Boeing issues safety warning on 737 MAX planes; Air Canada, WestJet respond

Boeing Co. has issued a safety warning to all operators of its new 737 MAX jets in response to last week’s fatal plane crash in Indonesia involving a nearly-new Lion Air jetliner.

At the centre of Boeing’s “Operations Manual Bulletin (OMB),” issued yesterday (Nov. 6), is a crucial sensor that was replaced on a Lion Air jet the day before it plunged into the Java Sea killing all 189 passengers aboard. 

“The Indonesian National Transportation Safety Committee has indicated that Lion Air flight 610 experienced erroneous input from one of its AOA (Angle of Attack) sensors,” Boeing said in a company statement issued to PAX. 

What is the "angle of attack"?

The "angle of attack" is the angle of an airplane relative to the oncoming current of wind or air. 

According to a story published by Bloomberg, who spoke with an anonymous source “familiar with the matter,” the sensor in question can produce erroneous readings from a flight-monitoring system and cause 737 MAX planes to “abruptly dive.” 

The sensor is reportedly designed to keep track of the angle of the aircraft’s nose in relation to incoming air and wind and prevents it from stalling. 

In its bulletin, Boeing has directed flight operators to review existing crew procedures on how to respond to situations when erroneous “angle of attack” data is involved. 

Air Canada & WestJet respond

Boeing's bulletin is the first solid action to come out of the Lion Air investigation into the Oct. 29th incident that unfurled on the coast of Indonesia. The tragedy marks the first crash involving a 737 MAX plane, which crashed minutes after takeoff, nosing downward at tremendous speed before plunging into the sea.

Chicago-based Boeing has reportedly delivered 219 MAX 737 jets since the new and advanced models debuted last year. 

The modernized planes feature larger engines, upgraded cockpits, larger glass displays, advanced aerodynamic wings, and are considered to be the more fuel-efficient version of the manufacturer's best-selling single-aisle 737 series.

Of all the airlines that have purchased Boeing’s 737 MAX planes, Air Canada is Boeing’s second biggest customer.

“We have received the bulletin from Boeing and are following its recommendations, as we do with all such advisories from manufacturers and government safety regulators,” Peter Fitzpatrick, a spokesperson for Air Canada, told PAX in a statement. “The Bulletin reinforces existing procedures which all Air Canada crews are currently trained on.” 

Reminders will be sent

Fitzpatrick also stated that Air Canada will be “sending all our crews a reminder of these procedures” and that it will monitor all developments and “respond accordingly to any recommendations that enhance safety.”

WestJet has nine 737 MAX planes in its fleet. PAX contacted the airline this morning for comment: 

"WestJet has received the Boeing bulletin and is following its guidance, which recommend[s] emphasizing established procedures that have been used and trained on WestJet’s existing B737NG fleet as well as the B737MAX. We are following the investigation into the Lion Air incident closely and will work with our partners at Boeing to ensure the continued safe operation of our Boeing MAX aircraft," Morgan Bell, an advisor in media and public relations at WestJet, said in a statement issued to PAX. 

Boeing stated that it is common procedure to issue safety bulletins “whenever appropriate” and that it will continue to cooperate and provide technical assistance while government authorities investigate the incident.