EC135T1 helicopters that have been operated by Britain's police forces for up to 10 years could soon be forced into what some see as a premature retirement.

New Instrument Meteorological Conditions (IMC) requirements mean a number of police forces' aircraft are due to be withdrawn by 2010, Police Aviation News reports. The legislation was brought in this March.

At the time of their introduction to UK police forces around 10 years ago, there was no CAA requirement for the helicopters to have Instrument Flight Rules (IFR) - Visual Flight Rules (VFR) were accepted.

The crash of a Strathclyde Police EC135T1 in 2002 - which all three crew members miraculously survived - is thought to have prompted an evaluation of the rules. At least two more T1s came down, worldwide, in 2005.

The Suffolk Constabulary is one of those which will have to replace its T1, registered G-SUFF. A source told EBAN that there is no decision about a replacement as yet: "We're going through the process of 'what can we have?'. It's out to tender at the moment," he says.

Northumbria Police Authority, which operates G-NESV, says that a consultation would be going ahead "soon".

A source at Central Counties, which operates G-CCAU, told EBAN it was his understanding that the 2010 deadline is far from certain.

"There is a question mark over the 2010 thing, because the assessment hasn't been done yet by the CAA.

The assessment will be done in spring 2008.

"Broadly, it looks as though it will stop night flights. It's not going to fall out of the sky, but night operations will be curtailed, which are obviously one of the most important things."

He says he has "an open mind" about his preferred replacement for the T1 - "if it comes to that".

"The 135 has been a good ship to us. Ours was the first one in the UK, it has flown 7,300 hours. It's got a lot of life left in it. It's just something that the air accident investigation branch at the CAA are coming up with.

"The original business case was for an aircraft with a 10-year life anyway. But it's still working well and if it ain't bust, don't change it."

Asked to put a figure on the number of fugitives G-CCAU had helped to apprehend over the years, the source estimated 2,000, with another 4,000 missing persons located.