I'll bet this has been asked before

[HAL]

avbug,

Thanks for all the info. I think it answers my questions, but I'm still left with just a little nagging doubt about a really short flight where you know (or can even see) that the weather is fine, even though the forecast calls for below minimums - and the question is - can you launch? I'm still a little confused since the FAR says the 'current observations or forecasts or any combination of them' for the ETA. Just wondering about how long the current observation is good for since the FAR says you may use that in the decision making process.

As for my attitude about flying 135, I was taken a little aback by your comment. Yes, I am certainly greatful that I have a flying job and am able to stay current. Most of my friends that are furloughed from Hawaiian are not flying. And anyone who knows me knows that the last thing I would want to do is denigrate any branch of aviation or the people who work there. Flying in Alaska is more fun and challenging than I ever did at Hawaiian, and the scenery is unsurpassed. The 'furloughed back to 135' comment was concerning the 50% cut in pay, bad weather, lack of jumpseat priviliges (while my family is 1300 miles away), and other things I deal with here that I didn't have to at Hawaiian. For four months after the furlough and before coming up here I was flight instructing, and loved every minute of it, even though the pay was far less than the 135 job. I had no complaints then.

I'm sorry if I offended anyone with that comment. I certainly didn't mean it.

HAL

 

[avbug]

Hal,

Not at all. I didn't intend to be judgemental, only to query. All too often I meet folks who have the "props are for boats" attitude, and it irks me. Obviously that doesn't apply to you.

If you're on a very short flight, and current weather reports show the destination being open, then it's probably doable. If the weather is questionable at all, however, then you're going to have a hard time justifying launching.

The FAA has interpreted the regulation to mean that even the suggestion that the weather might occasionally be below minimimums is enough to prevent the launch, when the weather speaks to the estimated time of arrival. If you're going to take off and be there in five minutes, and can see the airport, and see that it's clear, and the current weather advises so, that's a different matter. An official weather forecast for the ETA stating otherwise, however, is the show stopper.

From a practical point of view, of course, if the weather is questionable or forecast to be below minimums, is there any reason that one should launch?

A current weather report is valid for the time it's reported, only. It doesn't imply weather in the future; the forecast is for that. We've all seen weather that's well below minimums jump up to VFR in short period. Sometimes it's frost on a transmissiometer, or celiometer, other times it's really the weather changing that fast. Other times, we've all seen the weather drop and change suddenly. All we can go by is the forecast, and the FAA has determined that if the forecast even hints that the weather may be below minimums, we can't go.

 

[HAL]

avbug,

Thanks again for the info. The whole subject came up because the forecasts here in northern Alaska are notoriously inaccurate. If the flight is more than an hour away, even if the current conditions are clear I understand the restriction on launching the flight. However since some of our flights are less than an hour, and the FAR 135.219 states that you can use the current conditions or forecast or any combiation (emphasis added) to decide whether to go, there has been a lively debate among our pilot group as to whether (and when) you can use the current AWOS report to supercede the TAF.

Thanks again for the input. Your responses will be printed out and I'm sure will add a lot to the ongoing discussion.

HAL

 

[avbug]

Strictly interpreted, consider a current weather report as being valid for the exact time of issuance, backward...in other words, it carries no weight for the purposes of forecasting. If you hold a TAF or other forecast that indicates weather below minimums for the ETA, even if it just hints at it, it outweighs any actual report you have in hand.

When the regulation was written (and this is discussed in the legal interpretations and letters), the intent was to prevent launching if a forecast even suggests weather will be below minimums. As the forecast applies to ETA and a weather report does not, the forecast takes precedence, and outweights any current report.

Another interpretation which I did not post, regards company reports. In that case, an aircraft that was equipped for known ice departed into conditions of forecast ice. When no ice was encountered, a radio report was made to the company. Company aircraft not equipped for flight into known ice were then launched, and encountered ice. The Chief Legal Counsel noted that the report by the company aircraft that ice was not encountered was not an official weather report, and did not serve to help the case of the other aircraft that launched into those conditions.

This has applicability in this case, with respect to unofficial reports. For the purpose of forecasting, a weather report (hourly SA, METAR, Tower observation, etc) does not take the place of a forecast, nor can it be substituted, because it is not a forecast. It is valid only for the exact moment it's issued, and doesn't presume to know the future. A company report is also unofficial, and cannot be used.

Only an official weather forecast will serve for future use, such as in the case of an ETA.

Where the regulation identifies any combination of forecasts and reports, it doesn't imply that one can pick and choose which ones to use, and which ones not to use. In other words, if weather reports (METAR) indicates weather above minimums at 0900, and your ETA is 1000, and the TAF shows weather below minimums at 1000...you may not use the METAR because it appears more favorable. The fact is that information exists from an official source that shows the weather may be below minimums, and that is all that is sufficient to establish the inability to launch due to 135.

The third legal interpretation above (July 18, 1984) establishes that forecasts overrule hourly sequence reports when the forecast shows the potential for weather to be below minimums, but the hourly reports show it presently above minimums. Again, the hourly reports do not speak to the future, where a forecast does, and takes precedence.

Conversely, the July 18 interpretation also stipulates that where an hourly report may show weather below minimums, a forecast showing it above minimums is sufficient to permit release by dispatch.

 

[HAL]

avbug,

I've read the documents you posted again, and I agree that the forecast supercedes the observation. But my biggest problem is why then does the FAA list 'observation or forecast' as how to decide. Why don't they just say 'Forecast' and be done with it, instead of muddying the waters by keeping the 'observation' in there?

Sometimes you just gotta love those government regulation writers.

HAL

 

[cubpilot]

Celing vs vis

Check your op specs you will likely see that destination ceiling (& vis) are both controlling to depart and to begin the final approach. Note also if the captain has less than 100 hours PIC, his and your minimums are razed by 100 and ½ mi.

 

[avbug]

You have OpSpecs showing ceiling being controlling??

 

[HAL]

cubpilot;

Which section of your opspecs list ceiling as controlling? I've been through my current (135) and Hawaiian (121) opspecs and can't find anywhere that lists it that way.

HAL

 

[cubpilot]

I flew for a regional airline from 1985 to 1989. I do remember ceilings counting for the weather at destination, in the decisions you make, prior to takeoff and before beginning the final, but not at MDA or DH. If I can find my old op specs I’ll look it up. Some of these other posts were about FAA interpretations; maybe we had a FAA interpretation that made it so for us. You do what yours says, if its not in there its not in there. You had a captain telling you that ceiling counted. Ask for some instruction on how to find the citation. What does your Chief Pilot say? Other Captains?

 

[avbug]

Visibility is controlling. Specifically, where available, the TDZ visibility is controlling. Ceiling is not controlling. However, where ceiling lies below minimums, one may not reasonably be expected to obtain the adequate visibility for the approach, and will provide a limiting factor. It is not controlling.

In the legal interpretation below, David L. Bennet provides insight into the concept of what is controlling. This statement does not specifically provide direction on a Part 135 operation. However, the letter is applicable in general.

March 10, 1986

Mr. Larry K. Johnson

Dear Mr. Johnson:
This is in response to your letter of February 6 requesting an interpretation of Federal Aviation Regulation (FAR) Part 91, Section 91.116.

Specifically, you request clarification of the term "flight visibility" in connection with the requirement in FAR 91.116(c) that an aircraft not be operated below a published decision height or minimum descent altitude if the flight visibility is less than the visibility prescribed in the standard instrument approach procedure being used. The question arises as to whether descent below the DH or MDA can be made when the runway visual range (RVR) is reported at less than the published minimum RVR for the approach but the flight visibility is greater than that minimum.

The flight visibility is controlling. If the flight visibility exceeds the published minimum for the approach, than the pilot may proceed as long as the other requirements of paragraph 91.116(c) are met regardless of the reported RVR. The National Transportation Safety Board (NTSB) has upheld this interpretation in several enforcement cases. However, the pilot's judgment of flight visibility is not necessarily conclusive if there is a question as to the actual flight visibility conditions at the time of the approach. Reported visibility and other evidence of record may be considered by the Federal Aviation Administration and the NTSB in determining the actual flight visibility.

Enforcement action would be taken only in those cases in which the pilot could not reasonably conclude that flight visibility was at or above approach minimums, but the pilot nevertheless proceeded to land or descent below DH or MDA.

Sincerely,

David L. Bennett
Manager, Airspace and Air Traffic Law Branch
Regulations and Enforcement Division

 

[cubpilot]

Part 91 is not the issue. Part 91 operations can depart in any weather which allows them to land somewhere.

Once on the final approach Part 121 & 135 are like part 91 in that “flight visibility” determines if you can continue to a landing.

The issue is before takeoff (and before beginning the final approach) reported weather is the controlling factor. Is it visibility alone or does the ceiling apply too.

That said, maybe it is only visibility. I can’t find personally anything that proves otherwise. Someone else did post an interpretation that indicated both must be considered. I’d like to hear from some 121/ 135 drivers about how their companies apply this rule. It was a long time ago so I can’t remember how, but I believe I lost a similar argument in which I claimed the other side, back when I flew under part 135. Our company used both for the “reported weather” requirements.

 

[Deltoid]

Try and look at the difference between 135 & 121.


Here is the excerpt from 121.===>

(b) Except as provided in paragraph (d) of this section, no pilot may continue an approach past the final approach fix, or where a final approach fix is not used, begin the final approach segment of an instrument approach procedure -
(1) At any airport, unless the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, issues a weather report for that airport; and
(2) At airports within the United States and its territories or at U.S. military airports, unless the latest weather report for that airport issued by the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, reports the visibility to be equal to or more than the visibility minimums prescribed for that procedure. For the purpose of this section, the term "U.S. military airports" means airports in foreign countries where flight operations are under the control of U.S. military authority.

Notice 121 is verify specific as to the requirement of visiblity only...
Now look at 135====>


§ 135.225 IFR: Takeoff, approach and landing minimums.
{New-2003-21 (a) revised September 17, 2003, effective November 17, 2003}
(a) Except to the extent permitted by paragraph (b) of this section, no pilot may begin an instrument approach procedure to an airport unless--
(1) That airport has a weather reporting facility operated by the U.S. National Weather Service, a source approved by U.S. National Weather Service, or a source approved by the Administrator; and
(2) The latest weather report issued by that weather reporting facility indicates that weather conditions are at or above the authorized IFR landing minimums for that airport.

It says nothing about visiblity. But what it does say is minmums. Minimums is plural, meaning more than one, ceiling and visibility. When the FAA means visibility they will say it just as they do for 121. Furthermore there are interpretations on this issue for 135 and they are very clear as to the FAA's intent. So in a nut shell both are required for 135. I have been a check airmen and chief pilot for a 135 jet and turboprop company and have dealt with this issue enough times and have had my guys abide by the interpretation. Now that I have been flying 121 for years I could see how needing both would kill the 121 industry for getting to destinations.

Here is the interpretation from washington enforcement.

March 21, 1991
Mr. Glenn Rizner
Technical Specialist, Membership Services Department
Aircraft Owners and Pilots Association
Frederick, MD 21701-4798

Dear Mr. Rizner:

We recently received a letter from the Assistant Chief Counsel for the Eastern Region of the Federal Aviation Administration asking us to give a legal interpretation of a question you posed to them concerning Part 135 of the Federal Aviation Regulations (FAR). We apologize for the delay in answering your query.

The question was: Are both ceiling and visibility required in order for an FAR Part 135 air carrier pilot to initiate an instrument approach?

FAR 135.225(a) and 135.225(a)(2) forbid a Part 135 pilot from beginning an instrument approach unless reported weather conditions at the destination airport are at or above the authorized IFR landing minimums for that airport. So, even though ceiling is not a criterion on the approach plates, it must be considered by the pilot in his decision to initiate the approach, and in deciding whether the reported ceiling is above or below the decision height or minimum descent altitude for the approach. Similarly, FAR 135.225(b) forbids initiation of a final approach segment unless reported conditions are at or above minimums. Again, the pilot must know the reported ceiling and visibility before deciding whether that approach segment can legally be initiated.

This interpretation has been coordinated with the Air Transportation Division of the Flight Standards Service. We hope that this satisfactorily answers your question.

Sincerely,

/s/

Donald P. Byrne
Assistant Chief Counsel
Regulations and Enforcement Division




I hope this clears it up..


Deltoid

 

[HAL]

Deltoid,

Thanks for the info. I do understand the interpertation as you posted in your last message. However my original question deals with the decision whether or not to launch, not start the approach. It is FAR 135.219 that I was concerned with, regarding whether or not you can go if the ceiling is low but visibility is good. I do have a problem with the FAA saying, in essence, "Ceiling is not required, but we'll violate you if we feel like it. Sort of a catch-22.

Either you can go, or you can't. Allowing the PIC to make a decision, then have the FAA say you can't seems a little arbitrary.

HAL

 

[cubpilot]

Hal

This is an interesting topic so I keep poking my nose in where it probably shouldn’t be but here goes anyway.

From 1985 – 89 I flew metros for a commuter airline and both visibility and ceiling were required. I am now thinking we were operating with a letter of interpretation from our POI principal operations inspector, which means it was not likely given to anyone other than our carrier. The language was very similar to the letter cited by Deltoid, only our letter applied to any time reported weather was required. ie before take of, and before beginning the approach. The letter came about as a result of a similar discussion to this line. Someone asked, maybe me, if only visibility was controlling how did we apply the 100’ increase in ceiling requirement for a new captain?

Now I am asking anyone. How does the 100’ increased ceiling for new captains apply in 121?

As for your original question about current and forecast. The length of time a current observation is valid depends on some circumstances about the observation. Hourly station reports are made hourly with special reports made if the weather has a significant change. A significant change is defined to include, an increase or decrease in ceiling or visibility above the landing minimums of published instrument approaches for the field. Also I have seen letters, which explain that a weather report becomes invalid, when the observer leaves the field. While it is true that the observation is like a snapshot, these other considerations lead me to believe that hourly reports have a validity of up to one hour.

Next FAR 135.219 states in part “…the latest weather … indicates that the weather will be…” The word indicates was interpreted by our POI as giving the PIC the responsibility to use his judgment to decide what the combination of reports indicated. The specific example given for this was the forecast was for below minimums expected improve later (too later) to above minimums. Yet a trend of hourly reports showed that the improvement was actually ahead of forecast, the flight could depart.

You seem to be vary capable to exercise good judgment with regards to weather. So I assume you are more concerned here with the legal technicalities of this. My suggestion is to ask the POI which oversees your company. Be specific and ask as many questions as needed to cover all the scenarios. Then ask for a letter from him. If you get one, it will serve as a good faith effort to comply with the rule. Effectively making the rule what ever the letter says until you get a letter from someone with higher authority telling you, your other letter is wrong. Another technique, which is useful when you get verbal directives, but the POI is reluctant to put it in writing, is a reverse confirmation letter. This is where you write back some thing like “Thank you for answering my questions on the phone yesterday. From our conversation I understand …”
If the interpretation is reasonable, this should protect you from a legal catch-22, pending a better interpretation.

 

[Deltoid]

Hi Hal,

I was reading so many posts I lost track of original question. Here is an excerpt from washington in regards to using reports or forecasts to launch.

You ask if the above operations can be conducted under PAR Parts 121 and 135 when the weather forecast calls for conditions at or above minimums but the hourly sequence reports indicate that weather conditions are below minimum (examples 1 and 3). You ask also about the situation where the forecast is for conditions below minimums but the hourly sequence reports indicate that weather conditions are at or above minimums (examples 2 and 4).
FAR Section 121.613 states, in pertinent part, that an aircraft cannot be dispatched or released for operations under IFR or over-the-top unless appropriate weather reports or forecasts, or any combination thereof, indicate that the weather conditions will be at or above the authorized minimums, AT THE ESTIMATED TIME OF ARRIVAL at the airport(s) to which the aircraft is dispatched or released. Section 135.219 requires that in order to take off and operate an aircraft under IFR or over-the-top, the latest weather reports or forecasts, or any combination of them, must indicate that weather conditions AT THE ESTIMATED TIME OF ARRIVAL at the next airport of intended landing will be at or above authorized IFR landing minimums. With regard to alternate airports, Section 121.625 states, in pertinent part, that no person may list an airport as an alternate airport unless the appropriate weather reports or forecasts, or any combination thereof, indicate that the weather conditions will be at or above the alternate weather minimums specified in the certificate holder's operations specifications for that airport WHEN THE FLIGHT ARRIVES. Similarly, Section 135.221 requires that in order for an airport to be designated as an alternate airport, the weather reports or forecasts, or any combination of them, must indicate that the weather conditions will be at or above authorized alternate airport landing minimums for that airport AT THE ESTIMATED TIME OF ARRIVAL.

{p24}

The above cited regulations clearly indicate that the critical time period for purposes of determining whether an aircraft can be dispatched or operated under IFR conditions or whether an airport can be listed as an alternate is the estimated time of arrival. Weather forecasts which indicate that conditions will be at or above minimums at ETA are sufficient for operations under FAR Parts 121 and 135, even if hourly sequence reports state that weather conditions are currently below minimums. It follows that weather forecasts which indicate that conditions at ETA will be below minimums are not sufficient for such operations, despite what hourly sequence reports may indicate."


Essentially you can operate IFR based on forecast alone. The reg years ago was changed from report AND forecasts to reports or forecats so use may use the favorable of the two. Now remember you are 135 so you need ceiling and visiblity to even start the approach so if the forecast ceiling is below and visibility is good you still can't go if it is forecast as such. Its logical because if you cant' start the approach you should not even be going anyway.

Avbugs post is correct but only after the final approach segment has been started but does not address before hand the planning or starting a trip.



As for cub pilots question for a high mins captain..

§ 121.652 Landing weather minimums: IFR: All certificate holders.
(a) If the pilot in command of an airplane has not served 100 hours as pilot in command in operations under this part in the type of airplane he is operating, the MDA or DH and visibilitylanding minimums in the certificate holder's operations specification for regular, provisional, or refueling airports are increased by 100 feet and one-half mile (or the RVR equivalent). The MDA or DH and visibility minimums need not be increased above those applicable to the airport when used as an alternate airport, but in no event may the landing minimums be less than 300 and 1.

Again the FAA is very specific. MDA or DH and Vis is increased. This is the only time where a 121 pilot is limited by ceiling when flying and for good reason until they gain experience. Now it also says in NO EVENT can it be less than 300 & 1. No event means nada, zip, never in legal terms. After the math what ever is derived with the additives you are limited to a minimum of 300 & 1. Eg. an 1800rvr approach plus 2400rvr additive equals 4200 so you bump it to 5000rvr which is 1 mile. So if the report prior to final approach segment has a 200' & 3 miles the high min captain is screwed because in "no event" may it be less than bla bla. At our carrier this is how we operate in regards to high mins.
Now if you have started the final approach the NO EVENT would catch you if it is reported below while on the approach. No event leaves no option. They way I read it is if you derive a ceiling of lets say 450' & 1 mile and you start the final approach and a report comes in at a ceiling of 300' & 1 mile you are still good to continue since the visibility is controlling now and its above 1 mile. Any thing less than that you get into the "NO EVENT" regime.
In any event consult your OPS SPECS and if you can, like someone mentioned in a prior post, get a letter if you can from your POI. Some will be reluctant because of liability so don't be surprised if they will not do it.


Have a good one

Deltoid