From my experience as a private pilot I can tell you that driving a lorry and steering an airplane is not so different from one another. Basically, the tasks and circumstances are quite similar. We want to go from A to B and during the trip we have to keep an eye on other road users, find the best route, and pay attention to the speed and weather conditions. And drive/fly the vehicle/airplane in the most efficient way.
A large part of efficient flying (and efficient driving) is the correct management of speed and height, in the lorry you change the speed and in an airplane you change the height. In the plane the pilot decides the level of lift. In a lorry you cannot decide yourself. There you follow the roads. This means that in a lorry you have to take for example mountains in account where you actually slow down.
Metres in altitude are more difficult to control as it is to move one meter forward, the force of gravity always tries to win. A scheduled flight can travel about 900 km/h, whereas the speed can only reach 60-80 km/h when taking off. It is similar with a semi-trailer truck. On the highways it is not a problem to drive 90 km/h straight ahead, but overcoming a few hundred meters of altitude is much more difficult.
On a steep hill the right gearshift is important. Even with an automatic gearbox it can sometimes be helpful to switch to manual. The driver is the link between the road and the lorry. You learn to estimate the weight of the vehicle, how to understand it, to estimate the steepness of a hill and about the power available. The first priority with steep hills is to avoid losing sway, because the more speed you lose the more fuel you use.
Low gear is not always negative when driving uphill. Unfortunately, the system is often misinterpreted. The 12th gear with 1,000 – 1,300 rmp at 90 km/h is not fitted in such a situation. Nevertheless, many drivers still choose the 12th gear when “climbing” the mountain and then the automatic downshifts downhill and this causes unnecessary sway and an increase of used fuel.
Even though you always hear how important revs are, it can still be more sensible to drive uphill with maximum output. The trick is to choose the 11th gear a few seconds before the road starts going uphill which lets the vehicle run at 90 km/h with 1,600 revs depending on the gearing. The uphill begins and the vehicle already has a lower gear ratio in the ideal torque area and has enough steam below from the revs before the next gearshift.
Before reaching the end of the uphill you should leave the gear in the 11th and “let the vehicle drag itself” over the peak. Then shift from automatic into manual gear and let the 11th gear run down to about 1,000 revs. With this trick you save money and time as you save yourself of the unnecessary gearshift into the 10th.
If you can see that the mountain is going further up you have time to shift down to keep the engine in upper revs band of the torque hold. As a result you avoid unnecessary low gear shifts. With revs about 1,500 – 1,600 you will, in point of fact, drive most effectively and efficiently.
Facing smaller mountains or hills the driver in more modern vehicles is supported by the corresponding equipment from a cruise control which independently estimates the terrain.
Written by Ben Mikka Buchner.