While the US National Transportation Safety Board is satisfied with parts of an FAA proposal to expand cockpit-voice recorder duration to 25h, it is disappointed that the plan does not cover retrofit of older aircraft.

The FAA proposal will require the installation of 25h recorders on new-build aircraft across a broad range of operations and model sizes.

Retrofitting the current fleet, according to the proposal, would result in “significant” costs, because it would apply to more than 29,500 aircraft – a rise of two-thirds on the 43,470 new-build aircraft to which the proposal will apply over the next 20 years.

But the NTSB disputes this figure. The investigation agency – which originally recommended that retrofit apply to all aircraft current required to carry a cockpit-voice and flight-data recorder, to avoid a cost burden – estimates that retrofit would apply to 13,500 aircraft, less than half the FAA figure.

“This is a conservative estimate as this population includes many [aircraft] capable of single-pilot operations that would not require a [cockpit recorder],” it adds.

Cockpit-c-Unsplash Shandell Venegas

Source: Unsplash/Shandell Venegas

Under the FAA proposal new-build aircraft will be fitted with 25h cockpit recorders

The NTSB argues that the FAA’s analysis does not take into account the number of aircraft which would be removed from the US registry – through retirement or scrappage – over the five-year retrofit period the NTSB has recommended.

As a result, it says, it “cannot fully support” the FAA proposal because it believes a retrofit requirement should be included.

“We believe the FAA has inappropriately estimated the cost of retrofitting the existing fleet and urge the FAA to reconsider its position,” says NTSB chair Jennifer Homendy.

According to the FAA the equipment cost to retrofit 25h cockpit-voice recorders would exceed $740 million, far higher than the $195 million estimated by its proposal to limit the installations to new-build aircraft.

It also believes retrofit would incur additional expense through aircraft downtime and labour, but the NTSB rejects this suggestion, claiming that replacement of the recorders is relatively simple and could be undertaken during regular maintenance periods.