Flying overnight. Working on less than optimal rest. Landing at smaller airports. Carrying hazardous goods. These are some of the elements cargo plane pilots frequently encounter as part of their jobs, presenting them with different challenges than their peers who carry passengers. It’s not clear yet whether any of these factors played a role in Saturday’s crash of an Amazon Prime Air cargo plane outside Houston, but the accident has shined a spotlight on the conditions in which freight flights operate at a time when their demand is on the rise with the popularity of e-commerce. “Flying cargo is a different type of operation than carrying passengers,’’ said longtime pilot John Cox, who writes the Ask the Captain column for USA TODAY. “There are higher levels of risk and there are more hazards flying cargo than there are with passengers.’’ Cox, president of the consulting company Safety Operating Systems, is particularly concerned about the different rest requirements for commercial passenger and cargo pilots. When the Federal Aviation Administration implemented new rules mandating 10-hour rest periods for pilots in 2014, an exception was carved out for cargo pilots as a concession to the freight industry, so they were kept under the old regulations that called for eight hours. Cox is among those who consider that a mistake. “Fatigue has been either the direct cause or a contributor to several accidents,’’ he said. “The fatigue issue for cargo pilots is very real.’’ The National Air Carrier Association, a trade group made up of 16 carriers, did not return USA TODAY's calls and emails seeking comment. Crash history The industry’s safety record has been pretty remarkable, though not as impressive as its counterpart on the passenger side, which accounts for 15 times the number of domestic flights. Since Feb. 13, 2009, the day after a Colgan Air plane crash that killed 50 people (including one on the ground) north of Buffalo, the only casualty in an accident involving a U.S.-based airline came last April when a passenger was partially sucked out of broken window after an engine exploded during a Southwest Airlines flight. A Bloomberg report said Saturday’s tragedy represents the fifth fatal crash of a U.S.-registered cargo plane in the last 10 years, costing a total of 16 lives. When also counting smaller planes, though only those certified as capable of carrying at least 12 passengers, there have been 17 fatal accidents involving cargo aircrafts run by U.S. operators since 2009, compared with 12 for passenger airlines, according to the Flight Safety Foundation. More:Search continues for body of victim, black box in Amazon Prime Air cargo plane crash It is those smaller cargo planes that raise some of the biggest concerns, said Thomas Anthony, director of the Aviation Safety and Security Program at the University of Southern California. “A lot of cargo operations are back of the clock, so they’re flying at night,’’ Anthony said. “And especially the feeder operations, they’re not flying into those airports with the highest level of instrumentation for navigational aids and for air traffic. You see the Cessna Caravans that are feeders for FedEx, well, they’re flying everywhere.’’ Indeed, one Caravan and two Cessna Cargomasters made the list of 17 cargo planes that crashed. 'Fly by night' But Robert Ditchey, a former Navy pilot and airline executive and now a consultant and expert witness for litigation cases, says it’s important to sort through the numbers because flight operators can be very different, and it’s misleading to lump them together in the same category. Ditchey tells a story about the time he worked as an executive in Miami for National Airlines – later acquired by Pan Am – in the 1970s. He said a part of the airport known as “corrosion corner’’ was populated by the kind of outfits that lived up to the expression “fly by night’’ in every way. They were owned by questionable characters and would fly risky planes to dangerous places “That exists today,’’ Ditchey said. “They are vastly, vastly different from UPS or FedEx and so on.’’ Ditchey acknowledged flying into smaller airports with lesser instrumentation presents additional risks, and he said the amount of cargo can become a challenging factor on some flights. Freighters sometimes carry large loads of lithium batteries, which are limited on passenger flights because they can heat up and explode, and may also transport animals and hazardous materials. Their design also makes it more difficult to suppress fires. In 2010, the crash of a UPS plane outside the United Arab Emirates city of Dubai was traced to a fire from lithium batteries. Investigators also found that smoke-detection equipment took too long to alert the crew members, both of whom died in the accident. The Air Lines Pilots Association, which says on its website that it represents more than 61,000 pilots at U.S. and Canadian airlines, has posted a position paper in which it calls for equal security standards for passenger and cargo pilots. It also requests the same rest requirements and the installation of intrusion-resistant cockpit doors on cargo planes. Those measures may become more important as cargo flights continue to soar. According to the Bureau of Transportation Statistics, the number of cargo flights in the U.S. increased by close to 100,000 in the last five years, to an estimated 550,000 in 2018 (December figures are not yet available). That’s just 1/15th of the more than 8.5 million domestic passenger flights, but the amount is still significant. “Homeland Security and the Department of Transportation as a whole don’t have an unlimited budget, so they’re going to provide the greatest security where you have mom and pop and Bill and Joel boarding the airplane, as opposed to somebody sending toilet paper to sub-Saharan Africa,’’ Ditchey said. “The priorities are different.’’<doc-sep>The plane was transporting Amazon cargo from Miami to Houston 'No Sign of Survivors' After Amazon Prime Cargo Plane Carrying 3 Crashes Near Houston: Report An Amazon cargo plane crashed into Trinity Bay in Texas on Saturday afternoon, likely killing the three people aboard, officials said. “Knowing what I saw I don’t believe anyone could have survived,” Chambers County Sheriff Brian Hawthorne said in a press conference, according to KHOU in Houston. “It looks like total devastation from the aircraft.” Get push notifications with news, features and more. Hawthorne indicated that there is “no sign of survivors,” according to the outlet. The plane, a twin-engine Boeing 767, was operated by Atlas Air on behalf of Amazon. It was headed from Miami to Houston before it crashed into shallow water in Trinity Bay near Anahuac, Texas, just before 12:45 p.m. CST, according to the Federal Aviation Administration. Atlas Air confirmed that information in a statement on their website. The FAA issued an alert for the plane after they lost radar and radio contact with the plane when it was about 30 miles from its destination, Houston George Bush Intercontinental Airport. Amazon expressed their condolences in a statement shared with PEOPLE. “Our thoughts and prayers are with the flight crew, their families and friends along with the entire team at Atlas Air during this terrible tragedy. We appreciate the first responders who worked urgently to provide support,” Dave Clark, Senior Vice President of Worldwide Operations at Amazon, said. RELATED VIDEO: Mother and Son Among 5 Killed as Small Plane Mysteriously Crashes Into California Parking Lot Hawthorne said that the bay was filled with cargo from the plane. “When I got out there it was just floating debris. Everything from bedsheets to women’s clothing to cardboard boxes to a lot of fiberglass. Then as we got closer we started seeing plane debris,” he said.<doc-sep>An Atlas cargo plane flying on behalf of Amazon Air — Amazon’s own freight delivery service that competes with FedEx and UPS, among others — has crashed outside Houston, Texas, killing three people on board. Amazon and Atlas both confirmed the accident with short statements. Neither provided any details on the nature of the accident. “Our thoughts and prayers are with the flight crew, their families and friends along with the entire team at Atlas Air during this terrible tragedy. We appreciate the first responders who worked urgently to provide support,” said Dave Clark, SVP of worldwide operations at Amazon. “This is to confirm that an Atlas Air 767 cargo aircraft Flight No. 3591 operating from Miami to Houston has been involved in an accident this afternoon,” reads a statement from Atlas. “We understand the aircraft went down near the city of Anahuac, Texas, in the Trinity Bay. We can confirm there were three people on board the aircraft. Those people and their family members are our top priority at this time. Atlas Air is cooperating fully with the FAA and NTSB. We will update as additional information becomes available.” The Boeing 767 cargo jetliner lost contact on radio and radar around 12:45pm local time after crashing into Trinity Bay close to Anahuac, a small city about 30 miles from Houston. Local news reported officials on the ground saying there is unlikely to be survivors. The aircraft, Atlas Air Flight 3591, was flying from Miami on behalf of Amazon, according to flight tracking site Flightradar24. Many are reporting the crash as a “Prime Air” incident, but this isn’t completely accurate. Originally, Amazon Air was branded “Prime Air”, and this appears to be the logo that still runs on many of these planes — but Amazon rebranded the service in December 2017. Amazon Prime Air now refers to the company’s efforts to build a drone delivery network. As we have noted, it is not yet clear what caused the crash. The Federal Aviation Administration confirmed the accident in a statement, deferring the investigation to the National Transportation Safety Board, which said in a tweet that it has dispatched investigators to the crash site. Counting today’s plane, Amazon has 40 aircraft operating under the Amazon Air brand, serving some 23 airports in the U.S. One looming question is how and if today’s incident will impact Amazon’s bigger strategy with freight delivery. The company has been building its own network of cargo planes since 2015, a strategy that serves a couple of purposes. It gives Amazon more control (both in terms of scheduling and costs) over air-based logistics for the transport of goods that it sells; and it gives Amazon a shot at taking on some of the air shipping business that FedEx and UPS provide for other companies. Amazon Air has quietly but steadily grown over the years. Amazon currently has plans to add another 10 aircraft during 2019 and 2020, leasing them from Air Transport Services Group, an Atlas competitor. Notably, Amazon has stakes in both Atlas and ATSG as part of this bigger bet on taking on other larger cargo carriers with its own freight delivery service.<doc-sep>A wide body aircraft emblazoned with Amazon's Prime logo lands at Lehigh Valley International Airport in Allentown, Pennsylvania, U.S. December 20, 2016. Picture taken December 20, 2016. To match Insight AMAZON.COM-SHIPPING/ REUTERS/Mark Makela Federal investigators on Sunday combed through wreckage of a cargo plane flying for Amazon that crashed into a bay outside Houston, killing all three people on board. The Boeing 767-300, flying from Miami by Atlas Air Worldwide Holdings for the online shopping giant, was nearing Houston's George Bush Intercontinental Airport on Saturday when it nose-dived into a muddy and marshy area of a bay near the city, authorities said. Three people on board were killed in the crash, Atlas Air said. The remains of two people have been found at the site. One of the victims was Captain Sean Archuleta, a pilot for Mesa Air Group. Archuleta was riding in a jump seat on the plane, the regional airline said. Archuleta had recently been hired by United Airlines, but hadn't started working there, United said. "This is a sad day for the entire Mesa Family as we mourn the loss of Captain Sean Archuleta," said Jonathan Ornstein, Mesa's CEO and chairman. "Our thoughts are with Sean's family, the families of the two Atlas Air pilots, and the whole Atlas Air organization. This is a loss for all of aviation." A group of investigators from the National Transportation Safety Board's — known as the "go team" — arrived in Texas Saturday evening to begin the probe. Investigators are scrambling to recover the so-called black boxes that contain cockpit voice recordings and flight data to determine the cause of the crash, NTSB Chairman Robert Sumwalt told a news conference Sunday afternoon. "Obviously, recovering those is critical to this investigation," he said. "It is a painstaking process but it is a high priority for the NTSB." The black boxes send out signals so they can be located, but the thick mud of the area may complicate that effort. "The situation that we may be facing here is that those pingers may be embedded so much into mud that their effectiveness may be reduced," Sumwalt said. Divers may be sent to look for the black boxes or areas of the bay may be dredged. The plane appeared for five seconds in video captured from the Chambers County jail, about a mile and a half away, showing the aircraft in a "steep, nose-down" descent, Sumwalt said, adding that there was no distress call from the plane and it had no declared hazardous materials on board. The plane's crew was informed by air traffic control of light to heavy rain ahead but Sumwalt said it was too soon to know the cause of the crash. "Our entire purpose of being here is finding out what happened so we don't have to go through this again," he said. The investigators will review the employment and training records of the people on board and of the plane's maintenance records. The investigation, which will be led by NTSB, will also include the Federal Bureau of Investigation, the Federal Aviation Administration, Atlas Air and its pilots' union, as well as Boeing and General Electric, which made the airplane's engines. Amazon is not a part of the investigation, a spokesman for the NTSB said. tweet Atlas Air Flight 3591 was traveling from Miami to Houston when it crashed into Trinity Bay. Video taken at the crash site by local news outlets showed debris in the bay, including a piece of material that appeared to feature a part of Amazon's logo. Chambers County Sheriff Brian Hawthrorne said that law enforcement spotted items including bed sheets, women's clothing and cardboard boxes in the bay. Atlas Air is one of the cargo airlines that Amazon contracted to operate the Amazon-branded fleet, called Amazon Air, along with Air Transport Services Group. Each operates 20 Amazon-branded planes for the air freight service, which was previously called Prime Air. "Our thoughts and prayers are with the flight crew, their families and friends along with the entire team at Atlas Air during this terrible tragedy," Dave Clark, Amazon's senior vice president of worldwide operations, said in a statement on Saturday. "We appreciate the first responders who worked urgently to provide support."<doc-sep>
An Amazon-branded Boeing 767 freighter, nicknamed Amazon One, flies over Lake Washington during the Seattle Seafair Air Show on Aug. 5, 2016 in Seattle. A Boeing 767 cargo jet operating for Amazon crashed in a bay outside of Houston with three people on board Saturday afternoon, the airline and the Federal Aviation Administration said. Human remains have been found at the scene and there are no signs of survivors, according to the Federal Bureau of Investigation. Atlas Air Flight 3591 was traveling from Miami to Houston when it crashed into Trinity Bay, near Anahuac, Texas. Chambers County Sheriff Brian Hawthorne said eyewitnesses reported the plane crashed nose-first into the bay. "I feel like it's probably a crash that nobody would be capable of surviving," said Hawthorne said. The plane was operating for Amazon, Atlas Air said Saturday. Atlas Air is one of the cargo airlines that Amazon contracted to operate the Amazon-branded fleet, called Amazon Air, along with Air Transport Services Group. Each operates 20 Amazon-branded planes for the air freight service, which was previously called Prime Air. Video taken at the crash site by local news outlets showed debris in the bay, including a piece of material that appeared to feature a part of Amazon's logo. Hawthrorne said the crash site is in a muddy and marshy area of the bay and that law enforcement spotted items including bed sheets, women's clothing and cardboard boxes in the bay. The flight lost radar and radio contact about 30 miles southeast of its destination, Houston's George Bush Intercontinental Airport, said the FAA. "FAA investigators are on their way to the accident site, and the National Transportation Safety Board has been notified," said FAA spokesman Lynn Lunsford in a statement. "The NTSB will be in charge of the investigation." The NTSB said it was sending a "go team" to the crash site on Saturday evening from Washington D.C. Atlas Air confirmed that three people were on board the aircraft. "Those people and their family members are our top priority at this time," the company said in a statement. "Atlas Air is cooperating fully with the FAA and NTSB. We will update as additional information becomes available." Boeing, which manufactured the plane, said it in a statement that it "is deeply saddened to learn of the accident. "We are concerned about the safety of the three people reported to be on board the airplane," said the statement. Boeing added that it would provide technical assistance to the NTSB's investigation. The Boeing 767 was powered by GE CF6-80C2 engines, one of General Electric's most popular aircraft engines. The company said in a statement that it was aware of the accident and it has a team in place to "provide all the necessary support required." "Our thoughts and prayers are with the flight crew, their families and friends along with the entire team at Atlas Air during this terrible tragedy," Dave Clark, Amazon's senior vice president of worldwide operations. "We appreciate the first responders who worked urgently to provide support." -CNBC's Phil LeBeau contributed to this report.