As Northwest Airlines Flight 253 approached U.S. airspace on Christmas Day 2009, Umar Farouk Abdulmutallab, the passenger in window seat 19A, began his final preparations for death, a federal prosecutor said at the opening of the Nigerian defendant’s terrorism trial here Tuesday.

Abdulmutallab, now 24, went to the bathroom, where he purified himself with water, brushed his teeth and applied perfume to his body, Assistant U.S. Attorney Jonathan Tukel said in his opening statement before a jury of nine women and three men.

Abdulmutallab then returned to his seat looking out over the wing and covered himself with a blanket. He pushed a plastic syringe containing two chemicals into a small amount of explosive, triggering a fire and detonation that he hoped would blow up the main charge — seven ounces of PETN — and bring down the plane, Tukel said.

Passengers at first were confused as a fire blazed in Abdulmutallab’s lap.

“Hey, dude, your pants on fire,” said the passenger next to Abdulmutallab, according to the testimony of the first witness at the trial, Michael Zantow, who was sitting near Abdulmutallab.

Umar Farouk Abdulmutallab is shown in this December 28, 2009, booking photograph. (HO/AFP/GETTY IMAGES)

In a 95-minute opening statement, Tukel laid out what he called an al-Qaeda-inspired plot, described minutes of chaos on the plane as fire enveloped an impassive Abdulmutallab, and summarized a series of self-incriminating statements the defendant made to law enforcement and medical personnel.

Abdulmutallab, wearing a West African silver-gray dashiki with gold trim and a black skullcap, sat emotionless as Tukel spoke, even when the federal prosecutor pointed directly at him, saying that all of the 290 people on board had plans for that day, except the defendant, who wanted to die.

“His mission was for al-Qaeda,” said Tukel. “He thought he would end up in heaven because he wanted to be a martyr.”

The stand-by attorney for Abdulmutallab, who is representing himself, reserved the right to make an opening statement at a later date. Abdulmutallab originally had said he wanted to deliver an opening statement himself, then changed his mind last week and may have changed his mind again. U.S. District Judge Nancy G. Edmunds has ruled that the defense must give one day’s notice on whether Abdulmutallab or the advisory counsel, Anthony T. Chambers, will speak or question witnesses.

According to Tukel, Abdulmutallab went to Yemen in November 2009, having been inspired to get involved in violent jihad by the tapes of Anwar al-Awlaki. The radical American cleric, who was killed by a CIA drone strike last month, was an operational figure in al-Qaeda’s affiliate in Yemen, according to administration officials.

In Yemen, Abdulmutallab was introduced to a man called Abu Tarak, the prosecutor said. The two spoke daily about Osama bin Laden, martyrdom and attacking the United States. Tarak eventually suggested a plane attack, and Abdulmutallab met the Saudi bombmaker who designed the device he carried onto the plane, Tukel said. He was fitted with the device, which one witness described as being like an adult diaper, on Dec. 6 or 7, and wore it until the attack.

Tukel said that Abdulmutallab recorded a martyrdom video before leaving Yemen, telling his “Muslim brothers in the Arabian Peninsula” that the “enemy is in your land.”

Abdulmutallab was told to attack a U.S. carrier when it was flying over the United States, Tukel said. The details were left to Abdulmutallab. He was chosen because he was well educated and traveled, and had a U.S. visa in his passport. Educated in London and Dubai, Abdulmutallab, Tukel said, noted on one visa application for the United Kingdom that his father, a banker in Nigeria, earned about $150,000 a month.

Abdulmutallab flew to Ghana from Yemen and then home to Nigeria. He reserved and canceled a number of flights — to Houston, Chicago and California — before settling on the flight to Detroit from Amsterdam. At every stop after Abdulmutullab left Yemen, the device beat airport security, the prosecutor said.

A Detroit area attorney, Kurt Haskell, who was on the flight, has said the U.S. government conspired with Abdulmutallab, in part to speed the introduction of scanners. The judge said Haskell, who was in court this morning, could watch that proceedings because he may be called as a defense witness.

It was 11:44 a.m., six minutes after the plane had left Canadian airspace, when fire erupted around Abdulmutallab, who sat expressionless in his seat as he burned, the prosecutor said.

Some passengers rushed toward Abdulmutallab and tried to put out the fire with blankets before the crew sprayed the Nigerian with fire extinguishers. Other passengers were screaming, and panic spread through the plane. Abdulmutallab, his pants around his feet and his underwear largely burned away, was subdued by some passengers and brought to the front of the plane. As the Nigerian was walked to the front, the remaining explosive fell behind seat 13B, where it was later found by the FBI.

Abdulmutallab’s thighs and genitalia were badly burned. He was given a blanket to cover himself as he sat in seat 1G watched by crew members and passengers.

The judge rejected a motion from Chambers, the stand-by attorney, that the jury not be shown a picture of Abdulmutallab’s genitalia, which Tukel described as explicit.

The pilots were told within seconds of the incident that there was a fire on board the aircraft and initially believed it was caused by firecrackers. They declared an emergency, and air traffic controllers began to clear the air space in front of them, moving two planes ahead of the Northwest flight and designating a longer runway for them to land on.

The plane was at about 9,500 feet when the fire started, and the pilots began a relatively rapid descent, banking right and then right again. The crew shouted, “Sit down, sit down, sit down,” to the still-panicked passengers. The plane landed at 11:51 a.m.

At the gate, Abdulmutallab was met by Marvin Steigerwald from U.S. Customs and Border Protection, who asked him who he was involved with, Tukel said.

“Al-Qaeda,” responded Abdulmutallab in the first of a series of admissions, the prosecutor said.

Later, when a nurse at the University of Michigan hospital asked Abdulmutallab if he was trying to harm himself or others, he said no, according to Tukel’s account.

“That was martyrdom,” the Nigerian said.