Editor’s note: We were interested in the differences between operating the Boeing 737 NG and the 737 MAX. A pilot for a European airline with experience in the 737 NG and 737 MAX shares this report.
New generation aircraft such as those of the Boeing 737 MAX and Airbus A320neo families are vital to the continued profitability of the airlines that operate them, as well as the industry’s overall drive towards a lower carbon footprint. The Boeing 737-8, -8-200, -9 and the upcoming -7 and -10 are examples. The MAX family are modified variants of the successful Boeing 737 ‘Next Generation’ aircraft line, a group of aircraft that are amongst the most prolifically utilized and widely sold commercial aircraft in history.
The MAX features a raft of upgraded features, the most notable being the aircraft’s new CFM LEAP 1B high-bypass turbofan engines. These new powerplants drive a significant increase in fuel efficiency – notably a reduction in fuel burn of around 14% compared to the 737-800 (according to Boeing). Whilst these two aircraft have their subtle (and not so subtle) differences, they are covered by a common type rating, meaning existing 737 NG pilots only need to undertake ‘differences training’ in order to fly the MAX. That said, there are some notable differences that pilots have to take into account when flying each type of aircraft on the line. Let’s take a look at some of those differences from a pilot’s perspective, and what actions crews take to trap and mitigate any potential errors brought about by those differences.
The brakes, the cabin, and the turnaround
The construction and the logic of an aircraft’s systems frame the way the aircraft is managed when on the ground between flights (referred to as the ‘turnaround’). Turnaround time is a key factor to the day to day operations of an airline, and some budget carriers have targeted turnaround times as low as 25 minutes. Brakes are one system that can have a significant influence on that time. The Boeing 737 MAX is fitted with carbon fibre brakes. These provide superior performance at high temperatures and cool down faster than the steel brakes fitted standard to the Boeing 737-800 (some -800s have optional carbon fibre brakes. That faster cooling time means less time spent on the ground and more cost savings for the airline, one of many cost savings that are passed on to the flying public in the form of lower ticket prices! In fact, carbon brakes offer higher energy absorption, take on average 2,200 landings between overhauls (almost double that of steel), and reduce brake set weight by up to 320 kg per aircraft.
When pilots calculate their landing performance in flight, their onboard performance calculation will show the most appropriate brake setting to leave the runway at the point that will give them the shortest taxi route (again, saving time and money). When flying a Max, you will have a shorter brake cooling time and potentially a faster turnaround than a 737-800.
Another key consideration on the ground is weight and balance. An aircraft’s cabin is divided into ‘zones’ containing a set number of rows and seats. Passengers are seated in each zone to ensure the aircraft’s center of gravity is within the limits set out in the aircraft manual (that’s why it’s important to take your assigned seat when boarding!).
The 737 has 3 cabin zones – forward, middle and aft. The 737-800 typically defines the forward cabin zone as rows 1–5, with the aft covering the rear third of the cabin. On the 737-8-200, the forward and aft zones now include the first and last 6 rows. When calculating the loading, weight and balance for the aircraft, pilots must ensure that an appropriate number of passengers are placed in these zones, and account for any last minute changes (such as passenger no-shows).
During the preflight walkaround, the MAX’s Advance Technology (AT) Winglets also require inspection for unintentional ground damage.
Better engines, taxi, and takeoff performance
One of the most visible differences between the 737 NG and the 737 MAX is the engines. From a pilot’s perspective, this changes some key indications we expect to see from the engines, as well as tweaks to the way they are operated.
The CFM56 engines fitted to the NG are rated up to 26,000lbs of thrust, whereas the LEAP 1B fitted to the -8200 are rated up to 27,000. In practice, this means the 737-8-200 has a small but useful increase in available thrust, providing improved takeoff performance or allowing the same performance to be achieved at a further thrust derate, reducing engine wear and fuel burn. The LEAP-1B actually requires a slightly longer start sequence during engine start, as the engine control system carries out additional checks and a process called ‘bowed rotor motoring’. Once stabilized, the engines perform reliably, but start-up times must be factored into pre-flight planning.
Another difference is idle thrust. On the ground, the LEAP-1B produces more thrust at idle than the CFM56, which means the aircraft can often accelerate to taxi speed without additional power. This has the benefit of reducing fuel use during taxi, but requires careful handling in congested areas. Pilots consider this during their pre-taxi briefings as part of threat and error management (TEM), identifying it as a predictable factor that must be controlled during ground operations.
Positive rate, gear up!
Pilots transitioning between the two aircraft quickly notice one significant cockpit change: the landing gear lever. On the 737-800, the lever has three positions: Down, Up, and Off. After takeoff, crews typically move the lever to Off, which depressurises the gear hydraulics. On the 737-8200 however, the lever has only two positions: Down and Up. Hydraulic pressure is removed automatically about ten seconds after the gear is selected Up.
This may seem like a small difference, but highlights a potential area of risk that pilots tackle with threat and error management.. A pilot accustomed to moving the 737-800’s landing gear lever to off could instinctively move the lever, which on the 737-8200 would actually lower the gear. This is a clear example of where threat and error management comes into play. Crews brief this hazard in advance and monitor the lever closely during takeoff. Should a problem arise, memory items would be actioned immediately.
Checklists and decision-making
Checklists form the backbone of safe flight operations, and here the similarities between the two aircraft outweigh the differences. Memory items (the steps pilots must recall and carry out immediately from memory in an emergency) are largely unchanged between the 737 NG and 737 MAX. This consistency helps pilots move between the types without additional workload in high-stress situations.
Where the differences appear is in the Quick Reference Handbook (QRH). A number of the “read and do” checklists that pilots complete step-by-step using the handbook have been modified to account for changes in system logic or alerts. While the variations are relatively minor, they still require discipline. Once memory items are complete, crews apply structured problem-solving frameworks based on mnemonics such as TDODAR or PIOSEE. These models encourage the crew to slow down, analyze the situation, and decide on the best overall course of action, ensuring procedural differences do not compromise safety.
Approach, landing, and system indications
As the aircraft returns to the airport environment, a few further differences come into play. The speed brake system on the 737 MAX includes updated logic. In addition to the conditions that trigger the amber ‘Speed brake extended’ light on the 737-800, the MAX also monitors thrust lever position. If the thrust levers remain above idle for several seconds with the speed brakes armed, the warning light will illuminate. This extra protection can be useful, but it can also introduce new cockpit indications during a busy phase of flight, something pilots prepare for in their approach briefing.
Braking performance is again influenced by the use of carbon brakes. Unlike the standard steel brakes of the 737-800, carbon brakes do not lose as much effectiveness at higher temperatures. Additionally, manual braking using carbon brakes requires a slightly different technique, requiring gentle on-off application of brakes.
When operating in winter operations, there are also some changes to anti-ice indications. On the 737-800, valve lights illuminate blue when operating normally. On the 737-8, those lights instead illuminate amber when a fault is detected or a valve disagrees with its commanded position. This requires close attention, as the absence of a light now indicates both normal operation and certain other conditions, a subtle but important shift that is accounted for during cold-weather operations.
From the flight deck, the Boeing 737-8 operates and flies in much the same way as the 737-800, and pilots transitioning between the two find the flying qualities largely unchanged. The differences come in the details: from brakes and cabin zoning to engine characteristics, landing gear operation, checklist logic, and system indications. This is by no means an exhaustive list. These changes are addressed through differences training and reinforced every day on the line through the use of effective threat and error management.
Should abnormal situations arise, structured decision-making models such as TDODAR and PIOSEE provide a consistent framework for crews to analyse the problem, assess their options, and select the safest course of action. In this way, operational safety and consistency are maintained across both aircraft types. For passengers, these technical nuances are largely invisible, but for airlines they represent improvements in efficiency, turnaround performance, and ultimately cost control – factors that support the continued competitiveness of modern single-aisle fleets.
Tracking the Max on Flightradar24
Interested in getting a view of all the 737 MAX family aircraft in the air right now? Filters on Flightradar24 are the answer. Filters are available on your app or Flightradar24.com. Select filters, add a custom filter, and search ‘MAX’ in aircraft type. Selecting the aircraft you want to see will show you all the aircraft we are currently tracking.
