The Grand Canyon

''What's all the shouting about?'' I used to think as I flew over the Grand Canyon, enroute from New York to Los Angeles. From a height of around 30,000 feet, what I saw below seemed to be essentially a big ditch.

Then recently I stopped in Phoenix for a few days, mainly to attend to business. At the travel desk in the lobby of the historic Arizona Biltmore Hotel , I noted that several airlines offered airplane day trips to the Grand Canyon from the Phoenix-Scottsdale airport. Time to investigate all this fuss over the big ditch, I thought.

So, I signed up for the flight, and before the day was over the ''big ditch'' had become forevermore, in my mind, one of the greatest natural marvels of the world. I regretted having waited so long before seeing the Grand Canyon up close. Never again, with my new perspective, would I be able to belittle those spectacular gorges, buttes, mesas, and canyons.

Anybody flying to the West Coast who has not yet managed to see the Grand Canyon up close would do well to arrange a two- or three-day stopover in Phoenix , in the heart of what the chamber of commerce calls the ''Valley of the Sun.'' Besides the chance to take the quick tour of the Grand Canyon, Phoenix offers one of the landmark hotels of the Southwest - the venerable Arizona Biltmore - and one of the best ethnic museums in the country - the Heard Museum of Anthropology and Primitive Art.

The efficient public relations staff of the Arizona Biltmore is not being extravagant when it calls the hotel ''the jewel of the desert.'' This hotel, built by Albert Chase McArthur, was inspired by the architecture of Frank Lloyd Wright. Although opened in 1929, later expansions and interior design were the work of the Frank Lloyd Foundation/Taliesin West.

Set in the foothills of Squaw Peak, the Biltmore is surrounded by palms, wildflowers, and cactuses as well as canals originally dug by the extinct Hohokam Indians.

Aside from its luxury-resort facilities, which include two 18-hole golf courses, 18 tennis courts, 3 swimming pools, and a health club, this Westin hotel manages to combine its desert mountain and Indian heritage with the Frank Lloyd Wright influence.

It is famous for its architectural features - some public areas have copper roofs, gold-leafed ceilings, and Wright-inspired perforated-concrete blocks. There's a geometrical Wright bas-relief in the main foyer. Throughout the hotel, the renowned architect's geometric patterns are integrated into carpets, drapes, ceilings, and tapestries. In addition, murals depict Zuni and Hopi Indian legends.

To seasoned travelers used to high-rise hotels, the Biltmore may seem a bit like a luxurious motel since it is all on two or three levels. The fact is that the 500-room hotel is one of 12 resorts in the country rated five stars by the Mobil Travel Guide.

Although Phoenix boasts many cultural attractions, such as the Art Museum and the Phoenix Symphony, and although its environs offer exciting day trips to Taliesin West, Cosanti and Arcosanti, the Apache Trail, Montezuma's Castle, and the Mogollon Rim, because of limited time, I restricted my sightseeing to the Heard Museum and the Grand Canyon.

For an introduction to the area and orientation about native American life, the first stop out of the hotel should be a visit to a superb haciendalike building in the heart of Phoenix - the Heard Museum.

This unique museum has taken on the task of informing the general public about the native people of the Southwest. Its arts and crafts collections include exhibits of baskets, pottery, silver jewelry, kachina dolls, Navajo blankets, colonial furniture, Rio Grande textiles and native art from all around the world, but especially the American Southwest. The museum shows films, arranges lectures, and sponsors craft demonstrations and fairs. In addition to traditional native American works, there is often a showing of contemporary art by native Americans. And there are exhibits treating prehistoric native American history.

Experts in the field consider the Heard to be the most extensive museum of native American culture and history in America. It is now in the midst of a $4 million expansion program to assure the museum of its place in the vanguard of America's growing fascination with its own past.

If you are in the market for authentic gifts, the museum's gift shop offers the best in Southwestern arts and crafts, made by native Americans and chosen by museum personnel for excellence, fair prices, and authenticity.

A highlight of any trip west in America is bound to be the Grand Canyon - if you give it the chance. I was still suffering from the big-ditch attitude when I signed on with Scenic Airways, one of several airlines that make the voyage from Phoenix-Scottsdale to the canyon.

For $161, including tax, Scenic will pick you up at your hotel in Phoenix, drive you to the Scottsdale airport, give you an elaborate air tour of the area northwest of Phoenix, dive into the canyon itself, take you on a tour of the South Rim, feed you an adequate lunch, fly you back to Scottsdale, and drop you off at your hotel. The trip takes about seven hours.

The driver of Scenic's pickup vehicle pointed out the local sights as we drove to Scottsdale - Squaw Peak with its jogging trail to the summit, the Praying Monk Peak, Camelback, Barry Goldwater's house on the hill.

At the airport, I waited until the nine passengers for the Cessna 402 were assembled, and then we climbed into our seats (all by windows, by the way). For Otter VistaLiner that has a bit more window view.

Each seat in the plane is supplied with a set of earphones over which a multilingual voice (you choose your language) explains the sights: the Sonora desert and the lush Verde Valley; the ruins of the Hohokam civilization; the vivid red limestone buttes of Sedona; the snowcapped Bradshaw Mountain range; ponderosa pine forests; Flagstaff; the Navy's Lowell Observatory, where man first saw the planet Pluto; Mt. Humphrey, high place of the snow; the San Francisco peaks.

Suddenly, there it was. Under us, in front of us, to all sides of us, the big ditch itself. Only it was no longer a big ditch to me. Instead, it was the most spectacular sight I had ever seen, a monument to nature's power.

As the little plane entered into the east end of the canyon, it dipped, perhaps 1,000 feet below the mile-high rims.

The plane seemed to be playing leap-frog with the birds as the below-the-rim turbulence caused it to make heart-stopping drops in altitude. At one point, the upward bump was so strong that, despite my tightly fastened seat belt, the top of my head hit the air vent above.

Splashes of crimson and purple, fields of green, pure white snow, multicolored ridges, plateaus and buttes, craggy mountains overrun with fiery foliage, frightening crevasses, deep ravines through which poured torrential rapids and burbling waters. Ravens and golden eagles circled the trails on which one could make out tiny mule trains carefully making their way down to the hidden valleys below.

The Grand Canyon seemed to spread across the continent for hundreds of miles; only far in the distance could I make out the familiar sight of hills and fields unmarked by cataclysmic chasms.

There was not enough time on the ground to take any of the mule trips down into the canyon or any of the helicopter rides below the rim. There is also a Scenic overnight tour at $185, which includes one night's lodging, enabling tourists to see a bit more of the canyon.

Next time I visit, I plan to see and to do a lot more.

However, this trip there was enough time on the ground to visit several scenic points on the rims and a small museum - and even have an adequate lunch of barbecued chicken at the Grand Canyon Squire Hotel.

When the time came to board the little plane again, the pilot assured us that he would not dip below the rim on the return trip to Phoenix. It was an uneventful flight back and, when the Scenic bus dropped me off at the Biltmore in the early evening, there was still time for a good dinner at the hotel restaurant, the Orangerie.

I consider myself an experienced traveler. Now I realize that too often I have looked askance at those who waxed ecstatic over their Grand Canyon visits and trips to other major ''tourist attractions.'' Well, this day trip has been a sobering experience for me, a recognition that perhaps I have become too jaded about travel. Never again will I dare to think ''big ditch'' when I fly over the Grand Canyon.

Next stop: Niagara Falls. Practical Information.

The Arizona Biltmore Hotel can be reached at (602) 955-6600. Room rates range from $145 to $200 double in season (Jan. 2 to May 28), but drop to less than half that price between May 29 and Sept. 10. And for good reason. In summer the temperature often reaches 120 degrees F. It is only fair to warn summer visitors that the hotel was not designed for air conditioners and, although they have been added, there are still many ''hot spots.''

The Scenic Airlines number is (602) 252-0863.

There are other airlines that fly over the Grand Canyon and many other hotels in Phoenix. For information write: Phoenix & Valley of the Sun Convention & Visitors Bureau, 4455 Camelback Rd., Phoenix, Ariz. 85018

Admission to the Heard Museum is only $1.50; plan on spending at least four hours.

A tip: Since taxis are not regulated in Phoenix, it is wise to ask fares before you enter the cab. Even metered fares vary. The trip from the Biltmore to the Heard Museum should cost under $7 dollars, although the first time I blithely entered a cab after seeing that there was a meter, it cost me $11.