Why right engine of a dual engine aircraft is starting first?
There can be a lot of reasons why the engines are started in a particular order: 1) The engine closest to the batteries will often be started first in a small recip. 2) In smaller turboprops, sometimes the right engine is started first because passengers might still be boarding on the left side while the engines are started. 3) In the older B737s we would often taxi on one engine, and, that would often be the right one. This was because the APU did a lousy job of carrying the air conditioning load, and the only way to get both the APU and an engine working on cabin cooling was to run the right pack off of the right engine, and the left pack off of the APU—this was a restriction of the plumbing. 4) In newer B737s, B757s, we often single engine taxi on the left engine only because the APU can handle the cooling/heating load all by itself, and starting the left engine only allows for the loading of last minute bags which can’t be loaded with the right engine running. 5) Regardless of th
