The Annotated Flap Slat Rap: How Understanding the Lyrics Can Help You Learn the Secrets of the System.

You enjoyed the rap.

Now make sure you understand it.

Join us in this training and learn the meaning behind the song.

If you haven’t already watched the video, here it is.

Intro: (Quietly)

Not too slow and not too fast,

I got my mind on my speed when I run my flaps.

Not too slow and not too fast,

It’s the same way when I tap some ass.

When I started brainstorming the lyrics for this rap, I tried to think from First Principles.

First Principles is a way of thinking in which you approach a problem by breaking it down into its most basic elements. You start with only those things you know to be absolutely true and build from there.

And in the A320, when you have an issue with the Slat/Flap system, aircraft speed becomes your most basic problem.

You can’t go too slow, and you can’t go too fast.

That’s really the essence of the whole thing. Take a look, and you’ll soon see that almost everything in the QRH (Landing with Slats and Flaps Jammed) is a function of ensuring that the aircraft’s energy is neither too slow nor too fast.

 

Don’t care if you’re over Heathrow or Perth. 

Dallas or Doha or anywhere on earth.

Cuz if you work the flaps lever, and you hear a ding.

You’d better remember to do one thing.

This was a shout out to Bus drivers all over the world.

While there are lots of other cities I could have mentioned, these seemed to fit the rhythm of the rap.

I wanted to stress that fact that for any slat/flap problem, there’s one thing you need to do first…

 

Brother pull the speed, better do it fast,

The Chief Pilot’s always ready to chew on some ass.

Flaps and slats are dumb; they don’t know what they need.

And so it’s up to you not to over-speed.

Yep. 

Pull Speed.

Another unofficial Airbus Memory Item.

Quickly selecting the speed ensures that the aircraft will neither accelerate nor decelerate too far from the point at which the failure occurred.

This prevents exceeding the maximum and minimum speeds for the current configuration.

In other words, it helps to keep you from going too fast or too slow.

Botch this up, and you’ll likely be called in for a carpet dance in the Chief’s office.

Once there’s a problem with the slats or flaps, the system needs human intervention to prevent an overspeed event.

In other words, it’s up to you to ensure that flap speeds are respected.

 

Getting this part right is just the first of your worries,

There’s an ECAM and the QRH; I hope you’re in no hurry.

When guys first see a Slat or Flap problem, the ECAM looks pretty benign.

And without a deep familiarity with the QRH, most guys fail to appreciate the failure’s impact on landing speeds, landing distance and the go-around.

This leads many pilots to think they can get it sorted pretty quickly.

However, dealing with a Slat/Flap problem correctly involves several steps and will take a bit of time to complete.

The QRH should be read and understood long before it’s required for an emergency.

Don’t let the worst time be your first time!

So guard the capacity in your brain.

Stop and think about obstacles and terrain

When dealing with any problem, it’s a good idea to operate according to the Airbus Sequence of Procedure.

That means the first thing we do is to perform:

  1. Memory Items/OEB Immediate Action Items

Once these are complete, and before ploughing into the ECAM, I think it’s always good Airmanship to consider obstacles, terrain and just where the fuck you’re going before getting stuck into the ECAM.

You got limits on fuel, altitude and speed.

So baby-maybe a hold is just what you need.

If your slats or flaps are stuck in an extended position after takeoff, drag increases, aircraft performance is impacted and continuing to the destination might not be possible.

And if your slats or flaps are stuck in an extended position after a go-around, continuing to the alternate might not be possible.

Getting yourself into a hold can help create some time and space to take stock of the situation and make the right decision.

They’ll be no coffee and snacks for you.

No time to finish up that sudoku.

Just a small joke to further get the point across that things are likely to get busy. 

While the ECAM’s pretty easy it’s just a line or two.

And though it seems like there’s f- -k all to do.

You will get surprised when you take a look,

At that diabolical QRH book.

I can’t tell you how often I see otherwise competent crews quickly process the ECAM without fully appreciating what awaits them in the QRH!

Leaving the QRH until the last minute means things get rushed.

And this creates the perfect environment for mistakes and misunderstandings.

The QRH procedure is poorly designed,

Written by lawyers, not a brother on the line.

My apologies to the legal eagles out there, but the Airbus QRH is an absolute disaster.

I’m pretty sure that the legal team isn’t completely responsible for this, but I suspect they’re at least partly to blame.

Anyway, the lawyers are an easy target. 

To figure out the slat-flap, position for landing,

Just look at the STATUS; it ain’t that demanding.

The very first step in the A320 QRH procedure is to figure out your landing distance.

Usually, when we calculate landing distance, one of the main inputs for the calculation is our landing configuration.

However, when we have a problem with the slats and/or flaps, we become more interested in flap lever position.

The system will display the correct flap lever position on the STATUS page.

Then get her configured, like it says in the book,

Brother, don’t cock it up, it aint a good look.

Just set the speed to VFE next minus five,

Which is just fast enough, to keep you alive,

But still slow enough to run the next notch of flap,

And you’ll slow down without any more crap

In order to configure the aircraft for landing, the QRH advises you to:

  1. Select the speed to VFE Next -5, and
  2. As you pass through VFE NEXT, select the flap lever to the next more extended step.

You then repeat these actions until you reach the landing configuration. 

Remember, the term “landing configuration” in this sense refers to flap lever position, which you’ll find on the STATUS page.

Remember:

To figure out the slat-flap, position for landing,

Just look at the STATUS; it ain’t that demanding.

Now the overspeed alert and VLS that you see,

Are real, they’re true, brother they’re the OG!

See, they’re based on what’s out there, hanging right off the wing,

They’re aerodynamic, so don’t worry about a thing.

It’s important to understand that the Overspeed Alert (aural DING, DING, DING, DING, etc.) and VLS are computed according to the actual flaps/slats position.

That means you can always trust them.

If you hear the Overspeed Alert, you’re going too fast, and if you’re below VLS, then you’re going to slow!

But brother speeds-like-VFE, and VFE next,

They can appear just a bit more complex,

See their speeds are based on where you’ve put the flap-lever,

So don’t, chase them around like a golden retriever

A320 VFE and VFE next are based on flap lever poition

This is where many crews get confused.

While the Overspeed Alert and VLS were based on the actual slat/flap position, VFE and VFE NEXT are based on the position of the Flap Lever.

Remember, a flap or slat problem may prevent the flaps, slats or both from extending normally.

And since the displayed VFE and VFE NEXT are purely a function of the lever position, they may not accurately reflect the actual configuration of the aircraft.

Get a nice long final, and you won’t get burned,

Slow down to VAPP straight ahead, not in a turn.

Cuz, a base leg to final stall, will be a bust,

Keep the speed selected and use the auto-thrust.

This small note has some special meaning:

When in landing configuration and in final approach

-DECELERATE TO CALCULATED VAPP.

Sometimes I see crews get too far ahead of the aircraft and fully configure the aeroplane whilst on the downwind or base legs. If the aircraft is also slowed to VAPP, this can present a problem when turning from base to final, for if the g-loading increases, the aircraft’s stall speed will increase.

This could activate the angle of attack protection in Normal Law or stall the aircraft if in Alternate Law!

So don’t decelerate to VAPP until you’re on final. 

Keeping the speed selected prevents the system from flying the incorrect F speed.

Autothrust, if available, can be used and will help you preserve valuable mental capacity.

 

You’re gonna need to turn off the autopilot bitch,

And be sure to watch the attitude of your pitch.

Remember, the QRH states very clearly that the AP should not be used below 500 feet AGL.

Further guidance is provided in the FCTM and states that as the AP is not tuned for abnormal configurations, its behaviour may prove to be less than optimal.

Landing pitch attitudes may change considerably depending on the failure case and bring the aircraft closer to a tail strike.

Tail awareness is paramount during the flare and touchdown.

 

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Now when some guys go around, it’s a real shit show,

Cuz they only looked at the table and not the writing below.

You got to figure out your config for the missed

To be able to pick the correct speed from the go-around table.

This is more proof (not that we needed any) that what the QRH really needs, besides a better translation, is a competent graphic designer.

The way it’s currently laid out really fucks guys up.

Allow me to explain.

Let’s first imagine that you’re at some point on the initial approach and as you configure to Flap 2, the slats get stuck, as shown in the pictures below.

Let’s assume you get the aircraft into a holding pattern and have gone through the ECAM.

Now, as you go through the QRH, you come to the point where you must use the Go-Around table.

For reference, here’s a typical QRH.

Most crews that I work with will proceed in either of the following ways:

FO Blogs will say something like, ok, the slats are stuck at less than two. He then looks at the table and finds 1< S ≤ 3, and says, ok, the max speed is 200 knots.

FO Smithy tears a scrap of paper from the ACARS printer and starts making some notes as he says ok, slats are stuck at less than 2, and the STATUS page says use Flap 3 for landing. At this point he starts thinking to himself and says, Flap lever 3 means the flaps will come out to 3, but the slats won’t move any further because they’re stuck. He then finds the intersection of these two points and says, max speed is 185 knots.

So who’s right?

Neither.

The real problem here is that Airbus has put the instructions for using the table below the table.

You’re probably saying, “What instructions?”

“I don’t see any instructions.”

See those bullet points that start with If SLATS FAULT:

These are basically the instructions for how to use the table.

See, the writing below the table is often overlooked because it’s not clear that this is the guidance for how to use the table.

Because of the layout, crews naturally tend to calculate the speed before reading the notes under the table.

And having made the calculation, even if a crew ends up reading the notes under the table, in my experience, they never rethink their speed calculations.

So let me show you how to approach this correctly.

When you come to the table, skip it and go directly to the notes below.

You’ll come back to the table, but the writing below will show you what to do.

This is essentially a QRH procedure, so start at the square bullets.

First, ask yourself, “Do I have a Slats problem or a Flap problem?”

Next, move to the circular bullet and determine whether you intend to stay in the circuit (try again) or proceed to the diversion field.

Now you know if you’re going to maintain the current SLAT/FLAP configuration or clean up.

Because of the crap layout of this procedure in the QRH, most crews (and many instructors) don’t realise that it’s impossible to correctly determine the Max Speed without knowing if you’re going to get the aircraft cleaned up or maintain the current configuration.

The Go-Around table requires you to answer this question:

“What configuration will I have?”

If you’re going to “maintain the configuration,” you’ve got to know just what “maintaining the configuration” means in terms of slat and flap positioning.

And if you’re going to clean up, you need to figure out just what that looks like as well.

Let’s work through the example we started with, so you can see what I’m talking about.

First, let’s do a quick recap of the situation to make sure we understand what’s going on.

From the ECAM Flap Indication in the image on the left, we can see that the Slats are stuck between 1 and 2.

However, for the sake of clarity and consistency, let’s refer to this position as 1< SLAT ≤ 3, which is how it’s presented in the Go-around table.

We can see from the ECAM FLAP Indication that the Flaps are working normally (green).

The STATUS advises us to use FLAP 3, so we’ll be putting the flap lever in position 3 for landing.

Now we need to confirm jst where the flaps will be when we put the flap lever to position 3.

Because the slats and flaps do not extend equally with each notch of the flap lever, having a knowledge of how the slats and flaps extend, is very useful here.

In the diagram above, we can see that with the Flap Lever in position 3, the flaps will extend to 3 on the ECAM.

This corresponds to 2 < F ≤ 3 on the Go-Around table.

So, let’s tabulate what we know.

We know that for the approach:

  1. The Slats will be at 1 < S ≤ 3
  2. The Flaps will be at 2 < F ≤ 3

Let’s now go back to the process I described earlier.

First, ask yourself, “Do I have a Slats problem or a Flap problem?”

We have a Slats problem.

  1. The Slats will be at 1 < S ≤ 3
  2. The Flaps will be at 2 < F ≤ 3

Next, move to the circular bullet and determine whether you intend to stay in the circuit (try again) or proceed to the diversion field.

Circuit or Divert?

Let’s look at both options and see how they play out.

Circuit

As you can see, if we’re going to stay in the circuit and have to go around, we’ll need to maintain the configuration.

This refers to the configuration that we had whilst on approach.

This means that we have to figure out what this looks like.

As per the STATUS, we are landing with the Flap Lever in Position 3.

Recall that earlier, we figured this out as:

For the approach:

  1. The Slats will be at 1 < S ≤ 3
  2. The Flaps will be at 2 < F ≤ 3

Now that we know precisely what our configuration looks like, we can use this information to calculate the Max Speed from the Table.

You can see that although the Max Speed comes out to 185, there is a note telling us that the Recommended Speed is the Max Speed – 10.

Thus, 185-10 = 175.

So how do we fly this?

Well, the first thing to do is to agree not to call “Go-around, flaps,” since we’ll be maintaining the configuration.

You could say something like, “Go-Around, maintain the configuration!” or something similar. 

You’ll then pitch up, retract the gear and fly the SRS.

Once out of SRS, select the speed to 175, maintain the configuration and fly the circuit.

Divert

Diverting requires us to select the clean configuration.

This means that the go-around will look a bit more normal, and the Flap Lever will eventually be moved to position 0.

To figure out the Max Speed, in this case, requires us to ask the following question:

“After I move the Flap Lever to 0, what will my slat and flap configuration look like?”

When the Flap Lever is set to 0:

  1. Since the Flaps are working normally, they will retract to Position 0.
  2. However, the Slats are still locked and will stay at 1 < S ≤ 3.

Here is the point that many guys miss.

When using the Max Speed table, you have to consider just what your configuration will be, and that, of course, depends on whether you are staying in the circuit or diverting.

In this case, we get a Max Speed of 200 knots, but as per the note, the Recommended Speed is Max Speed – 10.

Thus, 200-10 = 190 knots.

So how do we fly this go-around?

First, call “Go-around, Flaps,” retract the flaps one step, pitch up, gear up and fly the SRS.

Once out of SRS, select the speed to 190 knots, accelerate and clean up.

Easy peasy!

And the fine print says, that the recommended speed,

could be slightly above, your VFE.

But not to worry my brother, remember VFE is tied,

to the lever position and not the surfaces outside.

This is a reference to the note in the QRH advising you that the Recommended Speed that you calculate could be slightly above VFE.

This can occur because VFE is simply a function of the Flap Lever’s position.

As long. as you’ve calculated the speed correctly, you will not exceed the VFE.

And if she’s heavy, you might get vexed,

Cuz VLS could be greater than, VFE next!

This is a reference to another note in the QRH.

In some overweight cases, the aircraft’s VLS could be greater than VFE Next, making configuring the aircraft for the approach a bit trickier.

However, the procedure is pretty straightforward.

When you’re ready to configure, simply set the Flap Lever to the next extended position, and at the same time, dial the speed back slowly.

As the surfaces extend, the VLS will also reduce, and the VFE warning can be avoided.

During this procedure, disconnect the autothrust during the speed reduction and re-engage it once complete.

So there you have it, Mate.

I hope this expanded your knowledge set and gave you a better idea regarding the concepts within the rap.

The A320’s Slat and Flap system is surprisingly full of twists and traps, even for an Airbus.

And sometimes, even after a thorough read of the FCOM, the FCTM and the QRH, things can still be about as clear as mud.

But I hope this look at the logic behind the lyrics helped to increase your operational understanding of both the system and the associated procedure. 

Be kind, be smart, fly well.

Until next time…

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Roca15

Brilliant presentation! Thank you very much 👍

PAOLO

OUTSTANDING!
Grazie Mille from Italy!

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