How TCAS Prevents Mid-Air Collision

[@AaronShenghao]

Worth to note that the only major mid-air collision since adoption of TCAS was not due to fault of TCAS, but due to regulations. The Russian pilots followed ATC descend instruction, instead of TCAS climb resolution. (ATC aware of potential collision risk and was trying to have a vertical separation, command came too late as TCAS already started to issue collision avoidance resolution). Meanwhile, the freighter on the collision course followed TCAS resolution and started descent as well... And the two planes collided. The sadiest part is when ATC noticed freighter is also descending, he told the Russian pilots to increase descend rate. While almost at the same time, TCAS instructed the freighter to increase descent rate as well. (TCAS will instruct a steeper descent if one aircraft is not following instruction or not climb/descend fast enough). Freighter's radio call to let ATC know they are following TCAS instruction was stepped on, because Russians were reading back instructions at the same time, thus ATC didn't hear the warning. Today, all aircraft are advised to follow TCAS instruction first instead of ATC instruction. (TCAS will also give alternative instructions should one aircraft not following the collision resolution. In the previous case, after detecting only one aircraft is following TCAS instruction, it will now change frighter's descent instruction to climb should the Russian airliner continue to descend according to ATC instruction.)

[@dude14377]

and a father whose family died on board decided to go and murder the ATC worker

[@gonzalomorenoandonaegui2052]

Thank you I'm designing a commercial airplane and your videos are very helpful

[@AircraftScience]

Glad to help

[@yfposer]

Can I have one

[@VTRXRY]

Ayo, you watching yt vids and creating an aircraft.

[@indianninja1423]

@@VTRXRY same question 🤣🤣🤣

[@XratedRC]

Remind me to never fly your plane..... building it off YT vids. Hahahah

[@P_double_H]

Fun fact: Separation between planes must be 1000 feet. However, when two aircrafts are going to intercept at some point even if it's 1000 feet apart the aircrafts not only throw a Traffic Advisory (TA) but also a Resolution Advisory (RA) which means it will modify your vertical speed for you and climb or descend automatically. To avoid this unnecessary maneuvering, Airbus developed something called TCAP (TCAS Alert Prevention) which will detect the situation, it will know for sure it's not a collision, but just the standard 1000ft separation, and it will decrease the vertical speed to a point where the RA is not triggered. Good job Airbus!

[@despe666]

I was afraid when I started reading this that they actually modified the TCAS system to prevent the alerts. 😲 They're just modifying the inputs to make sure the alert is not triggered.

[@motomaximum21]

у меня завтра экзамен по бортовому радиоэлектронному оборудованию воздушных судов,спасибо за видео,помогают)

[@calvinyin]

Hope you can introduce the B787 systems.

[@Blaze_0101]

What happens when there are more than 2 aeroplanes? How does this system resolve conflict as in which aeroplane to 'climb' or 'desend ' ?

[@nadirnazim9342]

I was in a flight yesterday where this probably got triggered. That 2g pull up was quite scary

[@itsacorporatething]

Is there a possibility of TCAS directing the plane out of a collision course with one plane and into a collision course with another plane?

[@Goldblasterblaze]

That might be likely, but that other plane should also have TCAS so it will not run into the plane responding to its TCAS

[@justalonelypoteto]

I don't know if there's been any reported case of this, but it could cause a chain RA reaction in congested airspace. The issue is that since it takes into consideration your vertical speed (usually a good thing), if you don't smoothly start to level off a good while before you reach your altitude, other planes' TCAS will interpret you as a threat and give RAs to their pilots, and since your climb rate during an RA is very steep, you'll undoubtedly trigger nearby planes to maneuver away sometimes. Another plane's TCAS doesn't know when you'll stop climbing/descending so it has to assume the worst case, which is your plane continuing to fly as it is doing right then

[@Sembel-xh9vq]

@@justalonelypoteto Kind of like a chain reaction, but still better than a crash

[@capt.imanuddinyunusshmh.6549]

Big Thanks... Appreciated

[@maxgremer7638]

I am absolutely sure I was once in a plane that was still safe but for normal’s circumstances and me as a non professional pilot very close or let’s say the closest you can get to a collision under normal circumstances und while still beeing safe and it was creepy… I was sitting in the front row of an A319 of an Eurowings flight operated by Croatian in like 2010 on a window seat on the left side so I guess it was like seat A1… And while observing the sky I noticed humanity like 5-10 sec before the “event” some kind of traffic or plane approaching really fast and almost at level. It came in like in a 45 Degree angle crosswide from the front like 1sec before both planes planes met I could not only see the Typ of aircraft and airline or something else relatively obvious for a trained eye (It was an A321 operated by Condor) but I was even able to read small things like registration code and all details like warning signs, antennas, sensors etc. you would only see within a maximum distance of like 100m especially if you consider the high velocity… Yeah and these two aircraft definitely met at the same point just with the crossing plane wit by king h a maximum of like 100m/300ft higher, you could even feel it a little bit of turbulence and vibration.m for a second… It was not creepy because it was so fast you had no time to get scared just to watch an wonder… Yeah it was interesting but not frightening but I am damn sure they had at least some tcas alert…

[@Rohitharrypotter]

Please make a video on air conditioning system like you did for Jet engine..

[@AircraftScience]

Thanks for the suggestion.

[@marcioferreira_staritap4]

Very good.

[@AircraftScience]

Thanks!

[@praveenshetty2066]

Thanks for the detailed information.👌

[@blueberry-rw1kr]

it’s also important to know that it’s very tough for planes to collide mid-air. cant make it happen even if you try. collisions are only a concern in high-traffic areas like near airports

[@grassytramtracks]

It's rare, but has happened at cruise altitude on a few occasions

[@d-X-es4vi]

if the tcas system fail, what is the backup system? THANKS

[@AircraftScience]

No backup for TCAS.

[@DoltonI]

Eyesight and luck.

[@andreizadasilvapereira5312]

Your phone's metal detector lol

[@paulstelian97]

TCAS _is_ the backup.

[@Edss-nr6xw]

I'm an avionics technician at a repair station. Every time a jet comes in we do a checklist of the cockpit systems (including TCAS). The odds of it failing aren't zero but they're pretty low imo. The ways it could happen are the computer crap out, a wire gets cut, or the antenna becomes damaged. If the TCAS computer stops communicating with the MAU you'd get a CAS message. If the antenna becomes damaged, I could be wrong this is just me speculating, you'd still have the other aircrafts TCAS system which would initiate communication via VHF which is a separate antenna. As with most safety systems on the plane there'd have to be a lot going wrong all at once for things to become deadly.

[@maxgremer7638]

I am absolutely sure I was once I a plane that was still safe but for me as a non professional pilot still creepy and very close… I was sitting in the front row of an A319 of an Eurowings flight operated by Croatian in like 2010 on a window seat on the right side so I guess it was like seat A1… Well and while observing the sky I noticed like 5-10 sec before the “event” some kind of traffic or plan approaching really fast and almost at the same level the plane came in like in a 45 Degree angle crosswide from the front like 1sec before both planes planes met I couldn’t only see the Typ of aircraft (A321) or airline (Condor) or something else relatively obvious for a trained eye but I was even able to read the registration code and all details you would only see within a maximum distance of like 100m especially if you consider the high velocity… Yeah and these two aircraft definitely met at the same point just with the crossing plane with a maximum of like 100m/300ft higher, you could even feel it a little bit for a second… It was not creepy because it was so fast you had no time to get scared just to watch an wonder… Yeah it was interesting but not frightening but I am damn sure they had some tcas alert

[@MeaHeaR]

Téa Cáss develop aftér aero mexicos cerritos crashes with aero plain

[@hiteshkumar6792]

well TCAS system failed at that time. Rip passengers and all crew members.

[@grassytramtracks]

There have been 2 midair collisions where the aircraft had been equipped with TCAS. In the Überlingen midair collision, TCAS was fully functional on both planes as it should have been, but the pilots on one plane, as per Russian rules, obeyed ATC direction over the TCAS instructions. In the 2006 Amazon midair collision, it worked on both planes, but on one it was turned off for some unknown reason