It has been revealed by the US Federal Aviation Administration (FAA) that there have been two ‘nearly catastrophic’ incidents involving the Airbus A220 and inadvertent engagement of the autopilot function. As first reported by FlightGlobal, the regulator has issued an Emergency Airworthiness Directive to address the issue.
A pair of close calls
The Airworthiness Directive from the FAA follows the issuance of a similar Emergency AD issued by Transport Canada on November 17th. It states that, in total, there have been 38 in-service events relating to this problem, a significant number given that only 230 of the type are in operation. Two of these events were described by the FAA as being ‘nearly catastrophic’.
Photo: Air Tanzania
The problem centers around the inadvertent engagement of the autopilot when attempting to engage the autothrottle during the take-off phase, or when re-engaging the autothrottle during other stages of flight. The FAA says that it is a design flaw with the control panel that it is so easy to mistakenly engage the autopilot in this way.
The regulator went on to describe one of the close calls, which occurred in September 2022. Without naming the airline or airport, it stated that there was an incident where an Airbus A220 was taking off, and the autothrottle disengaged. Flight crew attempted to re-engage the autothrottle but accidentally engaged the autopilot instead.
Photo: Breeze Airways
The end result was the A220 rotating (or taking off) at below the V1 speed. This sort of low-energy takeoff is very dangerous, as it could see the aircraft failing to climb quickly enough and therefore impacting ground objects nearby, or it could force it into a stall.
Neither the FAA nor Transport Canada gave details on the second near-miss incident.
Clearly, not much can be done to redesign the control panel of the A220 to prevent this from happening again. But it’s important that pilots of the aircraft are made aware of these incidents so that they can be mindful of the ease with which the wrong inputs can be made.
The FAA and TC solutions are to update the Aircraft Flight Manual (AFM) with a warning statement. The statement should read as below:
It might seem like a case of sticking a band-aid over a burst pipe, but there’s not a great deal else that can be done at this point. However, the FAA is taking things a step further than Transport Canada, which only required a warning to be placed in the AFM. The FAA is saying that, to avoid accidental engagement of the autopilot, pilots must not attempt to engage or re-engage the autothrottle function once the thrust levers are at takeoff setting.
It further reminds pilots that autopilot should not be engaged below 400 feet above ground level, something any pilot will be well aware of. Nevertheless, the issuance of an EAD without any consultation reflects the seriousness of the condition, as the FAA described,
The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to the adoption of this rule because inadvertent autopilot engagement below 400 ft above ground level could result in premature rotation due to inadvertent autopilot engagement, possibly leading to tail-strike, inability to climb, and loss of control of the airplane.
Simple Flying has reached out to Airbus for comment on the EAD; we will update this article with any further details.
Source: FlightGlobal, FAA