Departures 101

The two most critical phases of flight are the takeoff and landing. The accident record bears out that most accidents occur during a takeoff or a landing. Most accidents also tend to occur close to an airport, much like most car accidents occur close to home. When it comes to flying, pilots put a lot of thought and practice into landings. They are the hardest thing in flying to learn, especially when dealing with a crosswind, a short field, or an obstruction.

But not many of us think a whole lot about takeoffs. The tendency is to line up on the centerline, push the throttle forward, and go. Takeoffs don't beg for attention until the weight of the airplane, the density altitude, or the soft surface of a grass runway becomes critical. And judging by the number of accidents that occur under such circumstances, even those scenarios don't get the attention they deserve.

Here is a confession: I used to fly that way. Not until I was a commercial pilot, and especially a flight instructor, did I begin to appreciate the complexities of takeoffs. My eyes were really opened as a pilot on turbine equipment at an airline, where the regulations regarding takeoffs are numerous and detailed.

Fortunately, general aviation has not gone down this road, but there some particulars about takeoffs that we should study. Following are four things to think about before you taxi to the runway.

A rolling takeoff versus a static takeoff

A rolling takeoff is just that--one in which you taxi onto the runway without stopping, line up with the centerline, and advance the throttle, much as you would in a soft-field departure. A rolling takeoff is not a big deal. However, there are a few safety issues that should be considered.

If you are doing it to get out before the guy on final lands, you should just wait until he lands. It is not worth rushing. If you are doing it because the airport is empty, have at it. But, consider these points. First, if you inadvertently step on a brake, you could swerve and find yourself in the grass. Second, your attention will be focused on the runway (which is good), so you will have less time to take a last-minute peek at your engine instruments and directional gyro to confirm runway alignment (not good). Remember, the take-off roll is the last chance to avoid taking an unairworthy aircraft aloft. Third, if runway length is even remotely an issue, the extra time and distance you used to go to full throttle just made the runway that much shorter--unnecessarily so.

A static takeoff, on the other hand, is one that starts from a complete stop. There are two varieties of the static takeoff. The run-of-the-mill version works by lining up on the centerline, and then slowly pushing the throttle in and accelerating down the runway. The second version is what you use for a short-field takeoff: You hold the brakes, add full throttle, check your instruments, then smoothly release the brakes and accelerate much faster. Although this is primarily used on shorter runways, there is no reason you can't use it on longer strips.

The climb profile

Consider a steep climb versus a shallow climb. A steep climb will get you higher in a shorter distance across the ground, and it is what you will use if terrain or obstacles dictate. Some airports require a steep climb for noise abatement. A shallower climb covers more ground and requires more time to get to altitude. Shallower climbs also help with engine cooling. The pilot's operating handbook (POH) for your aircraft may well provide specific guidance for various conditions.

If you spend some time with the performance charts, you might be able to figure out the most fuel-efficient climb for a given scenario. Getting higher faster means being able to lean the mixture sooner, so you'll burn less fuel. A shallower climb might reduce the effect of a headwind. If the performance section of your POH does not help with this comparison, then fly a couple of flights in similar weather conditions and compare the results--with fuel prices what they are, the savings could be worth it.

If you are staying in the traffic pattern, especially a busy one, you may prefer to do some steeper climbs so that you can get to pattern altitude quickly and make yourself as visible as possible. Again, especially in the summer, pay attention to engine temperatures. If you are pursuing an instrument rating, become familiar with the differences in V_X versus V_Y climbs because certain standard instrument departures (SIDS) and obstacle departure procedures have altitude crossing restrictions on the climb profiles that you need to be able to reach.

Changing frequencies

You have just departed from a nontowered airport on a cross-country flight. The pattern is moderately busy. Because you want to activate a flight plan and request traffic advisories from air traffic control (ATC) as soon as possible, you need to change frequencies. When should you do it? When should you not do it?

Consider what will happen once you switch from the common traffic advisory frequency (CTAF) or unicom to the local flight service station or ATC frequency. With respect to the airplanes already established in the pattern, as well as those that are inbound but unannounced, you are effectively NORDO (short for no radio). Even if you announced before takeoff which direction you will be flying as you leave the pattern, odds are that others did not hear you or, if they did, it simply did not register.

The most considerate and safest route to take when you need to switch frequencies in a case like this is to climb to at least pattern altitude before changing frequencies. If you can climb higher, say another 500 feet, great. If you are constrained by controlled airspace above you (Class B), you may not have that option, but such circumstances are relatively rare. What you don't want to do is switch as soon as you are airborne, which will leave others wondering what your intentions are. Of course, if your airplane has two communication radios, you can continue to monitor the CTAF.

When pilots are on an instrument flight plan, ATC is aware that they must safely leave the pattern before initiating contact. You can still do so in a timely fashion by waiting until you have cleared the airport traffic area.

Safely leaving the traffic pattern

The Aeronautical Information Manual offers some guidance here, and this scenario actually goes hand-in-glove with the one we just discussed. Specifically, it mentions leaving at a 45-degree angle to the runway heading after you take off. This is great if that is the direction you need to go, and it does serve the purpose of getting you out of the traffic pattern expeditiously.

If you took off to the east on Runway 9 but are departing to the west, the safest avenue could be to fly to pattern altitude, join the downwind, and--once a mile or two past the airport--continue your climb (if necessary). In this case, you definitely want to announce your intentions on the CTAF; don't change frequencies until you are well outside the established traffic pattern.

You would not want to depart to the west by flying parallel to the runway on the opposite side of the traffic pattern. In other words, if the downwind leg discussed above is north of the airport, do not leave by flying on the south side of the airport. There may be an inbound airplane flying an upwind leg that you are not aware of yet.

Taking off and leaving the traffic pattern can be perilous if handled carelessly. But by combining good technique and good, old-fashioned common sense, you can make a safe departure. Just remember, the time to start thinking about these issues is before you even start the preflight, not when you start the takeoff roll.

A pilot since 1990, Chip Wright has been a CFI since 1994, and is now an ATP and a Canadair Regional Jet captain for Comair. His total time is 8,000 hours.

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Links to additional resources about the topics discussed in this article are available at AOPA Flight Training Online.