Monday, July 18, 2011

Techniques for the New Airbus Pilot

Techniques for the New Airbus Pilot: " I am learning exponentially on the Airbus, probably because at times I am flying five legs per day up and down the West Coast. Furthermore, through Airbus manuals, reading from the Internet, asking high-time Airbus Captains and obviously through my own experience flying the aircraft, I can comfortably say that at 100 hours, I feel 'pretty good' flying the Bus. However, in another 100 hours or even 1000 hours, my thoughts may be completely different. Funny thing is, the Airbus is so different from any other flying machine out there that I cannot remotely make a similarity to anything else that has wings.

Yes, the Airbus is a highly automated aircraft, but so is the Embraer 190 I flew before. However, there are HUGE difference between the two aircraft as they obviously have two different brains and react a completely different way. Being new on an Airbus brings new meaning to being new on lets say a Boeing aircraft. When I tell the Captain that I am new on the Airbus, I commonly don't get the standard response of, 'Oh, well that's okay,' from him or her. It is usually, 'Oohhhh, well, are you getting the hang of it now?' See the difference? That's because all I can tell you is that compared to a Boeing (or similar jet aircraft) the Airbus can give the impression of being a really wacky machine. That is until you get to learn its brain and naturally its logic. Even all the Check Airmen and Captains who have 9000-plus hours on the plane all comment that the Airbus is indeed very unusual. They even go on and say sometimes they see something new that they have never seen before. Well that's comforting, isn't it?

There's even an old joke about Airbus pilots:

How can you tell an Airbus pilot? (S)he's the one who says, 'What's it doing now?'

How can you tell an experienced Airbus pilot? (S)he's the one who says, 'It's doing that again!'

Unlike other aircraft I have flown, it was essential that I start to make my own Airbus notes that would keep me out of trouble. Obviously these notes are getting quite thick now, and I learn something on every flight. Honestly, I am glad I got 'thrown into the fire' out here in Long Beach because flying five legs a day makes you real sharp in the plane real quick. You take off, climb to cruise for about 20 minutes, set up the aircraft for approach and landing, then descend and land. I do that five times a day, whereas in Boston I would most likely fly one leg out to the West Coast and then one leg back the following day. Not too much to learn there. So far, I probably have 40 more landings than my simulator partner who is based in Boston.

Anyway, there is widespread agreement in the aviation industry that pilots do not acquire a complete understanding of the more advanced features of the autoflight system in training. In fact, some airlines do not attempt to teach highly automated lateral navigation (LNAV) or vertical navigation (VNAV) modes in training. It is left for the pilots to learn how to use these functions while flying on the line. Therefore, I have made the following notes as an aid for myself and for other new Airbus pilots who may need a little help when flying after they have completed their training. If you are interested, then please read on.


Why not labeled 'autothrottles?' Because the Airbus throttles don't move, unless you move them. After you pull them back from either Take-Off/Go-Around (TO/GA) or Continuous Thrust (FLX/MCT) to Climb (CL) at acceleration altitude after takeoff, you simply don't move them until you either click them off on approach or retard them to the idle position at around 40 feet above the ground on landing. By placing them in the idle position, they are disconnected and the plane can transition from the flight phase to the ground phase. If not, expect a big bump of power right on flare. So on a modern Airbus, you should see the throttles no longer as a physical sensor of the current engine setting, but rather as a huge selector lever to select a specific thrust regime.

Flight Phases

This is something that is good to know. From ground school we are taught that the Airbus Flight Management Guidance Computer (FMGC) uses several modes during the phases of flight to calculate vertical planning. As a pilot, one should become very familiar and aware of these modes and their changes. These phases are separated into 8 different modes: Preflight, Takeoff, Climb, Cruise, Descent, Approach, Go Around and Done. In addition, the FMS needs to know when the aircraft is in taxi, engine-out and landing modes. Be familiar with them.

Descent Planning

The descent phase (and to a lesser extent the approach phase) is is where most new Airbus pilots get into trouble.

Uh oh! Here comes that Top of Descent symbol (white arrow).

On my initial operating of the airplane, I was very relaxed, right up until I saw the Top of Descent (TOD) depiction creeping toward me at 8 miles per minute. Then my blood pressure would start to raise a little, and I begin to do those 3-to-1 calculations in my head to know when I really needed to start to descend, just in case the smoke and mirrors didn't work. In a perfect world, the magic works well. However, in a not-so perfect world like in New York Airspace, I was initially at a loss for words. Common phrases heard from new guys flying this plane (and I've made them all) are:

Now why is it doing that?

Now what should I do?

Will this work if I do this?

So why is it telling me it will cross this restriction when it really won't?

Why is it lying to me?


Oh, @!%?!*!!!

...and so on and so forth.

You either learn what the Airbus is doing or it will eat your lunch. For example, to start a nice descent while the plane is managing the route, you can simply dial down the altitude, and press the altitude knob, giving the Airbus a nice 1,000 foot per minute descent until it intercepts the calculated descent angle, where then upon reaching the descent path, it will automatically bring back the power to idle and the plane will descend at the current managed airspeed. With me so far?

Now if the aircraft is on a heading, such as given by ATC, then you can't dial down the altitude knob and do what I just said to do, because it won't do it. Trust me, I tried this on my OE, and nothing would happen. Naturally, the Check Airman starts to smile (and is thinking to himself) 'Oh, yes, the very common first mistake,' while I'm in the right seat trying to figure out the next thing to do and sweating bullets.

So there I am, trying to push the altitude knob, and yes, it will descend at 1,000 FPM, but that's it, while thinking to myself, "Okay you *&%!*?$ airplane, why aren't you descending? Well, we are on a heading, so I guess it won't do a Managed Descent, so I'll use the vertical speed knob."

I spin the VS knob down to 1,500 feet per minute, and the plane begins to descend. 'Okay, that worked. Remember to write that one down in your growing book of Airbus tricks.'

Naturally the Check Airman learns that I just learned something. Sometimes the best way to learn is by trial and error.

Managed vs. Selected

You may have heard from Airbus pilots some new terminology you won't hear around Boeing or conventional jet aircraft. The two words you will most commonly hear is managed and selected.

Simply put, managed basically means the aircraft is fully automated and is flying a FMC-generated profile full of its own determined speed and constraints. If there is no ATC intervention at all, the aircraft is designed to fly managed from 100 feet above the ground on takeoff to 100 feet above the ground (or perhaps all the way to the ground on an autoland) on landing. It will climb to altitude, and upon reaching the Top of Descent (TOD) nearing the destination, it will (upon pressing the ALT knob) descend all the way down to 1,000 feet above the ground on-speed and while the pilots are configuring the aircraft with flaps and gear, will make a normal touchdown every time. To fly in the managed mode, the pilot traditionally must push one of the modes on the flight control unit (FCU) located on the glareshield.


Selected means the aircraft is not flying in a managed mode, such as a selected speed where ATC has issued you a speed to fly, etc. In the case of selected speed, the pilot has more control of the aircraft, as he or she directly makes the inputs that control what the plane is to do. This is done traditionally by pulling any of the modes on the FCU. As some Airbus pilots say, push to give it all away, and pull to take it all back.

New Scan

As a new Airbus pilot, it is imperative to keep an eye on the Flight Mode Annunciator (FMA) all the time, especially when in the descent mode. Also get in a habit of including the N1 gauges in your scan. This is good for unexpected thrust changes, then you can pull for selected speed and stop embarrassing thrust changes before they get out of hand.

The FMA (top) tells you what mode the aircraft is in.

Managed Descent

Note the FMA says THR IDLE, as the aircraft is managing this descent to the first constraint from cruise altitude. Also note the VDEV (pink dot) just left of the altitude showing us on-profile.

Before we start, I want to point out if not within 200 nm of destination the aircraft will not initiate descent in PERF DESCENT mode. Descent will be made in PERF CRUISE mode as a “cruise descent”. During descent in cruise mode the FMGC will not “see” crossing restrictions in the flight plan. This is a gotcha. It is also good to note that the aircraft will not initiate descent automatically from cruise altitude when reaching the Top of Descent point (TOD).

Normally, the Managed Descent on the Airbus works great, just as long as you have plugged in the proper descent winds into the flight management computer. If you don't put in the winds and let's say you have quite a large tailwind, the aircraft will most likely overshoot the crossing restrictions. Internally, the Airbus computer divides the descent path into various segments, depending on the relative positions of the constraints. The Airbus VNAV calculates an IDLE descent from the Top of Descent (TOD) to the first constraint, then a geometric (straight line) descent for the next segment. After the first constraint, it will still want to descend (but not at idle) whereas on previous highly automated airplanes such as the E-190, it levels off until reaching the point where it would need to descend again to make the second restriction.

You can fix this issue on the Airbus by again reloading the next crossing restriction into the FMS when you fly over the first constraint. The E-190 was automatic and this step did not have to be done. You can also re-input the field temperature on the APPR page where we input the field conditions for our approach speeds.

Managed Speed on Descent

You can only normally change speeds on the descent in the FMS when in the cruise phase of flight. There are exceptions to this that I will explain later. So as long as ATC doesn’t assign a speed in descent, it is best for the Airbus to descend using a Managed Descent as the aircraft already has a calculated speed it uses to fly the descent most efficiently. Think fuel savings.

Selected Speed on Descent

Note, the FMA reads SPEED, because we are in selected speed of 280 knots, but we are still managing the descent. You will also see SPEED in a Managed Descent when the aircraft flies the geometric (straight line) descent between the first constraint and the second constraint, and so on.

However, if ATC gives you a SPEED while on descent, the easiest thing to do is to select the speed (pull) and use vertical speed (VS) or Open Descent (OPEN DES) to descend. It will however descend managed (pushing ALT) fine in selected speed, but one must watch the descent profile carefully as when in a selected speed (a speed that the plane is not using for descent) as the aircraft may get high slightly and will not honor any speed restrictions, i.e. - slowing to 250 knots prior to a fix. You must be the one to intervene and perhaps dial down the vertical speed (VS) or pull altitude for an OPEN DES (aircraft descends at the selected speed) to get low on the profile and then level off a few miles prior to the fix, and then dial the speed back (or push) for 250 knots.

Showing a Managed Descent of .77/282

So, what if I’m in a Managed Descent of 280 knots, and ATC tells me to maintain 310 knots?

1. Select (pull) speed 310 knots.

2. Revert to using VS or OPEN DES to make the crossing restriction (it can also be flown managed too, but with caution).

However, you can trick the Airbus a little if ATC tells you to give your best forward speed (or an assigned speed) in the cruise and on the descent before your Top Of Descent (TOD), you can try this:

1. Pull SPD for that selected speed,

2. Then go into the Flight Management Computer and go to the PERF/NEXT PAGE (managed speed will be in blue at that time) and input a faster speed on DESCENT. For example, if you see it as a managed speed of .77/288, then it will transition from .77 mach to 288 knots. So to fly a faster Managed Descent, you can change it to perhaps .80/310 or similar (maybe ATC assigned a speed of .80 with 310 knots or greater in the transition, for example). Therefore you can still fly in the managed mode, even though you calculated new managed speeds for the plane.

3. So just prior to the Top of Descent (TOD), you can push the ALT knob to descend at 1,000 feet per minute, and once on descent, the FMCU will transition to the Descent Phase of flight, and the FMS will announce SELECT MANAGED SPEED, so then just push the speed knob and the plane will go back to a Managed Descent using those new-inputted speeds.

However, one thing to note while the plane flies a Managed Descent is that the aircraft flies a window of +/- 20 knots on descent in order to meet the crossing restriction criteria. Sometimes during high tailwinds the aircraft may deviate away from the ATC-assigned speed of up to 20 knots in either direction, so as a pilot you have to keep that in mind and monitor the speed closely. If the speed doesn't stay within 5 knots of the assigned speed, then perhaps the pilot should revert back to selected speed by pulling the SPD knob and then using vertical speed (VS) or pulling the ALT knob and initiating an OPEN DES down to the crossing altitude. Hey, the plane may level off sooner than anticipated, but at least you made the crossing restriction.

Another Option...

Also in the case of above (selected descent) you can enter a new cruise altitude below your current altitude into the PROG page. This will cause the FMGC to revert back to the cruise phase and allow you to enter a new descent speed in the PERF DES page. This can also be done in the case of a level off at an intermediate altitude. So select the PROG page in the FMC and enter your new intermediate altitude. This will allow you to change the speed on the descent page to the new assigned-ATC speed if you wish to resume a managed speed. Then, when you descend again and re-establish the descent phase, you can push for managed speed. However, a new Airbus pilot must use this option with caution as to not push for managed speed while in the cruise phase of flight, as the plane will speed up to its previously calculated cruise speed until the descent phase is once again attained. Trust me, I made this mistake early on, and was yelling, 'Now why is it speeding up like this all of a sudden?' That's because I wasn't fully aware of its functions yet. Obviously now I am.

Yes, the FMGC may plan a much slower speed for descent in Descent Phase than in Cruise Phase. If the aircraft begins a descent and enters the Descent Phase when you wish to make a faster cruise descent you can once again enter a new cruise altitude on the PROG page below your current altitude. The FMGC will now revert back to Cruise Phase until crossing the new altitude. Be aware, however, that the FMGC does not “see” crossing restrictions when descending in Cruise Phase and will only descend at a set vertical speed. Use with caution.

Heading on Descent

If on a heading for any particular reason, then the Airbus will simply not manage the descent. This is mostly true for any other airplane out there too, as some will automatically resort to FPA (Flight Path Angle) or similar vertical speed mode. In this case, for let’s say weather or traffic (no managed NAV) I just use vertical speed (VS) or OPEN DES to descend.

Late Descent

If you get a late descent (past the TOD), I suggest dialing in some vertical speed (VS) to start a smooth transition down and then pulling the SPD knob for an OPEN DES to come down quickly. You can modulate the speed up to increase the rate of descent, and use the speed brakes if needed below 30,000 feet to recapture the descent profile.

Pulled ALT for an open descent, giving us a 2700 FPM descent. Note, the VDEV (pink dot to the left of the ALT) is showing us slightly low on the profile now, so we can probably resort back to a managed descent or VS.

If you still find yourself high on the profile, the last resort is to click off the autopilot and go to full speedbrakes. The aircraft only uses half speedbrakes with the autopilot engaged. If that doesn't get you down like the NASA Space Shuttle, then I suggest getting relief for ATC and telling them that they screwed up.

Other Useful Tips

As a general rule if you are going to manually select a SPEED or MACH by using the FCU SPD/MACH Push Button, use MACH in climbs and SPEED in descents. Make sure to pull for speed first before using the vertical speed (VS) knob as if the selected speed is below your current airspeed, the autothrust will roll back. That's not good if you're up in the high flight levels and still climbing very slowly.

Another thing to look after on the descent profile is as soon as you go into HDG, or select a speed, or anything, the FM-calculated vertical descent profile will be in error to what you are now actually doing. VDEV will also be in error. Keep that 3-to-1 profile in your head as a backup.

The VDEV on the PROG page shows us about 1,070 feet high on the profile. But are we?

Descent Exercises

Click on the KAYOH 4 STAR into Long Beach (KLGB):
Example 1 - You are inbound about over HEC at FL240. ATC clears Airbus 1 to cross DAWNA at 13,000 feet.

What do you do?
What will the FMA read?

You should dial down the ALT to 13,000, and upon reaching the TOD, push the ALT knob. The aircraft will descend at FLT IDLE to 13,000 and make the crossing restriction at DAWNA (granted you have plugged in the descent winds in a real-life scenario). You can also dial down to 13,000 and push the ALT knob now if you wish and the plane will descend 1,000 FPM until intercepting the profile, and then descend on profile at FLT IDLE until reaching 13,000 feet.

Example 2 - Same situation as above, but ATC clears you to descend NOW to FL240, and expect to cross DAWNA at 13,000.

What do you do?

You should dial down the ALT to FL240 and press the ALT knob. This will give you a 1,000FPM descent until intercepting the descent profile (represented by a lightning bolt, not shown) to cross DAWNA at 13,000. Upon intercepting, the aircraft will transition to a FLT IDLE descent on profile until reaching FL240 and then level off. If ATC then gives you the crossing restriction to cross DAWNA at 13,000 feet before you level off, all you need to do is continue dialing down the altitude to 13,000 feet. The aircraft (already on the descent profile) will continue down to 13,000 feet.

Example 3 - ATC clears Airbus 1 to descend NOW to 8,000 feet. You just passed DAWNA at 13,000, and will expect to cross DEJAY at 8,000.

What do you do?

You can simply dial in 8,000 and once again press ALT. The aircraft will descend at 1,000 FPM until intercepting the descent profile (represented by a lightning bolt) to cross DEJAY at 8,000. See the red ball on the path just prior to DEJAY? That is where the aircraft will decelerate from its current descent speed to be at 250 knots passing through 10,000 feet, as to make the crossing restriction at DEJAY at 8,000 feet.

You could also dial in VS or pull ALT for on OPEN DES if you want more that 1,000FPM and keep the speed managed. The aircraft will still slow to 250 knots upon reaching 10,000 feet (or prior) and you will need to modulate the VS to reach the crossing restriction at DEJAY, or let the aircraft slow on its own, thus trading some VS in order to do so while in an OPEN DES.

A Word About the Flight Directors

Simply put, if you are flying on autopilot down the glideslope and pointed directly at the runway and decide to click it all off at 1,000 feet to fly her down to the runway, by all means have at it. However, if you find yourself outside of this regime on a base leg or downwind and decide to hand-fly the aircraft, you should turn off BOTH flight directors and call for FPA, or 'bird on'. Why? Because turning off the flight directors will cause the autothrust to go to Speed mode. Therefore, you have speed protection while you are flying manually. If you don't turn them off, or leave one FD on, the aircraft is bound to do some weird stuff (like add lots of power) that you are probably not anticipating or expecting at the moment you are thinking about landing. It would be a shame to do a nice go-around wondering why the heck the aircraft did what it just did. At least it gave you a nice bump in thrust at the precise moment when you thought you had that visual approach in the palm of your hand.


In ground school they teach to pull the power back at 50 feet above the ground. Try SLOWLY pulling the power back at IDLE beginning at 40 feet, vs 50 feet and see what you think. On a hot day you may want to pull it back at 30 feet. The 'retard' callout is simply just a reminder that the autothrust should be at idle by the time the mains touch down. If not, plan for mucho power. Not good when you want to be at idle as your mains pass over the touchdown zone.

On landing rollout only when ready to apply manual braking, try putting all your feet on the rudder pedals and touching the TOE STOPS at the very top. This will stop asymmetric braking, thus one hotter brake than the other. Don’t get into the habit of putting your heels on the floor when braking like you did on other aircraft. Your braking will be sloppy.

Some Class B Airspace Departure Tips

When departing out of airports located underneath Class B airspace, the speed limit is 200 knots. There's basically 3 ways to set up the magic and accomplish this task:

1. You can plug in the presel green dot speed in the CLMB page until reaching the floor of the Class B airspace. This is probably easiest if you are new to the aircraft. When the flaps are retracted, the aircraft will automatically go right to the preselected green dot speed. When inside the Class B, you can push the speed knob and the airplane will accelerate for 250 knots.

Notice our V-Clean speed (0) is 205 knots (below):

If you press the NEXT PHASE key, you can manually add 205 knots to the PRESEL mode. When the flaps are retraced, it will aim for this number, no faster.

2. Or just press the EXPED button on the FCU after calling “flaps up”. However, if using the EXPED mode, upon altitude capture the aircraft will accelerate to 250 knots. This can be a gotcha if ATC gives you an intermediate level-off altitude lower than the floor of the Class B airspace, so be ready to just pull speed. The other thing to note when pressing the EXPED button is that upon entering the Class B, all you need to do is pull the ALT knob, not the SPEED knob and it will accelerate to 250 knots. Trust me, I made this mistake, and nothing happened.

3. Or, lastly right after 'flaps up,' you can pull speed for green dot, but beware if heavy, Green dot will be much higher than 200 knots. It may be upwards of 220. When flaps are retracted, wait to see what Green dot will be, and then set!

Well that's all for now. Happy Airbus flying, and don't get caught high!

Good references I used:



Ryan said...

Is there a reason why you have posted this content without approval from the original author nor any link or consent from ryanthepilot?

Trey said...

excellent read from a non-aviator. thanks for the info!

Daffman said...

Very nice article! Thanks a lot to the pilot who wrote it - Anonymous Flightsimmer

Post a Comment

Related Posts Plugin for WordPress, Blogger...