CoBlue Posted January 24, 2015 Posted January 24, 2015 Does anybody now what the minimums for an PRMG(ILS) approach are for the Mig-21bis? Also I heard that the minimums differed in war & peace time, is that true? The manual mentions that an ARK(NDB) approach should never be attempted, was that true for the Mig-21 IRL? I was under the impression that ARK approaches were used extensevly in the USSR. Thanx! i7 8700k@4.7, 1080ti, DDR4 32GB, 2x SSD , HD 2TB, W10, ASUS 27", TrackIr5, TMWH, X-56, GProR.
ttaylor0024 Posted January 24, 2015 Posted January 24, 2015 The issue in the sim is that we do not have approach plates. IRL, ILS approaches (PRMG for the MiG-21) take you down to 200' on average, however CAT III ILS can land you with 0 vis. NDB approaches would normally take you down to about 500'. These minimums differ IRL due to technical limitations and objects interfering with "safe" airspace, such as towers, etc that would require the minimums to be raised.
xxJohnxx Posted January 24, 2015 Posted January 24, 2015 Does anybody now what the minimums for an PRMG(ILS) approach are for the Mig-21bis? Also I heard that the minimums differed in war & peace time, is that true? The manual suggests that you have to have visual on the runway (or the approach lights) at 300m AGL. Not sure about the different minimums in wartime, but might be plausible. Everything is different in wartime... The manual mentions that an ARK(NDB) approach should never be attempted, was that true for the Mig-21 IRL? I was under the impression that ARK approaches were used extensevly in the USSR. Thanx! I guess a reason for that is, that the Bis only has one receiver. On a proper NDB approach you want to employ two ground stations simultaneously. The stations would be aligned with the runway course. During approach you would just make sure both needles (of each ADF) overlap. If they loose alignment from each other you know that you have deviated to either the left or right. With only one receiver this is not possible in that way. You still can do it by setting the station and then flying the exact curse, but it is more difficult and less accurate. Also, during a proper NDB approach, you would have to manually monitor altitude and distance to the airfield, to make sure you end up in the right position for approach. The instrumentation does not easily allow for this and being alone in the cockpit doesn't help either. Check out my YouTube: xxJohnxx Intel i7 6800k watercooled | ASUS Rampage V Edition 10 | 32 GB RAM | Asus GTX1080 watercooled
ttaylor0024 Posted January 24, 2015 Posted January 24, 2015 (edited) The manual suggests that you have to have visual on the runway (or the approach lights) at 300m AGL. 300m seems wayyyyyyyyy high, but everything in the manuals about the MiG is very, very cautious (such as not exceeding 19* AOA). I guess a reason for that is, that the Bis only has one receiver. On a proper NDB approach you want to employ two ground stations simultaneously. The stations would be aligned with the runway course. During approach you would just make sure both needles (of each ADF) overlap. If they loose alignment from each other you know that you have deviated to either the left or right. With only one receiver this is not possible in that way. You still can do it by setting the station and then flying the exact curse, but it is more difficult and less accurate. Also, during a proper NDB approach, you would have to manually monitor altitude and distance to the airfield, to make sure you end up in the right position for approach. The instrumentation does not easily allow for this and being alone in the cockpit doesn't help either. Not true about the 2 ground stations. This is an NDB approach to a local airport. I haven't even been in an aircraft that has 2 ADFs. As you can see, only one NDB is used (Flory). The VOR at the top (Salina, SLN VOR) is only used for the missed approach. To fly this without DME, you simply start a timer after passage of the NDB, and once your time's up and you don't see the runway you go missed. You can see this time chart on the bottom left of the approach plate. Ground speed is on top, time below. Edited January 24, 2015 by ttaylor0024
xxJohnxx Posted January 24, 2015 Posted January 24, 2015 Not true about the 2 ground stations. This is an NDB approach to a local airport. I haven't even been in an aircraft that has 2 ADFs. As you can see, only one NDB is used (Flory). Yes, I know the single NDB approach you are talking about. That's also what I meant here: You still can do it by setting the station and then flying the exact curse, but it is more difficult and less accurate.They were indeed quit common here in central Europe as well, though nowadays they mostly lost their importance. Quit hard to come by non-commercial airframes with dual ADFs as well. However, the classical NDB approach in Russia is flown with dual NDBs and dual ADFs. An example here: The D and DJ NDBs server as your dual NDBs while at the same time being the outer and middle marker. Decision height is at 135 meters for that NDB approach. Check out my YouTube: xxJohnxx Intel i7 6800k watercooled | ASUS Rampage V Edition 10 | 32 GB RAM | Asus GTX1080 watercooled
ttaylor0024 Posted January 25, 2015 Posted January 25, 2015 Yes, I know the single NDB approach you are talking about. That's also what I meant here: They were indeed quit common here in central Europe as well, though nowadays they mostly lost their importance. Quit hard to come by non-commercial airframes with dual ADFs as well. However, the classical NDB approach in Russia is flown with dual NDBs and dual ADFs. I've never even heard of dual NDB approaches. I've seen an approach in Greenland I believe that had multiple NDBs, but that was due to terrain. I feel as if a single ADF approach could be nearly the same accuracy, just gotta focus on the needle is all.
CoBlue Posted January 25, 2015 Author Posted January 25, 2015 (edited) However, the classical NDB approach in Russia is flown with dual NDBs and dual ADFs. Didn't know that, explains it for the 21, thanx:) The issue in the sim is that we do not have approach plates. IRL, ILS approaches (PRMG for the MiG-21) take you down to 200' on average, however CAT III ILS can land you with 0 vis. I've created many own made ILS & NDB approaches for the UH-1, F-86 & Mi-8. That's why I wonder about the 21's minimums Edited November 23, 2019 by CoBlue i7 8700k@4.7, 1080ti, DDR4 32GB, 2x SSD , HD 2TB, W10, ASUS 27", TrackIr5, TMWH, X-56, GProR.
ttaylor0024 Posted January 25, 2015 Posted January 25, 2015 I've created many own made ILS & NDB approaches for the UH-1, F-86 & Mi-8. That's why I wonder about the 21's minimums Here's one just above my apartment http://www.lfv.se/AIP/AD/AD%202/ESSB/ES_AD_2_ESSB_5-5_en.pdf & another http://www.lfv.se/AIP/AD/AD%202/ESNL/ES_AD_2_ESNL_5-4_en.pdf there are or were some in Sweden & many in Finland. maybe one day I'll get bored and make approach plates for categories like in real life. I instruct in the States, so don't know much about regs or approaches out of country. Thanks for the info though!
Recommended Posts