Releasing an Aircraft IFR on a METAR?

Rober2ca

New Member
All,

The way I read FAR121.613 is; appropriate weather reports OR Forecasts, OR any combination thereof.

So the question is the TAF is showing below legal MINS, however the flight is 40 mins and the latest observation is showing weather above WX mins.

Is it allowed to dispatch on a METAR
 

Spatchman

Well-Known Member
TAF still applies

"Any combination thereof" implies that both are controlling...

Cannot dispatch...

A good general rule of thumb in aviation to keep in mind is: nothing can help you, anything can hurt you.

Always dispatch on the side of conservatism.
 
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Rober2ca

New Member
That's the approach I mostly take. If i'm not sure I'll always go conservative.

That being said, I have been getting conflicting reports from Management and more experience dispatchers.

If no TAF is available then does the METAR become controlling?
 

who'swho

Don't hesitate. Penetrate!
TAF still applies

"Any combination thereof" implies that both are controlling...

Cannot dispatch...

A good general rule of thumb in aviation to keep in mind is: nothing can help you, anything can hurt you.

Always dispatch on the side of conservatism.
Don't ignore the "or" part. You can legally dispatch in the scenario in question. Is it a good idea? I wouldn't unless the wx is trending up and the TAF is clearly a "blown " TAF. Better make sure you have a solid alternate as well.

I'm definitely not a fan of Sheffield but I came across this article that I thought was pretty interesting. The part about different FAA inspectors having different opinions caught my eye as well.
 

948Heavy

Well-Known Member
Of course you can release a flight on a METAR! A perfect example is a weather redispatch where the point of redispatch is one hour from your final and intended destination. If the TAF is below mins you can release the flight based on the METAR (only if it is above mins). When you fly to places that have 24 or 18 hour TEMPOS, a weather redispatch is sometimes a crafty way you can get in to an airport. During a weather redispatch, you are releasing a flight to the initial airport first then during the redispatch window do you ascertain whether the flight can be released to its final destination. You present your analysis to the crew and the final discision rests with the Captain if he/she thinks it is safe and legal to do so or face going to the initial airport listed on the flight plan.
 

McCrosky

Well-Known Member
I have in previous lives used a METAR to move a flight on a short hop when the TAF was below mins. AT that time, it was pretty much standard ops. The carrier was supplemental, did not cat CAT 2/3 authorizations, or exemption 3585 (or whatever they call it now). It was usually a situation where the METAR was 3/4 SM and had been for a while but the TAF had a TEMPO 1/4SM in there. 121.613 is full of OR's I've always read it as OR as defined by the english language. IN that only one of those situations must be satisfied for dispatch.

In other words. You can drink a Guinness or a Harp, or any combination thereof. Doesn't mean you always need to drink a Black and Tan.

Conversely, if you have a legal TAF and trends of observations below mins for a 30 minute flight can you launch? Sure. Should you?? Opinions vary.... usually based on the level of management that opinion comes from.

Currently, my carrier has a policy not to dispatch using a METAR in leiu of a valid, legal TAF. But we have about 5 ways to get around a non legal TAF so it's usually no big deal.
 
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Rober2ca

New Member
I'm just trying to find the FAR's, mostly what i'm getting is interpretation. I have release a 30 min flight on a METAR after discussing it with the PIC and my Supervisor. The question has came up again, and i'm just trying to find the reference.
 

Spatchman

Well-Known Member
Don't ignore the "or" part. You can legally dispatch in the scenario in question.
Perhaps it comes down to Airline policy...

At my airline, if the TAF is below minimums, we can't dispatch period. Doesn't matter if the METAR is legal and it also doesn't matter if the flight is less than an hour...

The situation in question occurs often at my airline... especially our DEN-ASE flights.

We are expected to request a WSI RAM TAF (a second opinion on the TAF) and dispatch with a new legal forecast that better matches the current METAR

The way that I understand the FAR, is that ANY combination of weather that is currently available is controlling as to whether or not a flight can operate legally.

That being said, I understand your point, and agree that the language of the FAR leaves it open to interpretation... moreover, I am also now thirsty for a Black and Tan...
 

lionrock

Well-Known Member
When strictly analyzing 121.613, it is possible to argue that you can legally dispatch using either a METAR or a TAF, or both. However, a certificate holder dispatching under Part 121 is also bound by other regulations in that part. Using the combination of Sections 121.101, 121.599, and 121.601, one can come to the conclusion that it is indeed required to consider both the report AND the forecast weather conditions in order to dispatch and/or operate a flight.

I guess theoretically, you can still argue that a sole-source weather report (not forecast) is enough to satisfy 121.613 as long as you go by the same logic to satisfy the other 121 Sections I listed above. However as a dispatcher, would you really want to be put in this position especially in front of an investigative panel? I personally would not.

But as others above have said, most 121 Certificate Holders have different exemptions and authorizations to still be able to dispatch in "poor" weather conditions that such dissection of the regulations is usually not necessary.
 

Rober2ca

New Member
I told my supervisor, the Capt. and I were not comfortable releasing the fight until a better forecast came out.
Just trying to argue it wasn't an unnecessary delay.
 

who'swho

Don't hesitate. Penetrate!
I told my supervisor, the Capt. and I were not comfortable releasing the fight until a better forecast came out.
Just trying to argue it wasn't an unnecessary delay.
At the end of the day using your judgement to make the call to wait is why we don't have computers doing our jobs. Standing your ground isn't always easy.
 

4EngineETOPS

Well-Known Member
I would assume your manuals would have a section concerning dispatch using a METAR. I rarely release flights that are under an hour, but in the event that a short ferry/repositioning flight were to occur, there is a section in my company's dispatch manual and GOM in reference to releasing based on a METAR.

Essentially, we are allowed to release the flight using the latest METAR observation, provided that the METAR in question is legal and recent observations show a positive, legal trend. In practice, I would combine this with an EWINS forecast if I were to consider releasing at all. The only way I would consider releasing on a METAR would be with a TAF that is obviously inaccurate, taking into account all available legal weather sources. While the release would be based on the METAR, I would also take recent RVR trends, observations/forecasts at nearby airports, and other pertinent information into account (I understand the RVR readings that dispatch can see are not legal weather for release purposes, but it is valuable reference information). Even with all that said, I can't think of a scenario in which I wouldn't just order an EWINS forecast and release the flight under A010 instead of playing with fire and releasing under a METAR. The dynamics are probably different at a regional airline, but that is my thought process.

What it comes down to is what most everyone else has said: it can be interpreted to be legal (and may even have a process in the GOM/FOM/dispatch manual), but there are almost always better alternatives.
 

bbmikej

Well-Known Member
At my shop it actually states in the DPM that you can dispatch a flight on metar alone with an illegal TAF if the metar is above mins and the flight is less than an hour enroute.
 

Mainline_or_bust

Airplanes fly on PFM, Change my mind
If your airline doesn’t reference it anywhere in the FOM then you should legally and safely be able to dispatch based on the METAR IMO considering:

1) Current METAR is legal.
2) You have reason to believe that it’s not a mistake/fluke, as in for whatever reason 53 after the hour the visibility came up to 1/2SM for all of 75 seconds.
3) Supporting information such as ASOS or multiple METARs are legal.
4) The TAF is trending legal and not 28 hours from now.
5) Temp/Dew aren’t the same with calm winds.
6) Your alternate is rock solid, no where near alternate minimums.

In a nutshell, somebody hands you a Black and Tan with a smirk and says “you should drink this”. Be smart about it, see the whole picture and make sure that it’s Harp and not chilled piss.
 

Crop Duster

E pluribus unum
In other words. You can drink a Guinness or a Harp, or any combination thereof. Doesn't mean you always need to drink a Black and Tan.

Conversely, if you have a legal TAF and trends of observations below mins for a 30 minute flight can you launch? Sure. Should you?? Opinions vary.... usually based on the level of management that opinion comes from.
Tasty analogy, but I think @Spatchman's analysis is the one to go with. In other words, if Harp OR Guinness, OR any combination thereof results in a dark beer in the glass, then you can't drink either. If you're 91, life is easier 'cause you can just skip the glass and drink and never need see if the beer is dark or light. :)
 

noalternate

Well-Known Member
At my last airline, there was no official policy for releasing a flight based on a METAR only, but there was an un-written rule against doing it. At my most recent airline, our FOM spells out that for flights under 1 hour both TAF and METAR are controlling. But like others have said, if the METAR is well above forecast you have good grounds to order an EWINS TAF.
 

QXDX

Well-Known Member
All,

The way I read FAR121.613 is; appropriate weather reports OR Forecasts, OR any combination thereof.

So the question is the TAF is showing below legal MINS, however the flight is 40 mins and the latest observation is showing weather above WX mins.

Is it allowed to dispatch on a METAR
I've no idea on the legal question, but on the practical question, consider that a METAR is only valid until the next one comes out. What happens if a SPECI comes out 20 minutes into the flight.

In the absence of clear, unambiguous guidance, consider what you would say to the FAA if they asked why you did it. If you can't answer the question, you probably ought not be doing it.
 

McCrosky

Well-Known Member
The situation in question occurs often at my airline... especially our DEN-ASE flights.

We are expected to request a WSI RAM TAF (a second opinion on the TAF) and dispatch with a new legal forecast that better matches the current METAR
We have a policy against doing that. Unless you can show the Government TAF is unavailable or unreliable, we can’t get a RAMTAF..or “shop for a legal forecast”. There was a time we’d call the weather god Kavoris and he’d always give us mins for dispatch. Placed who like to use the 24 hour tempo tend to get this treatment (I’m looking at you former Soviet Union).

I've no idea on the legal question, but on the practical question, consider that a METAR is only valid until the next one comes out. What happens if a SPECI comes out 20 minutes into the flight.
.
What do you do if the TAF amends on flight? Same same.
 
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