Alternate minima

[mtruchon]

I was planning a IFR flight today with my instructor and we had a different interpretation the definition of “two or More Usable Precision Approaches–each providing straight-in minima to separate suitable runways” in the CAPGEN. For example, CYYT has an an ILS on both runway 11 and 16. To me, if the winds allow either runway, it means I have two separate runways with useable precision approaches and I get 400-1 / 200 - 1/2 minima. I interpret separate runway as meaning it can’t be two precision approaches on opposite ends of the same runway.

To my instructor, it means intersecting runways with pavement touching would not qualify since they are not fully separate. So, either two parallel runways or two runways like in CYMX where 11/29 and 06/24 don’t cross each other(share no pavement).

Which interpretation is correct?

[youhavecontrol]

You are correct. Just because two runways intersect makes no difference, they are still separate runways by definition. The only one you cannot count is the opposite end of the same runway.

[GoinVertical]

You are correct. Your instructor needs some instruction...

Are there any airports in Canada east of Montreal with 2 runways that don't touch? Other than maybe something with a parallel grass runway..?

[mtruchon]

None that I know of. Also, most airport with intersecting runways seem to have one runways served by an ILS and the other one being mostly RNAV. East of Montreal, only St John’s and Halifax seem to have 2 precision approaches that qualify for the alternate minima.

To be fair with my instructor, a lot of stuff if open to interpretation with transport Canada. Like do you log actual IMC only if in clouds or if you filed IFR, do you count that as actual IMC. That’s another can of worms.

[telex]

If your instructor is confused about the difference between IFR and IMC I might suggest a new instructor.

[trey kule]

My thoughts as well. Hard to believe someone teaching IFR did not know this...

A new instructor is a great idea

[mtruchon]

He knows the difference about IMC and IFR, I was just illustrating how hard it can be to know the correct interpretation of a definition in the AIM or car’s. When you write the commercial written, a sizeable chunk feels like a language test and guess the best interpretation. I was wondering about when to log actual IMC in the logbook, asked a few instructors and a quick search on here yielded many different answers. Some logbooks have a column for IFR and one for IMC.

Anyways, thanks for the answers on the alternate minima!

[Justjohn]

You are correct. Your instructor needs some instruction...

Are there any airports in Canada east of Montreal with 2 runways that don't touch? Other than maybe something with a parallel grass runway..?

Saint John NB

CYSJ

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[rookiepilot]

If your instructor is confused about the difference between IFR and IMC I might suggest a new instructor.

Endorse.
There is zero confusion about this.

[Big Pistons Forever]

Part of the problem is that selection of IFR alternates seems to be frequently taught as an aviation trivia contest instead of a practical flight planning issue

I teach that anyone flying IFR should plan on having up to 4 different alternate airports.

1) The legal alternate: That is the one that meets all the legal requirements

2) The commercial alternate: That is where you want to go if you miss at your planned destination because it is the cheapest and/or most convenient place to end up

3) The gold plated alternate: This is reserved for those really crap days with wide spread bad weather and a not particularly warm fuzzy feeling about the weather forecasts and is some place you are confident that you can squeeze into when the weather really craters.

4) The enroute emergency alternate. This is the place (usually the nearest airport to your present position) where you are going to go "if the bad thing happens". This will obviously not be pre-planned but is a natural extension of good situational awareness.

No 1 and 2 are often different and are where the real world renders the pedantry of those "gotcha" alternate questions so favoured by TC and the flight schools, irrelevant.

No 3 can only be developed from hard won experience and local knowledge. Crap weather that is foretasted to improve is a good example. Yes it becomes a legal alternate if the weather at the end of the becoming period is above alternate mins, but by what mechanism is the weather going to get better ? Poor vis due to fog is a good example where the "getting better" time seems to mostly generated by the computer random number generator and wishful thinking on the part of the forecaster. For new guys, this is a good time to talk to the FSS guys in person (Oh how I miss real weathermen at the old airport weather stations ) and get a feel for what is making the weather and then deciding how far I am going to trust the TAF.

[goingnowherefast]

All great points. When I miss, I rarely end up at my legal alternate. Often my "commercial alternate", and on rare occasion my "gold plated alternate".

There's merit to the idea of using an alternate for where you actually intend to go. When I get that uneasy fuzzy feeling, my "gold plated alternate" is often my legal alternate as well. I usually have a couple options. One or two legal alternates within fuel range, but several others that are likely to be above minimums and land-able for when the TAFs get amended and weather craps out. There's no worse feeling than finding out enroute that your legal alternate that you thought was a sure thing is now below minimums or even approach banned.

All of this depends on weather at destination too. If the destination is SKC and 10,000' long, I couldn't much care about the alternate.

I would add a maintenance alternate. Similar to "emergency alternates", but less urgency. Where are you going to take a gear problem? Do they have ARFF? How far are you willing to fly with an engine out? Where are you going to go with a flap failure? What if your destination and legal alternate are both shorter than your flap 0 landing distance? Nice to have a usable runway within fuel range that is long enough for these sort of problems.

[mtruchon]

I sent an email to the quebec transport Canada office on Sunday and a guy called me today after lunch. I was say I was quite surprised at how quick they respond.

He told me that runways intersecting don’t matter at all, pavement touching or not. He even told me that reciprocal runways could be used as a legal alternate if winds permit. He gave me this example:
Let’s say 06R/24L is closed in YUL and the winds in TAF are predicted at light an variable, 06L/24R each have an ILS approach and since they are both useable based on the TAF, that would qualify as 2 precision approaches to separate runways. I was surprised about that, I thought reciprocal runways couldn’t count.

The point from my instructor was what if someone crashes at the intersection, you can’t land. Well, bad weather or not, you have to wait or divert to another place anyways. From what I understand, the alternate minimums are based on the probability of weather permitting an approach when you get there, not on the unlikely event that something causes a runway to close.

He told me LPV approaches should qualify as precision approach for the alternate in the next year or two. Yeah!

All,of this came up when planning an IFR training flight last week out of CYQB to CYRQ and back. CYRQ having only LPV couldn’t qualify as an alternate, so we had to file CYHU. And I asked what if CYQB had ILS to both 29 and 24, could it be used as an alternate with 2 precision approaches if we were filed to land in Montreal. Anyways, it was a great training flight in actual IMC, my first time in actual IMC. Broke though the clouds at around 700-800AGL in CYRQ on the LPV for 23. Then back to CYQB and shot the LPV for 24 in 1 3/4 miles and overcast 700 or so. Trying to do everything on your own and brief the approach without an autopilot is a lot of work. Little aircrafts plus convective clouds and no rudder/aileron trim means it quickly wants to get itself in a spiral while you’re reading the approach plate. Need to get better at splitting attention on multiple things at once. I was done after the flight lol.

Great points BPF. for that flight, CYHU is my legal alternate, but if for whatever reason I couldn’t bet back in CYQB I could shoot the approach in CYRQ even though I couldn’t file it as an alternate. If the weather allows me to shoot the approach and land there, no reason to fly an extra 30 min to get to my legal alternate. CYRQ has maintenance hangars is way more friendly to general aviation. I was surprised at how busy CYHU is. I had to wait 6-7 minutes after my initial contact to ground for them to get back to me last week when I flew there.

[Big Pistons Forever]

Back in the 1990’s I flew a Navajo freighter part time. One time during Fogtober I bumped 500 lbs of freight on a Victoria to Vancouver flight in order to carry more gas. My gold plated alternate was Calgary. For that early morning flight I was pretty sure all the coast airports and all the valley airports we’re going to crater as soon as the sun rose. Strangely Abbotsford’s TAF still showed legal alternate limits.

Anyway I got into Vancouver by the skin of my teeth and had to hold inYVR until noon before I could get back to Victoria after Victoria went WOXOF at sunrise. The freight company was pissed at my bumping freight but I told them I get the final call on how much gas gets loaded.

[goingnowherefast]

A couple weeks ago, I was having an alternates discussion with my company. Weather was pretty crap at destination, but they wanted me to try anyway. So immediately I'm thinking I want a good alternate, not something marginally legal. So I picked an alternate 200 miles west. Let's pretend it was 1000 overcast, good vis and has usable 2 ILSs to different runways. It is also not a company base and would be a real operational pain in the ass if I landed there. Company didn't like this plan and suggested a base 150 miles east, but it was 300' and only has 1 ILS. It's land-able, but barely and I'm not committing to it should I miss the destination. That was a big no from me. However I suggested bumping a bunch if stuff so I could go to destination, miss, go 100 miles east to the company base, miss again, then go now 300 miles west to my good alternate. They agreed to that, so off the stuff came, more gas went on and time to go flying. Once airborne, the destination weather got worse, so was a joke of an approach, ATIS was well below minimums. The company base went up to 700' and trending upwards, so that's wonderful and where I eventually landed.

[goingnowherefast]

My understanding of the reason for lower alternate requirements with 2 usable precision approaches is to do with facility malfunctions. If the weather is 600-2, and the localizer breaks, just use the non-precision approach as it's still likely 500' and land-able.

With 400-1 and two precision approaches, if one localizer breaks, well there's a whole other precision approach to get you on the ground safely. That non-precision approach won't work at 400'

[rookiepilot]

A couple weeks ago, I was having an alternates discussion with my company. Weather was pretty crap at destination, but they wanted me to try anyway. So immediately I'm thinking I want a good alternate, not something marginally legal. So I picked an alternate 200 miles west. Let's pretend it was 1000 overcast, good vis and has usable 2 ILSs to different runways. It is also not a company base and would be a real operational pain in the ass if I landed there. Company didn't like this plan and suggested a base 150 miles east, but it was 300' and only has 1 ILS. It's land-able, but barely and I'm not committing to it should I miss the destination. That was a big no from me. However I suggested bumping a bunch if stuff so I could go to destination, miss, go 100 miles east to the company base, miss again, then go now 300 miles west to my good alternate. They agreed to that, so off the stuff came, more gas went on and time to go flying. Once airborne, the destination weather got worse, so was a joke of an approach, ATIS was well below minimums. The company base went up to 700' and trending upwards, so that's wonderful and where I eventually landed.

Interesting anecdotes from you and BPF on IFR decision making.

[altiplano]

"Airplane crashing on the intersection..." pffftt... I recall ridiculous stuff like this when I was coming up too...

Or how about if you use YVR as an alternate, and an earthquake happens, and both separate runways and Sea Island sink under 3 feet of water... are you still legal? Is that okay? I mean it's possible... Or can you still count it if you can plan for the westbound on the river and stopping at the Beaver for chicken wings? Jesus....

Make solid choices you can justify and don't worry about other people's semantics. Then go for chicken wings.

[telex]

Let’s say 06R/24L is closed in YUL and the winds in TAF are predicted at light an variable, 06L/24R each have an ILS approach and since they are both useable based on the TAF, that would qualify as 2 precision approaches to separate runways. I was surprised about that, I thought reciprocal runways couldn’t count.

I think your inspector might want to revisit his advice. One runway is not two separate surfaces.


FACILITIES AVAILABLE AT SUITABLE ALTERNATE

2 or more useable precision approaches each providing straight-in minima to separate suitable runways. (Two separate landing surfaces)