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razorseal

Localizer landing

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Hi all, this is my first post, being lurking a while :-waveI've had FS4 & now FSX deluxe, I'm a pretty crap pilot, & have only recently tried to nail down a few procedures, namely ILS using 737 & Beechcraft.I have now successfully worked out the ILS landing. As i was so pleased with myself, I decided to try a flight i have being on as a passenger, which was from Wick in Scotland, to Sumburgh on the Shetland Islands.I used a Beechcraft as it's a twin engine, & nearest default plane to what they actually use. I setup a flightplan using FSX at a height of 10K. using real weather.The flight went extremely well, as i got near my destination, i was vectored to capture the ILS. Everything was going splendid, captured the localizer, & started my descent to the runway, this is when i noticed my first problem, there was no glideslope!I thought okay, this is new to me, I'm in line up with the runway, my needle is in the middle, as i started my decent, I hit low thick cloud, I thought this was excellent, #### cool. I carried on descending with no G/S info & as you can guess came out of the clouds into fog,& about 2miles short of the runway 09:) With a bit of dodgy flying I eventually landed.Some Questions, The Sumburgh runway was at 09, but the localizer setting is 85, i thought Localizers were meant to direct you to the centre of the runway?. I taxied around Sumburgh & sure enough the localizer does line up parallel to the runway but five degree to the right of 09, how do you fly to take this into account.Or is that an error in FSXThe next question, is how do you fly a localizer approach without glideslope, when in bad weather. I guess it becomes a non precision landing, & if the runway is not in sight, i should fly to my alternate.How would you approach this landing!Thoughts Appreciated John:)

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I'm not instrument rated, so I may be talking squit ;-)First off, look at the approach chart: http://www.ais.org.uk/aes/pubs/aip/pdf/aer...es/32PB0801.PDF (you'll need a login, but it's free) Since it's a localiser only approach, it must be done with reference to the DME. At 10DME (I've ignored how you get to this point. Others more qualified than I would be able to explain the procedures in detail.) you should be at 2100ft. At 7DME begin your descent. There's a list showing how high you should be at each mile point on the descent, and also chart at the bottom of the plate that shows ft/min at various air speeds to give the correct glide slope.Runway 'numbers' (09 in this case) are rounded to the nearest 10 degrees, so the actual runway heading can be anything between 85 and 95 degrees. However, if you look at the bottom of the chart, you'll see that the localiser beam is actually offset 2.2 degrees to the South of the runway heading. Also, FSX uses data from 2005, and that may not match current charts and data.

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i thought Localizers were meant to direct you to the centre of the runway?.No - this is not their purpose. Localizers provide a course for the aircraft to fly.Quite often this can be 40 or more degrees away from the runway centerline course.LFPB has an offset localizer for Rwy 25 set at a course of 273 degrees true - for landing on a runway course of 247.18 - The 273 course is necessary to keep the traffic needing to land on Rwy 25 from crossing the takeoff pattern of LFPG. A 26 degree turn to final in the last mile is necessary for landing - this runway is used to land heavies.PHNL has an offset localizer for Rwy 26L set on a course of 314.7 true for an landin on a runway heading of 270 true - a 44.7 degree turn in the final two miles for B747 aircraft to land. This course is necessary to keep the aircraft clear of the mountains and avoid flying over the main part of the city.Localizers are also located where they are not used for landing at all. KASE has a localizer which is used for takeoff/ departure guidance. Since the runway had aircraft landing on Rwy 15 and taking off head to head on Rwy 33 - the takeoff procedure is to turn left to 270 once at 400 ft AGL and intercept the 300 back course of the IPKN localizer to be able to climb and not hit the mountains.At EGPB the localizer for Rwy 9 is offset 3.55 degrees. The high terrain toward the west end of the island is probably the reason only Rwy 27 has an ILS - but even that localizer is offset by 3.55 degrees.It is not at all uncommon for ILS and Localizers to be offset that much, requiring a slight turn to line-up with the runway for landing.These are not CAT II or CAT III systems - they all have minimums where the pilot must be able to see the runway at the MAP. If the weather is too bad to see the runway, the pilot must execute a missed approach and may need to divert to an alternate airport.

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Thanks for replies, just thought I'd explain I'm only a flight-simmer, wish i was a pilot though.Thanks for those most interesting explanations, & the link for approach charts, I've signed up & can now see what you mean about at 10kmiles i should be at 2100, & then need to descend at gradient of 5.24 degrees, and descent is dependent on type of aircraft & speed.There is a big cliff/hill (sumburgh head) there alright, which has Sumburgh Lighthouse on it, but if i recall it was on the southern tip of the island, great views can see the runway from up there :) http://www.lighthouse-holidays.com/pages/s...0Lighthouse.jpgSo after lining up with the 2.2 offset localizer, i also need to have tuned into SUB 108.50 vor/dme. to get & monitor that measurement.I notice from that approach chart they have Radar, as this Island has bad weather a lot of the time & has scheduled flights (Logan-Air)would these flights be radar guided in?Thanks againJohn

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Hi John,It sounds like you're using the localiser correctly but that's only half of the story. The ILS has the glideslope which completes the aids required for a precision approach (i.e. left/right and up/down guidance). Localiser only approaches are not uncommon (in fact at Heathrow they've been turning off the glideslope to 27L at times while still landing on it - weather permitting obviously) so as you have beautifully demonstrated (and I'm sure taught yourself a life long lesson at the same time :-)) you need some other kind of aid to get your altitude correct.In the case you are talking about the approach uses the DME and has check heights at certain distances so you can periodically work out whether you are high or low. This method is not as precise as a glideslope and as such this type of approach is referred to as a non precision approach. This information is generally only on the approach chart. At the risk of sounding like a nagging flight ops manager here's a few thoughts (add lot's of :-) :-)'s here)Check the weather at your destination before you go, if it's looking good then you could wing it (sim only here guys, I'm not advocating doing this in real life) but if it's looking a bit marginal then it would be worth getting hold of some approach charts and checking out the most likely approach.Before you descend brief yourself (I'm serious, don't laugh) but make it a practical brief. What am I going to do, what next, what will I do when...? What will I do if...? etc etc talk yourself through the approach with reference to the chart and your knowledge of the aircraft performance, don't assume anything. Make sure you cover the missed approach, you really don't want to be working that out on the fly while trying to fly it, it's a high workload time. That way when you pitch up at the airport you've got a good idea what you're going to be doing and won't suddenly be surprised ("There I was on the localiser, suddenly I realised there was no glideslope" :-)).Make sure you know your decision altitude (for precision approaches) or missed approach point (for non precision approaches). It's very important to know at what point you're going to say "Go around!" if you're not visual obviously.Hope this helps (and doesn't sound like a nag). In answer to your last question, if they have a radar (and it's switched on - don't assume anything) they may well vector you to the final approach point. However, make sure you're prepared to get there yourself (taking the local terrain and weather conditions into account).Hope this helps and I'm not teaching you to suck eggs, don't worry about the crap pilot bit, that's a great attitude to have, crap pilot but still learning. You'll live a long and happy life like that. As soon as you think you're not in that category there's a mountain/CB/technical failure/gravestone with your name on it.Take care,Ian

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that looks like a challenging approach! Seems like if you were to fly the full approach, you would tune the VOR SUM and intercept it, and fly outbound either on the 259 or 245 radial, depending on your aircraft category (min approach speed) minimum alt 2100. At the appropriate DME (note that you can use either SUB or SUM for DME) turn inbound to the LLZ course of 086. Note the step down minima lats of 1530 at SUB D9.4 and 300 after the FAF of SUB D6.4. It's hard to see on the chart, but the LLZ SUB is shown as a circle with a dot, indicating offset from runway centerline. Per the Note 1, when you are centered on the LLZ course, you should cross the rwy centerline 0.8 nm from the threshold (obviously, the runway should be in sight by then or execute a missed approach). The final approach is easier to see from the AD chart:http://forums.avsim.net/user_files/174960.jpgscott s..

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Thanks for all the tips, Don't mind sucking eggs :) Your right it is a valuable lesson to learn, even if I'm only using FSX.I used to think why do pilots need to check the weather for short flights; well I guess my short flight gave me my answer!I'd always think it's a nice sunny day here at my departure & my destination may only be 30 miles away. Pretty amazing what can happen in such a short distance.When i flew this with real weather using FSX the weather was clear & sunny at takeoff, but when i got to 20-30K from (EGBP) :) (i'm learning) the weather below me changed, without me taking much notice pretty cool, I thought.So yes, have a plan & fly it, & then have a backup. As to this being a difficult Airport, it seems to bear out, just found this-1979 July 31st. UK, Shetlands, near Sumburgh: Dan Air Hawker Siddeley H-748-1 overran a runway and crashed into the ocean; 17 people died, 30 survived.What you may not have noticed on that approach chart, is that a road crosses directly within the extended beginning of runway 09, I drove along that road, which takes you up to the lighthouse. As i was driving past I could see the piano keys & 09 markings. For me it was an interesting place to go(was working there for a week),I live in London, nothing as nice as that.Saw Oil Rigs in the North sea, on the flight from Aberdeen to the Shetlands.I noted there were two vor/dme's. I guess you could tune to both, I'm sure that would cause a mix up on DME, or would you tune one to VOR & other to DME. Thanks AllJohn

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I'm probably too late with the answer but you use navaids (vor/dme mainly) to judge your altitude. so when you are 15DME you are supposed to be 6,0000 feet. at 10DME you have to be at 4,000 feet, and at 2DME you haev to be 1,000 feet high. localizer min will be around 600 feet. if you don't see the runway of runway lighting time to go missed and try again.that is very generaly speaking. the distance/alts are on what we call approach charts. if you don't know DME is a distance measuring equipment, and tells you your distance from a VORTAC/TACAN (type of VOR)

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You mentioned radar in one post.The only experience I've had with something like that was in FS2004 multiplayer where someone using FSNav can vector and guide another FS pilot in to land - avoiding terrain and helping get him lined up with the runway which he cannot see yet.But the principle in the real world applies if the airport has the facilities.Another possibility of the comment is that the aircraft may be required to have a radar which can see/ warn the pilot of the terrain.For vertical guidance in the final stages of landing - the runway lighting system is often as good or better than a glide slope. This article is focused on flying at night in FS - but has a really good explaination of using the runway approach lights to maintain the proper descent rate - http://www.abacuspub.com/freepress/DontBeAfraidOfTheDark.pdfThere is a PAPI4 on that runway to help you get down safely.

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The charts give the altitudes and distances. At Sumburgh aircaft overfly the airport and fly outbound at 2100 ft on R259 (Cat A and :( or R245 (Cat c). At SUM 1O mn they turn right to interpept the localiser also about 10 nm and continue at 2100 ft to SUM 7 nmd begin their descent at 5.24%. The descent profile is SUM 6.6 nm/1960 ft, SUM 5.5 nm/1660 ft, SUM 4.6nm/1430 ft, SUM 3.3 nm/1030 ft. SUM 2.6 nm/710 ft, SUM 1.6 nm/390 ft.For true realism it's always worth checking the r/w charts.

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