Alternate Minimums 91.169

[Jester119]

I am about to go for my CFII ride and just have a question concerning the reg on alt min. I know about the 1-2-3 rule and then the 600-2 , 800-2. For example you had to file an alt b/c the weather was below the 2000ft, so you file an alternate. Once you fly to the first airport an were unable to land there so you fly to the alternate airport. I am sort of confussed with when you can start your decent to that aiport or what mins to follow at the alt airport for landing if anyone has any good place that explains it very well or could explain I would be thankful.

 

[vclean]

600-2 & 800-2 are only used to determine if an airport can be filed as an alternate, otherwise the charted minimums for the alternate (ie. 200 - 1/2) are used to fly the approach.

 

[EDUC8-or]

The WX can be above the 1-2-3 rule and you still may have to file an alternate. For example, if you file (EDIT, I said fly instead of file earlier) to an airport without an instrument approach you will still need the alternate, even if there isn't a cloud in the sky and visibility is unlimited.

Also, the 600-2 and 800-2 should be used only after you have checked to see if there are separate alternate minimums. They can be found in the index in the front of NOS/NACO plates, I haven't used Jepps in a while so I can't help out there. Also, lots of airports cannot be used as an alternate. In the NACO charts it will say A/NA in bold print on top left of the plate. For an airport to be used as an alternate there must be a weather observer present or the AWOS/ASOS must be monitored as well as the navaid that is providing guidance for the approach. Usually this leaves controlled fields for your alternates because there is a weather observer present.

If the weather is really bad at your original destination ATC will usually ask what you want to do in case you have to go missed or they will give instructions because they know the WX is crappy. If you have to proceed to your alternate, they will vector you for the approach at your next airport. They will descend you to their MVA, and if that is below the clouds and you call airport in sight you might be cleared for the visual. If you can't get out of the clouds they will vector you for the approach in use, or if they're really nice and not busy let you choose your approach. As stated before, you will use the minimums for the approach you are going to shoot.

Long answer to a short question that was answered in the above post. Good luck on your ride!

 

[pilotman2105]

For example, if you fly to an airport without an instrument approach you will still need the alternate, even if there isn't a cloud in the sky and visibility is unlimited.

???

Where are you getting this from?

 

[vossdr1]

see pt 91.139

 

[EDUC8-or]

???

Where are you getting this from?

91.169 (a)(2) Except as provided in paragraph (b) of this section, an alerternate airport.
(b) paragraph (a)(2) does not apply if:
(1) Part 97 of this chapter prescribes a standard instrument approach procedure to, or a special instrument approach procedure has been issued by the Administrator to the operator for, the first airport of intended landing; AND
(2) Appropriate weather reports or weather forecasts, or a combination of them, indicate the following:

As I interpret this, there must be an approach AND the WX must be above the 1-2-3 rule to leave the alternate field in your flight plan blank. Correct me if I'm wrong, I have been before. Just don't tell my wife!

 

[pilotyip]

Alternate mins for filing only

Are for filing purposes only, once you are airborne any airport is a destination and any approach anywhere can be shot if the weather is above minimums. If you miss at your destination say YIP (Willow Run) and LAN (Lansing), 45 miles away is your filed alternate. Weather a DTW (Detroit) 6 miles away is above minimums, you do not have to go to LAN, you can request to go to DTW, you do not have to go to LAN. Assuming no lost comm etc.

 

[pilotman2105]

Learning new things

91.169 (a)(2) Except as provided in paragraph (b) of this section, an alerternate airport.
(b) paragraph (a)(2) does not apply if:
(1) Part 97 of this chapter prescribes a standard instrument approach procedure to, or a special instrument approach procedure has been issued by the Administrator to the operator for, the first airport of intended landing; AND
(2) Appropriate weather reports or weather forecasts, or a combination of them, indicate the following:

As I interpret this, there must be an approach AND the WX must be above the 1-2-3 rule to leave the alternate field in your flight plan blank. Correct me if I'm wrong, I have been before. Just don't tell my wife!

Good call. Learn something new every day. I thought that you could file anything as a destination, and unless the 1-2-3 rules was not met, you did not have to file an alternate.

Thanks!

 

[philo beddoe]

To clarify a point for any newer IFR pilots here, Ceiling is ONLY a controlling value for FILING an alternate.

Once you divert to your filed alternate or anywhere else, charted VISIBILITY is the only controlling number as to whether you can descend below dh/mda and land.

Some approaches are not usable for filing for alternate as well.

For instance: Suppose your alternate has an ILS and a GPS approach.

The ILS has non-standard alternate minimums of
700-2 1/2.

The GPS approach is NA for alternate purposes.

You may file this airport as an alternate if you have the forecast ceiling and visibility, AND if the ILS is operational.

IF you divert to the alternate, you may fly the GPS approach if it suits you. You just can't file based on it.

Wait until 135/121 indoc. It gets worse.
One-approach rule, two-approach rule, 3585 conditional language exemption, marginal weather definition, second alternates, runway 'suitability'. Whew!

 

[minitour]

...
Wait until 135/121 indoc. It gets worse.
One-approach rule, two-approach rule, 3585 conditional language exemption, marginal weather definition, second alternates, runway 'suitability'. Whew!

WTF
Are you F*cking serious!?!?!?!

I keep asking myself why they have all these different minimums...why not just teach everyone the same minimums from the get-go?

-mini