30th January 2023

Aircraft V1 callouts

Initial Report

I’m an [Airline] 737 Captain, having transferred from [other Boeing] fleet a few months ago. I was surprised to find a handful of the fleet don’t have automatic V1 call-outs. Automatic V1 call-outs are a safety enhancement, however, having flown [other Boeing] aircraft for many years without them, this is fine too as one is conditioned to call it during every take-off as PM. Notwithstanding the small number of [Airline] 737s, many First Officers haven’t flown commercial aircraft without V1 call-outs, nor have we received any specific training on it during our simulator training and it’s notable the call is not always made in a timely manner, or sometimes at all. I have raised the issue informally with our fleet management, and the response was the regulator says it’s ok and it should be a briefing item when discussing the aircraft status. From my point of view either the entire fleet should have that functionally or none of them should. The latter was the case on the [Airline] [other Boeing] fleet and it never seemed to be an issue. At the very least some take-offs without V1 call-outs during recurrent simulator checks would be appropriate as this is the most critical stage of flight and we’re not consistently getting it right. To be fair to [Airline], the Aircraft Configuration Card (ACC) details the differences in aircraft fit and the company’s suggested briefing format includes aircraft considerations. Only 1 or 2 out of [Airline] 737s are equipped as such and a lack of familiarity seems to be the core issue, so a recurrent simulator session would aid familiarity across the pilot workforce.

Company Comment

The 737 aircraft has a long history of evolution and development, and as new features have become available we have taken advantage of them. This has resulted in a long period where a mix of aircraft functionality, including aircraft with and without automatic V1 callouts, have been operated successfully. This mix of aircraft capabilities has been addressed by a comprehensive set of aircraft specific briefing cards which are automatically made available to pilots specifically for each flight via the flight planning app.  There is a requirement for aircraft differences to be discussed during the pre-flight briefing.  The normal procedure for all take-offs is to ‘verify the automatic V1 callout, or call V1’.  In the event that an automatic callout fails to be issued, pilots are required to make a manual call.

CHIRP Comment

A positive check and callout of V1 is one of the key safety activities during take-off, and ideally these days as an automated alert. That some aircraft do not have automated capability is a fact of life but, in these cases, pilots should brief manual callouts as we all know. It is certainly less than ideal for there to be mixed capabilities in the same fleet but, again, that’s probably a fact of life and it would be detrimental to remove the capability from those aircraft that were fitted. But the corollary is that pilots must be aware of the modification state of the aircraft and the company should ensure that each aircraft’s capabilities are prominently highlighted. Either way, and as the company comment above states, in mixed-capability fleets the pre-take-off briefing and TEM assessment should include a positive discussion/reminder as to whether calls will be automatic or manual in that particular aircraft and non-handling pilots should be monitoring speeds such that they are prepared to make check-point calls if the aircraft does not for some reason (or make the calls even if the aircraft does have an automated system as a mitigation for any potential failure). This is a key responsibility of the Captain to ensure that both pilots are aware of the aircraft’s state and that the pre-flight briefing covers calls that will be made. Notwithstanding, we agree with the reporter that if there are differences in the fleet, then simulator training should cover this on a regular basis.