BY JOEL J. SMITH
The Detroit News

Even though air-traffic controllers told the crew of Comair Flight 3272 to slow to a speed some considered unsafe for weather conditions, the pilots had the authority to override the order, aviation experts say.

Controllers told the two pilots on the afternoon of Jan. 9 to slow to 172 mph as they approached Detroit Metro Airport to allow a larger, faster commercial jet to pass overhead and land first. The Embraer Brasilia 120 commuter turboprop ended up slowing to 166 mph, apparently too slow to handle a 40-degree banking turn in icing conditions, experts say.

The plane went out of control and crashed in a field in Raisinville Township, Mich., killing all 26 passengers and three crew.

''It's not uncommon that controllers will give you an order that you can't abide by because of safety concerns,'' said Todd Carpenter, a Boeing 727 pilot who has flown turboprop planes. ''They aren't familiar with your airplane.

''It's up to the pilot to agree to the order or to tell them you are unable. The decision rests with the pilot.''

Air maneuvers

Mr. Carpenter said he is often told to slow to speeds that are too slow for his airplane. He said that he sometimes tells the controllers that he can't and other times he simply lowers the wing flaps, which reduces the airspeed necessary to keep the 727 flying.

The flaps on the Comair plane were in the up position when it crashed, according to the National Transportation Safety Board.

A former Comair pilot, Beau Murphey, said that most controllers will ask whether a pilot can slow to a certain speed.

''If you can't, you just tell them,'' Mr. Murphey said. ''But the decision is with you.''

Officials of Embraer Aircraft Corp. in Fort Lauderdale, Fla., have suggested that wake turbulence, called vortex, caused by the larger jet passing 1,500 feet overhead on its approach to Detroit might have tossed the commuter plane out of control.

But a source close to the investigation said that ''vortex isn't an issue'' right now.

''Nobody is talking about vortex around here,'' the source said. ''Maybe it will come up down the road, but it hasn't yet.''

Reason for separation

Vortex is wake turbulence that rolls off the wing tips of an airplane. It is one of the reasons the Federal Aviation Administration sets a minimum time between takeoffs and landings on the same runway.

The turbulence can be severe enough to affect the flight of an airplane passing through it.

But C. William Kaufman, a professor of aerospace engineering at the University of Michigan, said that although vortex has played a role in a few crashes in which the airplane was on final approach to a landing, he does not know of any cases where it caused a crash of a plane in regular flight.

The Comair plane was at 4,000 feet when it went out of control. Mr. Kaufman said the jet that passed over the Comair plane supposedly was an Airbus A320, which has a unique wing design to ''de-energize the wing vortex'' to reduce drag. He said that would substantially reduce the wake turbulence created by the jet.

PROFILES OF VICTIMS
11 DAYS OF CRASH COVERAGE

Victims

First Officer
Kenneth Reece
Fort Wright, Ky.

Flight Attendant
Darinda Ogden Nilsen
Lexington, Ky.

PASSENGERS
Adams, Dexter
Cincinnati

Barrow, Gregory
Detroit

Bransford, Roger
Sandy Springs, Ga.

Brice, Arthur
Brookhaven, Miss.

Brownlee, Christine
Helena, Mont.

Brownlee, Scott
Helena, Mont.

Davis, Geoffrey
Detroit.

DeMarco, Maureen
Englewood, Colo.

Douchard, Greg
Wesson, Miss.

Felteau, Leo
Atlanta

Herman, Mark
Novi, Mich.

Jones, Betty Jean
Detroit

Jones, Charles
McComb, Miss.

McClain, Steven
Waterford, Mich.

Muskovitz, Teri
West Bloomfield, Mich.

Passariello, Kim
Lake Havasu, Ariz.

Raymond, Roy
Twin Falls, Id.

Raymond, Vernamarie
Twin Falls, Id.

Rosiak, Jennifer
Fairbanks, Alaska

Rosiak, Nicholas
Fairbanks, Alaska

Sharangpani, Arati
Holland, Mich.

Stearn, Richard
Whitmore Lake, Mich.

Takenami, Keita
Lexington, Ky.

Thomas, Douglas
Detroit.

Wansedel, Charles
Mount Clemens, Mich.

Zagar, Darlene
Danville, Ky.