The UK’s Department for Transport (DfT) issued its official proposal to prevent foreign-registered aircraft from being based in the UK “by limiting the time (for example, 90 days) such an aircraft may spend in the UK in any 12 months.”

While the DfT said in its notice that “no significant safety issues have come to light” regarding aircraft registered in the U.S., Bermuda and the Cayman Islands, the agency does not know what other registers are involved or the safety risks associated with those registers.

The DfT believes that many private and corporate aircraft based in the UK have been placed on foreign registers so operators can “take advantage of what are perceived as less onerous regulatory requirements.” The use of foreign-registered aircraft to “opt out of the UK regulatory system undermines the harmonized European standards,” the DfT asserted. There are also some “significant differences” even between the U.S. and the UK regulations, according to the DfT.

Moreover, aviation authorities in countries at some distance from the UK “can face practical difficulties in ensuring that aircraft on their register but based in the UK comply with their requirements.”

The proposal would also require pilots of foreign-registered aircraft to obtain a UK license and type ratings for operating under IFR. Comments, due October 28, should be sent to Ray Pusey at the Department for Transport, Zone 1/29, Great Minster House, 76 Marsham St., London SW1P 4DR or by e-mail to fra.consultation@dft.gis.gov.uk.