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ILS personal minimums   

48 members have voted

  1. 1. What are your precision approach personal minimums to plan?

    • 100ft above runway if you can see the lights
      3
    • 200-1/2
      12
    • 400-1
      12
    • 600-2
      5
    • 800-3
      7
    • 1000-5
      7
    • MVFR
      0
    • VFR
      0
    • Not instrument rated
      2
  2. 2. What are your precision approach personal minimums to attempt the approach?

    • 100ft above runway if you can see the lights
      5
    • 200-1/2
      18
    • 400-1
      11
    • 600-2
      6
    • 800-3
      4
    • 1000-5
      2
    • MVFR
      0
    • VFR
      0
    • Not instrument rated
      2
  3. 3. What are your precision approach personal minimums to go missed?

    • 100ft above runway if you can see the lights
      9
    • 200-1/2
      22
    • 400-1
      8
    • 600-2
      3
    • 800-3
      2
    • 1000-5
      2
    • MVFR
      0
    • VFR
      0
    • Not instrument rated
      2


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Posted

What are your current or typical personal minimums to fly a precision approach? 
 

3 similar but different questions. Assuming an ILS approach to a long runway with 200-1/2 published minimums with an approach lighting system, what are your personal minimums to:

-Plan this as a destination

-Attempt this approach

-Go missed at this altitude

 

Weather can be changing so it is entirely possible that the weather was forecast to be 800-2 when you were departing, became 400-1 when you initiated the approach, and actually turned out to be 200-1/2 when you reached DH.
 

Are your criteria for planning, initiating, and going missed for an approach the same or different? 
 

Vote based on the values closest to what you would consider your personal minimums and share your thoughts in the discussion.

Posted

It depends. On an approach that I'm familiar with, and I'm very current, and the autopilot is working, and there is not a lot of turbulence or wind shear reported, and there is a convenient alternate nearby with better conditions, I'll happily go to 200-1/2. If any conditions, or combination of conditions are not met, I will increase the planning minimums or cancel the flight depending on the severity or combination of conditions. Once near the destination, only low level turbulence or windshear will cause me to not shoot the approach. 

  • Like 5
Posted

I'm far more concerned with area weather and conditions at an alternate, and how much fuel I have.  The approach to mins, in and of itself, I don't view as the risk; not having a solid out is!

  • Like 3
Posted
21 minutes ago, midlifeflyer said:

Same. 

Interesting. For me they’re different. I don’t want to waste my time traveling to an airport that is likely not to work out. I also don’t deliberately want to plan or expect to be at the bare minimum. 
 

So I’d like to see about 500-1 to plan the trip or already start coming up with an alternative time or place. Just because I’ll fly to minimums doesn’t mean I’m seeking it out and I will preemptively try to avoid it.

But if on reaching the destination, I’m feeling good and everything is working out well (smooth, stable, etc), I’ll probably attempt an approach if it’s reporting at minimums. I will not go into the approach expecting to need to continue below DH to 100ft to see the runway. But if I’m on the approach and at minimums I have a really solid view of the lights and feel it’s going really well, I’ll probably go all the way as part 91 permits.

Posted

Agree with @MikeOH that it's less about the current weather and forecast at my specific destination than the overall weather scenario.  I wouldn't bother to drive to the airport if it's 200 and 1/2 for hundreds of square miles in any direction around the airport I'm trying to get to.  But if there is nearby widespread good VFR and forecast to stay that way, my minimums for planning the flight are basically zero/zero, and my minimums for commencing an approach are anything reasonably close to the legal minimums for the approach.

Some flights don't fall into these neat categories, of course, particularly if I've never been to the destination before.  Then I agonize like everyone else, and do my best to err on the side of safety.

Posted

planning, 1000ft,  i'm not going if i can't plan for this.

approach is mins including dip for lights. 

if before the approach, other aircraft are reported going missed, i'll divert to better conditions.

 

  • Like 1
Posted
2 hours ago, 201er said:

Interesting. For me they’re different. I don’t want to waste my time traveling to an airport that is likely not to work out. I also don’t deliberately want to plan or expect to be at the bare minimum. 
 

So I’d like to see about 500-1 to plan the trip or already start coming up with an alternative time or place. Just because I’ll fly to minimums doesn’t mean I’m seeking it out and I will preemptively try to avoid it.

But if on reaching the destination, I’m feeling good and everything is working out well (smooth, stable, etc), I’ll probably attempt an approach if it’s reporting at minimums. I will not go into the approach expecting to need to continue below DH to 100ft to see the runway. But if I’m on the approach and at minimums I have a really solid view of the lights and feel it’s going really well, I’ll probably go all the way as part 91 permits.

They are the same for me because I have personal minimums higher than published. I will be checking weather enroute and if it’s changed while enroute, may divert before I even try. 

  • Like 2
Posted
41 minutes ago, midlifeflyer said:

They are the same for me because I have personal minimums higher than published. I will be checking weather enroute and if it’s changed while enroute, may divert before I even try. 

So when you hit that number, even if you’re on the verge of breaking out, you slam in the power and go missed?

Posted

I don’t think I’ve ever quite understood how to answer questions like this as it’s so dependent on conditions. Meaning I might say it “starts” at legal minimums and goes up from there based on conditions and situation surrounding the flight.

night, single pilot, convection in the area, fuel status, fatigue, recency/proficiency, familiarity with area, lighting for approach and runway (or lack thereof), autopilot or hand flying, type of terrain/mtns/obstructions, etc.  These are all migitating factors that would increase my personal decision height.

But under ideal circumstances if you’re proficient and have a capable aircraft it’s absolutely NOT the approach “min” that’s driving my decision making process…rather it’s the idea of flying into an area that has few alternatives in an emergency.  So it’s not a “decision height” while on the approach, but rather my comfort (or not) to fly into an area with all the terrain obscured and how much height above terrain I feel is prudent. 

  • Like 4
Posted
14 hours ago, 201er said:

So when you hit that number, even if you’re on the verge of breaking out, you slam in the power and go missed?

So if you reach published minimums and you are in the verge of breaking out, you…?

Realistically, if everything was in target and stable and I had some (unofficial) visual references and it was above published minimums, although I hope I would go missed, I would probably not be able to resist the temptation to continue another 50-100’. I accept my human frailties.

Bottom line: I’m not a kid anymore. My personal minimums are higher now than they were when I was far less proficient and (I hope) knowledgeable and thoughtful than I am now. 

  • Like 2
Posted
19 minutes ago, midlifeflyer said:

So if you reach published minimums and you are in the verge of breaking out, you…?

If it’s published minimums, then yes! Go missed. They’re already pretty low with not a whole lot of extra margin built in. 
 

But explain to me this. What “minimums” do you brief for the approach? What number do you have in your head or saying out loud to go missed at? 

Ex:

TDZE 312’

DH 512’

With your not-a-kid-anymore personal minimums, where are you applying power to go missed? How do you remember the difference between the DH, personal minimum, and humility frailties minimum? Do you cross out the mins on the chart and write in your own?

(Im not being facetious or argumentative, genuinely just curious)

  • Like 1
Posted
13 minutes ago, midlifeflyer said:

So if you reach published minimums and you are in the verge of breaking out, you…?

I would go missed...PERIOD.  IMHO, not doing so is how you end up in the approach lights.

OTOH, I really have not understood the aversion to flying an approach TO minimums.  Approaches are very carefully engineered and tested and are designed to be risk free if flown as published.  Where I am ultra-conservative is KNOWING I have a place to go that will NOT be anywhere close to minimums (because I do NOT trust the weather forecasts!), AND have an abundance of fuel.  TIME is what allows me to eliminate risk.

  • Like 3
Posted

If I begin an approach, im happy to go to published mins as long as it’s stable.  If it might be close to DH (and there’s a lead in light system), I’ll use the drawing function in ff to write the tdze+100’ altitude on the chart.  Ive used that extra ~100’ several times, but I haven’t had to go around at 100agl yet as Ive always picked up the red termination bars or runway before it.  I have gone around that low in the sim at annual training… it wasn’t scary there ;).  In truth, a stable approach on autopilot at 90-100knots should take ~15 seconds for each 100’ down.  It shouldn’t be a “blur” and you should be ready (and willing) to execute the ma as you hit the dh.  Below 500’, I usually count out loud each 100’ - “500 to go, 400, 300, 200, 100, mins”.  But then I fly single pilot, so it’s just me.

  • Like 4
Posted

Question 1: 500-1, the boundary between IFR and LIFR, is generally the worst forecast I'll accept before leaving if planning to use an ILS (and many LPVs). I think this is the most rational choice many (most?) amateurs who are current and feel proficient - it wasn't listed as a choice here though.

Question 2: Once there, I'm sure gonna try it down to minimums (including using the approach lights down to 100ft) if I have good fuel reserves and easy outs that wouldn't be compromised by at least attempting it.  I bet this is true of most folks comfortable with a 500-1 forecast.

Question 3:  The question seems only subtly different from 2, and I bet very few people would break off an approach that they feel well stabilized on before reaching the legal minimums.  I think the key when faced with IFR and particularly LIFR conditions at the field upon arriving is having a lower threshold to break off the approach early if everything isn't going perfectly and one gets behind the plane. The survey categories do not capture  this key consideration.  

  • Like 3
Posted

Just curiosity: I wonder haw many have actually been faced with this? I’ve read that the most common instrument approach is the visual; that breaking out at or neat published minimums are  rare. I would expect those who fly several hundred hours per year to come across it more often than weekend warriors. We have folks who live in areas where flyable IMC is rare to begin with. I lived in Denver for 20 years - we would all rush out to fly and teach instruments in the 6-week May-June good cloud window.  Even in good IFR areas, LIFR is a rarity. I have a friend who flies about 200 hours a year, travels regularly on the east coast as far south as Florida and as far north as Canada and has not busted personal approach minimums. 
 

  • Like 2
Posted

My minimums are not a single number. I don’t say, for example, “I won’t fly a precision approach below X feet and Y visibility.” I try to assess flight risk based on a wide range of factors.  

The FRAT — Flight Risk Assessment Tool — app available for free on the Apple Store is an example of how a number of factors and their interactions are evaluated in concert to estimate the risk of a proposed flight.  

  • Like 3
Posted
19 hours ago, MikeOH said:

I'm far more concerned with area weather and conditions at an alternate, and how much fuel I have.  The approach to mins, in and of itself, I don't view as the risk; not having a solid out is!

My instructor and I flew from Phoenix to California to try an approach in real IMC for the first time (for me), and when we got there weather was far worse than expected/what was shown and briefed. Shot a LOC (where I learned the importance of making sure I brief the glide slope angle) and had to go missed. 

We shot the approach, went missed, did a hold where we briefed the surrounding airports and our fuel (which I had taken off with appropriate IFR fuel plus some), and realized Yuma was probably the best place to go, the weather was so bad -- definite VFR. When we got there, they kept asking us to hold, giving us vectors to wait for the F38's to land, etc. I was about to declare minimum fuel at one quarter tank and one 1/8 tank. They gave us the runway just before that.

After that, I learned the importance of how planning can be real. Plan the departure, the en route, approach, the hold (x2), and a viable alternate far away from the weather (for my skillset). It's made my M20K range a lot shorter, sadly, but I've never been frightened again.

All that to say, good point and @201er could add another poll question here about what are your personal minimums for an alternate. Mine is "two alternates, far away from weather, virtually guaranteed to land at".

edit: The flight was KIWA A39 KSEE KNYL, shooting the LOC-D which is a 6.88 descent. Whew. 

  • Like 1
Posted
5 hours ago, Jerry 5TJ said:

My minimums are not a single number. I don’t say, for example, “I won’t fly a precision approach below X feet and Y visibility.” I try to assess flight risk based on a wide range of factors.  

The FRAT — Flight Risk Assessment Tool — app available for free on the Apple Store is an example of how a number of factors and their interactions are evaluated in concert to estimate the risk of a proposed flight.  

I.agree with your first paragraph.

But I find most risk assessment tools penalize me for having a single engine and being single pilot. That pretty much rules out half of my flights with any other single risk, like landing after dark . . . So I ignore these things and decide for myself. There's no "risk" to flying my wife somewhere in my Mooney rather than being in a King Air (which is an order of magnitude out of my budget).

  • Like 2
Posted
3 hours ago, midlifeflyer said:

Just curiosity: I wonder haw many have actually been faced with this? I’ve read that the most common instrument approach is the visual; that breaking out at or neat published minimums are  rare. I would expect those who fly several hundred hours per year to come across it more often than weekend warriors. We have folks who live in areas where flyable IMC is rare to begin with. I lived in Denver for 20 years - we would all rush out to fly and teach instruments in the 6-week May-June good cloud window.  Even in good IFR areas, LIFR is a rarity. I have a friend who flies about 200 hours a year, travels regularly on the east coast as far south as Florida and as far north as Canada and has not busted personal approach minimums. 
 

I've shot one ILS where I had to go down all the way to DA and those conditions were widespread throughout FL. I would rather not do that again because I have no viable plan if I have an engine failure. 

I plan for 1,000 at destination I'm prepared to fly an approach to minimums if needed.

Posted
3 hours ago, midlifeflyer said:

Just curiosity: I wonder haw many have actually been faced with this?

Ironically, the only place I've been faced with it is here in that same Denver area you speak of, during that same small window of flyable IMC in late spring (it was really good this year, I've flown more actual IMC in the past month than in the last several years).  In my experience the last decade or so, flyable IMC here has been either totally uninteresting, or LIFR.  Between students and my own practice, I've only flown a few dozen approaches in IMC past the FAF.  But I have several stories of not seeing approach lights until right at minimums, and needing to go missed for real.

This has led me to something of a contrarian speech for my students, about personal minimums vs. what is often taught in training material.  The training material suggests that one might step down their personal IMC minimums over time.  Start with ceilings 1000' AGL, step down a couple hundred feet at a time as you gain experience.  That strategy just can't be executed in the Denver area, there aren't enough opportunities.  If you want to fly actual, you need to be proficient enough to go fly when airports are reporting LIFR.  I'm willing to do that partly because I've flown all the local approaches with ATC hundreds of times, and partly because there is essentially always good VMC within range of the airplane (I've yet to have to actually leverage that, but nice to know it's there).

So I think this just gets back to the fact it's situational.  I'm not some steely-eyed missile man because I'll fly low IMC in the Denver area when it happens.  It's a very specific environment and set of skills I'm comfortable with, after a lot of practice.  I'd bet some people here are very comfortable with coastal fog in a way I'm not, others with east coast weather, etc.

  • Like 2
Posted
3 hours ago, midlifeflyer said:

Just curiosity: I wonder haw many have actually been faced with this?

I have only ever done one missed approach with a diversion.  ILS-32 at KCMX due to fog about 10yrs ago.  200’ (you can go to 100’ with environment insight) and 1/2 mile is as you put it correctly really low.  
 
I have otherwise never had an issue getting in, though I have at times adjusted to an alternate (i.e. the VOR approach I know isn’t going to work so I land 10 miles down the road with an ILS).  200’ (100’) and 1/2 a mile is low low low.

I am with you on this.   

Posted
46 minutes ago, Vance Harral said:

Ironically, the only place I've been faced with it is here in that same Denver area you speak of, during that same small window of flyable IMC in late spring (it was really good this year, I've flown more actual IMC in the past month than in the last several years).  In my experience the last decade or so, flyable IMC here has been either totally uninteresting, or LIFR.  Between students and my own practice, I've only flown a few dozen approaches in IMC past the FAF.  But I have several stories of not seeing approach lights until right at minimums, and needing to go missed for real.

This has led me to something of a contrarian speech for my students, about personal minimums vs. what is often taught in training material.  The training material suggests that one might step down their personal IMC minimums over time.  Start with ceilings 1000' AGL, step down a couple hundred feet at a time as you gain experience.  That strategy just can't be executed in the Denver area, there aren't enough opportunities.  If you want to fly actual, you need to be proficient enough to go fly when airports are reporting LIFR.  I'm willing to do that partly because I've flown all the local approaches with ATC hundreds of times, and partly because there is essentially always good VMC within range of the airplane (I've yet to have to actually leverage that, but nice to know it's there).

So I think this just gets back to the fact it's situational.  I'm not some steely-eyed missile man because I'll fly low IMC in the Denver area when it happens.  It's a very specific environment and set of skills I'm comfortable with, after a lot of practice.  I'd bet some people here are very comfortable with coastal fog in a way I'm not, others with east coast weather, etc.

I fly over to Hillsboro Oregon and Seattle a lot (in a PA46T for work), and that’s generally where you can have a forecast for 800/3 except the dew point and temp appear pretty close and then suddenly it’s 0/0 in fog.  Sometimes you’re vmc at the faf but well above the fog.  The real bad part is it usually hits all along I5 in Seattle, so your nearest divert is on the east side of the cascades even though there are 6 or 7 airports much closer, they all have the same fog.  I’ve crossed back over the mountains twice in the last couple years flying for work.  Both times the forecast was reasonably good at the destination and the ceiling just kept falling during the flight.  Luckily the weather on the east side of the Cascades is night and day different.

In Spokane there’s often an ice fog in winter to come home to. Thankfully it’s typically lowest in the morning so we never leave due to possibly getting ice on the ground, but it’s not fun to come back through.

Finally, I’ve been to mins twice now in forest fire smoke when returning to KSFF from trips and hope never to repeat that. I saw only the lead in lights and straight down at DH on the ILS (in my Mooney).  breathing was terrible.  Forecasting smoke is also terrible, so figuring an alternate is much harder.

  • Like 3
Posted
3 hours ago, midlifeflyer said:

Just curiosity: I wonder haw many have actually been faced with this? I’ve read that the most common instrument approach is the visual; that breaking out at or neat published minimums are  rare. I would expect those who fly several hundred hours per year to come across it more often than weekend warriors. We have folks who live in areas where flyable IMC is rare to begin with. I lived in Denver for 20 years - we would all rush out to fly and teach instruments in the 6-week May-June good cloud window.  Even in good IFR areas, LIFR is a rarity. I have a friend who flies about 200 hours a year, travels regularly on the east coast as far south as Florida and as far north as Canada and has not busted personal approach minimums. 
 

Twice. Many years ago. One was the ILS 7 into KSBA; broke out 50' above mins with good (2-3 miles) visibility underneath. The other was the VOR 26 at KCMA (no GPS); at MDA (around 1000', can't remember exactly) was just under the ceiling and visibility was marginal (1.5 - 2 miles) and spotted the runway environment just as my time was up; I really thought I was going to have to miss on that one.

Both situations were due to the common (May/June) southern California marine layer which is typically NOT associated with any storm system. I had CAVU weather less than 30 minutes away at my alternate in the Mohave desert and had over 3 hours of fuel.

  • Like 1

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