A GoJet Canadair CRJ-550 had to return to St. Louis shortly after takeoff on July 18 after a lavatory smoke detector indicator alerted the crew to smoke in the toilet. The rear-engine 50-seat regional jet was operating as United Express flight number G7-4527 from St. Louis Lambert International Airport (STL) to O'Hare International Airport in Chicago (ORD).

The nearly 19-year-old plane registration number N502GJ was climbing after having just taken off from Lambert's runway 29. When at 5,000 feet, the crew aborted the climb to declare an emergency after indicators showed smoke in the lavatory. Requesting permission to return to St.Louis, the plane landed safely on runway 30R some 12 minutes after departure according to a report by the aviation website The Aviation Herald.

Once home to Trans World Airlines, Lambert Field, as it is more commonly known, has four runways, the newest of which is runway 29, which was completed in 2006. GoJet brought in a replacement CRJ-550 registration N533GJ, which arrived in Chicago after a 90-minute delay. The aircraft in which the emergency was declared N502GJ returned to service with GoJet 24 hours after the incident.

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Lavatory smoke detectors

I am sure that you have all heard the words"smoking is not allowed in the lavatories at any time," yet despite this and severely heavy fines, people still think they can get away with it! Federal Aviation Administration (FAA) regulations mandate that all aircraft capable of carrying more than 20 passengers must have a smoke detector in the lavatory.

Located in the ceiling and powered by the 28-volt DC left/right main DC bus, should smoke be detected, a warning light comes on in the cockpit. Some aircraft are also fitted with an audio system that sounds and flashes a light at cabin crew stations.

CRJ550
United Express CRJ-550 first class. Photo: Bombardier

You might not know this, but a functioning ashtray is conspicuously located on the doors of all airplane bathrooms. This is to provide a place to extinguish cigarettes should a passenger violate the no-smoking rule. Each lavatory must also have a built-in fire extinguisher that discharges automatically in the event of a fire.

I think we can safely assume that seeing as the aircraft in this incident was taking off there wasn't a person in the toilet trying to smoke.

 About the Canadair CRJ-550

Manufactured by Bombardier Aerospace in Quebec, Canada, the CRJ-550 is a re-branded version of the CRJ-700. Rather than the 73 seats found in the old CRJ-700, the CRJ-550 will only have 50 seats to enhance passenger comfort. In the case of the United Airlines version, it will feature ten first class seats, 20 economy plus seats, and 20 economy seats.

Other innovative features in the CRJ-550 include the following: 

  • Enough storage space to allow every passenger a roller bag 
  • Self-serve drinks and snack center for first-class passengers. 
  • More legroom per seat than any other 50 seat aircraft flying in the United States
  • In-flight WiFi

About GoJet Airlines

Headquartered in St. Louis, Missouri, GoJet airlines operate regional flights on behalf of United Airlines under the name United Express. Serving over five million passengers a year, GoJet operates more than 250 flights a day to 80 destinations. According to Planespotters.net GoJet has a fleet comprised of 32 CRJ-550s.

CRJ550 self serve snack bar
The self-serve snack bar on the CRJ-550. Photo: United

Have you ever flown on a United Express CRJ-550, and if so, how would you rate the experience? Please let us know what you think in the comments.