On 6th March 97 a PA34 crashed at Southend folowing an artificial horizon failure. As a result of that accident the AAIB placed a requirement on the UK CAA to review the test requirements for revalidation of Instrument qualifications. The SPA IR was modified to include a limited panel VFR section as a direct result of the AAIB recomendation. The IMC revalidation allready contained a limited panel section but; the MPA IR revalidation does not.
These changes occurred at exactly the same time as the introduction of JAR-FCL which also prohibited the privileges of a MPA IR from being exercised on a SPA Class or Type. At that time all SPA Instrument revalidations included a LP element.
It appears that various exemptions have been granted since that date that failed to acknowledge the AAIB recommendations and do not include any LP.