Here's a quote from a 2007 NPA-OPS 39B1 to JAR-OPS 1:
HF Communication Equipments alleviation (JAR-OPS 1.865)
2.1. Regulatory Background
The applicability of JAR-OPS 1.865 (b) could be interpreted such that with respect to the operation of “short haul” aeroplanes on particular routes in the MNPSA, these aeroplanes must be fitted with 2 HF systems, whereas ICAO MNPS regulations do not specifically require particular numbers of such equipment, simply requiring the ability for communication with corresponding ground stations. A similar situation seems to exist with FARs. In addition, it would appear that some states interpret the equipment requirements for MNPSA differently. According to one major manufacturer of transport category aeroplanes, about 80% of all short haul aeroplanes delivered have been equipped with 1 HF system only.
Due to the differences between the operational requirements for HF equipment for NAT MNPSA, JAA Operational Sectorial Team (OST) tasked JAA EQSG to address the issue, with the view of aligning JAR-OPS 1 with ICAO SARPs.
During the development of the rule material, an initial proposal was for an alleviation to apply to specific routes in the NAT MNPSA. However, it was the view of OST that this was too specific and requested a more general wording should be used, avoiding the reference to specific routes. Consequently, the reference to specific routes has been deleted and some general text has been inserted, reflecting the requirement for specific alternative procedures published for the area of operation in case of a temporary HF non-coverage.
I leave it to you to find the latest version of said document now and check its contents. From the same NPA:
JAR-OPS 1.865 Communication and Navigation equipment for operations under IFR, or under VFR over routes not navigated by reference to visual landmarks.
(See AMC OPS 1.865)
(a) An operator shall not operate an aeroplane under IFR, or under VFR over routes that cannot be navigated by reference to visual landmarks, unless the aeroplane is equipped with radio [(communication and SSR transponder)] and navigation equipment in accordance with the requirements of air traffic services in the area(s) of operation.
(b) Radio equipment. An operator shall ensure that radio equipment comprises not less than:
[(1)]Two independent radio communication systems necessary under normal operating conditions to communicate with an appropriate ground station from any point on the route including diversions [; and
(2) SSR transponder equipment as required for the route being flown.]
(c) Navigation equipment. An operator shall ensure that navigation equipment
(1) Comprises not less than:
(i) One VOR receiving system, one ADF system, one DME [except that an ADF system need not be installed provided that the use of ADF is not required in any phase of the planned flight (see ACL OPS 1.865(c)(1)(i));]
(ii) One ILS or MLS where ILS or MLS is required for approach navigation purposes;
(iii) One Marker Beacon receiving system where a Marker Beacon is required for approach navigation purposes;
(iv) An Area Navigation System when area navigation is required for the route being flown;
(v) An additional DME system on any route, or part thereof, where navigation is based only on DME signals;
(vi) An additional VOR receiving system on any route, or part thereof, where navigation is based only on VOR signals; and
(vii) An additional ADF system on any route, or part thereof, where navigation is based only on NDB signals, or
(2) Complies with the Required Navigation Performance (RNP) Type for operation in the airspace concerned. (See also IEM OPS 1.243.)
(d) An operator may operate an aeroplane that is not equipped [with an ADF or] with the navigation equipment specified in sub-paragraph(s) (c)(1)(vi) and/or (c)(1)(vii) above, provided that it is equipped with alternative equipment authorised, for the route being flown, by the Authority. The reliability and the accuracy of alternative equipment must allow safe navigation for the intended route.
(e) An operator shall ensure that VHF communication equipment, ILS localiser and VOR receivers installed on aeroplanes to be operated in IFR are of a type that has been approved as complying with FM immunity performance standards (See ACJ OPS 1.865(e)).
(f) With respect to sub-paragraph (b) above, for short haul operations in the NAT MNPS airspace, an aeroplane may be equipped with one Long Range Communication System only if alternative communication procedures are published for the airspace concerned (see ACJ OPS 1.865 (f)).