Buck
July 17th 03, 09:25 PM
> The data of Chapter 9
>
> Chapter 9 presents statistics on age and weather regarding foam loss
> events for all shuttle flights.
-snip-
> But the whole statistics of chapter 9 are invalid because the source
> of the foam loss data is invalid. Most loss is small and imagery cant
> show it.
A good example may even be found in table 3-6, where the CAIB reports
that approx 1 cubic inch came off the left bipod. How did they arrive
at that figure?
-snip-
> But the conclusions of chapter 9 are poor engineering science anyway.
> They had only 7 bipod foam losses and therefore a wide 95% confidence
> level. Then they concluded: "Therefore, data are inconclusive as to
> whether a correlation can be drawn about ET age and bipod foam loss."
from Fig. 9-1:
2 missions with younger than average tanks shed bipod foam:
STS-7 and STS-112.
5 missions with older than average tanks shed bipod foam:
STS-32R, 50, 52, 62 and 107.
> Figure 9.2, 9.6(!)and 9.8(!!) gives very clear hints.
9.2 shows that older tanks tend to shed bipod foam.
9.6 shows that tanks exposed to more total rain tend to shed bipod foam.
9.8 shows that tanks exposed to higher than average daily rain tend to
shed more bipod foam.
--buck
>
> Chapter 9 presents statistics on age and weather regarding foam loss
> events for all shuttle flights.
-snip-
> But the whole statistics of chapter 9 are invalid because the source
> of the foam loss data is invalid. Most loss is small and imagery cant
> show it.
A good example may even be found in table 3-6, where the CAIB reports
that approx 1 cubic inch came off the left bipod. How did they arrive
at that figure?
-snip-
> But the conclusions of chapter 9 are poor engineering science anyway.
> They had only 7 bipod foam losses and therefore a wide 95% confidence
> level. Then they concluded: "Therefore, data are inconclusive as to
> whether a correlation can be drawn about ET age and bipod foam loss."
from Fig. 9-1:
2 missions with younger than average tanks shed bipod foam:
STS-7 and STS-112.
5 missions with older than average tanks shed bipod foam:
STS-32R, 50, 52, 62 and 107.
> Figure 9.2, 9.6(!)and 9.8(!!) gives very clear hints.
9.2 shows that older tanks tend to shed bipod foam.
9.6 shows that tanks exposed to more total rain tend to shed bipod foam.
9.8 shows that tanks exposed to higher than average daily rain tend to
shed more bipod foam.
--buck