fitness88 Posted December 18, 2011 Posted December 18, 2011 Can someone please refresh my memory with regards to the Mig 29s mach/speed meter. The thick needle = the mach speed. What does the thin needle = IAS or TAS? Also in the SU-27 for example when you reach Mach 1 as indicated on the guage you break the sound barrier but I have noticed when the Mig 29 reaches Mach 1 as indicated on the guage it does not break the sound barrier unless you are flying at sea level. Does this me the Mig 29 Mach meter is not adjusted for altitude and all other variables...if so, what use is it if it can't calculate accurate Mach speed above sea level? Thank you.
GGTharos Posted December 19, 2011 Posted December 19, 2011 Sim bug, that's all. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
fitness88 Posted December 21, 2011 Author Posted December 21, 2011 Sim bug, that's all. Thank you for your response. Can you please clarify... Is the bug related to the sonic boom not sounding exactly on que when the mach meter indicates mach 1? Or, is the bug related to the Mach meter not indicating Mach 1 exactly when it should? Thank you.
GGTharos Posted December 21, 2011 Posted December 21, 2011 #1 :) [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
Vekkinho Posted December 21, 2011 Posted December 21, 2011 (edited) IIRC sonic boom sound is acivated when thin needle reaches M1.0 On the other hand MACH gauge is activated by air volume flowing thru pitot tube so lots of false data is possible. Planes like Su-27 have 3 pitot tubes in total (nose, left and right panel below canopy) to prevent this from happening unlike MiG-29 that has only one on the tip of the nose cone. Damn, I haven't flown my MiG for ages... Edited December 21, 2011 by Vekkinho [sIGPIC][/sIGPIC]
GGTharos Posted December 21, 2011 Posted December 21, 2011 Maybe ... I'm certainly aware of some issue with the sonic boom - it's known, one way or the other. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
fitness88 Posted December 21, 2011 Author Posted December 21, 2011 It's important to know that the Mach meter is accurate as for the timing of the sonic boom being off, that is not serious. Also this is occuring with the SU-27 as well. In FC 1 this was not a problem. Thank you for your replys.
IvanK Posted December 21, 2011 Posted December 21, 2011 IIRC sonic boom sound is acivated when thin needle reaches M1.0 On the other hand MACH gauge is activated by air volume flowing thru pitot tube so lots of false data is possible. Planes like Su-27 have 3 pitot tubes in total (nose, left and right panel below canopy) to prevent this from happening unlike MiG-29 that has only one on the tip of the nose cone. Damn, I haven't flown my MiG for ages... There is more than one source even in the MiG29 for pitot static indications. Data is also processed by the Air Data Computer (ADC) to take out various errors. The TAS guage is an ADC output not raw Pitot Static output. In either case errors in pitot static systems will always exist. The MIG29 Flight Manual implies +-0.05M. Displayed Mach number always takes into account Altitude and temp. Here is an explanation of the TAS instrument in the MIG29G ... display is in knots but the principal is the same.
fitness88 Posted December 21, 2011 Author Posted December 21, 2011 IvanK: Thank you for your reply and the info. To wingmen for example, I've always given my speed as a reference in Mach numbers as do real world pilots so if it'a not accurate I'll have to use IAS or TAS. Thank you.
IvanK Posted December 21, 2011 Posted December 21, 2011 Its good enough to use. 0.05M is next to nothing :) Being a Sim if there are any errors I reckon everyone would have the same error anyway. As to sonic booms they can (IRL) be generated anytime ANY portion of the aircraft structure has local airflow going supersonic over it. For example a high speed 0.95M beat up of the base with Speed brakes on the pitch out can easily result in much embarrassment as the local flow over the speed brake goes supersonic ... even though the aircraft is still "subsonic" MACH number displays in all aircraft (even those without ADC's) are not raw pitot static values. Mach number indications always have some processing (be it digital or analog) applied.
Vekkinho Posted January 18, 2012 Posted January 18, 2012 Although that Mach gauge pictured in Figure 1-36 isn't the one being used with MiG-29 cockpit. [sIGPIC][/sIGPIC]
Vekkinho Posted January 18, 2012 Posted January 18, 2012 Although that Mach gauge pictured in Figure 1-36 isn't the one being used with MiG-29 cockpit. On the other hand, this might be the gauge used with MiG-29G, it certainly isn't Russian bird! [sIGPIC][/sIGPIC]
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