Sunday, January 20, 2008

Supercruising F-16? Uh, No!

A few words from a "carried away" F-16 test pilot at Fort Worth to the media team from India, and we had our papers splashing reports of how the Fighting Falcon offered to India would be able to supercruise! A day later, Lockheed-Martin officials sheepishly confided that the incorrect report were the result of "over-enthusiasm" on the part of a test-pilot who presented the aircraft to the media team. After a tour of the Falcon Nest -- the F-16 production line in Texas -- we were taken to the flight line to see a tester F-16 in its hanger.

Here's what we were told by a test-pilot as we walked around the aircraft: "We routinely supercruise with this fighter on test-flights". The next day, over dinner, the people who actually run the Indian F-16 campaign (including a veteran Falcon pilot) said that the pilot in question had maybe got "carried away" by the moment. What he really meant to say, apparently, was that the Falcon routinely went supersonic in dives for a few seconds. Ok, even Hawker Hunters could break the sound barrier in dives, so this isn't such a big deal. And anyway, the definition of supercruise is the capability of an aircraft to cruise at supersonic speeds without engine reheat during sustained level flight. The General Electric F110-GE-132 turbofan that powers the Block 60 cannot push the Falcon into level supersonic flight without wet power. It's that simple.

As it turns out, the concept and reality of supercruise technology are not as simple as they appear. The F119-PW-100 which powers the Raptor and the Typhoon's Eurojet EJ200 are considered the only rate production turbofans that can push the airplanes they were designed for into the realm of supercruise. The F-35's F135 and F136 turbofans are not designed for supercruise -- there are those who feel that this alone is enough to erode the aircraft's fifth generation status. Either way, the MMRCA RfP doesn't ask for a supercruising aircraft. The advantages of supercruise are still not sharply defined. The pros aren't all black and white -- supercruising still chews jet fuel like pop corn compared to subsonic flight for the same distance. And engine wear and tear in supersonic flight is not lower enough than that caused by reheat to carve out for itself any unique advantage. Like the people here said, making supercruise capabilities second nature to modern turbofans is one of the most funded parts of jet engine and integration research today.

Well, to end on a lighter note, here's something that should tell us all a good deal about the IAF's legendary woes with Russia: the RfP for the MMRCA says that all spares for the chosen fighter should be "brand new".

7 comments:

faultybydesign said...

Shiv.....We know you like aircrafts more, but do tell us of Arjun tank also

Anonymous said...

Shiv, how do you know that the RFP does not ask for supercruise ability? I thought that the RFP was top secret. Or are you just speculating.

Shiv Aroor said...

anon: it doesn't. i cross-checked. the RfP only specifies a minimum engine rating, and makes no reference to supercruise, nor lists it as one of the mandatory performance parameters. so no, this isn't speculation

Anonymous said...

How about AESA? Does the RFP also state that the aircraft should be equipped with AESA?

Shiv Aroor said...

anon: yes, the RfP does specify that the primary sensor of the aircraft should be an AESA radar. by most accounts, if the selection process takes place fairly, this will be one of the most contentious elements of the competition. also, it steeply favours the americans since none of the AESA radars being fielded by the other countries (Russia's Phazotron Zhuk AE on the MiG-35 for instance) are proven.

Anonymous said...

u idiots, who said RFP is top secret?? I am getting a copy next week. Its no secret, never was....they can be flicked from anywhere

Anonymous said...

Really, so how about you go ahead and publish it on the web and leave a web address here. Thats if you can put your money where your mouth is.