The pilot should be aware of the possibility of uncommanded  lift (often referred to as “false lift”) and the possibility of an  unplanned descent caused by surface wind or an ascent from  a sheltered launch site. Pay attention to people and obstacles,  including the chase vehicle, fences, and particularly to  powerlines. Realize where all powerlines are and visually  locate them as soon as possible. One consideration that must be made at the outset of any  balloon flight is the possibility of experiencing phenomena  variously referred to as “false lift,” “false heavy,” or  “uncommanded buoyancy.” These terms all describe an  onset of various factors and conditions, which, despite  the differences in terminology, all relate to the result of  air moving over or under the balloon. The most important  thing to remember is a balloon encountering one or more of  these factors is not under the full and complete control of  the pilot, and is therefore a hazard. Pilots should be aware  of these conditions, avoid them if possible, and be aware  of procedures and practices to minimize their effect on the  balloon’s flight. not be sufficient lift to stay in the air, as a portion of the total  lift has diminished. Pilots are usually taught that the lift created by air flow over  the top is to be considered “false lift,” because it was not  created by applying heat to the envelope. The lift is real;  as long as the speed of the air flow and the balloon remain  sufficiently different, the lift continues to be generated. As  the balloon accelerates, the lift created by the air flow is lost  and more heat must be added to maintain the same rate of  ascent.  Three areas of focus warrant discussion: It is important to understand the total physics involved. While  the balloon is at neutral buoyancy on the ground, there are  two lift forces at work. The first is from the heating of the air,  creating buoyancy inside the envelope. The second is the flow  of air over the top. The lift from these two elements combine  to create the lift necessary to be at equilibrium. The addition  of a small amount of heat, through a short burn, increases the  total lift and allows the balloon to rise. The same condition can exist when descending through a  low level wind shear or jet. As the balloon penetrates the  lower boundary of the wind shear, the top of the balloon is  momentarily in a faster moving layer of air which increases the  air flow lift component of the total lift generated. For a short  period, there may be equilibrium with the two components of  lift, heat and air flow. As the descent continues, the top of the  balloon moves out of the faster moving air (the value of one  of the lift components), and air flow is diminished. The rate  of descent increases, unless the pilot takes action to increase  the buoyancy portion of the total lift by making a burn. Some  pilots, when experiencing this, believe it to be a “false heavy”  situation, an incorrect perception. During initial flight training, pilots are taught about the effects  of air flowing over the top of the envelope. While the balloon  is static on the ground, the shape of the top forces the flow  of air to compress over the top creating a low pressure area.  [Figure 6-16]  This low pressure area creates lift in much the  same way an airplane wing does. There are two components  of lift: heated air inside the envelope and the lift created by  the air passing over the top. As the balloon takes off and  accelerates to the speed of the air mass, the flow of air over  the top diminishes, thus any lift created by it is no longer  available. If the balloon is at equilibrium at launch, and there  is not some response by the pilot to add more heat, there will  False heavy is a condition which is the exact opposite of the  false lift scenario described above, except that it is happening  at another part of the balloon and the force generated has a  downward component. 6-15 False Heavy (Downward Lift) False Lift Uncommanded (False) Lift Figure 6-16.  False lift dynamics. Lift Wind L o w pr ess ure ar e a •  False lift •  False heavy (air flow under the lower portion of  balloon, creating downward lift) •  Envelope distortion causing diminished capacity