If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Crossing a stepdown fix high
Is there any problem with controllers or examiners if I cross a stepdown fix
several hundred feet above the depicted altitude? I believe that, legally, I can be at any altitude above the crossing minimum, but would this be a bust of the PTS +/-100 tolerance, or cause a problem for ATC? For example, take the SEA VOR 34L/R approach. Assume you are cleared for the approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT - 6.7nm - 1600 at DONDO, which is the last fix before descent to the MDA. I can set up a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and avoid even thinking about a level-off by crossing MILLT something above 3200ft. Would that be a checkride ding? -- David Brooks |
#2
|
|||
|
|||
When I was an examiner, I would have expected you to fly the approach
profile as published. Once upon a time I decided to forego the "descent and maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would stay at 3000 and intercept the glideslope high....got chided by Seattle Approach for doing so. Over the years I have learned that ATC expects you to do the expected. Bob Gardner "David Brooks" wrote in message ... Is there any problem with controllers or examiners if I cross a stepdown fix several hundred feet above the depicted altitude? I believe that, legally, I can be at any altitude above the crossing minimum, but would this be a bust of the PTS +/-100 tolerance, or cause a problem for ATC? For example, take the SEA VOR 34L/R approach. Assume you are cleared for the approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT - 6.7nm - 1600 at DONDO, which is the last fix before descent to the MDA. I can set up a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and avoid even thinking about a level-off by crossing MILLT something above 3200ft. Would that be a checkride ding? -- David Brooks |
#3
|
|||
|
|||
David Brooks wrote:
Is there any problem with controllers or examiners if I cross a stepdown fix several hundred feet above the depicted altitude? I doubt a controller would even notice (or care). The examiner probably will, and might ding you on it if you didn't explain why you were high. It sounds like you've got a perfectly good plan, however, and I suspect most examiners would be impressed with the level of pre-flight planning you put into this if you explained it ahead of time. The last thing you want to do on a checkride is do something unusual without explanation -- that leaves the examiner to come up with his own explanation, and it might just be that you're behind the airplane. On the other hand, don't just cross fixes high for no good reason. Depending on the approach, if you don't keep up (down?) with the step-down fixes, you may find yourself having to divebomb at the end to reach the MDA before you reach the MAP. I don't have a chart of the approach you're talking about, but the way you describe it, it sounds like you've already thought about that. I believe that, legally, I can be at any altitude above the crossing minimum, but would this be a bust of the PTS +/-100 tolerance, or cause a problem for ATC? For example, take the SEA VOR 34L/R approach. Assume you are cleared for the approach at 5000ft. Profile is 5000 at FACTS - 6nm - 3000 at MILLT - 6.7nm - 1600 at DONDO, which is the last fix before descent to the MDA. I can set up a nice smooth descent at 300fpnm, arrive at 1600ft well before DONDO, and avoid even thinking about a level-off by crossing MILLT something above 3200ft. Would that be a checkride ding? |
#4
|
|||
|
|||
"David Brooks" writes:
Is there any problem with controllers or examiners if I cross a stepdown fix several hundred feet above the depicted altitude? I believe that, legally, I can be at any altitude above the crossing minimum, but would this be a bust of the PTS +/-100 tolerance, or cause a problem for ATC? There's an interesting article from a 1998 Transport Canada newsletter called "CFIT - Why are aircraft flying at minimum IFR altitudes?": http://www.tc.gc.ca/civilaviation/an...rna/new198.htm One of the major recommendations is that the only time a pilot should fly at (rather than above) a minimum IFR altitude is MDA when weather conditions require; otherwise, leave a healthy safety margin. Of course, you'll have a hard time convincing a flight test examiner of this, but in real life, it makes sense to me -- my plane is a lot slower and can descend at a lot steeper angle than a big airliner, so I don't need a long, shallow approach slope anyway. Besides, ATC doesn't always know what approach you're flying anyway. Are you on the ILS 25, the LOC 25, the LOC/DME 25, the NDB 25, the NDB/DME 25, or the GPS 25? In my (so-far limited) experience, sometimes they mention a specific approach and sometimes they do not. All the best, David |
#5
|
|||
|
|||
"Bob Gardner" writes:
When I was an examiner, I would have expected you to fly the approach profile as published. Once upon a time I decided to forego the "descent and maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would stay at 3000 and intercept the glideslope high....got chided by Seattle Approach for doing so. But in that case, if I understand correctly, you had a specific instruction from ATC to descend to 2200 -- that's different from step-down altitudes in a published IAP. All the best, David |
#6
|
|||
|
|||
In a previous article, David Megginson said:
One of the major recommendations is that the only time a pilot should fly at (rather than above) a minimum IFR altitude is MDA when weather conditions require; otherwise, leave a healthy safety margin. Of course, you'll have a hard time convincing a flight test examiner of this, but in real life, it makes sense to me -- my plane is a lot slower and can descend at a lot steeper angle than a big airliner, so I don't need a long, shallow approach slope anyway. I don't know if this would be considered "a healthy safety margin", but my examiner said the same thing that my instructor did - that the PTS says +100 feet/-0 feet, so you should always fly 50 feet high to give yourself a bit of a buffer. -- Paul Tomblin http://xcski.com/blogs/pt/ Pascal - A programming language named after a man who would turn over in his grave if he knew about it. |
#7
|
|||
|
|||
I didn't say it was a smart move (:-).
Bob "David Megginson" wrote in message ... "Bob Gardner" writes: When I was an examiner, I would have expected you to fly the approach profile as published. Once upon a time I decided to forego the "descent and maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would stay at 3000 and intercept the glideslope high....got chided by Seattle Approach for doing so. But in that case, if I understand correctly, you had a specific instruction from ATC to descend to 2200 -- that's different from step-down altitudes in a published IAP. All the best, David |
#8
|
|||
|
|||
"Roy Smith" wrote in message
... The examiner probably will, and might ding you on it if you didn't explain why you were high. It sounds like you've got a perfectly good plan, however, and I suspect most examiners would be impressed with the level of pre-flight planning you put into this if you explained it ahead of time. Let me guess. Rather than preflight planning, this question sprouted from repeated attempts to pass the instrument check ride in Microsoft's Flight Simulator! Know this approach well. Must've flown in a hundred times trying to pass that stupid "check ride". If you're flying the approach IRL, my apologies for kidding around. -Scott |
#9
|
|||
|
|||
On Thu, 16 Oct 2003 20:13:36 GMT, "Bob Gardner" wrote:
When I was an examiner, I would have expected you to fly the approach profile as published. Once upon a time I decided to forego the "descent and maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would stay at 3000 and intercept the glideslope high....got chided by Seattle Approach for doing so. Over the years I have learned that ATC expects you to do the expected. Bob, Here at the other end of the country, I routinely stay at my assigned altitude until intercepting the GP. ATC doesn't care, nor does an FAA examiner with whom I've ridden several times. HOWEVER, my clearance is NOT descend and maintain 2200' ... Rather, I might be at 3000', and my clearance might be something like "maintain at or above 1800' until established; cleared for the ILS 14 approach". If I received a clearance that said "descend and maintain 2200', cleared for the approach" I would treat that as an altitude assignment, and descend to 2200' expeditiously. Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA) |
#10
|
|||
|
|||
Bob Gardner wrote: When I was an examiner, I would have expected you to fly the approach profile as published. Once upon a time I decided to forego the "descent and maintain 2200 feet" on the way in to BFI's ILS 13R, thinking that I would stay at 3000 and intercept the glideslope high....got chided by Seattle Approach for doing so. Over the years I have learned that ATC expects you to do the expected. The industry has worked hard to get away from dive-and-drive. A constant descent profile is a lot safer, provided it doesn't bust a stepdown. If a stepdown is mandatory it will so state on the Jepp chart, and have a line above, as well below, the altitude on the NACO chart. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
High Price of Flying Wires? | PWK | Home Built | 34 | October 8th 17 08:24 PM |
Fwd: [BD4] Source of HIGH CHTs on O-320 and O-360 FOUND! | Bruce A. Frank | Home Built | 1 | July 4th 04 07:28 PM |
high impedance, low impedance? | JFLEISC | Home Built | 5 | April 11th 04 06:53 AM |
MT. DIABLO HIGH SCHOOL CONCORD, CA PHOTOS | MT. DIABLO HIGH SCHOOL PHOTOS | Home Built | 1 | October 13th 03 03:35 AM |
High performance homebuilt in the UK | NigelPocock | Home Built | 0 | August 18th 03 08:35 PM |