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Woo, that's two planes flying in very close proximity to each other. Is this for real?
Dear friends and followers, welcome back to my channel and as you've just seen in the intro, you might have asked yourself,
"How can airplanes fly that close to each other? Isn't this dangerous? Is this maybe fake?"
The answer in today's video: "All you need to know about PRM and SOIA approaches".
So, let's get started!
How could it be that two airplanes fly in such close proximity to each other and seconds later land on the runway?
What you see here is no fake—
It's actually common practice at a few rare airports,
and it's called a Precision Runway Monitored approach. Now, for an airport to have a PRM approach,
there are a few criteria which have to be met.
First and foremost the runways have to be parallel and not
more than 3,000 to 4,300 feet apart from each other,
and if they are set up even closer due to geographical reasons, like in San Francisco International,
there is a second type of approach, even more daunting, which I'll show you in a minute.
So let's take a look at the PRM approach on runway 16L/R at Sydney's Kingsford Smith
International Airport, and the runways are approximately
3,400 feet apart. So as you start your descent towards Sydney
you'll check the current weather via the ATIS frequency and the ATIS will notify which runways are active and if
PRM approaches are operational. In case so you then read through the "Attention All Users of
ILS PRM" approach chart. There's vital information listed you should familiarize yourself with
before commencing such an approach.
For example, as a pilot, you have to be approved and certified for PRM operations by
previous training and simulator.
But probably the most important information on that chart is the dual VHF requirements.
In order to fly such an approach, you have to have two functioning radios on board.
Now, on the first radio, you tune in the tower frequency
which you listen and transmit on.
And then the second set, viewed with the same volume level as of the tower radio, you listen to the
PRM approach controller.
Why do you need to do that for? The approach controller's radar is updated every second and is much more
accurate than the ones by the tower controller.
Meaning in case you deviate from the localizer and fly too
close to the so-called "No Transgression Zone", which is set between the two ILSes,
the approach controller gets a visual and aural warning on his radar screen and will advise you to
rejoin the localizer by saying:
"Velocity 76, radar indicates you are deviating left of the localizer course!" If it gets worse and you've
entered a No Transgression Zone, the threatened aircraft on the other
ILS will get a traffic alert by the approach controller, followed by a breakout maneuver instruction, which can sound like this:
"Breakout alert, Singapore 11. Turn left
immediately heading 295, climb to 3,000 feet!"
Now, in case the tower is blocking the frequency as he's giving
simultaneously runway landing clearances, you are on the listening watch or monitoring the second radio set,
in case the approach controller is giving you such a breakout instruction
Now compare it as if you're on your mobile phone with your new girlfriend,
and your ex-girlfriend calls you on your second phone,
telling you to stay away from the new girl. Makes sense, right?
Now this little training video here perfectly shows how to fly a breakout maneuver.
"Landing gear."
"Down."
"Flaps."
"25."
"Landing checklist complete."
"BREAKOUT ALERT Oscar Juliet Alpha, turn right immediately, heading 240, climb to and maintain 3000."
[autopilot disconnect warning horn]
"Heading 240, 3,000, Oscar Juliet Alpha."
"Flap 20."
"Flap 20 selected."
"Positive rate, gear up."
"Positive rate, gear up selected."
"Heading 240 selected, altitude 3000."
"3000."
Please keep in mind, breakout maneuvers are rare,
but if requested by ATC, they have to be flown manually and as quickly as possible.
Most likely a climbing turn, but a descending turn can also be given but shall be flown at not more than
1,000 feet vertical speed per minute. You won't be assigned to descend below the minimum vectoring altitude.
So once ATC calls for a breakout alert, you turn off your flight directors, set the heading bu, and the altitude,
disconnect the autopilot and just fly your plane. You should not go head down and start programming the FMGS.
Immediate action is required.
Aviate, navigate, communicate. ATC will guide you and will state new intentions sooner or later.
But keep in mind, a breakout maneuver does NOT mean to follow the published missed approach procedure.
But in case during your breakout maneuver,
a TCAS resolution advisory is given,
follow TCAS orders, and inform ATC about your actions.
Now, the even more daunting and rarer approach is the so-called SOIA approach:
"Simultaneous Offset Instrument Approach". SOIA permits
simultaneous approaches to parallel runways spaced less than 2,000 feet to as close as
750 feet apart. And the best airport to show you a SOIA approach is San Francisco International
Runways 28R/L, which are only
750 feet apart.
Now let's look at both approaches in more detail. Runway 28L is a straight in ILS,
but it has to be flown and briefed as a PRM approach, meaning the same rules apply as mentioned previously:
dual frequency monitoring and breakout maneuvers, etc. The glide slope intercept point
is at 7.7 miles from the threshold, and the final approach course is 284.
So let's look at the LDA. Now, the localizer-type directional aid approach for runway 28R,
right next to it. It's more or less the same. It's an ILS with localizer and glide slope indications, but the key difference:
It's at three degrees
offset with an inbound course of 281, and an LDA missed approach point, and a visual segment,
but I'll come back to that in a second. Now, due to the offset of the LDA approach, there's enough space between the both
approaches, creating a No Transgression Zone, with the same procedures as on the PRM approach.
The major difference is, as the planes come closer and closer, the plane on the LDA approach
has to have visual contact with the plane on the PRM approach,
latest at the LDA point, and that's where it gets really interesting.
At the LDA point, besides having the traffic in sight with the preceding plane,
that pilot has to report the traffic to ATC, have the runway in sight,
then most likely has to switch to the tower frequency to receive his landing clearance, and then
disconnect the autopilot, and fly visually towards the runway threshold,
whilst maintaining a safe distance to the preceding plane. But if anything goes wrong, for instance, in this video,
it looks like as if the 747 on the LDA approach has either cut the No Transgression Zone,
or overestimated the turn on the visual segment, getting too close to the adjacent plane,
forcing the ATC controller to call for a breakout maneuver of the proceeding plane.
You can actually hear the 767 roaring out on the breakout procedure.
Maybe one of you guys has experienced such breakout procedures before,
so comment below—it wouldl be really interesting to hear your stories.
At the same time, the LDA is a missed approach point, meaning in case you have no visual contact with the other plane or you're unable to
see the runway due to reduced visibility,
the LDA is the latest and the lowest point you're allowed to fly,
and then would've had to perform a missed approach.
I have flown a SOIA approach and is by far one of the coolest experiences ever.
When you reach the LDA point and then you perform the turn over to the runway centerline,
but at the same time you're monitoring the distance to the preceding plane...
Challenging, but a lot of fun.
Wake turbulence plays a big factor when it comes to PRM and SOIA approaches, especially during calm crosswind conditions.
I was told that ATC tries to vector the heavies on the downwind side
to protect the lights and the mediums from flying into their wake turbulence,
especially during the SOIA approaches for the visual segment. That's it for today,
I hope you now have a better understanding for these kind of approaches. I admit they are rare,
so, please comment below if you know the airports which actually have such PRM and SOIA operations.
Thank you very much for your time. Hit the "Subscribe" button, and the notification bell
so you won't miss out on upcoming videos. And don't forget: A good pilot is always learning. See you next week, all the best,
your Captain Joe.
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