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bbrz

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Everything posted by bbrz

  1. Judging by the pitch attitude and vertical speed just before the flare, the rather large flare movement and the tail clearance on touchdown, I'd say that he was rather too slow than too fast.
  2. I don't understand why people are having problems with the nosegear on landing since you are not supposed to land in a 3 point attitude or on the nosegear. But even if you touch down on the mains, lowering the nosegear too fast can result in a serious high bounce. Just take a look at this RW MiG-15 bounced landing. This one could have easily ended in a disaster.
  3. Here's a very short pattern, didn't have any time for practise. Just to show that she's not too difficult to land smoothly. 29_pattern.trk
  4. Without FBW it can't be unstable, not even relaxed stability. It's a 'classic' stable design. She's simply very responsive. :)
  5. Where did you get this info from? Looking at the wing span, loading, its position, flaps/flaperon size and deflection angles, it's rather easy to calculate that there is ground effect. That it isn't noticable/effective during unflared landings, where you are descending rapidly through the ground effect, is a different story. Maybe even the FBW masks it.
  6. Ok, intercept and Gs are an entirely different story. It's only about the optimum climb speed with the maximum ROC. No maneuvering.
  7. The crossover altitude in this case is already FL330.... I don't think that there are specific climb programs, since there's only one optimum speed at which you can achieve the highest ROC. Flying a high performance jet isn't that complicated ;) In case of the Streak Eagle I agree with specific climb programs, but that's a completely different case.
  8. Ah, ok. I see....
  9. This has nothing to do with what I believe. Most likely test pilots have done quite a few other climb tests, but I'm not aware of other 'secret' performance manuals e.g. F-15 pilots get? Why would MCD and/or the USAF hide optimum performance data from their manuals, or not include them in the -1? Thinking of it, since it's (now) Boeing in case of the F-15, it might be the same case as with MCAS. It's there but they are not going to tell you or mention it in the -1 ;)
  10. I doubt that any pilot would use speed schedules that aren't written in the -1 / flight manuals.
  11. Well that's obvious ;) The original discussion was, why the F-15 uses the same, rather low IAS for mil and AB climb, while there's usually a big difference for most other planes.
  12. On many airliners, e.g. the DC-9 Vx and Vy are basically identical and hence Vx is not used. That's why there's on jets usually only a single optimum climb speed. Again, for the F-14A, the F-15 etc. there's apparently also only one single optimum climb speed. Since the Tu-154 isn't exactly a fuel efficient airplane I can imagine that there's a separate 'econ' climb ;)
  13. That's new to me. Especially on a jet which uses a lot more fuel at lower altitudes. So the max ROC results in the best fuel economy as well or am I wrong? Not aware that there are different climb tables e.g. in a C152.
  14. Can you point me to the additional climb schedules in the F-4, F-105 and Tornando flight manuals ? I didn't find any. The (rather slow) A320 standard climb is .78 and with a high drag index the F-14 climbs at M.62, I could never fly that slow with a heavy 767! I didn't find anything in the F-14A manual which mentions a 'best fuel economy rate of climb'. It simply 'climb speed schedule military power' which means max climb thrust and hence max ROC. Couldn't find an AB climb schedule either in the manual.
  15. That's an interesting question. Just did a few tests with surprising results. 160kts flaps half, gear down, above ground effect. 4.5°AoA, 85%N1 > ground effect 3.5°AoA, 83%N1 > no pitch down. No difference with the gear up except for a 4% lower N1. 160kts flaps full, gear down, above ground effect. -0.5°AoA, 85%N1 > ground effect -2.5°AoA, 84%N1 > no pitch down. (1% thrust difference between half and full flap?) 160kts flaps auto, gear up, above ground effect. 9°AoA > ground effect 8°AoA, no pitch down. Did another test at 220kts (flaps auto, gear up) and suddenly the pitch down occured, but only at a very low altitude. Estimated 10-20ft. Due to the rapid onset of the pitch down I wasn't able to get reliable stable AoA values.
  16. Hm, I don't think so. The F-15 and the F-5E both have a single fixed climb speed schedule for MAX power, there are no other speeds/climb schedules available for different circumstances. E.g. the F-4E and the Tornado are also much higher IAS, 595kias/M0.90. The F-105 even needs 615/0.93 and the F104 a slightly lower 610/0.925. What is surprising (for me) that the F-14A is a real Turkey with a climb Mach Number of 0.70 even in the clean case. That's a lot slower than every civil airliner!
  17. Only if you are using less than MIL/MAX power it's a 'cruise' climb. Since jet engines are using a lot of fuel at lower altitude you usually climb with max climb power in all jets. The above speeds are for the F-15C. 350 is surprisingly low for a MAX power climb since e.g. the optimum climb speed for the F-5E in clean config is 590kts / M0.93.
  18. bbrz

    Update

    That's why you should be patient ;)
  19. Have you checked the FFB settings? AFAIK these can e.g. ruin the airplane handling if set to ON without having an FFB joystick.
  20. Reducing the ROD is the tricky part due to the same 'reverse' ground effect like in the F/A-18. I hope ED fixes this bug and landing the MiG-29 will become even easier :) The unnatural pitch down moment requires an unrealistic pull which easily translates into PIO.
  21. Anyone else noted that the MiG-29 suffers from the same 'reverse' ground effect like the F/A-18? It's not as noticable as in the F/A-18 because the MiG-29 is rather pitch sensitive.
  22. Just re-tested. If ground effect for e.g. the stabilizer isn't calculated seperately, then it's indeee a 'reverse' ground effect and the pitch down moment is simply the result from the loss of lift. With the F/A-18 at 300kts I need an approximately 0.5° higher AoA in ground effect.
  23. Depends on the 'obvious' definition. As Yeti42 said, a missing wing is obvious, a missing fasterner not so much for most people...except F/A-18 maintenance staff... ;)
  24. Just did a few more tests and IMO it's definitely not an 'reversed' ground effect, it's a pitch down moment that is introduced at very low altitude, below 30-50ft. Noticed that exactly the same phenomenon occurs (at least) with the MiG-29 as well. At low speed and high AoA I could understand this effect, since the downwash of the very low positioned stabilator enters the ground effect before the wing does. This reduces the stabilator downwash, increases lift and produces a noticable pitch down effect. This effect is very noticable when e.g. rotating on take off IRL in big jets. As soon as the horizontal stabilizer descends into the ground effect you need to increase the pull on the yoke to keep the present rotation rate. Starting to climb, the stabilizer leaves the ground effect and you need to relax the back pressure. @Gripes, with this large flaps and flap angle on the F/A-18, there is for sure a 'theoretical' ground effect. But taking into account the high wing loading and that Hornet pilots usually don't shoot for greasers and the rather high ROD it's not noticable I'd say. But this pitch down even occurs at high speed, e.g. at 400kts where the relative position of the stabilator is higher and it produces much less lift.
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