An iPhone fell tens of thousands of feet from a Boeing 737 MAX 9 plane
Even as serious questions arise about why a door seal came off one of Alaska Airlines’ new Boeing planes last week and was forced to make an emergency landing, there was one question on the minds of many cell phone users: How did an iPhone somehow fall off? 16,000 feet from the plane and survive intact?
Social media channels have been full of discussions and speculation about how the phone’s survival might find its way into an advertising campaign. USA TODAY reached out to two scientists who explained how physics played a role.
David Rackstraw, a senior scientist at Lawrence Livermore National Laboratory in California, works with students as part of the lab’s science and mathematics education program. He often talks with students about cell phones, phone drop tests, and how students can perform complex experiments with their phones.
In this case, Rackstraw explained, at least three things would likely work in the phone’s favor.
First, phone manufacturers are making phones stronger and stronger, given the number of drops our mobile devices are exposed to, from much shorter distances. Phone cases and screen protectors also help protect the phone when it is dropped, he said. Finally, the phone’s landing location may have made a big difference.
vancouver, washington, man, sean bates, Published on X The iPhone was found on Sunday after the National Transportation Safety Board asked residents in the area to look for any parts that may have fallen from the plane during the emergency.
Bates told a local television station that he found the phone beside the road under the bushes. He said the phone was still in airplane mode, with the baggage receipt for the Alaska Airlines flight still displayed on its screen.
Bates turned the phone over to the NTSB, and on Monday, Safety Board Chairwoman Jennifer Homendy posted a message on X to Bates, thanking him for his help.
The exact model of the phone or the manufacturer of the case is not yet known.
How did the phone survive?
Rackstraw said that when any moving object is dropped, it has momentum, i.e. mass multiplied by velocity. What matters is when the body stops and what stops it. He compared it to the difference between hitting a brick wall versus falling onto a pillow. The pad slows the impact over a longer period of time than a brick wall.
That’s why passenger cars and trucks have airbags, to absorb the force by slowing down the moment of impact. This is also why steel and foam energy reduction (SAFER) barriers are installed at racetracks to protect drivers, by absorbing and reducing energy when the race car hits the wall.
He said that phone cases are made of a material that flexes slightly and is affected when impacted. “It has the ability to crunch a little.”
Lou Bloomfield, professor emeritus of physics at the University of Virginia, said the iPhone certainly reached terminal velocity early in its fall. That means its downward speed increased until the upward force of air resistance, also known as drag, “balances the downward gravitational force (the weight of the iPhone) so that the iPhone stops accelerating downward and simply moves at a constant speed,” Bloomfield said.
The iPhone may have tripped during its fall, encountering stronger air resistance, he said, and the phone’s speed estimate “wasn’t that fast — probably less than 100 mph and probably much less than that.”
In experiments with falling coins, the coins tumbled and struck at a terminal velocity of about 25 mph, Bloomfield said. “A stumbling iPhone should flap like a big penny, moving faster than a penny but not so fast that it can’t withstand a collision with a smooth lawn,” he said.
The main factor is where the phone fell. Had he fallen just a few feet to the side and hit the road instead of the bushes, it could have been a very different story, Rackstraw said. “The phone was lucky to arrive in a natural environment where momentum was slower.”
He said it was likely that the phone was bumping and jumping between branches as it fell, absorbing the impact of the fall long before the phone hit the ground.
“Phones are designed to receive very strong pulses. We’re trying to make that pulse happen over a longer period of time,” he said.
The worst case scenario is that the corner of the phone hits something hard.
Rakestraw and the students aren’t just studying what happens when someone drops a cell phone. The laboratory works with students in the program To improve science, technology, engineering and mathematics (STEM) education in the country.
He added that the laboratory has developed a website that includes thousands of pages of experiments that students can conduct using their smartphones. Cell phones “allow students in even the nation’s poorest high schools to have better experiences” than those conducted at some of the best universities.