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Well-known member
Feb 7, 2002
Have seen this done a couple of times at my company and question if it is legal. Flight is released as a part 91 flight from airport A to B with C as the alternate (wx at C meets the 1,2,3 rule). Wx at A is at min's. PIC informs pax's in the advent of a missed approach at B, what airport would you prefer to go to. Of course pax's tell PIC airport D which is close to A and has wx better than A, but the wx is still much less than 2000/3. PIC receives wx/notams via AFIS msg for D. What do you all think? Safe? Legal? What if we had been released as 135? Thanks for the help.
First off, the 1,2,3 rule that you refer to is criteria for determing the need for a destinatiion alternate, not the minimums required for the alternate. IOW unless the wx at your destination airport is forecast to be more than 2000/3 for an hour before to an hour after your eta, you need an alternate. Standard alternate mins are 600/2 or 800/2 depending upon the approaches available. Most 121 and 135 operators derive alternate minimums from a table in their ops specs. I don't think there is a problem, legality wise, changing the alternate from C to D as long as, if required, you can show that upon departure from A you met the fuel requirements. Is it safe or smart? Maybe, maybe not. Just how low is the wx at D and how do you rate your chances of getting in based on the approach expected? What was your actual fuel remaining once on the ground at D? Does your company recommend or do you have a personal minimum arrival fuel?
Your question is a little confusing but I'm assuming the PIC is asking the pax this question after they are already in the air. Once airborne, your filed alternate doesn't mean a darn thing. It is there for legality purposes. You can choose to fly to any "alternate" airport you want after you depart.

As Trainerjet pointed out, it seems you have your alternate requirements a little mixed up. If *B* is doesn't meet the 1-1-2-3 requirement you must list an alternate. The alternate, *C*, must be forcast to be better than 600' and 2 miles if it has an ILS, or 800 and 2 miles if it has a non- precision approach.

Is this legal? Absolutely, you have filed a legal alternate, C, and presumably have sufficient fuel. All the legal requirements are met. Nothing says you MUST go to C if you go missed at B. In the air, you do what makes the most sense based on the current situation and the current observed Wx.

Is this safe? Probably. D may not meet the requrements for an alternate, but it may be plenty safe to shoot an approach. Remember, D wasn't used as an alternate because it was *forcast* to be below 600/2 or 800/2 as required. An ILS with a 600 foot ceiling is a pretty safe bet, and besides, that was the forecast Wx, the actual Wx at D may be better after you go missed at B. The only time I would question the saftey of this, would be if D was really on it's butt, and you had little chance of getting in there legally, or if you were close on fuel and shooting an approach at D was compromising your ability to continue safely to C.

Sorry, had a major brain fart. I meant to say 600/2 and 800/2 vice 1,2,3. Thanks for the imput.

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