Sunday, May 25, 2014

It just might be working...

Those two or three of you who are regular readers know that I have been working on the "Essence and Finesse" project for a long time.  Put briefly, I have been exploring how the aerodynamic concepts of "essence," which is like energy only more so, and "finesse," which is the wing's glide ratio only more so, can explain various flying phenomena.  You can read more starting here.

But one thing that has always bothered me about this project was that, so far, I had not used it much in the air.  The reason for this is simple: a primary student has to pass the FAA knowledge test, and presenting an alternative approach to the basics of aerodynamics is more likely to confuse people than help them.

But if I can't teach it, then what's the point?

Our new glider club is appropriately strict about who instructs, and I needed to fly with the Chief Instructor before taking on students. We flew yesterday, and it was fun!  He asked me to do some things I haven't done in a while, which I enjoyed.

But I saw an opening.  We were in slow flight with almost continuous buffet (remember, few gliders have stall warning devices, so being sensitive to the buffet is important).  He asked me to do a 360 degree turn, so I put the ship into a 10 degree bank and started around.

The buffet increased so I relaxed just a little back pressure, not so much that we picked up speed.  The buffet was still there.

"That buffet is energy your glide doesn't have any more," I said softly.  ("Said softly" can be hard in a glider at high speed with the air vents open, even though there's no engine noise.  But in slow flight there' s much less wind noise so you can speak softly.)

Now, I didn't go into a long dissertation about essence and fuel and the psyche, just a simple statement about energy management.

There was an appreciative murmur from the front.

This stuff might be useful!

Sunday, May 11, 2014

But I had a job to do...

The experienced pilot was a successful businessman who had accumulated enough money to fill a hangar with beautiful classic airplanes, and he held a local aviation group in thrall discussing how he found and restored and flew them.

He'd been flying for a long time, and of course the conversation turned to how good we have it now.  These are funny conversations in aviation: nobody, and I mean nobody, talks about the good old days.  It's always "Man, we have it so much better now..."

"Let me tell you about GPS.  A few years ago I had one of the first GPS units in my Queenstar (the type has been changed to protect the guilty, but it's a pressurized cabin-class twin).  It was about this big (arms outstretched) and the screen was about this big (fingers pinching a quarter).  Well I was headed into White Pigeon (a well-known mountainous airport) one day for a job and it was beautiful VFR except for about 5 miles of fog covering the airport.

"But I had a job to do and I had to get in there."

The textbooks call this get-home-itis.  I started to squirm in my seat.

"So I set the GPS to navigate to the airport and followed it down into the clouds."

I squirmed a lot more.  No mention of setting a known waypoint on the final approach course, or following a published approach (there were none then), or extending the centerline, nothing.  Just "the airport" and I suppose he approached willy-nilly without any plan for a missed approach.  He had no idea where the GPS thought "the airport" was.  In all likelihood the airport reference point wasn't even on a runway so he was lining up with a 50' hangar with a remote altimeter setting so maybe he'd miss it by an inch or so if he was lucky that day.

"So got down to about 100' (one hundred feet!  At an approach speed of about 110?!?) and sure enough about a quarter mile (a quarter mile!  At an approach speed of about 110?!?) I saw the airport and landed.  Boy that GPS was great."

I was very uncomfortable.  I didn't want to rain on this guy's funeral procession, but that kind of crap (there is no nicer word) has gotten more pilots killed than almost any other kind of crap I know.  But (pardon my crudeness) if I spoke up I'd be the kind of asshole CFI who gives CFIs a "bad name."  So I held my tongue.

But one of my students was seated next to me.  I leaned over and tapped him on the shoulder.

"Don't do that," I whispered.

By the way, that approach speed was 110 knots indicated. At 5,000' MSL, the true airspeed is 10% greater, so call it 120.  That's a mile every 30 seconds, one-half mile every 15 seconds, and one-quarter mile every 7.5 seconds.  He had 7.5 seconds of forward visibility.  Now a glance at the GPS plus the time to refocus at a distance is probably about half of that.  If he had hit something he would never have known what happened.

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.