Murphy's Law: It's Complicated, Too Complicated

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August 23, 2009: The head of the Russian Air Force recently admitted that their new Su-35 fighter was having some serious problems with its engine (the AL-41), and would have to use the older AL-31 engines (used on the Su-27/30) in the meantime. But the more powerful AL-41s are needed to give the Su-35 some of its F-22 like capabilities. However, Russia has been working on the AL-41 design for over twenty years, and has never given up hope that they would work out all the problems. This is partly because the technology used in the AL-41 would enable the Russians to built more competitive engines for civilian aircraft. So far, the complexity of the AL-41 has proved to be a bit much.

Three months ago, Russian engineers determined that the April 26th crash of one of the two prototypes of the Russian Su-35, was an "engineering defect" in one of the two AL-41 engines. The engine failed during takeoff. Russian engines have long been noted for their low reliability, and short service lives.

There are currently two Russian engines being built for fighter aircraft. The $3.5 million AL-31 (for the Su-27/30, and the Chinese J-11, J-10) and the $2.5 million RD-33/93 for the MiG-29 and the Chinese JF-17 (a F-16 type aircraft developed in cooperation with Pakistan.)

The AL-41 is a AL-31 variant, generating 32,000 pounds of thrust, and developed just for the "next generation" (after the Su-27) fighter. It is supposed to be good for 4,000 flight hours (compared to 3,000 hours for the AL-31). Accidents like this are expected during aircraft development, although in the last decade, Western aircraft developers have avoided such losses by doing a lot more testing via computer simulation. The AL-31/41 has been the cause of several Su-30 mishaps recently, and the Russians are still seeking answers.

The Su-35 is a 34 ton fighter that is more maneuverable than the original, 33 ton, Su-27, and has much better electronics. It can cruise at above the speed of sound. It also costs at least fifty percent more than the Su-27. That would be some $60 million (for a barebones model), about what a top-of-the-line F-16 costs. The Su-27 was originally developed to match the F-15, which is larger than the single engine F-16. The larger size of the Su-27/35, allows designers to do a lot more with it in terms of modifications and enhancements.

The Su-35 is to have some stealth capabilities (or at least be less detectable to most fighter aircraft radars). Russia is promising a fighter with a life of 6,000 flight hours, and engines good for 4,000 hours. Russia promises world-class avionics, plus a very pilot-friendly cockpit. The use of many thrusters and fly-by-wire will produce an aircraft even more maneuverable than earlier Su-30s (which have been extremely agile).

The Su-35 is not meant to be a direct rival for the F-22, because the Russian aircraft is not nearly as stealthy. The Su-35 will carry a 30mm autocannon (with 150 rounds) and up to eight tons of munitions, hanging from 12 hard points. This reduces stealthiness, which the F-22 and F-35 get around by using an internal bay for bombs and missiles. But if the maneuverability and advanced electronics of the proposed Su-35 live up to the promises, the aircraft would be more than a match for every fighter out there except the F-22. If such an Su-35 was sold for well under $100 million each, there would be a lot of buyers. Russia says it will begin production, and sales, in three years.