NASA Compton Telescope Balloon Launch Mishap / summary
1. Protection of the public.
a. No one responsible for crowd control b. Hazard area not defined c. Hazard area moved
2. No written procedures
a. Reliance on past success has become a substitute for good engineering and safety practices. b. No contingency plans c. Crew made decisions based on current conditions instead of written procedures.
3. Inadequate ground crew training 4. inadequate safety equipment for crew
a. Hard Hats b. Gloves
Majority of issues were Human Error because proper written documentation and procedures did not exist.
A. No standard procedure exists at CSBF to cover the launch process. After reviewing all of the procedural documentation, no prescribed process was found for launching the balloon and there was minimal information provided in the documentation for on-the-job training.
B. Training did not provide sufficient guidance to deal with all credible situations during launch. Interviews indicated that no specific training is provided to deal with anomalies or failed launch attempts. After this point, the logic follows the path shown in Figure 60 and will not be repeated in the report.
C. Launch process is fragile. Without clear definition and procedures for dealing with anomalies, the launch process is highly sensitive to human error and general awareness as well as environmental conditions, such as terrain and weather. This is evident from interviews and documentation review.
* Hot Air Balloon site selection. Based on 300FPM rate of climb. Our balloons will climb faster than 300FPM, so these numbers will exceed our requirements. They will provide guide lines for us to use.
SELECTION OF LAUNCH SITE. The appropriateness of any launch site involves much more than its physical size and absence of obstructions, even though these are important considerations. Of equal or greater importance is the direction the balloon will track following the launch. Any site selection made should include consideration of local winds as determined by pibal, smoke, trees, or other physical indications; forecast and reported winds aloft; and local phenomena peculiar to the specific site (determined by personal knowledge or by consulting with local balloonists). Also, location of obstructions along the projected flight path and available suitable landing sites down range should be considered. Once a launch site is selected and flight preparations have begun, any situation that may adversely affect or change the planned flight (wind shift, lowering clouds, or obscuring phenomena such as fog or smoke) should be carefully considered. If the change or adverse situation is unacceptable, the launch site should be moved to another location or the flight should be canceled. The adage, “better to cancel and fly another day than to make a mistake along the way,” is a useful guideline. TAKEOFF, DEPARTURE, AND CLIMB. a. Before launching, care should be given to departure and climb considerations. An obstacle assessment should be made. Where power lines or any other obstacles are present, the pilot should have alternative courses of action available. b. To compute the minimum distance between the launch point and obstacles downwind, multiply the wind speed expressed in miles per hour (mph) by 100. (See figure 1.) The result is the approximate distance the balloon will travel during its first minute of flight. Next, estimate the height of the obstacle and add the amount of clearance desired when passing over the obstacle; e.g., a 100-foot obstacle plus 200 feet of desired clearance over the obstacle totals 300 feet. Lay the balloon out at least the computed distance from the obstacle. Upon takeoff, establish an initial rate of climb of 300 feet per minute (fpm). The balloon should clear the obstacle by 200 feet. In another example, the wind speed is 4 mph and there is a 75-foot line of trees downwind at the end of the field. Using the above formula, multiply the wind speed by 100 (4 x 100 = 400). In order to pass 100 feet over the trees after takeoff, add 100 feet to the tree height of 75 feet, resulting in a total of 175 feet. Lay the basket at least 400 feet upwind of the beeline. Upon takeoff, establish a minimum initial rate of climb of 175 fpm. The balloon should pass 100 feet over the trees. FIGURE 1. WINDSPEED MULTIPLICATION FACTOR
Surface Windspeed Multiplication Factor Minimum Horizontal Distance 2 MPH X 100 200 feet 4 MPH X 100 400 feet 6 MPH X 100 600 feet 8 MPH X 100 800 feet 10 MPH X 100 1000 feet c. To provide an allowance for errors in distance estimation and changes in surface wind or other unforeseen occurrences, pick out a significant landmark halfway to the obstruction. If it should appear that the balloon will not achieve a minimum of half the clearance altitude by that halfway point, immediately terminate the flight by activating the deflation port (“rip out”) before reaching a critical altitude (usually about 20 feet above the surface). d. With a small launch site and close obstacles, it may be appropriate to issue the “weight off” instruction before launch to accomplish a rapid initial rate of ascent. Whatever takeoff procedure is used, the ascent profile should ensure safe and expeditious clearance over and around all obstacles along the departure path. It is also important to maintain a positive rate of climb during the departure until the balloon is at or above the appropriate minimum safe altitude prescribed in § 91.119 in VFR conditions.