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Aviation Human Factors Industry News

January 09, 2005

Vol. II, Issue 2.

Hard Work Key to Fulfillment

Working hard towards a goal helps people feel happy and satisfied, according to researchers in Sweden. This conclusion was reached after studying hundreds of interviews with people all over the world about what makes a person feel fulfilled. Apparently it is the journey and not the destination that makes people feel the most content. Additionally, they discovered that people who were most active got the most joy. Along with hard work, the researchers cited having good relationships as another key to happiness. ("Why Hard Work Makes People Happy." BBC News, January 3, 2006.)

Sometimes in the daily grind of work, we lose track of the big picture and fail to see what we are accomplishing. To avoid this and help workers get more enjoyment out of life, managers should set clear goals for their employees to achieve. By working towards a common goal, employees can bond and feel as if they are contributing to the team. Furthermore, once a goal is achieved, managers should congratulate the team and establish a new goal for the team to target. By continually setting attainable new goals you can have productive company and a happy workforce.

3 Alaska Air mishaps blamed on ground crew
Jan 6, 2006, 19:00 GMT

SEATTLE, WA, United States (UPI) -- Employees of the company handling Alaska Airlines` outsourced ground operations have made errors damaging jets three times in the past two weeks.

Two of the incidents involving Menzies Aviation workers occurred at Seattle-Tacoma International Airport, the Seattle Times reported, including one that caused a plane to lose cabin pressure at 26,000 feet. The other was at Los Angeles International Airport.

The airline fired 472 union baggage handlers and ramp workers in May and hired Menzies to take care of ground operations at Sea-Tac. At the time, executives said the change would save $13.7 million a year.

In the most recent incident, Thursday, an employee operating a tug that moves aircraft to and from gates went into reverse by mistake, pushing the plane several feet. The accident damaged a door hinge and engine cowling.

Last month, an employee did not report a collision with a plane, saying later he had 'grazed' it. In fact, the plane had a foot-long, 6-inch wide rip in the fuselage. The plane was able to return to Sea-Tac safely.

An airline spokeswoman said that the accident in Los Angeles caused 'minor' damage.

NTSB Issues Probable Cause on '04 NC Sheriff Helo Crash

A controversial fatal helo accident, involving a civilian Hughes 269 being flown for the local Sheriff by an improperly licensed pilot, has been ruled the result of material fatigue and inadequate maintenance.

According to the pilot, the purpose of the flight was an ongoing program directed at drug eradication. He stated that shortly after takeoff, he felt two vibrations and then heard a loud bang from the back of the helicopter. He stated the helicopter yawed to the right,

and he entered an autorotation and maneuvered toward a small clearing in the wooded area he was over at the time. The main rotor blades struck a pine tree approximately 30 feet tall on the edge of the clearing and impacted the ground on the helicopters left side. A review of information on file with the Federal Aviation Administration Airman's Certification Division, Oklahoma City, Oklahoma, revealed that the pilot did not have an airman's certificate indicating he was rated in helicopters nor could he provide evidence that he was trained in helicopters. A review of records on file with the FAA Aero Medical Records Division revealed the pilot was issued a third class medical certificate on September 26, 1988. The pilot reported on his application for the medical certificate that he had accumulated 39 total flight hours.

A review of maintenance records revealed that the last recorded annual inspection was completed on March 21, 2004, at an airframe total time of 5,506.2 hours. On March 13, 1980, the FAA issued an Airworthiness Directive (AD) 80-05-05 addressing Schweizer Helicopters Model 269 series equipped with a tail boom center support (saddle) fitting certificated in all categories. The AD was issued to prevent fatigue failure of the tail boom center support fitting and the resultant loss of the tailboom. A review of the maintenance records dating back to March 13, 1980, found no logbook entries that indicated the required inspections outlined in the AD had been accomplished. Examination of the tail rotor assembly found the tailboom saddle attachment broken. Further examination found rubbing on the tailrotor drive shaft near the broken tailboom saddle attachment. Examination found that the tailboom support fitting fractured as a result of fatigue initiating at the base of a large corrosion pit on the tip surface of the forward wall. This surface, which was in direct contact with the tailboom, was only partially covered by paint, and contained extensive pitting damage. Following the fracture of the saddle support fitting the tailboom dropped and rubbed against the tail drive shaft fracturing it in overstress.

Structural Failure May Have Led To Chalk's Air Crash

Investigators are homing in on metal fatigue, probably aggravated by corrosion or sloppy repair, as a primary cause of the Chalk's Ocean Airways fatal accident on Dec. 19, 2005.

The right wing separated from the seaplane shortly after takeoff from Miami, and the crash into the coastal water killed all 20 aboard. The wing was recovered from the water on Dec. 20 and National Transportation Safety Board (NTSB) engineers and metallurgists quickly observed that the wreckage indicated fatigue fractures. As an immediate result, Chalk's grounded its remaining fleet of Gulfstream G-73 airplanes. The Federal Aviation Administration (FAA) did not order grounding, preferring instead to advise operators of what happened but confessing it does not know what action it should mandate at this time.

The FAA action seems puzzling, as the wreckage reveals that the failure likely started at the location where two offset drill holes are located. Inspecting other airplanes for such holes seems a prudent first order of business. The term "offset drill holes" is perhaps a gentlemanly way of referring to a carelessly drilled second hole that ruins the first.

When this occurs, the appropriate step is to open the hole to a larger size so that only a clean new hole is left. This can be a tedious procedure with little forgiveness for ruining any of the holes in the mating surface.

There are limits to this stratagem. If the standard engineering criteria for hole edge distance to the edge of the structure (usually three to four times the fastener diameter), or to any next fastener hole edge, and a doubler cannot be utilized, normally the fitting must be replaced.

When the fasteners (bolts, Hi-Locs or rivets) are reinstalled, the sloppy repair ("offset drill holes") is hidden until cracks develop and migrate outward. From the shading in the cross-sectional view on the NTSB photograph, it appears that the cracking existed for some time - as evidenced by the large area of darker colored metal.

The fracture photographs suggest also that stress was raised as a result of the offset drill holes, and salt-water corrosion would exacerbate the structural weakening. Corrosion can occur anyplace, but it can manifest especially in drilled holes after production, where the surface may have a coarse texture (as in an improperly drilled out hole). The two different sides of the hole shown in the NTSB photographs appear to have two different types of fatigue initiations at their surface, which could possibly constitute abusive machining or corrosion on one side and secondary initiation on the other.

What is evident are two separate drill holes, not parallel to each other and apparently merging together. It would seem that such an action would create a stress concentration.

The inexpert drill work should raise an obvious question in the engineering community's mind, specifically, why are there two offset drill holes in this particular location which have removed maybe 15 percent or more from the horizontal leg of the spar cap?

The resulting fatigue induced failure (whether corrosion-related or not) would seem to have inevitable consequences in just a matter of time and flight cycles after those offset drill holes were inexpertly made.

Recall that there have been spar problems recently on the Beech T-34 (see ASW, Dec. 8, 2003). Also, several firefighting aircraft were found to have cracked or broken spars. As in the case of the G-73, these aircraft were designed many years ago, before designers fully understood metal fatigue.

Safety in the skies

The Association of Licensed Aircraft Engineers (ALAE) was not at all surprised by your excellent article (Watchdog slams BAs air safety, Insight, News, last week).

Your statement: "BA employs 6,000 engineers, compared with 9,500 in 1995 but its fleet remains at a similar size as 10 years ago" hides some shocking truths.

Our figures show that only about a third of the 6,000 engineers employed by British Airways are in fact fully qualified licenced aircraft engineers.

The aviation industry has seen the numbers of licenced engineers dwindle from 24,000 in 1979 to 12,000 today.

Yet during the same period, aircraft numbers have more than doubled. BA, like other airlines, is under financial pressure and staffing levels are stretched.

BA operates a policy that involves the licenced engineer only appearing at an aircraft if requested to do so. Something that was unheard of in the past.

Even pre-flight inspections, the last line of defence in uncovering anything untoward, has been taken away from the licenced engineer. The Australians refused to accept such a policy on the basis that it clearly affects safety.

END - Lets Be Safe Out There