Incidents allegedly involving contaminated air on 10 Belfast-bound flights have prompted a protest by cabin crew.
Flybe says it is confident that its planes are properly maintained
The BBC discovered noxious fumes leaked into cabins on the Flybe flights.
During a flight from Birmingham, two stewards collapsed after being overcome by fumes. Another flight was aborted after the crew had to use oxygen masks.
Staff said they were concerned about health risks. Flybe is to withdraw the aircraft concerned early next year.
The protest involves the British Aerospace 146 fleet, which is generally used on domestic flights.
All the affected flights took place between Birmingham and Belfast or Gatwick to Belfast.
In July, seven crew members were taken to hospital in Belfast after the stewards collapsed on a flight from Birmingham.
One was off work for more than a month.
Some cabin crew are so alarmed that they are boycotting the 146.
One flight attendant said: "I will not get back on the 146 again. I'm angry that my health has been put at risk."
The view is echoed by one of the company's pilots who said that if he was asked to fly the 146 he would say "go take a walk".
The BBC found there is no proven link between aircraft air and ill-health, and a recent report by the Committee on Toxicity (CoT) for the government was inconclusive.
British Aerospace said there had never been a single fatality caused by technical failure on the 146 making it "one of the safest commercial aircraft in operation today".
The company also said that design enhancements since its introduction to service mean "cabin air quality on the BAe 146 continues to be better than the industry standard".
It pointed out that neither the CoT study nor other investigations have ever found a causal link "between the presence of cabin air contamination and the symptoms complained of by a very small minority of cabin and flight deck crew".
However, the CoT study did call for further investigation and the Department for Transport (DfT) is now embarking on more tests.
Flybe, which operates more than 100 routes in the UK and Europe, told the BBC: "Flybe is completely confident that its aircraft are operated and maintained to the highest industry standards.
"In line with many previous public announcements, Flybe took a commercial decision several years ago to reduce the number of aircraft types operated from three to two.
"As a result the BAe 146 fleet will have been withdrawn by February 2008."