Lost Procedure vs. Diversion

Prop Bending Forward on Take Off (digital camera artifact)


Diversions and lost procedures often cause students grief on the private check ride because they are high work load items. High work load items are not an uncommon occurrence for the pilot. For example, the instrument approach is a high work load item. There is a lot of preparation and situational awareness activity on the pilot's part to make sure that the approach is successful.

Executing a lost procedure for real is also a high workload activity with added element of fear that comes from not knowing where you are located (how much fuel do I have? Do I fess up? Help!).

Once you are beyond an initial difference, lost procedures and diversions are one in the same activities. The initial difference is that with the diversion you know where you are located on your flight plan (we hope) and for the lost procedure you do not know your location. Once your location is known, processes for a successful outcome are identical: turn the airplane towards a desired position, estimate time and fuel required to get there. The lost procedure is covered in all basic aviation texts. You start by circling, climbing and determining your position. Circling keeps you over the same place. Find a ground reference and keep it in sight. A barn, a pond, etc. work fine. In short, if you don't know where you are at, don't go somewhere else - keep your present position. A circling strategy for most small GA aircraft is to reduce power (around 2200 RPM in most 160-180 horsepower engines)and attain an airspeed of around 90 KIAS. Add necesary power to keep 90 KIAS, but don't get carried away because you are trying to conserve fuel and you aren't going anywhere because you are lost. Bank about 15-20 degrees which tends to form a rather stable bank and do a gentle slow climb. You can do a faster climb with more power if you know that mountains will block VOR reception. You climb to see more things and get better radio reception. If you see something you know is on the chart, point the aircraft at that object until the magnetic compass is stationary and note the heading on the compass, then resume your position hold by restarting the bank you had a moment ago. If you use the reciprocal of the direction to the object you aimed at, you can draw a line of position (LOP) on your chart from that object. You are on this line. A VOR radial will do the same. Crossing two LOPs or using a radial and a range (DME value) will allow you create a position on your chart.

Ok, now we are past the initial difference. From this point on the diversion and the lost procedure are the same.

1. Determine where you wish to go from here - the desired position

2. On your chart, position a straight edge between current position and desired position

3. Obtain the magnetic direction to the desired position (see below)

4. Turn the aircraft towards the desired position and maintain the determined magnetic direction using your heading indicator (make sure your HI is correct!)

5. As soon as you turn from your known position, start a timer

6. While enroute to your desired position, determine the amount of time and fuel it will take to get there. Can you make it? No, then start circling and come up with a better plan

7. If an airport is your desired position, then start preparing - see below

Obtaining magnetic direction:
The best device I have seen for this purpose is a multifunction tool one my students devised to simplify the determination of direction, time and fuel. It is a transparent straight edge. Note that distance, time and fuel are linearly related to each other for a given airspeed (at a given power setting). My student used indelible ink to tick off 5 NM increments on the rule (sectional scale in her case). On a row immediately below each 5 mile tick, put amount of fuel consumed and on another row below that put time in minutes.

Ok, I realize that "speed" really means ground speed. If you use the ruler in a no-wind situation, it will tell you how far, how much fuel and how long with no math - one value below the other. If you know that you will encounter head winds (or tail winds) estimate the percentage difference. For example, I expect to fly over the ground about 10% slower than my true airspeed. This means you add about 10% to time and fuel. Of course, if you have an air data computer on board, use the wind/ground speed data to estimate the effects of wind. If you only have a GPS, start heading to the desired airport and once you have cruise airspeed look at the estimated time enroute value (ETE) and reassess remaining fuel - will you make it?

Borrowing from marine charts, magnetic direction is obtained by lining up your straight edge on your current position and your desired position (creating a desired track). Taking great care, move the straight edge towards a VOR magnetic rose keeping the edge parallel to the desired track (mariners use parallel bars). Obtain your magnetic heading off the VOR rose. With some practice it is amazing how accurate this can be as long as your ground track is reasonably short (perhaps less than 25-30 NM).

Preparing for an unplanned airport after departing from a known position
So far, so good. Now the workload really starts. Here are the essentials perhaps in the correct order:

1. Obtain the CTAF and automated weather frequency if available

2. Obtain the automated weather or contact the UNICOM or traffic at the airport to get traffic/pattern advisories.

3. Determine pattern altitude at the airport

4. Determine other pattern characteristics (left, right, obstructions, etc.)

5. When do I start my descent? Do I intend to overfly the airport at TPA+1000' to inspect windsocks and runway conditions or will I want to be at TPA 2-3 miles from the airport? Use the 4 NM/1000' rule of thumb for descent planning purposes. If you are at 5000' MSL and you need to descent to 1500' MSL subtract: 5000-1500 = 3.5 thousand feet. Multiply: 3.5 * 4 = 14 NM. This rule of thumb is based on a 120 kt ground speed and a descent of 500'/minute. If you plan to be at 1500' at the airport, then start the descent 14 NM from the airport. If you plan to be at 1500' 3 NM miles from the airport, then offset the descent slope by 3 miles and start at 17 : 14+3 = 17 NM.

6. After how many minutes from my departure point will I cross 10 NM from the airport? Announce my intentions on the CTAF to airport traffic at 10 NM, or have a handy 10 NM easy to identify ground feature in mind to clue you when to report. This can also be a VOR cross radial. If you are using GPS then look at the distance to destination value

7. Estimate how and where you will enter pattern before you arrive

8. Estimate a drop dead time - I missed the airport and it is behind me. Start another lost procedure process and find the airport from this new position. Another procedure is to use a "sentinel" which can be anything that "guards" the backside of your route. A VOR radial, a highway, a railroad, etc. Once you have crossed your sentinel, you know you missed the airport - stop, do not keep going.

The Main Message
The lost procedure and diversion are both high workload activities and can lead to significant stress, especially if you are lost because of the fear factor, and in both cases you have likely opened yourself to unknowns such as new airports, new terrain, will I have enough fuel, etc. Success depends on your ability as a pilot to keep a cool head and carefully follow the recipe (a procedure) for success. Using a diversion or lost procedure check list is a good idea. Success in all aviation high work load situations have the same demand: a cool, analytical head and clean execution of the proper procedure, one step at a time.

Be nice to your engine - some tips

Runway 17, Alpine County (M45)

Reciprocating engines use petroleum oil to lubricate surfaces. A running engine's critical surfaces are kept apart by a very thin film of oil. A piston pushes on a rod which pushes on a crankshaft bearing surface (called a journal). This is where reciprocating movement is changed into rotational movement. The downward force by the fuel burn on the top of the piston is tremendous. It's 0.5-2 thousands of an inch of oil that keep metal-to-metal contact from occurring at the bearing surface when these forces occur. Also, protection of this surface under high load conditions requires that the oil is warm (usually around 180 degrees F.). Putting a high load on a cold engine immediately after starting is destructive because oil that was on the surface when the engine last ran has drained off, it is hard for the pump to move viscous cold oil to the bearing surface and when the oil flow reaches the surface its lubricating properties are poor until it warms up. Learn to position the throttle so that when the engine starts RPM is around 1000 or less.

On cold days with cold engines, prime the engine early, right after checking fuel quality. An engine will not start unless vaporized fuel is available to the cylinders. An engine will not start well or at all on atomized or liquid fuel. Trying to start an engine without vaporized fuel and flooding are the common causes of pilots grinding on the starter motor to get the engine to start. Grinding a starter motor for extended periods can deep cycle the battery. On a cold day with a cold engine, an early prime allows time for fuel vaporization. By doing this you will usually find that your engine starts up easily with very little load on the battery. Be sure to skip the priming item in your check list if you do an early prime. If you would rather to do it according to an approved check list, then prime, but wait a minute or so (with the master switch off!) before activating the starter motor. Large, high horsepower engines start noticeably easier when primed in this fashion. Bonus question: why wait until after checking fuel quality before doing an early prime?

Airplane batteries are not made for deep cycling. This means that if you severely draw an airplane battery down a few times, it's ready for the trash heap because it will never again hold a charge. (Cruising sailboats have deep-cycle batteries because they are drawn on for many hours between engine operation when the battery is recharged. Automotive batteries will fail after about 30 deep cycles whereas they will last for thousands of cycles if only used for starting, a 2-5% discharge. Marine batteries are designed to handle 80% discharges over and over.). If you find this topic electrifying, see http://www.windsun.com/Batteries/Battery_FAQ.htm.

If you have cowl flaps and it is a cold day, don't open the cowl flaps during start, taxi and run up. Most manufacturers state something to the effect: open cowl flaps as required. Watch your temperatures. Cowl flaps are required with high cylinder head and oil temperatures, not likely for a first start of the day and several minutes after on a 40 F. morning. With the cowl flaps closed, your engine oil will heat faster. Run ups should be done with the oil temperature needle in the green and this can take time with a cold start on a big engine especially on a cold day. When you cycle the prop you are making sure the governor and prop are functioning and at the same time applying warm oil to the prop hub cylinder. That oil isn't going to be very warm if you do the prop cycle with cold engine oil. (I won't get into the religion of prop cycling during run up)

Be kind to your engine and it will be kind to you (and your wallet).

How to make good landings

Cotton Under Wing

Introduction

I tried to write about the entire landing process. I gave up - it's too much so let's start at the beginning and I will end at the end at some other time.

It is said that the good landing starts long before reaching the runway. For your information, I have re-discovered that this is true and I spend a good deal of my time as an instructor convincing others that this is true. A good landing starts with a mind set by the pilot long before the final leg. The good pilot pays attention to his perceptions and carefully executes measured responses to these perceptions. Landing an aircraft is very much a skill of executing a picture based on one's perceptions. Merriam-Webster defines art as a 'skill acquired by experience, study, or observation'. Another definition of art is the 'creation of beautiful or significant things'. I know a beautiful landing when I see one and I know it requires a skill acquired by experience and observation.

Paraphrasing those, on whose shoulders I rest, "landings are one possible outcome of a go-around"; if you happen to see a good landing evolving in your go-around attempt, take it and then glow in the cult karma of 'the wheel greasers'. The flip side of this coin is that if the landing is going to be something other than greased, then by all means, have a nice go-around. And by the way, kudos because your perceptions told you your art was bad, you weren't drawing the correct picture. This is the first step to being good at landing. The go-around model of landing is great advice: if it ain't working, go around, don't force a landing that was not meant to be. Some pilots have many more good landings than go-arounds. Why? What leads one pilot to grease the wheels on almost all landing attempts and the others have this experience at a low frequency even after years of flight? The answer is that those who fully understand the picture they are supposed to create using their brushes (pitch, roll, rudder, power, trim) become good landers.

The Pattern Before Final
After initial descents or climbs into the pattern, a good pilot maintains pattern altitude and an airspeed that is not too fast and not too slow, but just right. This will vary from aircraft to aircraft and with external conditions. When it is gusty, a pilot will want a slightly higher airspeed for better control of the aircraft. (I would mention some airspeeds for typical trainers, but I would rather not broach religious topics in this blog - see your clergy person at your local Faith Based Operation otherwise known as an FBO). As the good pilot closes in on the working end of the runway, s/he is tightening tolerances by catching lateral, altitude and airspeed errors earlier and earlier in order to minimize how much the aircraft position must be changed to correct an error.

The Final Approach
Recall that tolerances are being tightened by the pilot; there is less and less room for corrections as the pilot nears the runway. Here is the key: big corrections near the ground are at best the worst thing you can do and at worse dangerous. The good pilot is catching errors while they are almost imperceptible to the eye and corrects with control changes that are of the smallest required movement to make the appropriate correction. Whoa, that last sentence was vague - what does that mean? It means that sometimes little tiny corrections are needed to move the aircraft a few centimeters to stay on the two dimensional glide path, and sometimes big control movements are needed to move the aircraft a couple of centimeters to stay on the glide path, but in either case, the parameter in error is corrected by exactly the right amount and the magnitude of the correction is small. Do you see the common thread? In one case a slight puff or perhaps a slight reduction of cross wind velocity made the aircraft move off line and in the other case, it was perhaps a serious wind shear. In both cases, the correction was a few inches, not a few yards, if you will allow me to mix my metrics. A lot more control movement was required in one case, but in both cases it was just the right amount and it led to very little movement of the aircraft. The 'right amount'? The right amount is the amount of paint an artist uses when conveying her mental perception onto paper with a brush. The 'right amount' is the amount of control reactions (throttle, ailerons, pitch, rudder) the pilot uses to create a picture of the perfect landing. Picture, what picture? The picture is the view the pilot sees looking out the window. If you are having trouble with your landings, ask your instructor to do landings more often and relax, listen and watch the picture s/he draws in and out of the cockpit as the artist works her palette. As an instructor, I am frustrated that many pilots insist that they attempt all the landings during training when I know they don't see the picture. The best artists study the art of other artists to help them develop their skills and yes, the best artist try, try and try again. It takes a keen understanding of what exactly the art is and then repetition to improve one's skill to accomplish the art. If you don't have the picture, you will never get the art.

Why is Early Error Correction so Important on Final?
It is simple: last minute corrections destabilize your artistic effort. Bank and pitch changes used to correct large errors are dangerous when applied near the ground. This is because on short final your aircraft is slow and draggy and it requires large bank and pitch changes to correct errors. Massive attitude changes near the ground can cause all kinds of problems from stalls to planting a wing tip or nose wheel into the ground, etc. Understand the forces working against you long before reaching the runway and correct early when errors are minute. As you approach the runway, airspeed should be nailed to a perfection, the aim point doesn't move and you have the aircraft tracking the extended center line. Mess this up and it's a given that you will have either a messy landing, or a wonderful go-around opportunity - your choice.

Some interesting URLs for All Pilots

Another cruddy day over San Francisco

AOPA:
You may have to be an AOPA Member to see these, I am not sure. I find the following articles interesting and these and many more can be found here.

Your airplane:

To download a set of flashcards that you fill in to describe important facts about your airplane click here (1.7MB PDF). Fill in details such as emergency procedures, air speeds, fuel data, etc., and use the cards later for a mental refresh.

Runway Markings:

If you want a great way to learn and review runway markings, click here for a 700KB low resolution version or here for a 3.4MB high resolution version of the same file.

Accident reports:

All pilots should read the Nall Report on a regular basis to understand the common causes of accidents. If you click here you will get a list of accident reports by the year. Another interesting AOPA web page, known as featured accidents, in which accidents are highlighted and used to illustrate how pilots get into trouble. Featured accidents are updated every two weeks, so reference this page often. Pilots should read accident reports to understand what to do and what not to do when they encounter situations similar to those that led to these accidents. It's useful to second guess a pilot that has had an accident, but what would you do during an adrenaline rush if the same thing happened to you?

Why I Like to Fly

Final Approach Alpine County (M45)

I like to fly for many reasons. Why? It's fun, it presents scientific and artistic challenges. In some cases flying is practical, but it's mostly fun. There's the great view, the challenges of managing myself and an aircraft to have fun and stay safe all at the same time - they go hand in hand. Since I am a flight instructor, I am guilty as charged for getting paid to fly which arguably adds to the joy of flight. It's a tough life, but someone has to do it.

However, no matter what justifications I use I always come to a root cause for my desire to fly: risk. Risk? You fly because you like to do risky things!? No, I fly because there is risk over which I have a lot of control. It's exactly this same concept that made me want to do blue water sailing in a past life. I crave the challenge of being put into an environment in which I can reduce risk by exercising my knowledge, my skills and my judgment. "Oh, flying isn't for me", you say to yourself; "it's too risky". Do you drive on freeways? You may not like driving as much as I like flying, but being on a freeway means exercising your knowledge, skills and judgment (at least I hope this is true!) to reduce risks and driving on a Bay Area freeway is very much a risky business.

On a final note, being good at risk control means continually getting better at risk control. Risk can never be eliminated, but through diligent effort it can be brought down to acceptable levels and continually reduced. To me the constant learning this implies is frosting on the cake. I love to learn and believe me, there is no such thing as a pilot so good that s/he can't be better. It's a life long endeavor to increase and improve one's knowledge, skills and judgment.

Have fun, stay safe.

Flying the Airport Pattern Safely

Coming over the ridge into a high final at South Lake Tahoe (KTVL). Runway 36

(Note to readers: the following was inspired by pattern work at Palo Alto, California which is a towered airport with a single runway. Tower manages simultaneous left and right traffic. However, the comments are relevant to all airports.)

Pilots, do you want to have a mid-air collision while flying the pattern? It's easy! All you have to do is fixate on the runway, especially when you make the down wind to base turn and the base to final turns. I encounter this behavior all too often; while flying downwind the pilot fixates on the runway behind the aircraft. Later s/he turns base or final, again while fixating on the runway. By staring at the runway you set yourself up for a mid-air collision. If you are on the down wind, expect to collide with the slower traffic preceding you on downwind. If you are making left traffic, expect to get whacked on your right side while on base by an aircraft on a long final or T-bone an aircraft on final or have a high velocity head-on with an aircraft on an opposite base. All it takes is for two pilots to be fixated on the runway and the probability of a mid-air experience in pattern goes up.

Would you like to avoid a collision? This is also easy! Know where your preceding traffic is located. Before turning downwind to base, look at the path of final abeam your aircraft and then scan away from the runway, inspecting both the extended final and opposite down wind legs for traffic. This is a good habit to guard against an announced straight in approach or a fellow pilot on the other side of the final line. As you turn to base, look straight out the front windscreen for close-by traffic you may have missed in your earlier scan and to obtain pitch and bank data from the horizon to control the turn. Level your aircraft's wings while looking forward and once level, take a quick look towards the runway to judge when you should consider turning onto the final leg. When you decide it's almost time to turn towards the runway onto the final leg, again look out the window at the intersection of your base to final and the opposite downwind. Make sure you know where opposite down wind traffic is located. Continue your scan away from the runway onto a long final to determine that there are no aircraft on a straight-in approach then begin your bank towards the runway. Turn to final looking straight out the window, referencing the horizon, for all the same reasons I mentioned above. Once the runway is in view, your mid-air danger potential is from one of a base turn made in front of you by another pilot (left or right) or you catching up with preceding traffic.

When changing pitch or bank angle, good VFR pilots reference the horizon by looking forward out the wind screen for reasons of both turn control and collision avoidance. Keep in mind that the aircraft you are likely to collide with in pattern is directly in front of you or is on an extended final or is on the opposite downwind and you both turn into each other on opposing base legs. Be careful out there.

Flight a real thrill

Truckee Airport (KTRK) Near Lake Tahoe

When I get some time, I will post little blurbs on aspects of the knowledge a general aviation airplane pilot is expected to possess. Topics will likely cover aerodynamics, airplane systems, etc. I am open for suggestions.