Question: Waylon Smithers appeared an episode of The Simpsons that originally aired on January 21, 1990, and that has Homer promoted to what position?

Context articles: Waylon Smithers
Homer's Odyssey (The Simpsons)
Dancin' Homer
Flaming Moe
Homer's Night Out
Homer the Smithers
Mr. Burns
Hans-Georg Panczak
So It's Come to This: A Simpsons Clip Show
Who Shot Mr. Burns?

Waylon J. Smithers Jr., usually referred to as Mr. Smithers or simply Smithers, is a recurring fictional character in the American animated sitcom "The Simpsons", who is voiced by Harry Shearer.
 Smithers first appeared in the episode "Homer's Odyssey", although his voice could be heard in the series premiere "Simpsons Roasting on an Open Fire".
 He is the consummate executive and personal assistant of Springfield Nuclear Power Plant's owner Mr. Burns.
"Homer's Odyssey" is the third episode of the first season of "The Simpsons".
 It originally aired on the Fox network in the United States on January 21, 1990.
 In this episode, Homer becomes a crusader for citizen safety in Springfield, and is promoted to his current position as Nuclear Safety Inspector for the entire power plant.
 It was written by Jay Kogen and Wallace Wolodarsky and was the first "Simpsons" script to be completed, although it was the third episode produced.
"Dancin' Homer" is the fifth episode of "The Simpsons"<nowiki>'</nowiki> second season.
 It originally aired on the Fox network in the United States on November 8, 1990.
 In the episode, Homer fires up the crowd at a Springfield Isotopes baseball game and is chosen to be the team's new mascot.
 He immediately becomes a popular attraction and the Isotopes start a winning streak.
 As a result, Homer is promoted to a team in Capital City, the Capital City Capitals.
 The Simpson family moves there, but Homer fails to enthrall the crowd, and the family returns home.
"Flaming Moe" is the eleventh episode of "The Simpsons"<nowiki>'</nowiki> twenty second season.
 It originally aired on the Fox network in the United States on January 16, 2011.
 It follows the efforts of Waylon Smithers to earn Mr. Burns' respect by turning Moe's Tavern into a successful gay bar, leading Moe to become more popular as a gay man than Smithers.
 Meanwhile, Principal Skinner looks for love with the substitute music teacher.
"Homer's Night Out" is the tenth episode of "The Simpsons"<nowiki>'</nowiki> first season.
 It originally aired on the Fox network in the United States on March 25, 1990.
 It was written by Jon Vitti and directed by Rich Moore.
 In the episode, Bart orders a mail-order spy camera, which he uses to secretly take a photograph of Homer dancing with an exotic belly dancer. Marge makes Homer apologize to the exotic dancer to teach Bart that women are not objects.
 Sam McMurray guest stars in the episode as Gulliver Dark, the man that introduces Homer to the crowd at the burlesque show.
"Homer the Smithers" is the 17th episode of "The Simpsons"<nowiki>'</nowiki> seventh season.
 It originally aired on the Fox network in the United States on February 25, 1996.
 In the episode, Mr. Smithers takes a vacation and hires Homer to take over as Mr. Burns' assistant.
Charles Montgomery Burns, known as C. Montgomery Burns and Monty Burns, but usually referred to simply as Mr. Burns, occasionally as Mr Snrub, is a recurring character in the animated television series "The Simpsons", and is voiced by Harry Shearer.
 Mr. Burns is the evil owner of the Springfield Nuclear Power Plant and is also Homer Simpson's boss.
 He is assisted at almost all times by Waylon Smithers, his loyal and sycophantic aide, adviser, confidant and secret admirer.
Hans-Georg Panczak (born 19 July 1952 in Düsseldorf, Germany) is a German television actor and voice actor.
 He is best known as the German voice of Waylon Smithers in "The Simpsons", of Mark Hamill in the original "Star Wars" trilogy, and of Glen Quagmire in "Family Guy" since the fourth season.
"So It's Come to This: A Simpsons Clip Show" is the eighteenth episode of "The Simpsons"<nowiki>'</nowiki> fourth season.
 It originally aired on the Fox network in the United States on April Fools' Day, 1993.
 In the episode, Homer plays a series of practical jokes on Bart, and to get even, Bart shakes up a can of Homer's beer with a paint shaker.
 Homer opens the can, resulting in a huge explosion that lands him in the hospital, where he goes into a coma.
 At Homer's bedside, the Simpson family reminisce, mainly about moments relevant to Homer's life.
"Who Shot Mr. Burns?"
 is a two-part episode of the American animated television series "The Simpsons".
 Part One is the twenty-fifth and final episode of the sixth season and originally aired on the Fox network in the United States on May 21, 1995, while Part Two is the season premiere of the seventh season and aired on September 17, 1995.
 Springfield Elementary School strikes oil, but Mr. Burns steals it and at the same time brings misery to many of Springfield's citizens.
 Part One has a cliffhanger ending where Mr. Burns is shot by an unidentified assailant.
 In Part Two, Springfield's police try to find the culprit, with their main suspects being Waylon Smithers and Homer Simpson.