The Queensland Court of Appeal recently overturned a primary judgment in favour of the Robinson Helicopter Company Incorporated (Robinson Helicopter) on the basis its instruction manual did not provide adequate guidance to Licensed Aircraft Maintenance Engineers (LAMEs) performing periodic inspections.
As discussed in the May 2014 newsletter ‘Robinson’s R-22 Maintenance Manual: No defect, no liability’, a Robinson helicopter crashed at a large cattle station at Tobermorey, west of the Queensland-Northern Territory border. Sadly the pilot, Mr Kevin Norton, did not survive his injuries. The plaintiff, Mr McDermott (appellant on appeal), the only passenger, did survive but was badly burnt.
It was held the crash occurred because a critical part of the helicopter’s drive mechanism (the forward flexplate) failed. One of the four bolts through the flexplate had not been properly tightened.
The helicopter was regularly serviced at proper intervals (every 100 hours) by technically trained LAMEs. The LAMEs who conducted services of the helicopter in March and May 2004 did not detect a problem, nor did the deceased pilot Mr Norton or four other pilots who had flown the helicopter.
The plaintiffs’ case was that the Robinson maintenance manual failed to specify an adequate inspection procedure to ensure any defect would have been discovered in time. In particular, its directions failed to require the tightness of the four bolts through the flexplate to be checked by a method more stringent than simply observing whether markings on the bolts, called torque stripes (strips of paint over the length of the bolt) were in a proper condition. The theory was that if the torque stripes were in place, the bolt was adequately intact.
At trial, the court was satisfied the instructions in the Robinson maintenance manual pertaining to torque stripes was sufficient to prevent the accident. The trial judge regarded the maintenance manual as giving adequate instruction as it required torque seals to be applied and 100 hour inspections to check their movement.
The appeal – Queensland Court of Appeal
The plaintiff appealed the decision on the basis a torque stripe was an unreliable indicator of bolt looseness and the Court of Appeal agreed, finding the maintenance manual’s reliance upon torque stripes as a method of verifying security was inadequate. This finding essentially came down to two issues.
Firstly, in coming to its decision to overturn the trial judge’s decision, the Court of Appeal stated the manual did not make it clear to LAMEs that a visual inspection of torque stripes may not be sufficient to indicate whether critical fasteners were correctly assembled. The Court found, for example, that where the bolt was first incorrectly assembled on a contaminated surface, the torque stripe over it may be incorrectly applied and not give a reliable or trustworthy reading of tightness. The Court of Appeal referred to photographs produced during the trial of other helicopters which showed that torque stripes can deteriorate to a point where they may not be readily visible or discernible, raising immediate questions about their reliability and dependability as a safe method of verifying the security of bolts.
Secondly, the Court of Appeal had regard to evidence which established a torque wrench or a simple spanner could be easily used to verify a bolted joint, and that this was a method prescribed in maintenance manuals of similar aircraft.
The plaintiff’s case will be remitted to the trial division of the Supreme Court for an assessment of quantum payable by Robinson to the plaintiff.
Conclusion and comment
It is not common to see in Australian courts manufacturers held liable for shortcomings entirely confined to a maintenance or service manual. Often other issues and causes of a loss are at play at trial which may create an alternate finding in negligence, or at least shroud any underlying issues in a technical specification or service manual. This case is an interesting example of product specific and technical directions from a manual where it seems a warning or a more thorough direction would have prevented the loss. The judgment highlights just how important, as a yardstick of reasonable product maintenance, a manual will be; and the need for manufacturers to continually undertake due diligence not only on industry standards, but to ensure best practice is communicated effectively through manuals for those relying on them.