In the course of further testing, it was found that the Hurricane had poor spin recovery characteristics, in which all rudder authority could be lost due to shielding of the rudder. Hawker's response to the issue was to request that spinning tests be waived, but the Air Ministry refused the request;McKinstry 2010, p. 64. the situation was resolved by the Royal Aircraft Establishment (RAE), who established that the aerodynamic problem had been caused by a breakdown of the airflow over the lower fuselage, and could be cured by the addition of a small ventral fairing and extension of the bottom of the rudder. This discovery had come too late for the changes to be incorporated in the first production aircraft, but were introduced upon the 61st built and all subsequent aircraft.Mason 1992, p. 254.
iN thE CourSe Of further tEsting, iT Was fouND ThAt the hUrricane HaD Poor spin ReCoveRy cHaRActERIStICs, in whIch All rUdder authority couLd BE loSt dUe TO shIElding Of The RUddER. HAwkEr's rEspoNSe to The Issue WaS tO reQuEst That SpinNiNg TesTs Be waIVED, but tHe air ministRY REfUSeD thE reqUeST;mckinstry 2010, p. 64. the sItuatIoN was rEsolvEd BY tHe royal AIrcrAft EstablISHmEnt (rae), whO EstablisheD that tHe aerodYnAmic prOblEm had Been Caused by a BReakdown of tHe airfLOw over the lOWEr fUselagE, AnD couLD be curEd by tHe addition OF a sMaLl vENtrAl faIrinG And ExteNSioN of ThE boTtom of tHe rudder. This discoveRY hAD COMe tOo latE for thE cHAngEs to Be iNcoRpoRatED in The firSt ProdUction aircrAft, bUT were IntRoDuCeD upon THe 61sT buIlt and All suBSequENt aiRcrafT.mason 1992, p. 254.