The high cost of heavy braking
Back In the 1960’s, the Douglas Aircraft company published a flight safety newsletter that included an article titled The Hard Cost of Heavy Braking. It quantified the cost in dollar terms, of wear and tear on tyres per landing. While frequency of landings was an obvious factor, pilot braking technique was the main culprit affecting cost.
Having retired from flying Boeing 737’s for most of my airline career I was recently offered a flight in an Airbus A320 simulator. It was the first time I had been in that aircraft type. The instructor was very patient with me both in the pre-flight briefing and the simulator. He let me fly the simulator while he did all the setting up using the FMC where required
For landing we used an 8000 ft sea level runway and no wind. My touch down was just average and as I was about to shift my feet up on the rudder pedals to apply the brakes, the autobrakes cut in and we pulled up quite quickly. It caught me by surprise as I had expected to use the brakes manually. I queried this during the post flight de-brief only to be told the company used auto-brakes for all landings regardless of runway length.
During the ten years I served with one Pacific island operator flying the Boeing 737-200, it was left to the captain to decide whether or not autobrakes were used for operational reasons. Our runways varied between 5000 ft to 10,000ft in length with the surface either coral based or normal hard surface. Being near the equator, heavy rainfall making runways slippery was an occasional hazard.
Auto braking was very rarely used unless operationally necessary. Accurate airspeed control and point of touch down was the key to good landings without having to use heavy braking. From the company point of view, cost of brake wear and tear was never a factor in a decision to use manual or autobrakes. As it should be of course.
Since then I have flown the 737 with several other companies who mandate the use of autobrakes for every landing - regardless of runway length or whether operationally necessary. When I read the 1960's Douglas Aircraft survey on the dollar cost of each landing it didn’t surprise me that using auto-braking substantially increases brake and tyre servicing costs rather decreasing them. I don't know if that is a valid statement in this present era of flying. That said, auto brakes do at least ensure equal wear and tear on tyres, whereas manual braking relies on pilot technique. Heavy footed pilots do not always brake evenly on both pedals.
In a similar vein, it is well known that in terms of overall cost saving, use of reduced thrust for take off can give significant savings in maintenance. Yet it seems many operators disregard the potential cost savings available on tyre wear and tear with manual brake landings. For pilots, their manual braking skills inevitably decline due lack of use. Does that matter nowadays? Probably not.