jetracer5

The answer is flat out no you can not land 121 without certain weather being reported on the ASOS or a trained weather observer on the ground where you are landing. Better fill out a ASAP or NASA form. It can be clear in a million and you still wont be able to land. I recommend you open your FOM next time before you land without the weather and also before you ask about it on the internet.

hendefea

what 121 do you work for? Like the last post said, follow your op specs. I cant find in ASA's op specs anywhere about getting your own wind and altimeter setting. I agree with you about the approach stuff, however that is basic instrument rules. I believe this poster is talking about no asos from the begining. And for that you MUST follow Op Specs (unless emergency). I have had a couple occasions where data is missing or inaccurate and we have had to delay departure or call up someone to get the information. It sucks, but its part of all the sometimes dumb rules associated with 121 flying.
On a side note, I cant really say that i have ever actually seen a "weather observer" or heard of anyone actually using one. Are these guys left over from olden days or are they still actively used?? (I dont mean atc type folks either) Any stories anyone?

Airsupport

please re read my post. I said that you have to have a faa approved weather source to take off and be dispatched. I never said you can just take off without that information.

Twin Wasp

As has been said, read your Ops Specs.

Using a "nearby altimeter" has to in your Ops Specs on an airport by airport basis.

The landing minimums are based on Flight Visibility so the flight crew can determine that. The flight crew is not an approved source of weather data under 121.

The last job, the landing data charts had PA v temp. The job I'm furloughed from we feed the ATIS into a laptop and it won't preceed without a temp. I was also wondering how he was going to depart.

The old school observers have been pretty much replaced by AWOS/ASOS boxes. In the long run the box is cheaper, plus the WX Service gets 24 hour coverage. Their computers do better with more data so the more obs the better. I think the days of floating a ceiling balloon on your hand, removing the wood block and timing it into the clouds are gone.

subicpilot

Seems to me that you took off with a valid observation and forecast, and lacking other information, you could use the last valid observation you had to satisfy the legal requirement for landing weather. Every airline is different. Our FOM prohibits a visual approach if it is the captains first time at a particular airfield.

Someone else alluded to captains authority, and I agree. If, in the captains judgement, it was safer to land than to divert, then that's all he (or she) has to say to anyone who asks. End of discussion. That's why we get paid the big bucks! Safe, legal, reliable. In that order.

rickair7777

The obvious potential problem is that you don't know what the winds are, so you could possibly exceed tailwind/xwind limits.

I agree that it is probably a technical violation unless your FOM says otherwise.

joepilot

At an airport with a part time tower, my company uses one or more ramp workers, who have been trained, as official weather observers. If we are late and the tower is closed, they radio us the weather on company frequency. Not a frequent occurance, but it does happen.

Joe

kronan

Reading poweful1's clipping from the FAR makes me wonder what the FAA would consider the "latest" weather? The last obs I received would seem to be valid to shoot an IFR approach w/out any additional information. After all, I should have a forecast indicating the worst case weather for a specific period. And, as a pilot, I should at least have a glimmer of an idea whether I think that forecast is valid or simply a WAG.

And, as was mentioned, even if I have an ob that says the vis is good, if I get to mins and don't agree that the vis meets the requirements for the approach I'm going around. And, the opposite is true as well. If I get a below mins ob and I continue to mins and feel that the vis is meets that required for the approach, I'm landing

deadstick35

+1

We had the official observer out at 1am on several occasions when we were delayed and the ASOS was down. Gotta have it.

kronan

And if I was NORDO, what would I do?
If it was severe clear, I'd land.
If it was cloudy, I'd shoot the approach and try and land?

I haven't read any FAR that indicates that the latest weather obs must be hourly. And, I have landed at several airports with ATIS 2-4 hours old.

I can't depart without knowing the current obs and forecast, so, I just don't think diverting on a severe clear day is the appropriate response in general.
At FedEx, we'd be on the carpet tap-dancing if we diverted in this situation.