It seems that Boeing has made enough of the right noises to get the fix approved and passed by the FAA, with the FAA approving Boeing’s proposal to fix battery issues on the 787, allowing them conduct limited test flights on two aircraft even as a safety investigation continues.
The fix involves three layers of protection to prevent overheating of the lithium-ion batteries that power the 787’s auxiliary power unit. These involve
- Improving the separation between the battery cells
- Installing ceramic-plated spacers between each of the cells
- Adding a containment and venting system so smoke cannot enter the cabin.
FAA administrator Michael Huerta. states:
“We are confident the plan we approved today includes all the right elements to conduct a comprehensive evaluation of the battery system redesign,”
“Today’s announcement starts a testing process which will demonstrate whether the proposed fix will work as designed.”
The FAA goes on, to state:
“The plan establishes specific pass/fail criteria, defines the parameters that should be measured, prescribes the test methodology and specifies the test setup and design.”
US Transportation Secretary Ray LaHood sums up the process by saying:
“This comprehensive series of tests will show us whether the proposed battery improvements will work as designed,”
“We won’t allow the plane to return to service unless we’re satisfied that the new design ensures the safety of the aircraft and its passengers.”
Two planes will fly in the test programme, and will have prototypes of the new containment system, with the purpose of the flights to validate if the fix works as advertised. The two planes that will be involved will be:
- Plane 86, which will be used in tests to demonstrate that the proposed solution works in flight and on the ground and also on planes already in service.
- Test aircraft ZA005, which will conduct engine improvement tests unrelated to the battery issue.
- Boeing could also bring in additional aircraft as needed.
The plan will require a series of tests to show how the improved battery system will perform in normal and abnormal conditions.
Boeing is pinning a lot on this, and has confidence according to Boeing Commercial Airplanes president and chief executive Ray Conner say
“Working with internal and external experts in battery technology, we have proposed a comprehensive set of solutions designed to significantly minimise the potential for battery failure while ensuring that no battery event affects the continued safe operation of the airplane”
Currently, 50 787’s are grounded pending positive testing completion of the fix.
However, Is this fix enough?
One of the biggest dangers in the air after the flight critical phases and engines not turning is the risk of fire in the air – remember that on Swissair Flight 111, the reason that the plane went down was due to faulty wiring that lead to a fire.<
Me? I'll need to see that this fix works, and if a failure happens, how it is contains safely. Remember, a fire can spread fast on a plane, and if you're at the theoretical 3 hours plus from the nearest airport (the ETOPS 240/330 standard for which the 787 is rated for), but personally – I'd want to know a lot more and see some of these batteries cycled in and out of planes – and the performance of these batteries before I'll consider stepping on a 787 for some time.