- Thousands of flights have been canceled since all of Boeing's 737 Max airplanes were grounded on March 13.
- As summer travel results in more demand, travelers should check their travel arrangements to make sure they are not on a canceled flight.
- Don't expect last minute deals.
- Rebook affected flights rather than canceling them.
Thousands of flights have been canceled since all of Boeing's 737 Max airplanes were grounded on March 13, forcing American, Southwest, United and many international airlines to scramble and adjust schedules, rebook passengers and figure out what comes next.
Airlines expect Boeing to issue software updates and new training procedures for the 737 Max planes soon, but there is no set date yet for when the aircraft will be recertified and return to the skies.
And now the summer travel season is about to kick into high gear.
Here's what airlines and travel experts are telling passengers about how the 737 Max grounding may affect fares and summer travel plans.
On Thursday, Southwest said it is examining the situation every 30 days since it doesn't know when it will be able to use the 34 Max jets its operates. The airline provides updates on its Boeing 737 Max update page, and its cancellations now run through Aug. 5, impacting about 160 flights a day.
American Airlines has canceled about 115 737 Max-related flights per day through Aug. 19. The airline's reservations and sales teams are continuing to work with affected customers to manage their travel plans.
"We've made an initial outreach to everyone affected with either new flight numbers or flight timings and will continue specific, individual work to ensure each of our customers is handled to their satisfaction," said Southwest Airlines spokesman Brad Hawkins.
In some cases, thanks to aircraft-type substitutions, flights previously scheduled on Max planes aren't being canceled.
"American's Reservations team will contact affected customers directly by email or telephone," the airline said in a statement. "Customers who booked through a travel agent will be contacted by their agency directly."
United Airlines expects 130 Max-related canceled flights during both April and May and has decided to pull Max flights out of its schedule through early July.
"By using larger aircraft on those routes, we have been able to protect our customers' original itineraries to cover almost all of the Max flights," said United Airlines spokesman Frank Benenati via email.
While airlines are being proactive about rebooking passengers whose flights are canceled or changed, Liana Corwin, a travel expert from travel app Hopper, urges travelers to be sure to review their itineraries themselves.
"If you see something is different and you're not happy with it, contact the company where you made your booking," said Corwin. "If it was through a travel agency, contact them; if through the airline directly, contact them."
Henrik Zillmer, the CEO of AirHelp, a company that helps passengers claim compensation for canceled or delayed flights, urges consumers to consider rebooking rather than canceling their travel plans, if that's an option offered by an airline making 737 Max schedule adjustments. This is especially if it's a flight operated by a foreign carrier.
That's because "travelers who cancel their flights would not be eligible to claim compensation if they decide to do so," said Zillmer. "Passengers do not have a right to compensation or reimbursement for tickets purchased if they choose to cancel."
For those shopping for fares now, Hopper's Corwin says the 737 Max grounding is just one factor that may be contributing to higher fares.
"Given the multitude of factors that go into determining the cost of airfare, and considering that the 737 Max seats represented only a small percentage of overall capacity, what is more likely to happen is that summer travel prices will continue to be driven by larger economic forces, such as oil prices and competitive pressures," she said.
Whatever you do, if you're planning on buying an airplane ticket for summer travel: "Don't procrastinate," said Rick Seaney, co-founder and CEO of FareCompare.com.
"While you may save money by being flexible about which city you travel to, this summer there are not going to be cheap deals popping up at the last minute," he said.
Summer is typically the busiest time of year for airlines, and Seaney says 737 Max issues are removing about 50,000 seats, or the equivalent of a football stadium full of people, from the system each day.
"Demand will overstrip the supply, and the 737 Max issue exacerbates that. And that's never a good place to be inside of 30 days of buying your ticket," said Seaney. "You're playing right into the airlines' hands if you do that."
— CNBC's Emma Newburger has contributed to this report.