Passengers frustrated by re-booking policies for airlines flying Boeing 737 Max 8 

SAN FRANCISCO -- After two Boeing 737 Max 8 fatal crashes in less than five months, passengers arriving at San Francisco International Airport Monday on one of Air Canada's Max 8's were measured in their response.

"I trust Air Canada and it is worrisome to a certain extent but I didn't put too much attention to it, I mean we don't know the reasons for the incident," said Stacey He from Montreal.

RELATED: 157 killed, including 8 Americans, in Ethiopian Airlines plane crash en route to Kenya

In October a Lion Air Boeing 737 Max 8 crashed in Indonesia killing 189 people after a sensor malfunction.

Sunday's Ethiopian Airlines Boeing 737 Max 8 crashed just six minutes after takeoff-- 157 people died including eight Americans. The pilots had been struggling with control issues, called the tower and said they wanted to return to the airport.

"Lion Air was clearly the result of inadequately trained pilots and an airplane that should never have been dispatched 1:24Here we don't know what we've got for sure but it does not appear to be something that would be directly related to pilot action," said John Nance, ABC News Aviation Contributor.

Ethiopian Airlines grounded its four other Max 8s. Regulators in China and Indonesia are doing the same.

The Max 8s continue to be in service here in the United States.

RELATED: Ethiopian Airline crash: Black box found after 157 die in plane crash

Travelers on Twitter have been less measured in their response.

One tweeting in part, "Does anyone want to play Russian Roulette? Just fly on one of @AirCanada 24 Boeing 737 Max 8 aircraft."

Air Canada tells ABC7 News it has extensive analytical data supporting the safety of these aircraft.

In an emailed statement writing"

"We have operated this aircraft type since 2017 and currently have 24 in our fleet. We have extensive analytical data supporting the safety of these aircraft, which have also performed excellently from reliability and customer satisfaction perspective.

We continue to monitor the situation and based on current information, and recommendations by government safety regulators, including Transport Canada, the FAA, and the manufacturer, we continue to operate our normal B737 schedule.

Our current re-booking policies remain in place."

Air Canada, Southwest and American Airlines say their normal re-booking policies remain in place.

Southwest Airlines emailed ABC7 News, "Our heart goes out to the families and loved ones of the passengers and Employees on Ethiopian Airlines Flight 302. As Southwest operates a fleet of 34 Boeing 737 MAX 8 aircraft, we have been in contact with Boeing and will continue to stay close to the investigation as it progresses. We remain confident in the safety and airworthiness of our entire fleet of more than 750 Boeing 737 aircraft, and we don't have any changes planned to 737 MAX operations.

We are fielding some questions from Customers asking if their flight will be operated by the Boeing 737 MAX 8. Our Customer Relations Team is responding to these Customers individually, emphasizing our friendly, no-change-fee policy, However, we remain confident in the safety and airworthiness of our fleet of more than 750 Boeing aircraft."

Julian Broue said he had no idea the aircraft he flew to San Francisco today is now in question.

RELATED: Lion Air 737 crashed into sea with 188 people on board

"The flight returning back home that hopefully will not be the same type of plane but then again we bought our tickets so," said Broue.

"Maybe would have changed our flight if we knew," said Noemi Sigouin.

The union representing American Airlines flight attendants issued a bulletin saying if they feel unsafe to work the 737 Max, they will not be forced to fly it.

While the pilots' union is cautioning its members against speculation.

You can click the flight number or details during the booking process to see the aircraft info. If you've already booked, you can try searching your flight number, or go through the same steps as if you were booking again and click on the flight number or details to see that info.