sector altitudes
Moderators: sky's the limit, sepia, Sulako, North Shore
sector altitudes
With GPS approaches becoming more common, I would like to know which altitudes one can use. Example, sector altitude within 25nm of GPS FAF in 6000' on the GPS approach plate, however, the corresponding VOR approach plate has a sector altitude of 4300' centered on nearly the same position. Now you're flying the GPS approach but have the VOR tuned up as backup and you know your distance and position. Can you drop down to the 4300' sector and save yourself the chop and drop after your initial GPS waypoint or do you stay at the GPS safe sector of 6000'. In this particular instance the safe sector 6000' drops to 4100' after the initial approach fix, establised on course, which gives only a few miles before the second waypoint and a hard turn. It would be a substancially easier approach to fly (and easier on pax) to start from 4300' instead of 6000'. Secondly, in order to know your distance from the FAF for the 25nm safe while going direct to the initial AF, you need to take the gps unit off of the navigation page over to the enroute page to see distances. Which is safer and which is legal? Hope the situation makes sense...
To me you answered you own question.
Your doing a GPS approach as a means of primary navigation so those are the altitudes in which you use. I don't know why there is different altitudes that would be one for the experts on this stuff.
Where I fly there is numerous approaches that have ndb and gps tracks within 5 deg's of each other, and alt minimums of 200 feet difference. But if I am flying the NDB approach I am to use the NDB minimums.
Also, if you are in the middle of an approach you don't want to be looking at 2 different plates as your safety level will go down.
safety is #1.
cheers
Your doing a GPS approach as a means of primary navigation so those are the altitudes in which you use. I don't know why there is different altitudes that would be one for the experts on this stuff.
Where I fly there is numerous approaches that have ndb and gps tracks within 5 deg's of each other, and alt minimums of 200 feet difference. But if I am flying the NDB approach I am to use the NDB minimums.
Also, if you are in the middle of an approach you don't want to be looking at 2 different plates as your safety level will go down.
safety is #1.
cheers
unless you are on the airway with a lower mea/moca, you do have to stay at the 10nm safe until 25nm back. my question is once down to the lowest alt, do I pop back up because the approach I'm using says safe sector is higher up but all the other plates say the lower is safe. this question is assuming you have TC sitting beside you, not actual practice...
You can use whatever minimum altitudes you can find. 25 nm sector altitudes from different approaches, airway altitudes, whatever.
Just because the 100 nm safe for your planned approach is 10 000, doesn't mean you have to stay there until you get to 25 nm safe does it?
****
While I think I understand the sentiment "ahramin" was getting at...I would suggest that the interpretation of his comments might lead some down the wrong path. You "CAN" use whatever proper altitude that "IS" applicable......
Your safe altitude is well defined by the plate/chart you are using. Because the runway is common to two different approaches, however, do not assume that any of the altitudes are applicable to the other. There are well defined rules to navigational accuracy versus potential transgressions that, certainly are conservative but also, are there for a reason.
If you are honestly using a lower altitude of over 1000' on a GPS approach that you are taking from a VOR approach plate.....I would be a little concerned. By all means, as "ahramin" has said....there is nothing wrong.......so long as you are correct about where you are. Do you have the same navigational aid and accuracy for which the altitude was prescribed? IF NOT GET THE HELL BACK UP!
And as for the pax comfort......
Flew to Castlegar and Terrace and the like many times.....If they live in the mountains they know better than to bitch about steep descents. In fact many might know if you do something different. Of course when you find a hill in the middle of a cloud the pax opinions will mean even less than what I had to say here.
Fly well,
Gumbo
Just because the 100 nm safe for your planned approach is 10 000, doesn't mean you have to stay there until you get to 25 nm safe does it?
****
While I think I understand the sentiment "ahramin" was getting at...I would suggest that the interpretation of his comments might lead some down the wrong path. You "CAN" use whatever proper altitude that "IS" applicable......
Your safe altitude is well defined by the plate/chart you are using. Because the runway is common to two different approaches, however, do not assume that any of the altitudes are applicable to the other. There are well defined rules to navigational accuracy versus potential transgressions that, certainly are conservative but also, are there for a reason.
If you are honestly using a lower altitude of over 1000' on a GPS approach that you are taking from a VOR approach plate.....I would be a little concerned. By all means, as "ahramin" has said....there is nothing wrong.......so long as you are correct about where you are. Do you have the same navigational aid and accuracy for which the altitude was prescribed? IF NOT GET THE HELL BACK UP!
And as for the pax comfort......
Flew to Castlegar and Terrace and the like many times.....If they live in the mountains they know better than to bitch about steep descents. In fact many might know if you do something different. Of course when you find a hill in the middle of a cloud the pax opinions will mean even less than what I had to say here.
Fly well,
Gumbo
