How do airplanes stay in the air? Physicist explains

A viral video of a commercial plane seemingly “frozen” midair has left netizens amazed and amused—but what does a physicist have to say about it? 

As seen in Kuya Kim’s report on “24 Oras” Thursday, the clip, taken by Quezon City resident Jannah Grace Kiskisol while passing through Las Piñas, shows what appears to be an aircraft suspended in place. 

“Pauwi na po ako nun. Naka-motor po ako. Then biglang nakita ko, may airplane. Para siyang nakalutang lang. Naka-stop lang sa ere. Sobra akong na-amaze. Ayun, vinideohan ko siya,” she said.

However, such a scenario is not physically possible for a commercial airplane. According to physicist Ryan Victorio, for a plane to stay in the air, it must maintain forward motion to generate lift, the upward force that keeps it aloft.

“Ang lift ay tumutukoy doon sa upward force na siyang nagiging sanhi nung pag-angat or 'yung paglutang ng isang bagay kagaya ng eroplano sa hangin,” Victorio said.

If an aircraft slows down too much or almost stops, it loses lift. Without sufficient lift, the plane can no longer sustain flight and may begin to descend. 

“Kung ang eroplano tumigil na lamang sa kanyang paggalaw, so maaari itong mag-descend o mahulog doon sa kanyang kinalalagyan,” he explained.

Meanwhile, the airplane appearing to have stopped midair in Jannah's video was just an optical illusion known as the parallax effect. 

“Iyan 'yung visual technique kung saan gumagawa ito, illusion of 3D effect, kung saan ‘yung objects, kung malapit ito sa 'yo, mabilis 'yung pagkilos nito at kung malayo naman ito sa 'yo ay parang hindi na halos gumagalaw or parang tumatakbo kasabay na ng paggalaw ng tao,” he said.

But how does this happen?

“Depende kung nasaan ‘yung tinatawag na fixation point. At 'yung tao na mismong gumagalaw talaga nagbabago 'yung kanyang view doon sa object depende sa distance," he said. 

"Kung malayo ito, halos hindi na gumagalaw 'yung kanyang nakikita na object at kung malapit naman, mabilis naman 'yung paggalaw ng object."

—Jade Veronique Yap/CDC, GMA News