Guys - A few points
1. Airbus has more than one structural test wing set. 150% will be achieved on a set built closer to the final build standard (see below).
2. Luoto - the final destructive test is only completed at the end of the life cycle tests. So the wing set in question would have completed as many cycles as any aircraft achieves in service...then failed at 147%
3. 150% may not sound like much but if you check out the pictures you will see the wing tips at around 90 degrees to the horizontal before the final failure. Hands up who has ever experienced anything like this in flight.
4. Throughout the 18 months of extreme fatigue testing minor failures are induced (this happens on every aircraft type). The repairs weaken the wing prior to the final destructive test. See coments on stress allowances below.
5. At day one development wings are weaker than the production wings for two reasons.
First - The first seven aircraft each have hundreds of miles of Flight Test Instrumentation cable passing through scores of extra holes drilled in the rib / spar wingbox structure.
Secondly - Despite the fact that Airbus assembly personnel have massively superior training than their American opposite numbers...EVERY first off aircraft ever built has hundreds of design "concessions" on each wing. These are , for example, slightly oversize holes...drill runs...tooling causing loss of land on hole edges.
These errors are a fact of life in the E Fatigue and E Static wings and Flight Test only aircraft... but are iorned out before the production batch. Stress engineers will theoretically factor these weaknesses into the final stress calculations. If you have ever spoken to a stress engineer though you will know that they are the most conservative people on the planet. Built into their calcs are huge comfort factors so a critical concession which could cause a 10% reduction in rib 2 strength will either be assumed to have no effect or, they will begrudgingly allow between 1 and 2% to the fatigue testing people.
Bottom line wing set probably achieved closer to 160% rather than 150%. It really is not a big deal.