▁are ▁alter ed ▁according ▁to ▁the ▁stage ▁of ▁flight , ▁or ▁desired ▁characteristics . ▁One ▁methods ▁of ▁ach ieving ▁this ▁was ▁with ▁a ▁teles cop ic ▁wing , ▁where ▁wing ▁sections ▁of ▁bigger ▁aer of o il ▁section ▁and ▁area ▁are ▁teles cop ed ▁out ▁over ▁the ▁original ▁wing . ▁He ▁designed ▁the ▁R K ▁to ▁use ▁a ▁teles cop ic ▁wing ▁ ▁with ▁six ▁sections , ▁of ▁gradually ▁increasing ▁size , ▁extending ▁out wards ▁from ▁the ▁fus el age ▁to ▁the ▁dem ands ▁of ▁the ▁pilot . ▁ ▁The ▁air frame ▁of ▁the ▁R K ▁was ▁a ▁simple ▁structure ▁of ▁steel ▁t ube ▁fus el age ▁and ▁a ▁wire ▁b rac ed ▁mon op lane ▁wing ▁of ▁constant ▁M - 6 ▁section ▁constructed ▁of ▁wood . ▁The ▁extending ▁wing ▁sections ▁were ▁each ▁ 4 6 0   mm ▁wide ▁and ▁were ▁extended ▁by ▁the ▁observer ▁in ▁the ▁rear ▁co ck pit ▁operating ▁a ▁hand - c rank ▁connected ▁to ▁c ables ▁via ▁a ▁pul ley ▁system ▁to ▁pull ▁each ▁section ▁out ▁in ▁turn , ▁with ▁each ▁section ▁pulling ▁the ▁next ▁behind ▁it . ▁Success ful ▁flight ▁tests ▁starting ▁in ▁ 1 9 3 7 ▁led ▁to ▁author isation ▁for ▁a ▁f ighter ▁with ▁teles cop ic ▁wings ▁to ▁be ▁designed ▁and ▁built ; ▁The ▁R K - I ▁( R az d v iz h no ye ▁K ry lo ▁- ▁Ist re bit el ▁– ▁extending ▁wing ▁f ighter ). ▁ ▁Spec ifications ▁( R K ) ▁ ▁See ▁also ▁