The airline system in America is pushing the breaking point. According to the Federal Aviation Administration, airline delays are already at an all-time high. And with the crowded summer season approaching, the problems caused by full planes, limited crews, ground delays and lost luggage are only going to get worse. The root cause is the airlines’ drive to improve profits. But what’s good for investors in the short run — high load factors and a lean workforce — is bad for passengers and eventually will bite the investors in their financial rear ends.

Until then, travelers will need to practice defensive flying.

High load factors

The biggest problem for summer air travel is high load factors. When everything works perfectly, full planes are an executive’s delight, but if a thunderstorm or an air traffic delay or a late crew gets thrown into the mix, disaster can strike. If a flight is canceled or a connection is missed, the airlines cannot easily accommodate the displaced passengers. In the old days, the solution was to put passengers on the airline’s next flight, but now that flight is often packed, as is the next flight and the next. Nor are there empty seats on other carriers. Miss your flight or a connecting flight, and you’ll spend a lot of time in the airport waiting for a seat to open up on any airline.

American, Continental, Delta, United, US Airways and Northwest airlines are all flying with load factors in the 80 to 85 percent range. That means that the average 757, which holds 188 passengers, is flying with only 28 empty seats. An MD-80 with capacity for 136 passengers would on average have 20 empty seats. A 737, which seats 124, would have 19 empty seats.

These are average load factors over the past few winter months. During the summer, these loads are expected to creep even higher. It is easy to see that if one of these flights is canceled, the displaced passengers will have to be accommodated on an average of six other airplanes. And then there’s the domino effect. Once those six flights are filled, the next canceled flight will have passengers looking far and wide for a plane to get them where they need to go. From small airports, you might wait days, not hours.

Understaffed air crews

The airlines have also, over the past few years, reduced their payrolls. From a business management point of view, the workforce reduction seems prudent, but airlines need to factor in the inevitable weather, ground and air-traffic delays. When one crew can’t make it to the flight, a reserve crew must take its place. When there are no more reserves because personnel have been reduced dramatically, flights get delayed and canceled.

If the airlines were a happy family of employees, the workers might bend some nonessential employee rules to help out the passengers. But after recovering from financial disaster and bankruptcies, airlines are no longer particularly harmonious when it comes to relations between executives and employees. In fact, there is a great deal of dissatisfaction about the way some executives are paid at a time when frontline workers’ paychecks and pensions have been cut.

At American Airlines, for example, the executives decided to pay themselves more than $100 million in bonuses (almost the entire annual profit) before negotiating with the carrier’s pilots, flight attendants and other workers for minimal raises. Similarly, at United Airlines, the top bosses rewarded themselves millions of dollars as they came out of bankruptcy while stripping their workers of their pensions and forcing them to take reduced salaries over the past two years.

Northwest Airlines, which isn’t yet out of bankruptcy, has already received a vote of no confidence from its rank and file after the employees learned that the CEO was planning to snatch a bonus of millions after imposing wage cuts through the courts. And US Airways, which recently merged with America West, has managed to get the pilots grumbling at each other as they begin to merge two different seniority systems from the two airline-pilot unions. This pattern will no doubt be followed by similar disruptions when flight attendants, mechanics and ground workers are unified.

Understaffing and unhappy workers are not a good combination when facing already stressful working conditions. The University of Michigan’s American Customer Satisfaction Index released in May 2007 rates airlines below the Internal Revenue Service when it comes to satisfaction. The report also indicates that airlines that have poor employee relations are ranked up to 26 percent lower in customer satisfaction than those who have good esprit de corps.

Understaffed air traffic control systems

Understaffing is not limited to pilots and flight attendants. Air traffic controllers have seen their ranks thinned by inadequate hiring, too. Airline captains are now complaining openly from the cockpit about the lack of air traffic controllers, a situation that is leading to long ground delays at crowded airports even on crystal-clear days.

My recent flights through JFK airport in New York have been delayed by ground holds even though there were no clouds in the sky, no nearby thunderstorms and no strong wind gusts. According to the pilot, who had been fighting the controllers for the entire day as he shuttled between Boston and New York, it was simply a case of not having enough controllers to manage the ground traffic.

In an article published in mid May, Trent Lott, the ranking member of the U.S. Senate’s Aviation Subcommittee, argued that the air traffic system needs modernization. But even if his program passes congressional muster, it won’t help in the near term and certainly not in time for this summer’s traffic.

Lost luggage

Lost luggage has been a recurring problem ever since liquids were banned from carry-on luggage, a measure that has increased the number of checked bags dramatically. That problem will not go away with more travelers in the pipeline and no increase — at least none that I have heard of — planned for baggage handlers and ground crews by major airlines.

Survival tips for summer travel

So what is the summer air traveler to do? Fly defensively, that’s what.

• Fly on early flights. This way, you can minimize the domino effect of late flights, short crews and afternoon thunderstorms.

• Fly nonstop if possible. Even if you must pay more, take a nonstop flight whenever you can. Remember a “nonstop flight” is different from a “direct flight.” Direct means only that your flight number will not change, but there will be a landing and maybe a change of plane somewhere between your departure city and your destination.

• Leave at least three hours for connections. This is my rule of thumb during the summer months. If you arrive early and there is an earlier connecting flight, by all means try to get aboard. And if you arrive one or two hours late, congratulate yourself for your foresight. With that three-hour cushion, you should make it to your destination on time.

• Take only carry-on luggage. Pour your liquids into small bottles that fit into a quart-size zip-top bag that you can carry on board the plane. Remember, it costs far less to buy a tube of toothpaste or a bottle of shampoo than to stay overnight at an airport hotel because you’ve missed your connection waiting for your checked bag. Plan your packing and take fewer clothes if you have to. It beats waiting around in the terminal.

• Split your packing. If you must check baggage and you are traveling with a companion, split your clothing between two bags. That way, if only one bag arrives, both of you will have clothes to wear.

• If you need to rebook, call the telephone reservation center. If a flight is canceled or delayed and it looks like you will be missing a connection, call the airline’s reservation phone number and get a reservation as soon as you can. Do not wait in line at the airport (unless you are on the phone at the same time) or available seats will be parceled out to others.

• Fly Southwest. Southwest Airlines has one of the lowest passenger load factors, lowest lost-baggage rates and relatively happy employees, so it can deal with delays more easily than other carriers. JetBlue and Air Tran also have low lost-baggage rates and good employee morale, but their planes are flying with high load factors these days.

• Write your congressman. Let your representative know you support increasing funds for the nation’s air traffic control system. If our congressmen and senators don’t hear from us, they will continue to fiddle while the air traffic system burns in the summer heat.