With 38 million Americans expected to hit the roads, rails, and skies this Memorial Day weekend, the Transportation Security Administration is asking fliers to check their pockets, carry-on bags, and handbags before arriving at airport security checkpoints, where lines have been an hour or longer.

No grenades - real or fake. No drills or saws, knives or blades. No toy guns or hammers, and leave the bullets and brass knuckles at home.

TSA public affairs manager Michael McCarthy showcased for reporters Tuesday how a security lane at a Philadelphia International Airport checkpoint moved four times faster if people followed proper procedures. Delays arose when they attempted to go through X-ray screening with a water bottle, pocket knife, laptop, and a firearm concealed in carry-ons.

"We don't get firearms every day, but when we do, that truly stops that lane," McCarthy said. The TSA demonstrated the delays with 10 volunteers who went through the line twice, the first time correctly emptying their pockets, and making laptops and permitted liquids and gels visible.

They went through again, this time carrying banned items, including a gun.

The time difference: one minute and 45 seconds versus eight minutes.

"Every time something alarms, an officer has to do a bag search," McCarthy said. "That takes an officer off the line."

The demonstration occurred the same day reports surfaced that Kelly Hoggan, head of security for the TSA, had been removed from his position after the agency was criticized for long lines at airport security checkpoints.

Airlines and airports, including PHL, have added private security to ease congestion, but long lines are still forecast. TSA advises air travelers to arrive at the airport two hours early for domestic flights and three hours ahead for international trips.

The agency reminds fliers to put liquids, aerosols, gels, and creams limited to 3.4 ounces in a clear quart-sized bag. Remove shoes, empty pockets, take off belts and shoes, and remove laptop computers from carry-on bags.

"A record number of passengers are expected to travel by air this summer," airline analyst Helane Becker of Cowen & Co. said in a client note. "Friday is considered one of the busiest travel days of the year."

Airlines for America, the industry trade group, said travel between June 1 and Aug. 31 is expected to increase by 4.2 percent, spurred by an improving economy, cheaper gas, and lower fares.

Meanwhile, the TSA has cut staff due to budget reductions, from 47,147 in 2013 to 42,525 at nearly 440 airports this summer.

Security wait times have stretched to 60 to 90 minutes or worse at some airports this spring, including Chicago O'Hare and Newark Liberty, because of the increase in travelers, fewer airport screeners because of congressional budget cuts, and tighter security measures after terror attacks in Paris and Brussels, Belgium, and the downing of a chartered airliner over Egypt's Sinai Peninsula in October.

Congress has given the TSA authority to hire 768 additional screeners, but airlines say that is not enough. Homeland Security Secretary Jeh Johnson said the agency will pay overtime to screeners this summer and will increase use of bomb-sniffing dogs.

Airlines and the TSA are encouraging vetted customers to enroll, for an $85 fee, in a prescreening program called TSA Pre-Check. Passengers in the program, which requires an interview and a background check, can get through security lines more quickly because they do not have to take off their shoes or remove laptops and liquids from carry-on bags.

However, not all terminals at Philadelphia International have Pre-Check lanes.

If you are looking for faster Pre-Check lines, go to Terminals A-East, B, and D-E.

Terminal C only sporadically has an open Pre-Check lane, based on projected passenger volumes, the TSA said.

Terminals A-West and F do not have Pre-Check lanes, the agency said.

American Airlines plans to spend $4 million to hire private contractors this summer to help manage security lines at its hub airports, including Philadelphia. American operates 70 percent of the flights in Philadelphia.

In Philadelphia, McGinn Security and PrimeFlight Aviation, subcontractors for American Airlines, will be working under TSA guidance to assist with "nonessential" security functions, such as distributing and retrieving bins and keeping passengers moving through screening lines.

McGinn has hired 15 to 20 new employees. PrimeFlight will use existing employees and allocate them as needed to help in TSA screening areas. The increased staffing will begin Memorial Day weekend.

Airlines for America has created a website, ihatethewait.com, and is encouraging fliers to use the hashtag #ihatethewait to post photos of long lines, in the hope of pushing officials to solve the problem.