Wayne Crook, 40, of Banwell, North Somerset, smashed up computers, windows, a 4×4 and toilets at the Bristol Flying Centre on 6 June.
He also daubed “gross misconduct” in blood on one wall, the court heard.
Judge Martin Picton, sentencing at Bristol Crown Court, said: “You caused a simply enormous amount of damage.”
A restraining order was also made on Crook during the hearing.
The court heard how Crook had been sacked after moving an aircraft in a hangar – something he was not qualified to do.
He began proceedings for a tribunal but accepted a settlement from the firm before the case was due to be heard.
Judge Picton added: “Whatever resentment and anger you felt about the process that had led to your dismissal – and the failure to pursue your complaint through an employment tribunal – none of that can justify what you did.”
It was a horrible and targeted attack”
The judge said he had embarked upon a course of “wanton destruction” that must have taken a “little while” to achieve.
The 40 year-old admitted charges of burglary and criminal damage.
Tristan Harwood, defending, said Crook had no previous convictions and his actions were “completely out of character” and added that he felt “terribly sorry for what he did”.
The company, based at Bristol Airport, handles business aviation such as engineering services to private charter flights.
Speaking after the case, the company’s chief executive, Philip Brockwell, said: “It was a horrible and targeted attack. Each desk had been visited and destroyed.
“He smashed 42 pieces of glass in the building and there was a single hole in 35 computer monitors from where he had smashed them with a hammer.
“He smashed every toilet and basin. It was a systematic attack to try to bring down our infrastructure.”
The restraining order will prevent Crook from contacting former and current staff at Bristol Flying Centre or visiting the premises on his release.