Do you know what the fuel requirements are for IFR?

[ragedracer1977]

I thought I did. I want to know if I’m an outlier or not. 

I was taught that, on an instrument plan, you have to plan to depart with enough fuel to fly to your destination, then your alternate, and then for 45 more minutes. Like VFR, as long as you planned it, but flight conditions were different than forecast, you were legal.

I learned that is not true. 

If you plan for 45 minutes reserve, but the winds are worse than forecast or you’re giving holding instructions, a reroute, etc that cut into that 45 minutes, it’s illegal to continue to your intended destination if the conditions are 2000/3 or worse.

 Did you know that?

[N201MKTurbo]

What if your alternate is now below 2000/3?

yes, I knew that. 
 

I can’t remember an IFR Flight I made where that would be an issue. If I was making an IFR approach to minimums with less than 45 minutes of fuel in the tanks, my jeans would be sucked so far up my rear it would be hard to fly.

It would be a hard call if your intended destination was closer than your alternate.

In reality, it only matters if you actually run out of gas, then you have got some explaining to do.

Edited October 17, 2021 by N201MKTurbo

[toto]

There’s an interesting oldish Flying magazine article on this topic from the early aughts ..

https://www.flyingmag.com/rules-and-fuel/

[Ragsf15e]

The alternate is only for planning and filing purposes too, so that further complicates it as you could easily choose to land/divert somewhere else with better (or worse) weather if you decide you can’t continue to your destination.

You can also “update” your planned alternate in flight, so if you realize you no longer meet fuel requirements for the original one, but weather requirements are met for something closer, you might still be able to continue.

Just like @N201MKTurbo said, the only explaining you need to do is to the ntsb if you run out of fuel or to your wife if you soil yourself.

[ragedracer1977]

26 minutes ago, Ragsf15e said:

The alternate is only for planning and filing purposes too, so that further complicates it as you could easily choose to land/divert somewhere else with better (or worse) weather if you decide you can’t continue to your destination.

You can also “update” your planned alternate in flight, so if you realize you no longer meet fuel requirements for the original one, but weather requirements are met for something closer, you might still be able to continue.

Just like @N201MKTurbo said, the only explaining you need to do is to the ntsb if you run out of fuel or to your wife if you soil yourself.

Right.  I just had no idea it was actually illegal. I was taught it was like VFR flight planning.  As long as you planned to have that much when you departed, it was A-OK to land with 5 minutes of fuel.

[ragedracer1977]

2 hours ago, N201MKTurbo said:

What if your alternate is now below 2000/3?

yes, I knew that. 
 

I can’t remember an IFR Flight I made where that would be an issue. If I was making an IFR approach to minimums with less than 45 minutes of fuel in the tanks, my jeans would be sucked so far up my rear it would be hard to fly.

It would be a hard call if your intended destination was closer than your alternate.

In reality, it only matters if you actually run out of gas, then you have got some explaining to do.

Same.  Just interesting.  I, right now, have airline captains arguing with me that it’s a departure planning requirement and not an in flight requirement.  

[GeeBee]

Yep, had to bust a Captain once on a line check for it. He had plenty of warning too. "Insufficient fuel" came up 3 times on the FMS while he was in the holding pattern for the destination, but rather than say, "I need to bust out and go to an alternate" he cleared the message and continued to hold in the belief his destination would "open up." So if any of those Captain's are arguing with you that it is planned, not actual on fuel, tell them it is a good way to bust a line check. The second you no longer have filed destination+alternate+45 you need a re-dispatch. Perhaps a new alternate closer in, perhaps a "no alternate dispatch" if weather at the destination has cleared up, but you need by law a new plan.  Long story short, I could not take it anymore,  I disqualified him on the spot, removed him from the seat, notified the company I was in command and took the airplane to the nearest alternate, not the filed alternate. Landed with 50 minutes of fuel.

We just had a discussion about "disabled aircraft" in the Safety Forum, so what if blow through your "alternate + reserve fuel" holding then you get cleared inbound and as you cross the FAF the guy ahead of you closes the runway? How is that going to work out? Not good.

[1964-M20E]

I was taught the same that you need to plan 45 minutes after reaching your alternate for the conditions at the time of takeoff.  Once you are in the air your destination or alternate are flexible to meet the current conditions you are experiencing in the air. 

You should always be evaluating the situation and updating you plan.  That is why ADSB weather or XM weather is so great today.  You can easily look an hour or two hours ahead of your current location and update you plan accordingly.

[GeeBee]

FAR 91.167 "No person may operate a  civil aircraft in  IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to -.......

"Carries" is a continuous condition, just like "airworthy" is a continuous condition and you have to discontinue flight when you are no longer "airworthy". If it were not a continuous condition it would be worded, "may not take off unless if carries enough fuel."

By the way there is a third way to get out of the jackpot if you are a part 91 operator besides 2000/3. Anyone care to guess?

 

[AIREMATT]

59 minutes ago, GeeBee said:

Carries" is a continuous condition, just like "airworthy" is a continuous condition and you have to discontinue flight when you are no longer "airworthy". If it were not a continuous condition it would be worded, "may not take off unless if carries enough fuel."

“Carries” may be a continuous condition, but it doesn’t mean you have to land immediately. You may have to implement Plan B or C to reduce fuel burn such as speed, altitude, or route change and still continue to your destination. 
Airlines operate under Part 121 and are required to partner with a dispatcher on a Plan, different Plan if fuel changes, and maybe a different plan if the weather changes. Airlines have multiple ways to affect the fuel on arrival between speeds, altitudes, routes, and even swapping airplanes in a holding stack through ATC for an airport. If flights immediately discontinued a flight every time they initially projected less then 45 min fuel on arrival, many more flights would be delayed and rerouted every time there was a weather event. 
Airlines don’t even need 2000/3 weather to avoid listing an alternate. Based on Ops Specs, they may be able to use 1000/3 or even as low as 1000/2 weather as minimums to not list an alternate. Auto land systems and training programs allow them to use whichever of these minimums the FAA will approve in the Ops Specs for them.
GA pilots don’t have the aircraft systems or pull with ATC or planners to work with to make these alternate arrangements. They have to do it solo. Keeping track of fuel and having plenty in case a GA airport becomes unusable due to WX, runway closure, etc. May make a 45 min reserve wholly insufficient and other times overkill with fluctuating WX above and below 2000/3 due to limited WX information.

[GeeBee]

No, but airlines have even a stricter requirement in the form of 121.631, 121.639 because the dispatcher has to be the continuous monitor and re-dispatch or affect plan changes. I understand all the things dispatchers can do, I have experienced just about every trick in the book, but the moment the airplane is no longer in position to complete the flight within the FAR's and operations specifications it is in violation just as any part 91 flight that runs through its reserve fuel. Just like un-airworthy, you are not.......until the moment you are and then you must take action. For instance, if you burn through your discretionary fuel, and into your reserve fuel waiting for take-off and you take off without a revised plan are you illegal? Heck yeah you are illegal. That is why you have minimum takeoff fuel number. That is true Part 91 too.

 

[midlifeflyer]

I sure hope I knew since I wrote about it in my 2018 "Planning versus Flying" article in IFR Magazine. (Sorry, it's subscription required. I have no control over that.)

[Bob R]

§ 91.167 Fuel requirements for flight in IFR conditions.

(a) No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to -

(1) Complete the flight to the first airport of intended landing;

(2) Except as provided in paragraph (b) of this section, fly from that airport to the alternate airport; and

(3) Fly after that for 45 minutes at normal cruising speed or, for helicopters, fly after that for 30 minutes at normal cruising speed.

(b) Paragraph (a)(2) of this section 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:

(i) For aircraft other than helicopters. For at least 1 hour before and for 1 hour after the estimated time of arrival, the ceiling will be at least 2,000 feet above the airport elevation and the visibility will be at least 3 statute miles.

(ii) For helicopters. At the estimated time of arrival and for 1 hour after the estimated time of arrival, the ceiling will be at least 1,000 feet above the airport elevation, or at least 400 feet above the lowest applicable approach minima, whichever is higher, and the visibility will be at least 2 statute miles.

[carusoam]

Dang! You guys are good!

1) Great question!

2) Complex answers.

3) Thanks for including the FAR…

4) Thanks for interpreting the FAR…

5) Thanks for pointing out how the interpretation applies to various forms of flying…

6) Thanks for pointing out how to handle things as they change at each point of a flight…

7) The discussion kind of points out how and why running out of fuel isn’t very common for advanced pilots…

 

Kind of helps us all get to the level of being a better advanced pilot!  

Best regards and thanks again,

-a-

[ragedracer1977]

15 hours ago, GeeBee said:

 

By the way there is a third way to get out of the jackpot if you are a part 91 operator besides 2000/3. Anyone care to guess?

 

Besides canceling IFR, I don’t know.  I can’t even guess.

[AIREMATT]

22 hours ago, Ragsf15e said:

You can also “update” your planned alternate in flight, so if you realize you no longer meet fuel requirements for the original one, but weather requirements are met for something closer, you might still be able to continue.

A great reason to plan a distant alternate with good weather. It allows you to change to closer alternates with less than good weather but that still meets alternate mins. if your fuel situation changes. Plans B and C… before you even depart.
All depends on the day. Large regions of low ceilings may make it difficult sometimes, but you can give yourself options.

[Ragsf15e]

56 minutes ago, AIREMATT said:

A great reason to plan a distant alternate with good weather. It allows you to change to closer alternates with less than good weather but that still meets alternate mins. if your fuel situation changes. Plans B and C… before you even depart.
All depends on the day. Large regions of low ceilings may make it difficult sometimes, but you can give yourself options.

Definitely.  You can also keep those options in mind if you actually have to divert too - nothing says you actually have to go to your planned alternate.  ATC doesn’t even know what your alternate is.  You might have gas to get somewhere far after going missed at your destination but choose to land somewhere closer even if the weather there is not great, but because you know other planes are getting in there.  You’d still need appropriate alternate fuel, but the actual divert location is up to you.

[Skates97]

5 hours ago, midlifeflyer said:

I sure hope I knew since I wrote about it in my 2018 "Planning versus Flying" article in IFR Magazine. (Sorry, it's subscription required. I have no control over that.)

Thanks for the link, I'm always looking for something to read. My DPE for my IFR checkride a few weeks ago told me about IFR Magazine and I signed up when I got home. 

[midlifeflyer]

45 minutes ago, Skates97 said:

Thanks for the link, I'm always looking for something to read. My DPE for my IFR checkride a few weeks ago told me about IFR Magazine and I signed up when I got home. 

Not completely sure but I think once you are registered online, you can get older issues too.

 

[toto]

3 minutes ago, midlifeflyer said:

Not completely sure but I think once you are registered online, you can get older issues too.

 

 

https://www.ifr-magazine.com/full-issue/download-the-full-march-2018-issue-pdf/

[Skates97]

1 hour ago, midlifeflyer said:

Not completely sure but I think once you are registered online, you can get older issues too.

 

Yep, you get access to all the archives. I've been reading a few articles each day working my way backwards through whatever catches my eye.

[Bolter]

On this topic, I recall being told that when you are at 45 min reserve, is when you declare a fuel emergency.  Not when you "think" you are low on fuel and decide it is an emergency.  How accurate is that?

[Hank]

53 minutes ago, Bolter said:

On this topic, I recall being told that when you are at 45 min reserve, is when you declare a fuel emergency.  Not when you "think" you are low on fuel and decide it is an emergency.  How accurate is that?

I'm low on fuel well before only 45 minutes worth is left in the tank . . . .

[Bolter]

42 minutes ago, Hank said:

I'm low on fuel well before only 45 minutes worth is left in the tank . . . .

Me too.

I think it is more about daring pilots who consider it an emergency at LESS than 45 minutes, and declaring when there is no time to effect a change.  Better phrasing may have been, "it is appropriate to declare emergency at or before reaching 45 minutes remaining fuel".  

[Jim Peace]

What about the special liberties that need to be taken in a 20 series Lear?