Does particle marker "o" belong in this sentence?

わたしわにほんがにせんげつにひこきでいきました。 (Watashi wa) nihon ga ni sengetsu ni hikoki de ikimashita.

Hi Yanagi! を is unnecessary in the above sentence because when you use 'mode of transport' you always use "で" to mean I came "by" bus/train, etc. It is also unnecessary because verbs like come/go/present (来る・行く・いる) don't require "を" but rather "に" because they are preceded by a place and the person is not really doing the action. I recommend switching the word order as well. Subject + Time + Place + Mode of Transportation + Verb. You can switch the order around for Mode of Trans. and Place but it is quite natural to use time after the subject. 私は先月日本へ飛行機で来ました。 私は先月日本に飛行機で来ました。 The particle "へ" and "に" can be used interchangeably here. Hope it helps!