Mark Point for creating an ILS approach
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I was reading “Viper Pilot: A Memoir of Air Combat”.
In chapter 8 he used a Mark Point to create an ILS approach path.
I have tried with the last version of BMS but, after setting the mark point at the beginning of the runway, I wasn’t able to find a way to use the created mark point as an ILS beacon.
I tought I have to put the instrument mode in ILS/NAV but I only got the distance to the mark point no the glide slope.
Is there a way to do it? -
Haven’t read the book, but sounds like he’s creating sort of a VOR/DME approach.
Setting the mark at the runway threshold -> stay in NAV and you have the distance to touchdown. All you need is the appropriate course, and you can manually follow a 2.5° glidepath yourself (250ft AGL per NM iirc)
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You can’t create an ILS with a mark-point… not on the sim nor IRL.
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bluc69, perhaps you’re thinking of a GPS / RNAV approach using LAT / LONG coordinates?
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Hi my friend “bluc69”.
Well “You can’t create an ILS with a mark-point… not on the sim nor IRL” as correct said “Dee-Jay” and
“perhaps you’re thinking of a GPS / RNAV approach using LAT / LONG coordinates” as correct said “Moose”.
So this is what you think/want, a GPS approach but with 2.5 deg. descent (and not 3 deg. as advised by “Eagle-Eye”, and that for maximum precision because inside HUD you have the 2.5 deg. pitch ladder dive when the gears are down).
So you just want to mark the runway threshold and set the runway heading at your HSI course and set the INSTR MODE to NAV. Then with mark point current just put the 2.5 deg. pitch ladder dive and your FPM (Flight Path Marker) over the middle of the steerpoint and also the top of AOA bracket just side to the 2.5 deg. pitch ladder dive (for an 11 deg. AOA) and just keep them there. This will guide you with great precision to threshold of the runway that you have had the mark point.
Just see below an example of GPS approach to RWY 30 of Abu Suwayr (Abu Swayur inside map) airbase in Egypt of Israel theater:
And this is the chart, in order to have a better idea:
I hope to be a little more clear now my friend ;).
Nikos. -
Very well said Efstratiou.
Not to hijack this topic but just worth noting: that a new technology is emerging called GBAS (Ground Based Augmentation System) which effectively provides a “GLS” - a GPS based ILS signal. A good read on the topic is on the attached pdf…
Moose
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Thank you for the answer, but that’s the phrase from the book:
“I’d fly us down to the end of the runway using GPS guidance and take a MARK point, a precise latitude and longitude for whatever piece of ground I chose. It could then be coupled with the aircraft’s Instrument Landing System and would generate horizontal and vertical steering to that point on the ground”.
Later he wrote:
“At about eight miles, the little horizontal bar on my ILS symbology fluttered and began its slow drop.”To me it means that the he generated an ILS approach from a mark point.
So two possibilities: or that’s the true or this Viper pilot has written a lot of shit… -
“I’d fly us down to the end of the runway using GPS guidance and take a MARK point, a precise latitude and longitude for whatever piece of ground I chose. It could then be coupled with the aircraft’s Instrument Landing System and would generate horizontal and vertical steering to that point on the ground”.
? Well ???
Try with NAV/ILS? … I will take a look to the real -34 … But I do not think such feature (vertical guidance on a steer-point) does exist in the real stuff … We would have already noticed that !?!
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This exact topic (among others) has been discussed extensively here: https://www.benchmarksims.org/forum/showthread.php?13711-Been-reading-Viper-Pilot-some-odd-thoughts-about-HARMs/page6
You have to remember that this is a book for the general public and not directed at the F-16 enthusiast. Some details are left out either intentionally (classified) or because they were of no interest/too complicated/edited out for the average buyer or simply lack of long term memory about little details.
Anyway, I am not sure how you can follow a glideslope when, well, there isn’t something emitting at the other end.
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Anyway, I am not sure how you can follow a glideslope when, well, there isn’t something emitting at the other end.
It “does exist” on some a/c … but not called ILS (ILS is necessary radio beam for guidance coming a ground emitter like for the MLS) but some FMS can provide a vertical guidance on a steer-point (my plane does) … but guidance is less precise when approaching the point than a ILS cause FMS guidance error is linear … for an ILS, precision is angular.
Note also than a ground station emitting is safer than any on-board GPS system cause not depend on coordinates precision. (GPS receiver guiding on manually programed point) unless the a/c is equipped with a certified Navdata database.
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Thank you for the answer, but that’s the phrase from the book:
“I’d fly us down to the end of the runway using GPS guidance and take a MARK point, a precise latitude and longitude for whatever piece of ground I chose. It could then be coupled with the aircraft’s Instrument Landing System and would generate horizontal and vertical steering to that point on the ground”.
Later he wrote:
“At about eight miles, the little horizontal bar on my ILS symbology fluttered and began its slow drop.”To me it means that the he generated an ILS approach from a mark point.
So two possibilities: or that’s the true or this Viper pilot has written a lot of shit…not the first time this has been discussed bluc69; I opened a thread on this not so very long ago… which a brief search should have shown.
you’d have found that the consensus was that he used an existing acronym to explain the concept to an audience that largely won’t understand the finer points.
and as Dee-Jay pointed out; its not in the manual.
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Sorry for not having use the search function :oops::oops:
Anyway, I have done some test to simulate the situation described in the book.
You have to make a first passage under the clouds to mark the beginning of the runway, then you just need to put your FPM on the mark and both on a -2,5° pitch descent, line up with runway direction and you can easily land also with very low visibility. -
Anyway, I have done some test to simulate the situation described in the book.
You have to make a first passage under the clouds to mark the beginning of the runway, then you just need to put your FPM on the mark and both on a -2,5° pitch descent, line up with runway direction and you can easily land also with very low visibility.While “possible” in the game… this is not valid in really live. You can’t do such approach if it is not an authorized or published procedure. IRL, altimeter system is not as perfect as in the game … even if you can make a mark point passing overhead the point, even a a correlated radio/baro elevation … you will be not able to apply anything else than visual minimals to be authorized to proceed.
If ILS is not available … you will fly a TACAN (or VOR/DME, or SPAR etc …) approach instead. Easier, safer, and authorized.
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from memory DeeJay, in the book he described a hellish situation for a flight lead, with 12 jets airborne and a massive sandstorm covering the country. the airfield he was trying to land at was the last possible divert still remotely visible; no radio navigation aids though. the nearest other airfield was already down to 0 visibility. it was a very extreme example, but he (apparently) talked all 3 flights down and landed last.
and yes, the following day he was grounded by a beaurocrat who thought that he should not have busted minimums, and instead should have stayed airbourne and waited for fuel to run out.
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Sure that he would not have bailed out while the possibility to land still remains. But can’t be taken as a “regular” solution… Personally, I’ve already landed in the desert by night using 6 plastic bottles filled with light sticks. Sure it works.
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Sorry for not having use the search function :oops::oops:
Anyway, I have done some test to simulate the situation described in the book.
You have to make a first passage under the clouds to mark the beginning of the runway, then you just need to put your FPM on the mark and both on a -2,5° pitch descent, line up with runway direction and you can easily land also with very low visibility.It seemed that you got it easily and nice ;).
Nikos. -
Mark Point for creating an ILS approach:
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This is not ILS. This is using other systems on the jet to compensate for a lack of ILS.
Also, quite an old thread to resurrect. There are much newer ones on the same topic; they would have been a better place to post that.
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Nice trick Tavor! Another way and smart use of offsets to gain SA.
It can be useful some day. :headb:
Thanks!!