Getting to altitude involves more than crawling into an airplane, starting the engine, and pointing the nose up. Pilots must consider many aspects factoring into the initial climb and the following ascent to cruise altitude. Some of these include the headwind or tailwind component, the climb corridor, clouds, and outside air temperature.
There is a great deal more to climbing an airplane than merely understanding the difference between Vx and Vy. Most students and almost every private pilot understand the best rate of climb (Vy) gets you to altitude in the least amount of time. They also know the best angle of climb (Vx) attains the highest altitude gain over the shortest horizontal distance. In addition, when it comes to actually getting to cruise altitude, the important question is which climb technique to use in which particular situation.
For instance, every pilot knows in order to clear an obstacle at the end of a takeoff, the appropriate speed to use is best angle. They also know when it comes to climbing the airplane to altitude, the fastest way to get there is by using a Vy climb.
But what of the cruise climb? What is it and when should a pilot use it? What are the advantages to using cruise climb over other climb techniques? Should the winds aloft be taken into consideration? How can a pilot best use different climb techniques for the most efficient use of the airplane?
When it comes to getting over obstacles, flight instructors teach student pilots short field take off techniques. This includes using every available foot of the runway, holding the brakes, running the engine to full power, releasing the brakes, accelerating to rotation speed, and then climbing out at a specific attitude – explicitly a pitch attitude resulting in an airspeed of Vx. Once clear over the obstacle, the pilot lowers the nose to allow the airplane to accelerate to either Vy or cruise climb. Nothing could be simpler, right?
Other considerations, such as making certain you don’t get too slow is a very important concern, one that occasionally appears in NTSB accident reports with the curt phrase, “Failed to maintain flying speed.” This is why flight instructors and designated examiners pay very close attention to a student pilot’s control of the aircraft during climb. They also want to make certain students and applicants are knowledgeable regarding the dangers of stalls and spins in this flight regime.
Beyond the initial climb concerns, the techniques used to get the airplane to cruise altitude involve safety and other operational issues. For instance, climbing the airplane at Vx involves a higher nose attitude, making it difficult for the pilot to see traffic out in front. Fortunately, this climb does not last long. The Vy climb attitude is better, but also hampers forward visibility. Flying a cruise climb at higher airspeeds affords better forward visibility but as with the two previous climb examples, also limits visibility to some degree.
The solution to seeing traffic over the nose is to S-turn throughout the climb. By turning the aircraft slightly, the pilot is able to clear in front of the nose prior to entering that airspace. This practice, simple as it seems, can be life saving.
The wind is another consideration to keep in mind while climbing. If you are going to fly the majority of your flight with a headwind, don’t be in such a hurry to get the airplane to altitude. The more time you spend with a headwind, the more fuel you’ll burn inefficiently. If on the other hand, you are going to be cruising with a tailwind, you will want to get up there as soon as possible to take advantage of the tailwinds.
© 2010 J. Clark