How Do You Know If the Wx Is Good Enough for VFR X/C?

[Hedley]

One thing I see sometimes is a reluctance of low-time pilots to leave their local area, and actually go someplace with an airplane. This is because these pilots have a morbid fear of death, and realize they lack experience in flying VFR X/C, so they don't get any. A catch-22.

How to break out of that? Well, here is a simple receipe for you to determine if the wx is good enough for VFR X/C.

Draw a line on your VFR chart/sectional - you do have a map, right? GPS is great, but let's also bring along a map - from your departure to your destination airport. That line will cross many boxes with big blue numbers in them called MEF's. What is the biggest MEF number on your route? Let's say it's 2.5 for example. Let's at 1500 feet to that number. So, we want no cloud below 4,000 ASL, which you determine by looking at TAFs for airports along the way, and the NavCan GFA. Bonus points for looking at the dewpoint spread and using the dry adiabatic lapse rate.

While we're looking at the NavCan forecasts, let's ensure that forecast visibilities are at least 5 miles with no precip.

So, you've ensured that you have at least 5 miles vis and no cloud below 1500 AGL for your entire route. Another thing you want to check is the radar on intellicast.com and weatheroffice.gc.ca to ensure that there is no precipitation. Animate both of the above to look for trends.

Last thing to check for is sunset. Even if you have a night rating, when you're starting out flying x/c plan to arrive before sundown.


Let's review our concrete criteria for safe VFR X/C wx minima:

1) no cloud below 1500 AGL
2) 5 miles visibility
3) no precipitation (rain, snow)
4) no night-time

Now, obviously, as you gain experience, you can fly VFR without these restrictions. But I humbly suggest that until you do get experience, you observe the above limits which will keep you safe.

One last suggestion: fill your tanks. The only time you have too much fuel is when you are on fire, or hit the trees at the departure end of the runway. Plan for a minimum of one hour of fuel remaining after you land. Measure your distance of your leg. Calculate the minimum groundspeed you will require to land with one hour of fuel - eg 105 knots. After you level off, look at your groundspeed on your GPS. If it's less than 105 knots, time to flight plan another fuel stop. Continue to monitor that number during the trip, to watch out for increasing headwinds in the second half of the leg.

The above should help low-time pilots prepare for and fly VFR X/C trips with some confidence that the trip won't get really exciting, painful or expensive.

NB I hope this helps some people. This is all seems pretty obvious to me, but I've been flying for decades and I just pulled an all-nighter writing code and drinking red bull so my perspective may be a bit warped. Time to go to bed.

[photofly]

5 miles vis and 1500' ceiling can look pretty daunting, until you get used to it. I think instructors should pretty much make their students go and fly in that kind of weather, before they get a licence.

[172PIC]

Thanks for those guidelines, what would you suggest for wind limits for someone with a PPL building time for the CPL?

[iflyforpie]

Things can be quite different in the mountains though. Valley flying (Fraser Valley, Okanagan Valley, Columbia Valley) is not much different than local flying in other parts of the country. But I think even more so than regular cross-countries, the mountains here terrify the uninitiated. So called 'mountain checkouts' are usually too abbreviated and often miss the basics.

Adding 1500 feet to my MEF from Invermere on my way to Calgary, and I would not be able to fly unless the GFA said ceilings were at 14,000. Though most flatlanders do their cross countries at 11 or 12,000 feet, you can still be very safe (IMHO safer) by going low level through the passes on a recommended VFR route.

That being said, you need to know a few things before you do so (in addition to recommended mountain training).

First, selecting a route. The recommended VFR routes are always the best of everything. Most follow highways and rail lines, so take you through the lowest passes and can leave you pretty close to help if you have to set down. But other routes can be better under different circumstances. If the weather is good, you can 'cut the corners' on VFR routes or forgo them all together and go direct, but the further you get away from them, the less likely you will survive a crash or be rescued.

Some alternate routes are good for weather deviations, and some are better than the VFR routes because they are less confining, like the Blaeberry Pass to Abraham lake through the Rockies vs the Kicking Horse Pass following the #1. Point is, make sure you know your route and possible alternate routes. Know the pass heights and the terrain features that will set a minimum altitude to travel (most passes in BC it is at least 1500 feet above the summit as an absolute minimum. Also, know which way the water flows, because water always leads you to lower terrain. Pay attention to the warnings printed on the maps.

Some may not know this, but the 'caution, route subject to rapid weather change, min 5500' recommended altitude' on the VNC east of the Lower Mainland was put in as the direct result of an accident.

http://www.tsb.gc.ca/eng/rapports-repor ... 4p0074.asp

Unfortunately, that was not the last plane to be swallowed up by that area...

http://www.tsb.gc.ca/eng/rapports-repor ... 2p0109.asp

The 'Sunshine Valley' by Hope Slide is the most misnamed valley in the world.

So on to weather. In spite of VFR into IMC into mountains being the most obvious difficulty, the first place I go when planning to fly in the mountains is FDs and the GFA turbulence forecast. There are lots of absolutely severe clear days where it is deadly to fly in the mountains.

Generally, anything above 15 knots for the altitude you are flying is going to be rough. 20 knots is very uncomfortable. 25 knots is dangerous. 30 knots is deadly. If there is a mountain wave, the currents will be unpredictable if you don't have any clues from the clouds and will extend far beyond the mountains (just ask anybody who flies around Waterton or Pincher Creek). Local terrain features, like narrow valleys, steep terrain, or converging valleys will amplify the effects.

Knowing which way the winds are going is important too. That is what I find GPS the most useful for, but cloud behaviour (cumulus clouds coming off mountains will always point the direction the wind is going), and drift are good too.

For clouds and precipitation, it gets a bit more complicated unless you are flying on a severe clear day (which is what most unexperienced pilots choose to do in the mountains). But predicting weather is very difficult. The GFA for BC will just about always say 'LCL CIGS 8-12 AGL' which would be prohibitive for flying most days.

What I do is make sure the GFA ceiling is high, generally at least 7 or 8000 feet for the Eastern Ranges or Coastal Mountains, with the plans that it will probably come down. Everything had better say P6SM because me as an experienced mountain pilot isn't going in less. P6SM can quickly go to 3 or less, which if I know the area well is challenging. For the uninitiated, you can lose your bearings too fast and perhaps turn up the wrong valley. Precipitation and mountains is a no no, but if it is localized and can be navigated around is fine.

The other thing about the mountains is they separate areas of completely different weather. Just driving up the Coquihalla from the Lower Mainland, how many of you have noticed? Rain in Hope, huge snowflakes going through the Snowshed, clearing at the toll booth, and wide open skies at Merritt. Lots of times there isn't enough information if you want to go from the Interior, where it is VFR, to the Lower Mainland, where it is VFR.

The VFR route forecasts on the AWWS are helpful, but I prefer to take a look myself. So I look up weather cameras. The AWWS is getting more and more, and of course they are nicely oriented at the sky with a guide to help you estimate distances and elevations. But there aren't nearly enough.

When going through the Rockies, I use the web cams at Sunshine, Norquay, Lake Louise, and Nakiska Ski Hills to judge the weather. Going through the highway passes in BC, I go to Drive BC and use their highway cams. Note that I don't use these to see if I can 'get through', I use them to see if I should even bother.


The final bit of cross country wisdom I can add is the going back part. Out on my ramp right now is a 182 that has been here for well over a week. I don't know how many times I've woken up, thrown the curtains open to a CAVU sky, decided I was going somewhere because it was a day 'made for flying' and either wound up taking the Greyhound home or .. running because the weather crapped out. This typically happens if you didn't notice that weather front moving in on the GFA, or with highly unstable air that builds into huge thunderstorms. Just because you made it there doesn't mean you can make it back, even the same day or only a few hours later.

[Grantmac]

Thanks for those guidelines, what would you suggest for wind limits for someone with a PPL building time for the CPL?

Aircraft type and wind direction heavily influence that decision.

[Hedley]

You can divide any wind up into crosswind component, and headwind component.

Don't land with a tailwind until you get a lot more experience.

Start off with 5 knots of direct crosswind component. Get used to that, move up to 10k crosswind component. Get used to that, move up to 15k. Then 20k. Then 25k. Rome was not built in a day.

Headwind component is generally helpful - it slows down your groundspeed and makes thing happen slowly, which is good.

However, when there are strong winds around, be alert for loss-of-headwind shear on final, where at a couply hundred feet it drops out on you, and you must be quick with the power to compensate.

There's a better way to deal with loss-of-headwind shear, but no one ever bothers. Let's say you want to indicated 70 knots airspeed on short final, and looking at the windsock there's 10 knots of headwind component. You know that your groundspeed should be 70 - 10 = 60 knots on short final. So, on long final, set your airspeed so that your groundspeed is 60 knots. Because of the stronger wind aloft, initially your airspeed on final may read slightly higher than normal, requiring you to lower the nose to reduce the AOA. However, when you hit the wind shear, the airspeed will decrease to what it should be on short final, with no change required in the momentum of the aircraft. Just raise the nose ever so slightly.

However, no one ever does this. Instead, people approach much too fast when it is windy, and often end up wheelbarrowing down the runway on the nosewheel, or even get a porpoise going which can destroy the nosewheel. I know a guy who did that in a T-33.

[trey kule]

a good post. If I may add a couple of comments (and I believe I may.)

I notice many pilots living outside the greater metro areas seem to be nervous about communications. It would help a great deal if COPA clubs, flight clubs etc, put on a little seminar for a couple of hours once or twice a year to go over radio prcedures at the busier airports.

The other thing is that TAF and GFA's are not snapshot weather like a METAR. They are forecast Wx. Something that a lot of pilots (and fss types) including the commercial ones forget and treat them as gospel. They should be compared to the METARs along or near the route to see if the Wx, is in fact progressing as forecast, or better or worse. It is the reason that when you ask for a metar on NavCanada...you get the last three hours... I have seen commercial pilots who should no better ignoring a TAF and basing flight go , no/go decisions on a GFA...means "AREA" big "Area"

[Hedley]

Radio work is easy, once you realize that ATC says the same thing over and over again.

Every initial radio call you make to ATC takes the form of the 4 W's:

1) Who you are talking to
2) Who you are
3) Where you are
4) What you want to do

For example, I take off CYSH and head into CYOW. I called OW TML on 127.70 and say something like this:

"Ottawa Terminal,
Cessna Fox Uniform Charlie Kilo"

I want until OW TML responds, then I say, in the structure of the 4 W's:

"Ottawa Terminal,
Uniform Charlie Kilo
is 20 southwest at 2.4,
inbound north field"

Now, since CYOW is a slighty larger airport, it has an ATIS, so before I call OW TML I might listen to the ATIS on 121.15 (from CFS or VNC) and get the phonetic letter - say Whiskey - of the current ATIS information, and tack onto the above call at the end, "with Whiskey".

That's it.

[trey kule]

More pro pilots in your area I guess. I was just speaking to concerns I hear from private pilots.
I also hear things like "we have the ATIS" not "with Whiskey"..and lots of fumbling. Surprising how many pilots dont understand why it is wrong to say we have the ATIS...What does that tell you?

VEry simple for those of us that do it routinely. Not so much for some others who do it only occassionally.

But I just realized, radio and vf procedures are not part of the topic..sorry about that.

[Hedley]

No problem. It's all the same topic of developing VFR pilot x/c proficiency.

[Old Dog Flying]

More pro pilots in your area I guess. I was just speaking to concerns I hear from private pilots.
I also hear things like "we have the ATIS" not "with Whiskey"..and lots of fumbling. Surprising how many pilots dont understand why it is wrong to say we have the ATIS...What does that tell you?

.

From my experience in ATC, someone who uses this phraseology is generally lying because he did not listen to the ATIS.

Good thread Hedley!

[trey kule]

ODF:

Are you sure? I mean a pilot lying to cover up a basic mistake? I am going to have to take your word on it because I just cant fathom any pilot ever lying to cover up anything.

This is a good thread if us old guys with to much coffee in them on a Sunday morning would stop taking it off topic with silly posts.

[cgzro]

1) Who you are talking to
2) Who you are
3) Where you are
4) What you want to do

Here are some podcasts that the Rockliffe flying club made a year or so ago to go through various radio procedures going into and out of say YOW.

http://www.rfc.ca/en/rfcpodcast

The other thing that helps is to listen to liveatc.

Peter

[Big Pistons Forever]

1) Who you are talking to
2) Who you are
3) Where you are
4) What you want to do

Here are some podcasts that the Rockliffe flying club made a year or so ago to go through various radio procedures going into and out of say YOW.

http://www.rfc.ca/en/rfcpodcast

The other thing that helps is to listen to liveatc.

Peter

A good effort by the RFC but I take exception with one part. They follow the AIM example of starting every communication with the aircraft call sign, instead of using the Industry Standard which is you start with the aircraft call sign when intiating a call to ATC but put the call sign at the end of the conversation when replying to an ATC communication. Even though it is not required for VFR I am also am a strong believer in reading back altitiudes and routes when in controlled airspace.

[Big Pistons Forever]

a good post. If I may add a couple of comments (and I believe I may.)

I notice many pilots living outside the greater metro areas seem to be nervous about communications. It would help a great deal if COPA clubs, flight clubs etc, put on a little seminar for a couple of hours once or twice a year to go over radio prcedures at the busier airports.

The other thing is that TAF and GFA's are not snapshot weather like a METAR. They are forecast Wx. Something that a lot of pilots (and fss types) including the commercial ones forget and treat them as gospel. They should be compared to the METARs along or near the route to see if the Wx, is in fact progressing as forecast, or better or worse. It is the reason that when you ask for a metar on NavCanada...you get the last three hours... I have seen commercial pilots who should no better ignoring a TAF and basing flight go , no/go decisions on a GFA...means "AREA" big "Area"

My personal enroute quality control on GFA/TAFS is wind direction/speed at altitude. If the wind is significantly different at cruise than was forecast you can take you preflight Wx print out crumple it up and stuff it into the crew door/storm window crack that that is blowing a cold draft on your neck. Now nice and comfy it is time to get serious about finding out what is really happening and developing plan B and C

[DanWEC]

Hedley, great advice to get out and FLY. I always love your spontaneous, informative posts my friend.
If I might offer an opinion however, I have found that many flying schools have an extremely conservative (almost Cavok or nothing) assessment of weather. Many times I've seen students at various schools I've been at (including myself while a student) been told not to fly because of a prob30 of 3 mile, hours later, or even things that don't even come down to VFR mins.
Of course, while part of being a pilot is to have upmost respect and knowledge of weather, I think that a bit of the reluctance to fly in anything but perfect weather then rubs off on the student, creating some apprehension. Also could lead to some surprises later on when flying in inclement weather becomes part of a job, or at least a requirement to get back home from a pleasure trip.
I can understand that obviously you wouldn't want your planes bombing around in TCU's at the helm of a student, but sometimes the criteria seem a little extreme at some clubs.

I remember one time only a few months back, I went to do some circuits for rental currency, was a crappy day, but 6nm vis, clg was 1000 foot above circuit altitude with no precip, and wx was improving by the second. (as was forcasted) When I walked into the club the guys behind the counter were stunned, and saying , "whaa? It's IFR right now" (It wasn't) So after they all spent 2 min hunched around the computer mumbling, they signed the plane out. By the time I finished my flight an hour later there wasn't a cloud in the sky......

I was almost talked out of a 4 hour trip because of a prob15 for the destination field of 3 mile 1000 foot.... 4 hours after my planned arrival! I'm all for playing it safe, but that's pretty limiting.....it turned out to be a beautiful clear day.

[loopa]

One last suggestion: fill your tanks. The only time you have too much fuel is when you are on fire, or hit the trees at the departure end of the runway. Plan for a minimum of one hour of fuel remaining after you land. Measure your distance of your leg. Calculate the minimum groundspeed you will require to land with one hour of fuel - eg 105 knots. After you level off, look at your groundspeed on your GPS. If it's less than 105 knots, time to flight plan another fuel stop. Continue to monitor that number during the trip, to watch out for increasing headwinds in the second half of the leg.

On the subject of fuel, I teach my students to create a FTT (Fuel Trend Table) something that paints a picture of approximately how much fuel you have in your tanks because the FD's are typically forecasted and may not be exactly the case.

Let's look at a few legs so the FTT can be put into use.

On your NAVLOG you have the following

POINT A -> POINT B PLANNED @ 30min WITH GPH of 10 = 5.0
POINT B -> POINT C PLANNED @ 22min WITH GPH of 10 = 3.7
POINT C -> POINT D PLANNED @ 45min WITH GPH of 10 = 7.5
POINT D-> POINT E PLANNED @ 11min WITH GPH of 10 = 1.8

When you reach over point A take time, when you reach over point B, take time, use the time to determine revised fuel burn, and subtract it off of the FUEL you had at take off.
When you reach over point C take time, use the time from B to C to determine revised fuel burn, and subtract it off of the FUEL you had at point B to see how much fuel you have.

Example

Point A @ 1000LCL / Point B @ 1039LCL = 39min @ 10GPH = 6.5GAL
Take Off Fuel of 40gal - 6.5GAL = 33.5GAL instead of the 35GAL you had planned to have over POINT B.

POINT B @ 1039LCL / POINT C @ 1054LCL = 16min @ 10GPH = 2.6GAL
Point B Fuel of 33.5GAL - 2.6GAL = 30.9GAL instead of the 31.3GAL you had planned to have over POINT C.

And the idea is that you are comparing how much fuel you are burning with actual winds in comparison to what you had planned, hence being able to catch contingency plans much earlier than a Revised ETA comparison. I still get them to do RETA as well to confirm that the numbers line up and for Flt Planning purposes.

As always, great post hedley!

[Shiny Side Up]

People are strange when it comes to flying cross country. Odd as it may seem it holds the greatest terror for some, not enough terror for others. Its also the only interest for some and no interest for others. Each will achieve often the ability they desire in this regard. For say all the students who all recieve identical navigation training, they all do different things. That's not really to say any of them are wrong. I kow some guys who do whatever they can not to fly through controlled airspace. Some had a bad experience with ATC, some are incredibly shy about talking to someone else on the radio, a few even are paranoid enough to think ATC is part of a "Big Brother is Watching" campaign.

Some new licensees are gone before the ink's dry on the back of their SPP. One guy was on his way to New York from Calgary in his private plane the next day. Some have absolutely no interest in going anywhere, they can see the same farmland over and over and just have a ball. To each their own. Aviation has no rules about how you're supposed to enjoy it.

If being afraid of it is what's holding you back though, I only have small bits of advice to add.

1) Start small, work big. Stretch your nav comfort zone out on your own pace. For most PPLs realistically this is going to be their bladder endurance rather than their fuel endurance. Many though make the mistake of assuming that they got to go on that fantasy trip or its not worthwhile - consequently if they're holding out they never go, and if they get the opportunity it becomes a terrifying prospect because they're so out of practice.

2) Make the time to do it. Time to spare? Go by air! Completely get rid of any "get home syndrome" or "get there syndrome" scenarios to be starting out. Smart guys who make this mistake scare the shit out of themselves, not so smart guys bend airplanes. Either way, now it holds real terrors for them, I know of plenty of fortunate cases where airplanes went for sale cheap after one of these trips.

3) Keep it simple stupid. Cross country trips don't need to be complex. Fly there, fly back. Best part is the way home should be easier, you've already seen it before. If you're going to stop somewhere, close the plan, then file again when you're going to leave. While you can plan to make a precisely timed stop and continue your plan, life of a fun flier doesn't need to be that hard. The guys on the phone for flight planning don't bite and if you stumble through the list on the back of the CFS they'll get over it and you'll get more competent (hopefully!)

Anyhoo, good thread.