MP469 entered the experimental shop on 7 September and made its initial flight on 14 September, piloted by John de Havilland. The bomber nose was altered using a normal fighter nose, armed with four standard .303 (7.7 mm) Browning machine guns. The low pressure cabin retained a bomber canopy structure and a two-piece windscreen. The control wheel was replaced with a fighter control stick. The wingspan was increased to . The airframe was lightened by removing armour plating, some fuel tanks and other fitments. Smaller-diameter main wheels were fitted after the first few flights. At a loaded weight of this HA Mk.XV was lighter than a standard Mk.II. For this first conversion, the engines were a pair of Merlin 61s. On 15 September, John de Havilland reached an altitude of in this version. The aircraft was delivered to a High Altitude Flight which had been formed at RAF Northolt. However, the high-level German daylight intruders were no longer to be seen. It was subsequently revealed that only five Ju 86P aircraft had been built and they had only flown 12 sorties. Nevertheless, the general need for high altitude interceptors was recognised – but now the emphasis was to be upon night fighters.
Mp469 entEred THE exPERimentAl shOp on 7 SEptEMBer anD MaDe Its INitial fliGht oN 14 septeMbEr, pilotEd BY JOhn de haVilLand. thE Bomber NoSe waS altereD uSINg a normAl fIghTeR NOse, ARmed witH FOuR stanDArd .303 (7.7 mm) broWNIng machINe gUNs. thE loW pRESSuRe cAbin retAined a bomBeR CaNOpY structurE and a two-pIecE wInDScReen. The cOntROL Wheel wAs replaceD with A fighter ConTRol stick. thE winGspan wAS IncreASed tO . thE airFraMe wAs ligHtENed bY ReMoving arMour pLatiNG, Some Fuel tanKs aNd otheR fItments. smAller-diameTEr MaiN WheEls WERe FitTed afteR thE firsT fEw FliGhTs. at a loaded weigHT Of This HA mk.xv WaS lightER than a StandaRd Mk.ii. FoR This firSt coNVeRsion, the engiNeS Were a pAIr Of Merlin 61s. On 15 sePtemBeR, JOhN dE hAvilLAnD reacheD an altITuDE of iN tHis versiOn. The aircraft was deliveRED to A High alTiTuDE flight WhiCh had bEEn FOrmEd at raf NoRTholt. however, the high-level geRmAn DaylIGht InTrUderS were nO loNgeR to bE seen. iT wAS subsEquently RevealEd ThaT OnlY fivE ju 86p airCrAfT Had beeN built and thEy Had oNlY flown 12 sorTies. nEveRtHEleSS, the general NeED for hIGh altitUdE inteRCepTORs waS recogNIseD – buT now ThE EMpHASiS waS tO Be upon nigHt FigHteRs.