Wednesday, June 15, 2011

Long Cross Country - Part II - Preflight

This is part II of the story of my long cross country solo flight. Preflight, before every flight there is preflight. If you get preflight right, you may have an enjoyable flight :)

Before a student cross country flight the flight instructor has to review the student's flight plan and certify, in the student's log book that the plan is correct and the student can make the flight safely under known conditions.

There is a lot of work that goes into getting that endorsement. As you saw in my previous post, first you need to plan your route and determine the course and distances. A big thing for me is to go beyond just the calculated course and use the chart to figure out what big picture landmarks I should use to supplement the calculated course/heading data. You saw my notes on that in Part I. You also need to learn and record important details about the destination airport (Pattern altitude, runway altitude, length and width, where's the windsock, do they have fuel, where is transient parking, etc, etc.), and what radio frequencies (for weather, CTAF, ATC, etc) to use. Here's a pic of some of my notes for the Lodi airport.

Of course you have to take into account airspace, terrain and the runway you think you'll be using. You also need to develop your climb, cruise, comm and descent plans. They don't have to be complex, but they do have to be well thought out. This is what I had for Lodi. You can see some last minute erasing was done.

You can do that days or weeks ahead of time. And, you can review that with your flight instructor ahead of time as well. They may provide additional pointers as to what to look for or what you might see as you fly.

Weather or not
Then comes the biggy - weather. The day of the flight, preferably a few hours before planned take-off, you get a full weather briefing from Flight Services and learn the likely conditions of your flight. The winds, the temperature, clouds, rain, fog, smoke, dust, the dreaded mountain obscuration, etc... all of which can make you adjust or cancel your flight depending on safety.

Those of you who know pilots have probably noticed, we're obsessed about weather. The closer we are to an important flight, the more obsessed we become. Pilots watch the evening weather forecast with critical eyes, carefully noting the placement of the cloud graphic on the weather map. They may groan if the weather man says words like "foggy" or "low clouds" because all of these things can prevent or delay a VFR flight. Some may mutter about how totally useless the term "partly cloudy" is in a weather forecast, it is so inaccurate! Ask a pilot how the weather will be tomorrow on any given day and he/she can probably give you not only the temperatures, but forecast winds and cloud heights and amount of clouds (few, scattered, broken or overcast) especially for the home airport. Pilots start to learn the rhythm of the seasons and things like the way winds tend to pick up in the afternoon in late spring/early summer in the bay area, or how the low clouds and fog usually burns away by 11AM or 9AM if you're lucky. But I digress...

Back to preflight. The night before the proposed flight (Sunday) I checked the weather forecasts online, things looked pretty good, the morning fog was predicted to burn off early, winds looked like they would be generally light. My main concern was the forecast winds at 3000 feet in the SFO area. They were forecast to be blowing at 22knots. My CFI, Scott, had said its not a good idea to fly with winds aloft over 15 knots because that makes holding a heading rather hard for the inexperienced. That made me think my flight might be scrubbed again. However, forecasts being what they are "horoscopes with numbers", conditions were close enough to right to give it a shot and plan to meet with Scott the next morning.

Monday morning I got up extra early and checked the forecasts again. Winds seemed lower (with the exception of the 22knots at 3000 ft in SFO area) and clouds predicted to clear even earlier. Good news! So I drove down to the flight club to get my weather briefing and complete my flight plan.

The briefing was relatively brief. Good old "mountain obscuration" was predicted for the area but the briefer could see on satellite (and I could see out the window) there wasn't a cloud in the sky. Winds were predicted relatively light for all locations and the winds in the Sacramento valley were light as well. Everything looked great except those 22knot winds predicted for SFO area. The briefer mentioned that would be over 20% of my expected airspeed of 110 knots, so that made it an adverse condition for me. [Yes I know 22 is not 20% of 110, but that's that the guy said.]

I wondered if that meant I wouldn't be flying today. I didn't want to go through the 45 minute process of completing calculations for over 250nm of flying if I was going to be canceled. So I called Scott and left a message to see if I should call it off for those winds. He called back and said no, I could go ahead and do the plan. I wouldn't be in SFO area for long, and he was pretty sure the forecast was wrong.

This put me in a bit of a conundrum. To do a flight plan using pilotage and dead reckoning, the wind at my proposed cruise altitude was needed to determine what actual heading I would fly. If the winds were not as predicted, my headings would be wrong, either slightly or majorly depending on how wrong the forecast is. But, it is what it is, so I did my calculations based on forecast and knew my headings would likely not work so I would have to rely on the pilotage part (the big picture part) to keep me on course if the headings did not work out.

Here is a picture of one of the three pages of my flight plan/navigation log:

Eventually Scott arrived and we reviewed the plan. He had me walk him through the whole route to Lodi and Colusa and back to RHV, what landmarks I would use (again) and key information at the airports I was flying to. If I opened a flight plan or if I was planning on using flight following, etc. He insisted I should have at least three different ways to find each waypoint, at a minimum the heading and time I calculated, plus two more landmarks or sets of landmarks for each. He also gave me some tips as to what I would see when approaching a couple airports that are particularly hard to find.

We talked about the winds and what would happen over the Calaveras reservoir if the winds really were as forecast. I have been in a small plane over Calaveras in high winds before it was "moderately" turbulent, meaning things that weren't tied down were bouncing around. He said simply if the winds were that strong, it would be turbulent. I'm definitely more comfortable with turbulence now than I was a year ago, my first cross country had some light turbulence. I was really hoping the forecast was wrong.

I had to redo my descent plans because I planned on getting to 500' over pattern altitude too early. Not surprising since this flight was the first one that I was likely to have to cross midfield and then turn into the pattern, twice. Once at Lodi and once at Colusa. This was a maneuver I've never done successfully before, the last time I attempted it with my CFI I ended up turning the wrong way and getting totally mixed up. He made sure I knew which way I should turn.. and believe me, it was one of those mistakes you only make once. I'll never forget you have to go left to go right and right to go left. But, I was a bit worried about doing that right... I knew though. If I had a problem on the approach, just announce my intentions, fly away from the airport, and try again.

In the end, Scott was satisfied with my plan and endorsed my log book.

This time he suggested I actually get out of the plane and take a break at one of the airports, it was going to be a very long trip. He said he wouldn't be worried about me until after 4PM. I was hoping to be back well before then because I was concerned the wind would pick up in the afternoon, as it normally does. With a parting "good luck, be safe and make sure to clean the windscreen" I was off. Time to preflight the airplane (that was just preflight planning!) and go.

No comments:

Post a Comment