What do pilots do during the turnaround?

The turnaround process and in fact the vast majority of our day-to-day job is split into two distinct roles. For the most part these are known as Pilot Flying and Pilot Monitoring and I explain a bit about these roles here to provide context to the rest of the blog post.

Pilot Flying (PF)

This is pretty much exactly what it says on the tin. The pilot in this role is the designated flying pilot for the subsequent flight. The pilot flying can be either the Captain or the First Officer and the delegation of each flight is typically decided in the crew room before the days work begins. For example, the Captain may fly the first and last flight of the day with the First Officer doing the middle two. That same delegation of flights may also be established based on the weather at each location as Captain's weather limitations are often higher than a First Officers.

Pilot Monitoring (PM)

This pilot is the pilot flying's best companion. The pilot monitoring's role is to monitor everything about the subsequent flight as well as be the pilot liaising with air traffic control. The pilot monitoring is a crucial role in modern aviation as he/she works to ensure procedures/gates are met at each point in the flight. This includes among others, ensuring the aircraft is on a safe trajectory, at safe speeds and in the correct configuration (flaps / gear) during final approach. The PM essentially pilots the aircraft in their head all while the actual PF does the flying. If the two pilots mental models don't align it's up to the PM to question the PF and confirm they're both on the same page. 

Now that you have context on our roles, I'll introduce these into the turnaround.

1. Post-flight Paperwork...

From the moment we pull on stand the timer begins and all parties collectively strive to turnaround the aircraft in as little as half an hour. Shortly after the engines are shut down it's time to complete the paperwork from that previous flight and begin preparing for the next one. The First Officer takes note of the times we landed and set the brakes as well as writing down the final fuel in the tanks on to the flight plan paperwork. The captain completes the aircrafts tech log with pretty much the same information. After that both pilots will discuss the fuel requirements for the following flight - if they haven't already - and notify the fuel company. At my airline we do this with a numbered flip-card which sits in the First Officers' window. This speeds up the fuel process as the re-fueller can crack on without us having to even speak to them. Meanwhile in the cabin the front and rear doors are only just opening and passengers begin to disembark. 

Once we've finished the admin from the previous flight we typically switch roles with the PM becoming the PF and vice versa. The PF will begin to check the cockpit is setup ready for a new flight. Meanwhile the PM typically fetches the weather and sets up his/her tablet such that it holds all of the information required for the departure airfield in preparation for completing performance calculations (more on that later). 

Where weather is concerned we refer to reports in many ways: METAR, TAF and ATIS and it is the latter we use for departure. ATIS stands for "Automatic Terminal Information Service" and tells us the weather overhead the airfield in the last 30 minutes including winds, runway condition etc. They generally provide us with information like this in either printed form (from the aircraft printer) or a looping aural broadcast on a dedicated frequency. We then use that weather for our decision making processes.

Here's an example ATIS in an easy to understand format:

EGGP
- Information November
- Time 0720 Zulu
- Runway In Use 27
- Wind 270º 6 Knots
- Few 1200ft
- Scattered 2300ft
- Temperature 15º
- Dewpoint 5º
- QNH 1019hPa
- Ground Frequency Closed

After doing his/her bits the PM will get up and complete a walk-around of the aircraft. The walk-around exists to check for anything abnormal with the airframe itself that would hinder our ability to safely operate the flight. On the A320 family we start this just below the front door on the left side of the aircraft and walk around the entirety of the plane checking sensors / ports / openings, tyre condition, brake condition etc etc. If anything odd was found which wasn't otherwise noted within the aircraft tech log we'd contact our maintenance teams to have it looked over. 

Back in the flight deck the PF will be setting up the flight computers for the next flight. The flight computer or FMGS (Flight Management & Guidance System) as it is known on the Airbus A320 is effectively the main brain behind the aircraft. We input data into it via an interface known as the MCDU (Multifunction Control Display Unit) adjacent to the thrust levers which is shown in the above photo. The MCDU has a small screen, keyboard and various function keys for the purpose of interacting with the aircrafts various systems. 

The FMGS needs to know information such as:

• Departure Airport
• Destination Airport
• Alternate Airport (in case destination were to be unavailable)
• Cruising Altitude / Flight Level
• Atmospheric Conditions (temperature, tropopause, winds etc)
• The calculated Zero Fuel Weight (weight of plane, passengers and cargo exc. fuel)
• Amount of fuel loaded (to calculate takeoff weight by adding it to the Zero Fuel Weight)
• The expected departure route from the airport (known as a SID)
• The expected arrival route into the destination (known as a STAR)
• The expected route between the two (although in most cases this is automatically downloaded - or 'uplinked' as we call it)
• And much more...

The FMGS will then use all of the entered information and run several calculations. It also shares data with a variety of other systems on board such as each engines dedicated computer system, known as a FADEC. If all runs like clockwork then the PM generally returns to the flight deck mid-way through the setting up of the FMGS coinciding nicely with the next set of passengers starting to board. 

* Airbus FlySmart Performance application on Electronic Flight Bag - Source: Panasonic *

Next up is the calculation of the aircrafts performance. 

What is performance?

Performance is essentially the measurement of how well something completes a task and it's not just limited to aircraft. For example, you may run 100m in 'x' amount of time but if you were to repeat that same 100m on a full belly of roast dinner, after drinking a few pints of your favourite beer, I'm sure it'll be a bit tougher, right? Therefore, your performance is much better on an emptier stomach.

Another example I can use here is your car. It's manufacturer will tell you in the glossy magazine to expect 60mpg however, you and I both know that they've come to that conclusion in near perfect conditions, on either a rolling road or motorway. I'm quite confident in saying you'd probably struggle to hit that number 99% of the time. 

In both of the above examples there are variables at play. The first is how full your stomach is and the second depends on how fast you drive and whether or not it's on a motorway or around country lanes etc. The output of performance is entirely related to the input in terms of those unique and daily variables. Hopefully this is making sense so far... 

Performance in aviation

If we now focus on aviation once again we know that we're sat in an aircraft. That aircraft - with no fuel, passengers or baggage - will weigh the same from one day to the next. What will differ though is the variables. These will be, among others:

• Total passenger numbers
• Where those passengers are sat
• Total bags in the holds
• Distribution of bags within those holds
• Amount of fuel we're carrying 
• The weather outside
• The length of the runway
• The condition of the runway (dry, damp, wet)
• And so on...

Knowing the above data we as pilots have a legal obligation to determine whether or not we can safely get airborne. To help us achieve this manufacturers have to prove takeoff and landing performance to aviation authorities as part of the aircraft certification process. Each manufacturer subsequently has a pretty good idea as to how weight and other conditions affect the performance of their aircraft. They then produce a series of graphs and tables we can extract this data from, or in the case of Airbus, develop an app for our tablets which can do all the number crunching for us.

The application, known as FlySmart (shown in above photo), makes our lives easier and contributes towards the swift turnarounds of short-haul operators. Using the app we input the registration of the aircraft we're flying, the airport we're at, the runway we're to use for departure and the weather outside as taken from the ATIS. The app will then tell us if we'd be able to get airborne without any passengers or cargo. However, being an airline we also want to know if we can get airborne with everyone onboard. This is where the dispatcher comes in.

* Me, working as a dispatcher at Bristol Airport back in 2016 * 

At a particular point in the turnaround process the dispatcher will come and speak to the flight crew and provide us with a loadsheet. This loadsheet provides us with the missing variables, such as passengers and baggage.

We then input all of the loadsheet data into the relevant section of the FlySmart app and re-run the performance calculations. The output then tells us information about the takeoff. If it's not possible given the inputted data the text on the screen turns a rather visible shade of red. However, unless the weather outside truly is horrendous then in most cases we're provided with the following:

• Total runway distance required in metres
• Total runway distance required in metres with an added percentage factor, dictated by the aviation authorities.
• A set of speeds, known as V1, VR and V2, Green Dot, S Speed, F Speed.
• The engine thrust required.
• A series of altitudes applicable for that runway (i.e. Flap retraction altitude)

Both pilots will then review this data. At my airline we both run the calculation on our own tablets and crosscheck the information to ensure no computer calculation error. If there's any obvious discrepancy we look into it as a crew and re-run the calculations as required. In order to takeoff the total length of the physical take off distance for a given runway must generally not be shorter than the factored distance required by the aviation authorities. 

i.e., Actual runway length: 2000m, FlySmart Take Off Distance Required: 1700m, Factored Take Off Distance: 2125m. The take-off is not possible, despite the actual distance required only being 1700m. 

What happens if the performance deems you can't takeoff?

A number of things can happen but it generally requires using another runway (if available), moving bags to other holds, moving passengers to other seats, changing the flaps used on departure or re-calculating the performance assuming full take-off thrust.

* Bristol Air Traffic Control Tower - Photo: NATS *

With everything now input into the various computer systems and the performance calculated it comes to briefing time. The primary purpose of a brief is to link both pilots mental model as mentioned earlier. If I was to be the PF for the specific sector the briefing is my opportunity to go through all of the data I have entered into the FMGS one final time and discuss it with my fellow pilot. This looping through the FMGS allows either myself or my pilot monitoring colleague to catch any data omissions or alterations that are required prior to our pushback.

Briefings generally follow a framework and by far the most common is what we call WANT. 

This stands for:

• Weather
• Aircraft
• NOTAMS (NOtices To AirMen)
• Threats

Here's an example I might decide to brief:

Weather
From looking out of the window the weather appears to be suitable for our departure. However, both the ATIS and forecast did mention the chance of embedded thunderstorms so when we line up on the runway i'll take a moment to have a sufficient look at the weather radar. Once you and I are both happy to continue we'll go.

Aircraft
As per the tech log one of the navigation bulbs on the wing for system one is inoperative. The manual says this isn't a problem for flying in the daytime and we've selected system two as a result.

NOTAMS
The NOTAMS identify that the ILS is out so in the event of us needing to return for whatever reason we'll use the RNAV (GPS) approach.

Threats & Terrain
With it being nice weather we might expect to see light aircraft flying about so we'll keep our landing lights on for visibility and both keep a good visual lookout to aid the TCAS system. The highest terrain is to the south and 3,000ft will keep us above it.

I'll then go on to discuss the "how" in respect of how I wish to fly the departure, i.e. autopilot on shortly after takeoff due to a higher than usual workload or keeping the autopilot off until a point agreed by both pilots. Briefing removes the opportunity for surprise when both pilots expect the same thing. Our briefing also incorporates emergencies. It's something we and our passengers hope will never occur but should we experience engine issues on departure we brief all of the actions we need to take. 

By this point if we've not done so already then we'll fetch our departure clearance from air traffic control. The vast majority of the time air traffic control simply respond to our request permitting the very same departure as that on our flight plan. However, from time-to-time they change it due to weather or other flow-control purposes and in such an event we would adjust the departure in the FMGS, recalculate the performance if required and re-brief the pertinent parts for that new departure.

If everything has run like clockwork to this point then the dispatcher will return to the flight deck to complete what we call Last Minute Changes, known as an LMC for short. LMCs notify pilots of any adjustments to their passengers / cargo from that originally given on the loadsheet. The most common reason for adjustments are passengers not turning up to the gate despite checking in for the flight. When this happens we also need to find their bags and offload them too! Another common LMC is the addition of bags to the hold whereby the space in the cabin is too restrictive for the amount of cabin bags carried by our passengers.

Given LMCs have the possibility to adjust our take-off performance calculations both pilots review the information and then enter it into the FlySmart application's LMC section. FlySmart then re-calculates the speeds, thrust etc and produces a final take-off weight centre of gravity which we set on the trim-wheel on the centre pedestal. Once that's all done the captain signs the paperwork, lets the dispatcher leave the aircraft, provides consent for door closure and finally completes his welcome PA if he/she hasn't already done so.

After the Captain has completed the welcome PA we crack on with our before start checklists and liaise with a ramp team member over headset. He/she will confirm that all doors and hatches are secured and that the tug and tow-bar are connected and that they are ready to commence a pushback. This is then the cue for the PM to radio the tower/ground controller and request push and start clearance. Once the clearance is granted that's it.. we're on our way! 

The turnaround stops at the very moment the aircraft wheels begin to move. We call this "Off Blocks". 

So there you are... the turnaround process from the flight deck perspective. We do that up to 3 - 4 times per day. I hope you found this blog post insightful. 

Should you have any questions about the turn around, anything else aviation related or have any suggestions for future blog posts then let me know in the comments section below or feel free to contact me from the Contact Us page or via Social Media. 

George.