a crash of one of these aircraft? “If a single-engine aircraft loses an engine, say in the event of a bird hit, the IAF loses the aircraft and possibly also the pilot. If a twin-engine aircraft loses an engine, the IAF loses an engine, which can be replaced,” says the representative of another vendor in the contest. But single-engine fighter aircraft vendors claim that engines in current twin-engine aircraft have very few failure modes that allow an engine to run in case the other fails and that they are so closely fitted that an engine down due to bird hit or weapon strike would probably result in an explosion, causing the other to malfunction.

Most aircraft in the MMRCA competition are fairly recent developments and do not have an operational history lengthy enough to get an idea of their reliability in terms of the number of their engines.

The United States Air Force (USAF) figures tabulating engine-related Class A mishaps for single-engine and twin-engine aircraft tell an interesting story. Class A mishaps are those where the total cost of damage is $1 million or more, and/or involves destroyed aircraft, and/or fatal injury, and/or permanent total disability. The USAF Air Safety Center has tabulated charts up to March 31, 2010 and, in general, the rate of engine-related Class A mishaps is higher in single-engine combat aircraft than in twin-engine aircraft.

From 1972 to last December, the F-15 had chalked up 5,783,436 flight hours. In this time, 140 of these aircraft suffered Class A mishaps with 118 aircraft destroyed and 50 people killed, including 43 pilots. Since 1975 to December 2009, the F-16 had flown 9,217,670 hours, suffering 339 Class A mishaps, with 309 aircraft destroyed and 116 people killed, including 80 pilots.

The USAF Air Safety Center has put together statistics for engine-related Class A mishaps of F-16 aircraft running on four different engines and F-15 aircraft running on three different engines. Two engines are common to both aircraft. According to these statistics, the F-16 has suffered 70 engine-related Class A mishaps after 6,408,377 Engine Flight Hours running on the four different engines (not counting the record of the aircraft running on the F100-PW-200 engine), while the F-15 has suffered 31 engine-related Class A mishaps after 11,409,530 Engine Flight Hours on the three engines listed.

When comparing the reliability of both aircraft in terms of common engine usage, the F-16 experienced 23 engine-related Class A mishaps after 2,062,376 Engine Flight Hours on the F100-PW-220 engine since 1991. The F-15, powered by the same engines, suffered 9 engine-related Class A mishaps after 3,105,962 Engine Flight Hours, since1989.

The F-15, powered by the F100-PW-229 engine, suffered 4 engine-related Class A mishaps after 859,542 Engine Flight Hours, since 1997. The F-16, running the same engine, suffered zero engine-related Class A mishaps after 244,846 Engine Flight Hours till date.

Lockheed Martin dismisses the idea that these figures indicate single-engine aircraft to be less reliable than twin-engine. Its Director of Advanced Development Programs, Michael Griswold, points out that engines have improved over time and that even the next generation F-35 runs on a single engine and is safe enough to be envisaged for operations off aircraft carriers. He also thinks this kind of comparison between the F-16 and other aircraft isn’t necessarily valid, as they have ‘totally different missions’ and ‘different roles’.

But for the IAF, this comparison may well become relevant considering the variety of aircraft in the MMRCA contest.