Since its launch 35 years ago, Southwest Airlines has grown from a local Texas airline with three planes in its fleet to become the US domestic air carrier that flies the most passengers. It now employs 33,000 employees and last year brought in $9.1 billion in revenues while flying 83 million passengers on 3,300 flights to 63 US cities.
Premium customer service is goal one for Southwest; it's posted the lowest ratio of complaints per passengers of any American airlines since the Department of Transportation began tracking those statistics in 1987. But without top-flight fleet maintenance, high-flying customer service would simply not be possible.
Southwest now maintains 450 planes, and the longer they are on the ground, the fewer flights they are making which results in cancelled flights or delayed ones. Neither of those alternatives makes for happy customers, nor do they help company revenues. If a plane is on the ground being maintained, it's not in the air with fare-paying customers bringing in money.
But the worst kind of maintenance is the reactive type - something goes wrong that no one suspected so the plane is grounded. Instead, Southwest relies on preventative maintenance that can be scheduled when it knows a problem is likely in the near future and can schedule maintenance and get the plane up and flying again fast. But flying planes is Southwest's core competence -- monitoring the condition of its planes is not. That's why it uses its outsourcing partner, Smart Signal, for equipment monitoring services to keep Southwest's maintenance crew apprised of equipment malfunctions before they happen.
The How To of Aircraft Performance Monitoring
Specifically, Smart Signal monitors most plane engine functions. According to Bill Roberts, Senior Power Plant Engineer at Southwest, the maintenance crew collaborates with Smart Signal to set up performance parameters for functions like oil pressure, engine vibration, and engine speed (how fast the engines are turning) that can signal when maintenance is needed. "We try to be overly conservative in setting parameters," says Roberts. For instance, he says normal oil pressure for plane engines is about 40 to 50 pounds per square inch (PSI). Southwest maintenance has set parameters of five pounds less or more than that range so that Smart signal knows when to report a problem.
Instead of using extraneous sensors to capture engine data, Smart Signal taps right into native engine functions. For instance, Roberts says, "We use an oil pressure transmitter like one on a car for oil pressure, thermal devices provide us the exhaust gas temperature, and there's a accelerometer on the engine that picks up vibration."
Roberts says Smart Signal transmits signals from functions like these using a specific computer program and converts performance data into readable format in graphs and charts for Southwest. But, he explains, first the data from the engine is transmitted as it would be normally to the flight data recorder. From the flight data recorder it's then transmitted to Southwest, and Southwest then transmits it to Smart Signal.
Smart Signal breaks out performance into graphical form so engineers used to dealing with numbers, not words, can easily check on the present health of the engine and communicate with other maintenance staff in language they understand.
With a fleet of 450 planes, some of the planes are going to need routine tweaking. So whenever a function falls outside of its parameters, Smart Signal flags it and informs Southwest. Roberts says Southwest's monitoring personnel get that info via computer link and write up a maintenance task, and its maintenance planning department then schedules the plane for specific maintenance. Southwest's maintenance crew therefore is making adjustments every day to one plane or another to solve small problems before they become large enough to ground a plane.
If a critical problem arises that needs immediate attention, Smart Signal can call the maintenance crew directly by cell phone. This may be the case when the monitoring service detects several flags from several engine functions at once. For example, says Roberts, "If the oil pressure gets too high, one of the causes of this is restricted oil tubes, and if we get restricted tubes that means a bearing is not getting appropriate lubrication.If that's true, it could cause a bearing failure that could cause engine failure which is very costly."
Preventative monitoring and maintenance pays off big because poor engine performance or breakdown creates a ripple effect that is not only costly for the airline but inconvenient and annoying for the customer.
The routine lifespan of an airplane engine, says Roberts, is seven-to-nine years before it needs a complete overhaul. An overhaul can cost about $100,000. Obviously, any addition to the routine lifespan saves Southwest money on maintenance or the cost of a new engine. But Roberts says also that "the longer you can keep an engine in operation, the less money it costs to operate." In other words, the better the condition of the engine going forward, the longer it can fly, and it costs less per flight because it's operating at peak efficiency.
For instance, if the gauge the measures outside air temperature at different altitudes is not functioning accurately, the aircraft will burn more fuel, explains Roberts. That's because as a plane climbs, the air gets thinner, there's less resistance and the plane needs less fuel to maintain speed. Multiply malfunctions like this several times, and it shows how a less efficient plane can really burn up costs. With rising fuel costs, fuel has become the number one cost of airlines in the last few years, ahead of even personnel salaries and benefits.
But a major part of Southwest's value proposition is low-cost fares. Therefore, lower costs are critical when the airline is competing on price.
If planes are in the hanger less, there are fewer delayed flights. Roberts says this is a bigger factor affecting customer service than one would immediately think. That delayed flight backs up other flights for the entire day which hurts customer service for people on all those flights.
So preventative maintenance is absolutely key to Southwest's core goal of the superior customer service
Lessons from the Outsourcing Journal:
- Outsourced engine performance monitoring saves money for airlines like Southwest because it prevents reactive large-scale maintenance like complete engine overhauls.
- It also cuts other costs - most notably, fuel, the highest cost for airlines - by enabling the engine to run as efficiently as possible.
- Better running planes make for fewer delayed and cancelled flights which contributes to better customer service, a prime differentiator for lower-cost airlines like Southwest.