FDR tolerated a firm "No!" from Juan Trippe. Chiang Kai-shek entrusted him with an earthshaking message to Truman. Ike liked his ideas. LBJ insisted on sending a White House limousine to pick him up. And Trippe's criticism prompted a secretary of defense to resign right on the spot.

Robert Daley never convincingly substantiates such schoolboy dreams, but in "An American Saga" he clearly documents how Trippe constructed a billion-dollar empire able to flex muscles on every continent. Although Trippe is not a Carnegie, a Rockefeller, even a Howard Hughes, he belongs to a subclass of moguls important for the insights into American life their actions suggest.

Unfortunately, Daley -- whose nonfiction work on the New York City police, "Prince of the City," was a recent best seller -- offers no such analysis. Pan Am's role as "chosen instrument" of the State Department, its dealings with foreign dictators and its destruction of competition pass almost unnoticed amid an overwhelming compilation of data. More is needed, especially now that the recent merger with National Airlines makes Pan Am a new and significant domestic force.

"An American Saga" does, however, depict a fascinating slice of aviation history. Flying was once exciting, elitist and altogether different from what it is today. Until World War II, for example, international air travel was primarily via seaplane. Ground crews often wore bathing suits. Some planes had large, standup steering wheels, and crew members distributed printed passenger lists, just like on the luxury liners sailing below. For long voyages, passengers either slept in berths or in special hotels located on remote islands.

But Daley's writing is best when he describes how Trippe regrouped his far-flung fleet on Dec. 7, 1941, as the Japanese struck from the Philippines to Pearl Harbor. His clippers were "the only long-range, heavy pay-load aircraft in the world," and Uncle Sam needed them. To get home, one gee-loaded Pan Am plane flew just barely above the waves, unable to locate Midway until guided by Japanese-ignited fires.

Another clipper was marooned in New Zealand after Pan Am facilities became military targets. The undaunted pilot then flew over Indonesia, India and Saudi Arabia, often landing where no seaplane had been before. At Khartoum, he glided down onto the Nile. From there, he crossed Africa to Brazil and flew up the Caribbean to New York. "Pacific Clipper, inbound from Auckland, New Zealand," the pilot nonchalantly informed La Guardia's control tower.

Throughout Pan Am's development, crew members showed considerable courage. Radio communication was poor, and navigation was primitive; flasks filled with aluminum powder had to be dropped to permit mid-ocean fixings. Pilots sometimes flew in the wrong direction, realized their mistake, and then frantically searched for land -- any land -- before their fuel ran out. Once an experienced crew mistook the planet Jupiter for a lighthouse blinking in what they assumed to be an open sea.

Of course, passengers often faced danger, too, only they didn't know it. A near-disastrous landing of an aircraft with prominent newspaper publishers aboard went unreported because "they had too little experience with flying boat landings to realize that anything unusual had happened."

Even the complaints of professionals remained secret. One of the first pilots to land at Wake Island walked into company offices cursing about how unsafe it was. After a discussion with executives, he signed a magazine article which described only drops of water turning "the great wing into a brilliantly glittering strip of jewels."

Daley's failure to assess the true impact of such cover-ups makes Brian Moynahan's "Airport Confidential" particularly provocative. Moynahan contends that even today's airlines cut safety corners. For example, seat belts could be more securely fastened to the floor. As it is now, some passengers survive a crash only to be hurled around the cabin.

But "the most common cause of crashes," Moynahan says, "is pilot error." One DC8 captain made a "pillow soft landing in the Pacific," thinking it was San Francisco airport. Pilots also show extraordinary skill: When four engines of another huge jet went out at 37,000 feet, the pilot guided it to a safe landing.

The number of near-accidents is frightening. British Airways had no fatalities in 1975, yet recorded "99 stall warnings and 230 abandoned take-offs, and 625 engines were shut down in flight." The first six months of 1976 brought British Airways "35 air misses," or near-collisions with other aircraft.

Moynahan emphasizes that "most accidents are on takeoff and landing, where the speed is not great and where the impact itself is usually survivable. It is not the crash . . . that kills but suffocation or poisoning [from chemicals in the smoke] later."

Studies show that "about 60 percent of fatal crashes have survivors" and that they have "60 seconds to get out." The survival-minded should sit next to an emergency exit. Second choice should be the forward or tail section, depending on the aircraft, because this avoids "fuel lines which may rupture in a crash."

Escape statistics reveal unpleasantries about human nature. "In one crash" Moynahan notes, "32 of 37 men got out of the aircraft, but only 15 of 36 women, children and elderly."

Although chances of death during flight are calculated at "three in a million," fear of flying is common. JFK airport alone has at least 20 daily cases of "flight hysteria."

"Airport Confidential" also includes the less serious perspective. An example of in-flight relaxation is the couple -- strangers until they fastened their seat belts -- who began to consummate an intimate relationship in full view of fellow passengers. Crew members asked them to stop. They refused. Finally, the pilot radioed ahead for a "senior official" to meet the aircraft. fBut the two passengers were sound asleep when the plane landed. The captain decided that they posed no danger to his aircraft, so the airline simply filed an incident report and let them continue their flight.