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About mkellytx

  • Birthday January 23

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  1. That's not flutter, at least not the aeroelastic type. What occurred in that video is disturbed air, namely vortex flow hitting the vertical, happens on the Bugs also. Flutter is by definition the convergence of two oscillatory frequencies, usually bending and twisting caused by aero forces. It can often be destructive, although there are some cycle limited types.
  2. Indeed it is Overall, jumbled the O definition happens as we get older and don't take off the distance glasses to read the small print lol. Of course on the jets I flew we always went by EPR. Personally wiki isn't the first source I'd reference although my old Jet Propulsion text book was wrong, but did at least have a table comparing lots of engines on one page. The SR-71A-1 page 1-4 gives "8.8:1 pressure ratio compressor". Turns out Mattingly used an old reference from the 80's. That said, 6, 8.8 is quibbling they're both low.
  3. The fallacy here is that the same engine in another airframe should produce the same results. The difference is that the vast majority of GE powered Vipers have a different inlet than the Pratt powered Vipers specifically designed for the 110. The 110 dropped into the Tomcat pretty easily since they were almost the same size as the TF30's and were about the same mass flow rate. So, everywhere except the upper right hand side of the envelope performance increased. That said, the effort to get that performance wasn't worth the cost. No doubt it could have been done, but budgets were shrinking in real terms, those were real cuts, not "Washington" cuts. At what cost would that performance come? No Super Bug, no LANTIRN? The potential existed to get the performance, the money and mission requirements just weren't there after the hordes of Backfires disappeared. The fact that the F-15 rescheduled their inlets for 110's shows that it could be done, unlike the Navy, there were some wealthy Gulf States willing to foot that bill... The tricky bit is once the Mach number starts getting higher than 1.5 matching the compression of the inlet to the compression of the compressor becomes really important and isn't easily intuitive unless you spend some time with supersonic aerodynamics, thermodynamics and some rotating machinery. It's hard stuff, been 20 years since I've done it, found I liked the performance and handling qualities stuff much better and flight test is much more fun to boot.
  4. A lot folks, wrote a lot of stuff, one thing not yet mentioned about the difference between the two engines is the Overall Pressure Ratio (OPR). The TF30 is a 20ish OPR engine while the F110 is a 30ish OPR engine. Lower OPR engines do better at higher Mach numbers, J58 (SR-71) 6ish OPR, RR Olympus 593 (Concord) 10ish OPR. The inlets do a lot of the compression at high Mach through multiple oblique shocks (ramps/spikes/half cones), good for pressure rise but also raises the temperature. The higher OPR compressor will run into temperature limits faster, not so good for sustained high Mach numbers. That said, the higher OPR engine is the more efficient engine subsonic. So, in the case of the Tomcat, by the time they got F110 the high fast intercept was less of a concern in the late 80's and 90's. Hence don't spend the money to schedule the ramps, the better subsonic efficiency and higher thrust subsonic/transonic is good enough for the expected threat. Edit: corrected incorrect acronym
  5. The unusual attitude recovery course has some safety value to it, never mind that I've done that for my flight test work. That said the real reason for not pushing the issue is if Elon can get the trip to Mars down to $100K like he promises, then I bet there will be Moon flights for $30-50K. That's a once in a lifetime experience worth fighting over!
  6. A very good approach that might work if she weren't a musician and done several 'once-in-a-lifetime' things herself, Prince Albert Hall, Europe, backstage at Disney Hall... Doesn't quite work when I flew professionally on bombers, tankers and transports. The cost/value proposition of $15,000K to go supersonic just isn't there. Now the Me-262 thing totally could work...
  7. Apparently they still do offer flights, but you must have a valid multiengine ticket with a valid medical to fly the jet, same goes for their Me-262. The TA-4J they only require a PPL and a valid medical. Gave it some serious thought myself, until the wife saw the prices...
  8. Only idiots in DCS, IRL their missiles may not work if an EWO knows their stuff.
  9. Guns went away in the early 90's, about the same time as the G models (50 cals). The H's would be a bore for the 60's as all they did was sit alert. The F's, D's and G's flew Arc Light and Linebacker I/II.
  10. The H model was a late cold war bomber, add back the Vulcan in the tail and the model would work if you don't put a T-pod on it. The H's though mostly sat alert. A conventional BUFF would be a D or a G with J57's, water injection and ma deuces in the tail.
  11. Definitely good folks, summer of 2006 I was flew Iraqi planes out of Kirkuk. The Air Force refused to give us radios or offer CSAR if we got shot down. The Kiowa guys gave us their number and promised to come get us if we needed. Fortunately, we never did, but no Kiowa pilot will ever need pay for their drink around me.
  12. Thanks, it's getting close to 20 years since I've played with that stuff so the memory fades a bit...
  13. It's a basically a shotgun blank pushing sand for the "puff", not lethal but you can lose workdays over it.
  14. Yeah, it doesn't look very real. Just for reference here's a YT video of a bomber dropping 5 of them on Smoky, which is one of the ranges my old Bones from DY use.
  15. The BDU-50/56 are concrete shapes, no charge. Any puff is dust/sand kicked, I seen many loaded, and dropped quite a few IRL. The BDU-33 on the other hand can have a spotting charge. Fun fact, the munition responsible for the most injuries is the BDU-33 (at least according to the maintenance officer training) since it weighs only 25 lb. it is the most dropped and there really isn't a good mechanism to prevent the charge from going off.
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