Message posted by Magoo on October 25, 2000 at 22:41:25 EST:
Norio The amount of time a model spends at an RCS range could really depend on many different things. e.g... - How much fine tuning of the design is required to achieve the goals that have been set. The model may need to be taken away to be modified, or it may be possible to do it at the site. This may take months or even years to achieve. Or, they may get it right first time and it will only take a matter of days/weeks to verify! - On whether LO is the prime objective of the design (e.g. F-117), or whether they are trying to minimise the RCS on an otherwise conventional design (e.g. F/A-18E, B-1B), or whether they are testing new theories of LO/minimal RCS design etc on otherwise non-descript shapes (e.g. ball bearings, darts etc). - On whether there are several stages of prototype an aircraft is scheduled to go through before a production representative example is ready (e.g. JSF, F-22, F-117). They may choose to make running changes to the airframe to reduce the RCS with each new protoype, rather than modify a single airframe. Therefore, a particular airframe may only be there for a few days. - On what frequencies and power levels of radar the model is designed to defeat (e.g. K-band, S-band, J-band etc). Every known frequency may have to be tested on every possible angle of the model, and then all figures would undoubtedly be double-checked afterwards. If the aircraft is primarily an interceptor (e.g F-14D), then they would probably 'tune' it to defeat fighter, air-to-air missile and AEW radars. If it is a long range bomber (e.g. B-2), then it would be 'tuned' to defeat the whole ground/sea/air based Integrated Air Defence System (IADS) and search/track and SAM radars, with a secondary anti air-to-air missile capability as well (in other words, the whole box and dice!). As you can see, there are many, MANY variables. As for the JSF, I doubt too much time was spent at the range, as I'm sure much of the RCS modelling was probably done on computer. In fact, this may be the reason why many RCS facilities are closing down these days, because the computer modelling is so good! The X-32/35 is due to go through three prototype generations before a production example is flying. After two 'X' airframes, there will be two or three 'YF-' examples, followed by perhaps four to six pre-production test beds, and then the first run of production representative aircraft. There are plenty of opportunities to fine-tune the RCS along the way between now and 2007/8 when the aircraft is due to start entering service! Magoo
In Reply to: Re: How to get to Lockheed RCS test facility in Helendale posted by Norio Hayakawa on October 25, 2000 at 11:07:09 EST:
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