Yukon Excitement
7 years 3 weeks ago #14302
by Westcoast
Yukon Excitement was created by Westcoast
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<div><span >I had an exciting afternoon in the Yukon today. I have been doing the Ketchikan Center Econ flights. As you already know, these are the no excuses, no do-over flights. There are 25 of these, and today I was flying number 14: Ketchikan (PAKT) to Terrace (CYXT). Today the weather was not good. Ketchikan was 7 SM in Light Rain, Few 800, Ceiling 1400 BKN, 3/3. In other words nearly freezing rain under a low ceiling. However, Terrace, over in the Yukon Territory of Canada was worse: 200/3, 5 SM, Few 300, ceiling 800 Ovc, 0/0. To make matters worse, Terrace has a field elevation of about 700’ and lies at the north end of a mountain valley, surrounded on the east and west by mountains rising to nearly 7000 feet.</span></div>
<div><span >Clearly this was going to be an IFR flight and an instrument approach. Plan C indicated the presence of an ILS on Rwy 33. So, that would have to be it, even if the wind was from the south. Usually I cannot find an instrument approach chart for these little Canadian strips, but today I was in luck. Navigraph charts had an ILS chart for runway 33, complete with a vertical chart. These are essential for making a descent in weather in mountainous terrain. However, the chart states that “Minima not published” for this approach. That seems unusual and would appear to be equivalent to something like “lots of luck”. On the other hand, I couldn’t be faulted for landing below minimums if something went wrong.</span></div>
<div><span >Even though I had the IAP for ILS 33, I was confronted with the usual FSX IFR question: to pretend it’s VFR and land anyhow when the tower denies permission, or to file IFR and follow either the ATC approach instructions, or fly the approach plate and switch channels to mute the ATC. Today I chose the former, but I soon had ample cause to wonder if I had made a mistake.</span></div>
<div><span >Once I was at my cruising altitude of 11,000’ and well east of the coast, I had towering scattered clouds and on and off visibility of the high peaks, well below me. However, I could also see that the mountain valleys between the peaks were filled with what looked like fog – clouds that extend all the way to the ground. But, the forecast indicated that I should have a ceiling of about 800’ as I approached the strip, so I pressed on.</span></div>
<div><span >Some distance out ATC vectored me off my filed flight plan to south. That made a lot of sense, since I was going to have to line up with the north-south valley that led to the airstrip and the best approach was to come in from the south. That also lined up with the approach chart, since it called for intercepting the localizer 24 miles south of the runway threshold at an altitude of 7100’. On top of that, I brought up the approach on my GPS and opted for “vectors to final”, which would give me a live graphic display of where I was relative to the localizer.</span></div>
<div><span >However, ATC vectors caused me to approach the extension of the localizer well south of the IAP, over terrain which was quite high and also gave me instructions to descend to 4500’ while I was still 28 miles south of the airstrip, whereas the IAP would have had me at 7100’ 24 miles south of the threshold. This had two consequences: first, I was well beneath the extension of the glideslope and second, I was quite close to the terrain vertically. Given that I only had occasional visibility of the peaks below me and was mainly in “white out” conditions, this caused the “pucker factor” to increase substantially. I had visions of the “controlled flight into terrain” penalty annihilating my average profit per flight score. In fact, 13 miles out, I was at my assigned altitude (OK, 250’ below) and on the localizer, with the glideslope above me and armed, but my radar altimeter indicated a terrain clearance of less that 500’. I’m pretty sure that breaks some kind of rule, but I was reluctant to pull up for fear of losing the glideslope, and with an 800’ ceiling, I couldn’t afford to overshoot the approach.</span></div>
<div><span >I eventually locked on the GS and tracked it for a while, but then fell below it for some inapparent reason. I finally broke out, still on autopilot, but a little below the GS at 1347’, 3 miles from the threshold with a terrain clearance of about 420’. Since the strip elevation is 678’, this indicates that the terrain below me when I broke out was 249’ higher than the threshold, so that the effective ceiling was just over 400’. If there were published minimums, I would have just made it for a 200’ Cat I minimum.</span></div>
<div><span >Even though I was a little below the glideslope, I turned off the autopilot, reduced my descent rate and made a good landing on the center of the runway. Whew! Film at 11.</span></div>
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<div><span >I had an exciting afternoon in the Yukon today. I have been doing the Ketchikan Center Econ flights. As you already know, these are the no excuses, no do-over flights. There are 25 of these, and today I was flying number 14: Ketchikan (PAKT) to Terrace (CYXT). Today the weather was not good. Ketchikan was 7 SM in Light Rain, Few 800, Ceiling 1400 BKN, 3/3. In other words nearly freezing rain under a low ceiling. However, Terrace, over in the Yukon Territory of Canada was worse: 200/3, 5 SM, Few 300, ceiling 800 Ovc, 0/0. To make matters worse, Terrace has a field elevation of about 700’ and lies at the north end of a mountain valley, surrounded on the east and west by mountains rising to nearly 7000 feet.</span></div>
<div><span >Clearly this was going to be an IFR flight and an instrument approach. Plan C indicated the presence of an ILS on Rwy 33. So, that would have to be it, even if the wind was from the south. Usually I cannot find an instrument approach chart for these little Canadian strips, but today I was in luck. Navigraph charts had an ILS chart for runway 33, complete with a vertical chart. These are essential for making a descent in weather in mountainous terrain. However, the chart states that “Minima not published” for this approach. That seems unusual and would appear to be equivalent to something like “lots of luck”. On the other hand, I couldn’t be faulted for landing below minimums if something went wrong.</span></div>
<div><span >Even though I had the IAP for ILS 33, I was confronted with the usual FSX IFR question: to pretend it’s VFR and land anyhow when the tower denies permission, or to file IFR and follow either the ATC approach instructions, or fly the approach plate and switch channels to mute the ATC. Today I chose the former, but I soon had ample cause to wonder if I had made a mistake.</span></div>
<div><span >Once I was at my cruising altitude of 11,000’ and well east of the coast, I had towering scattered clouds and on and off visibility of the high peaks, well below me. However, I could also see that the mountain valleys between the peaks were filled with what looked like fog – clouds that extend all the way to the ground. But, the forecast indicated that I should have a ceiling of about 800’ as I approached the strip, so I pressed on.</span></div>
<div><span >Some distance out ATC vectored me off my filed flight plan to south. That made a lot of sense, since I was going to have to line up with the north-south valley that led to the airstrip and the best approach was to come in from the south. That also lined up with the approach chart, since it called for intercepting the localizer 24 miles south of the runway threshold at an altitude of 7100’. On top of that, I brought up the approach on my GPS and opted for “vectors to final”, which would give me a live graphic display of where I was relative to the localizer.</span></div>
<div><span >However, ATC vectors caused me to approach the extension of the localizer well south of the IAP, over terrain which was quite high and also gave me instructions to descend to 4500’ while I was still 28 miles south of the airstrip, whereas the IAP would have had me at 7100’ 24 miles south of the threshold. This had two consequences: first, I was well beneath the extension of the glideslope and second, I was quite close to the terrain vertically. Given that I only had occasional visibility of the peaks below me and was mainly in “white out” conditions, this caused the “pucker factor” to increase substantially. I had visions of the “controlled flight into terrain” penalty annihilating my average profit per flight score. In fact, 13 miles out, I was at my assigned altitude (OK, 250’ below) and on the localizer, with the glideslope above me and armed, but my radar altimeter indicated a terrain clearance of less that 500’. I’m pretty sure that breaks some kind of rule, but I was reluctant to pull up for fear of losing the glideslope, and with an 800’ ceiling, I couldn’t afford to overshoot the approach.</span></div>
<div><span >I eventually locked on the GS and tracked it for a while, but then fell below it for some inapparent reason. I finally broke out, still on autopilot, but a little below the GS at 1347’, 3 miles from the threshold with a terrain clearance of about 420’. Since the strip elevation is 678’, this indicates that the terrain below me when I broke out was 249’ higher than the threshold, so that the effective ceiling was just over 400’. If there were published minimums, I would have just made it for a 200’ Cat I minimum.</span></div>
<div><span >Even though I was a little below the glideslope, I turned off the autopilot, reduced my descent rate and made a good landing on the center of the runway. Whew! Film at 11.</span></div>
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7 years 3 weeks ago #14303
by jer029
Replied by jer029 on topic Yukon Excitement
Yikes Mike, that would have been a white-knuckle flight. I had a scary econ flight earlier when my AP failed to follow the back course localizer approach. I had to take it off AP and fly the CRJ700 manually in whiteout conditions to realign with the runway. Fortunately the ground was relatively level, but then the CRJ700 doesn't react to control inputs like smaller aircraft. The thought of slamming into something always crosses my mind while flying in zero-visibility, and even without the conflicting sensory inputs a real aircraft has, I still found myself having to concentrate on keeping the aircraft level with moderate inputs to keep my passengers from screaming.
On an unrelated note, but related to your earlier post on your approach to Juneau PAJN offset approach to RWY 8. I actually edited the AFCAD for PAJN to eliminate ATC from vectoring me to ILS approach to RWY26 because none existed. I also decided to watch the AI aircraft to see how they handled the offset RWY8 approach out of curiosity. For those unfamiliar with this approach, I believe the offset is due to a 588 foot hill directly aligned with a straight-in approach. To stay on a controlled descent, the ILS flight path is about 10 degrees offset of the actual runway heading to avoid the hill. This requires a 10-degree turn while at very low altitude, and right before landing. Anyway - the AI aircraft simply ignored the offset and flew a straight-in approach - flying right through the obstructing hill. Oh well, just another limitation of realism in flight-simming. Regardless - this is a really fun RNAV approach - scenic and challenging.
John<br /><br /><!-- editby --><br /><br /><em>edited by: jer029, Jan 07, 2018 - 09:32 AM</em><!-- end editby -->
On an unrelated note, but related to your earlier post on your approach to Juneau PAJN offset approach to RWY 8. I actually edited the AFCAD for PAJN to eliminate ATC from vectoring me to ILS approach to RWY26 because none existed. I also decided to watch the AI aircraft to see how they handled the offset RWY8 approach out of curiosity. For those unfamiliar with this approach, I believe the offset is due to a 588 foot hill directly aligned with a straight-in approach. To stay on a controlled descent, the ILS flight path is about 10 degrees offset of the actual runway heading to avoid the hill. This requires a 10-degree turn while at very low altitude, and right before landing. Anyway - the AI aircraft simply ignored the offset and flew a straight-in approach - flying right through the obstructing hill. Oh well, just another limitation of realism in flight-simming. Regardless - this is a really fun RNAV approach - scenic and challenging.
John<br /><br /><!-- editby --><br /><br /><em>edited by: jer029, Jan 07, 2018 - 09:32 AM</em><!-- end editby -->
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