Likely cause of ZA002 incident determined

The diligence and determination of the engineering team that has been investigating the cause of the incident on ZA002 earlier this month in Laredo has been exceptional.

Today we announced some of the findings from that investigation and the steps we will be taking to improve the power distribution panels on the 787.

That team has been tireless in their pursuit of understanding. They explored several possibilities and determined that the foreign debris is the likely cause of a short circuit or arc in the power distribution panel.

Whatever this foreign debris was, it wasn’t something big - such as a tool - it was probably something small. We’re taking the right steps to ensure the power distribution panels are better protected against foreign debris. In addition, we’re improving the 787’s software to help it better isolate faults.

The team will work just as diligently to complete the redesign and software updates as it did on the investigation. We will continue to update the Federal Aviation Administration as we progress through this process and move toward returning the 787 fleet to flight test.

These findings will no doubt have you asking question about the first 787 delivery and the program schedule. That is under review now by the program and as soon as we have a definitive answer, we’ll share it with you.

We test our airplanes vigorously to ensure they meet our high standards, aviation regulations and the expectations of our customers.

Every time we have a finding in testing, we get smarter about how to design our airplanes and how to conduct testing. The 787 has benefitted from what we have learned on the programs that came before it.

Our next test programs will benefit from what we have learned on the 787. And, the 787 will have the needed improvements before it enters revenue service. The test program is working.

Comments (18)

Mike Masino:

Just make sure you have enough time for the vigorous testing instead of making unrealistic schedules and rushing it through.

If you need another year or two, so let it be a few more years instead of constantly announcing yet another delay a few month after announcing a delay.

Vero Venia (Montreal, Canada):

So, it was not a lunch box inadvertently left by someone. ;-)

I suppose the flight tests will resume very soon.

Sid Watson (Seattle, WA):


Thanks for sharing this. This has been a painful episode, but it is far better for this to have happened in flight test than during service with an airline. As you said, the 787 test program is working.

Sid Watson
Boeing Test & Evaluation
Seattle, WA

Daniel Tsang (Hong Kong):

While the statement of "the flight test program is working" is true, it has cost not only Boeing billions of dollars, it also cost airlines lost opportunities.

How could Boeing convince me to believe that its new schedule will be met again?

When you hold high expectations and enthusiasms toward the 787, only to have it heavily disappointed 1st time, 2nd, 3rd, 4th... up to 7th time, I am really frustrated and do not believe Boeing again until it successfully delivers the 787.

Though I'm still squarely committed to supporting Boeing and the 787, albeit with a high level of skepticism.

Ed (Fort Worth, TX, USA):

I have no doubt the B-787 will prove to be an outstanding airliner, exceeding all of Boeing's promanced performance and capabilities.

No doubt the Airbus cheerleader squad will dispute this, as well as the integrity of Boeing.


Glad to know it was just "bad old FOD" and not a design flaw that caused the fire; a design problem at this stage would have been disastrous.

I know it's been a painful process thus far for Boeing to get the 787 into service, but on such a groundbreaking program these were lessons that had to be learnt - whether on this program or the next. Hope Boeing has a smooth run on the next new airplane development program, be it the 737 or 777 replacement.

Matthew Wong (Hong Kong):

Good work Boeing! We look forward this beauty can fly commercial in the sky and deliver the benefit to airlines and also the environment. Hope everything will be smooth and not affect the delay.
Thanks for sharing with us Randy!

Yechiel Rosenfeld (S&IS - Satellite Development Center, El Segundo, CA):


Thank you for sharing this information and insight. As someone who has worked on many of Boeing's products over the years, I am always proud to see our technical teams turn an event of adversity into an opportunity for improvement.

As a member of the team which drafted the Boeing RCCA process, I do wish to add a perspective borne of experience.

Here in El Segundo, we advocate a three-pronged approach to the initiation of an anomaly investigation:

Prong 1: Investigate the Cause and Effect relationships of the Anomaly, to arrive at all of the Root and Actionable causes.
There almost always multiple causes, so don't stop the investigation after finding the first apparent cause.
Look for Cause Interactions!

Prong 2: Look for All MISSED OPPORTUNITIES TO DETECT the problem.
Why did we not detect the problem earlier?
How can we reduce future risk by improving our ability to detect an impending condition before it develops into a problem?
How can we exploit existing resources (people, software, sensors) to improve early visibility of off-nominal performance of all subsystems?

Prong 3: Ask "Why now?, Why here?".
Many of our issues occur in processes and products which were considered to be 'nominal' for some time. Our vigilant scrutiny of these processes and products is somewhat impaired by the confidence level we have developed in their invariable performance.
So we need to ask: What was unique about this set of circumstances, to both 'rule-in' a diversity in perspective for the anomaly investigation, and rule-out risk to other, similar systems.


Yechiel Rosenfeld
Associate Technical Fellow
Six Sigma Master Black Belt
Root Cause & Corrective Action SME
Boeing Space & Intelligence Systems

Bob Fitts (Kailua-Kona, Hawaii):

While I'm glad the test exposed this vulnerability of the plane, I join a host of other folks in the loss of confidence in Boeing. All the way around, from the "Intercontinental", to the strikes, the 2 and 1 half year delay....I'd be surprised if Boing doesn't have a major spate of cancelations. That coupled with no relatively no orders for the 747-8, Boeing, what is going on?

Paul Allard (Renton):

I am surprised that onboard Test equipment or procedures have not been raised as a possible contributing factor. The potential for Test equipment to overload power systems is usually carefully monitored and is an ongoing concern in testing.

Phillip Halverson (Frederickson, Wa):

Thanks for the open free flowing information. I appreciate the knowledge of what is happening.

John Madison (Seattle):

If indeed the cause of the short circuit was "foreign object debris", (FOD), it really re-emphasizes the mandatory requirement for FOD Training for all employees, and it should be extended throughout the supply base if it hasn't been already. Airline Customer employees and maintenance personnel should also be trained in FOD prevention/awareness. Anything left behind in during manufacturing or maintenance processes, or even during a tour of an aircraft can have potentially damaging or catastrophic downstream impacts.

Valuable lessons were learned from this incident and thankfully the plane landed safely without significant injuries or loss of life.

Kinbin (Taipei Taiwan):

The growing pains of managing a production supply chain spanning the globe, that is neither owned nor managed by Boeing.

That said, when the processes at the partner sites have been made more robust, it will turn out to be more cost effective and resource efficient, maximizing on market dynamics.

Norman (Long Beach, California, United States):

FOD observation and removal cannot be emphasized enough, it was one of the first lessons taught at aviation maintenance school. Fortunately minimal damage was done and I hope the delay of the 787 will be minimal.

Beck Nader (Belo Horizonte, Minas Gerais, Brazil):

Excellent comments in this topic. For me Mr. Yechiel Rosenfeld's exposition highlights the seriousness this matter is being dealt with.
If we remember the fatal AC447 accident on 1 June 2009, at the cost of Brazil which unfortunately has not been completely understood until now, we may accept this non-fatal incident as a blessing for uncovering a potentially severe defect.
Good that flight tests like these are so detailed and careful.

Best Regards,


Wizzard (Long Beach, CA):

Are you guys really buying this? The fact that ZA002 would be used to "certify max current demand of the electrical systems by connecting resistors" is well documented. Together with the fact that the "wiring had to be changed on the first three test aircraft, to save weight", leads me to wonder if Boeing may be hiding a design flaw.

Randy Tinseth:

Wizzard, the company's not hiding anything. In our press release (, 787 Vice President and General Manager says we're "are moving forward with developing design fixes."

Beth Wiseman (Huntington Beach, CA 92649):


I think you are at the bottom of the second 0 from my right in 8,500.
You are holding your orange hat up and you have a man on your right in a blue jacket and on your left a security person in fluorescent green. Your jacket is black.

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