Weigh Off

Objective

• To develop the student's skill in launching with a hand held weigh or inflation restraint release

Elements

• Use of weigh off procedure to control ascent rate and false lift during launch

Equipment

• In-flight maneuver

Instructors Actions

• Pre-flight discussion of launch procedure including use of inflation restraint, equilibrium, safe ascent rate, and effect of false lift
• Bring balloon to equilibrium.. Rocking basket will indicate equilibrium approach. In calm condition release inflation restraint.  All crew clear of basket. One crew person applies 20 pounds downward pressure on pilot's outstretched hand.  With basket clear of ground the 20 pounds excess weight will allow the balloon to ascent at 100 fpm.
• Discuss ascent rate.  Ideal rate is 100 fpm. Or rate necessary to clear obstacles. Slow ascent rate is necessary for safe multiple balloon operation and not to alarm first time passengers.

Student’s Actions

• Perform handhold and inflation restraint weigh off
• Discuss the cause of false lift

Completion Standards

• Student should demonstrate smooth launch procedures with controlled ascent rates and be able to explain the cause of false lift

Common Student Errors

The instructor should anticipate the common student errors associated with:

• Weigh off

  • Recognition of equilibrium
  • Failure to direct ground crew
  • Failure to coordinate tie-off quick release line; and
  • Poor control of ascent rate

• Launch over obstacles

  • Failure to determine height of obstacle and presence of false lift
  • Improper selection of launch site relative to obstacle and wind conditions- and
  • Failure to act decisively in order to clear obstacle safely