Thursday, May 8, 2014

Doing Something About The Weather

I have long taught that the best and simplest pilot weather briefing is the "Standard Briefing."  I admit that I haven't had a phone briefing in a loooong time, but the Standard Briefing option is available from all of the online providers in the USA.

(In my cynical Part 135 days, I called this "spreading the liability," especially when concerned with Temporary Flight Restrictions or weather below 14CFR135 minimums.)

But I admit that this is not, in fact, my practice.  Don't get me wrong: I always get a standard briefing, even for a short local sight-seeing flight with one of my kids.  I save it to my Dropbox and cache it before the flight so I can refer to it later.

But that's not all I do.

For one thing, I like to take a look at the GFS-NAM forecast, which is a little hard to track down but I've provided a link.  A meteorologist friend says that he would never use this to make decision, but it's the only aviation forecast I know that provides a temperature outlook.  It's a little hard to interpret but not that hard; most of the problem is that the ceiling and visibility values are categorical.

Another is the radar picture from any of the commercial providers or apps.  I'm old enough to remember the grid in the Flight Service Station that you used to decode a Radar Summary like this:

SGF 2235 AREA 1TRWX 55/84 125/56 48W MT 330 109/36 C2129 AREA 5RW++ 40/117 192/128 160W MT 330 109/36 C2129 AUTO ^HN143 IN344 JN24532 KN25551 LM125541 MM345541 NM125452 OL1223434 PK1 PM22342 QM33442 RK11223.  
(The notation "KN25551" meant that on line KN of the grid the radar intensities were, going left-to-right and box-by-box, 2, 5, 5, 5, and 1.  Nowadays I know how to get the report but not how to get the graphic of the grid, and I'm not going to learn because there are a hundred apps that will give me the radar picture in much finer detail.  I do have to admit, though, that given that this report corresponds to the picture at left, I'm unlikely to go flying.)

This was more than enough to keep me legal.  But what about safe?

Now the National Transportation Safety Board says that this is. in fact, not enough.  Their report makes very interesting reading.  They claim that the FAA's weather dissemination apparatus makes it impossible to inform pilots of hazardous conditions that are, in fact, known to forecasters, and they provide several examples of accidents that were caused by known hazardous weather that was not mentioned in any aviation product.

Most of their concern is addressed to mountain wave activity (MWA).  It's one thing to contact the upward part of the wave in a glider, but it's another thing to be in the downward part of the wave in a Cessna 172 flying at best-rate-of-climb speed but descending, at night, at 400 feet per minute.  As Joni Mitchell might have sung, "I've looked at wave from both sides now..."

(One might argue that these accidents might have been avoided by an attentive pilot, but since mountain wave conditions can be invisible I am reluctant to judge.)

So now the NTSB is calling on the FAA to improve the situation, but I'm frankly not interested in waiting for somebody else to intervene for my safety.  So what else can I do?

One thing to do is to be aware of the possibility of adverse MWA.  When a strong wind is perpendicular to a ridgeline, wave is a distinct possibility, so expect it.  If you know the winds aloft (which you would if you'd had a standard briefing) you can fly with or against the wind to get out of the wave.

And always be in a position to turn toward lower terrain.

The thing is that  if you fly a lot your life should become one continuous weather briefing.  Don't just look at the METARs and TAFs: look out the window, call your friends and compare observations, look at the radar picture someplace nasty.

It takes 3,000 square miles of activity to generate a SIGMET; for anything smaller, you have to keep your eyes open.

And one more thing: make PIREPs.  This seems to be a lost art with better information available in flight, but let's help each other out.

And, please, be careful out there.


0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

Links to this post:

Create a Link

<< Home