Editing Avro Shackleton (section)

===Avro 716 Shackleton Mk.3===
[[File:Shackleton-WR974-295.jpg|thumb|MR3 on display in 2008]]
Shackleton MR.Mk.3
Tailwheel undercarriage replaced by a tricycle undercarriage, nose entrance hatch added and wingtip tanks fitted to increase fuel capacity.<ref name="aero75" /> To increase crew comfort the inside was sound proofed, better crew seats were fitted and the tactical team positions rearranged.<ref name="aero75" />  To make room for some of the internal rearrangement the dorsal turret was deleted.<ref name="aero75" /> The first MR.3 flew on 2 September 1955; the aircraft had problems with stalling characteristics and crashed on 7 December 1956.<ref name="aero75" /> The variant entered service with 220 Squadron at RAF St Eval in August 1957.<ref name="aero75" /> The RAF ordered 52 aircraft but later, following the 1956 Defence Review, the order was reduced to 33 aircraft.<ref name="aero75" /> An additional aircraft was also built to replace the aircraft lost during stalling trials.<ref name="aero75" /> An additional eight aircraft were exported to [[South Africa]].

The aircraft underwent several phased modifications:

The Phase 1 update introduced changes mainly to the internal equipment.<ref name="aero75">{{cite journal|journal=Aeromilitaria|title=Avro Shackleton MR.3 in Royal Air Force Service|year=1975|issue=2/75|publisher=[[Air-Britain]]}}</ref>

The {{anchor|Shackleton MR.Mk.3 Phase 2}} Phase 2 update introduced [[electronic countermeasure|ECM]] equipment, the distinctive [[Orange Harvest]] 'spark plug' [[Electronic warfare support measures|ESM]] aerial and an improved High Frequency radio.<ref name="aero75" />
[[File:Avro Shackleton XF708 left wing engines from rear 1992.jpg|thumb|right|MR.3 XF708 left wing showing outer engine nacelle (left) with propellers at front and Viper turbojet exhaust at rear. Compare with inner nacelle.]]

The Phase 3 update introduced two [[Armstrong Siddeley Viper]] turbojet engines at the rear of the outboard engine nacelles to be used for assisted takeoff. The wing main spars had to be strengthened due to the additional engines. A new navigation system was also fitted and there were some modification to the internal arrangement, including a shorter crew rest area to give more room for the tactical positions.<ref name="aero75" /><ref name="jeff 103">Jefford et al. 2005, p. 103.</ref>