Thermals, Etc.

For the pilot new to light aircraft such as the Challenger, thermals and other air disturbances can be a little disconcerting. Due to the light wing loading of the Challenger, it is affected more by these disturbances than heavier wing loaded GA and Commercial aircraft, it 'feels' the air more. This is a normal situation and you should not let it disturb you. Thermals are 'bubbles' of hot air rising from the ground and are eagerly sought after by soaring enthusiasts but can cause concern for someone not used to them. The Challenger soars very well, engine off, but that is a different subject, this article is for the newer pilot first beginning to experience thermals and other light disturbances in the air.

When you first begin experiencing thermals, you will probably feel it as a strong lift and you may go up rather forcefully. This strong lift may also cause your airspeed to go up, sometimes too far up. This situation is perfectly normal and is easily handled if you know the proper procedure. First, remember that a thermal is a rising column of air and for every rise in air, there is a corresponding down movement of air. The thermal, the up column, is usually concentrated and more forceful while the downdraft, down portion, is usually around it and therefore more spread out and not quite as forceful. Sometimes in air disturbances caused by other situations besides a thermal, the down can also be quite forceful. Second, anytime you enter any distubance of the air that is strongly moving the aircraft around, slow your airspeed to lower the stresses on the aircraft but not so much as to risk a stall. Third, when your aircraft is being strongly moved around by an air disturbance, thermal or otherwise, concentrate on two things, attitude and airspeed. Never mind the altitude unless close to the ground, just let the aircraft go up in the rising column and down in the descending column, keep the airspeed where you want it by throttle and keep the aircraft relatively level.

When you are being lifted, sometimes your airspeed will go up and you will want to reduce throttle to maintain your correct airspeed. This requires an engine that will deliver usable power at the reduced RPM. When you go into the down moving air, you will have to throttle back up, sometimes strongly, to maintain your airspeed and this requires an engine that will also deliver usable power at that RPM.

The Challenger is a strong aircraft and will handle fairly strong disturbances but the pilot must prepare and train himself to handle these situations. 'Rough' air is sometimes a fact of flying and strong thermals can actually be fun, just know the limits of the aircraft and your own personal limits. Take the time to ease your way into windy and thermal conditions as you are beginning to learn about your aircraft and enjoy it's full capabilities.

Author:   George Hurt