Document
N S0 23511
I n s upport o f a sta ll / sp i n c o G e ar oh p r o gr a m a t the N ati o n al & e r on a uti o s and Sp a c e A _i n is_ =a tion (NA _ A) , L a ngley R esear Oh Cen t e r (L d C) , an e m e r gency i n- f l i gh t egr es s s y st_ iS be ing i ns t alle d i n a lig h t gene ;al a vi a t ion ai r- plane. The a i r plan e has no p rov _ sio n f o r egr ess on t h e le ft s i de. A left-si de egr e s s o pe n i ng wo u l d g r ea t ly enhanc _ t he p il o t ' S a _ il lt y fo r ba i lou t , pa _tl o u - lar l y in a ri gh _ sp i n. To avo i d a m ajo r s tr u ctur al r edesi g n £ or a mec han l oal d o o r, an a dd-on 11 .2-kg (24.6-Ib) p yco te0hnlo-ac tu ated syst em was developed tO c r e a t e an Opening i n the existing st r u c t ur e_ Th e skin o f t he a irp lane will be e _p lo sl vel y_e ve r ed ar o u nd t he side window, acr oss a cen t r al stringer, an d d o wn .... _ o t he f lo o_ , crea ti n g an opening of approx im a t el y 76 by 76 cn (30 b y 30 i n.).
The ' Sev e c ¢_ p an elw i lt be Jet tiso ned a t an in ltl al vel o Cit y o f ap p r o xi ma tel y 1 3.7 a g s ec (45 _t / s e c ). Syst em d evelopment i n O l u ded a t o t a l o f 68 explosive s eve r ance t e st s on alu m i num m at eri al usi n g sm a l l s am p le s , sm a l l and f ull - s c al e fla t -panel a ir cra f t s tru c tu ra l mo ck- u p s , and an ac t ual a i r cr a f t f u selage.
These tests proved explo s ive s iz i ng / s everan ce m a r g i ns, explosive initiation, i explOs i ve pr odu ct co nt ain m en t , and s ys t em d _ lamlo s . This t e c hn o lo gy is appl ic able t O anl U_ LE _ _a _ of silll a r _ o _ s t_ c ti on.
INTRO DUCTI O N Ai r pl a ne s , up o n s t a ll ln g , ma y beg i n a r o tating , si nkin g m o ti o n c al led a s pin. S t a 1 1 / spl n is a prime c a us al fa ctor in fatal g ene r al aviati o n a c c i de n t , .
Sev er al l ight airplanes a r e be in g spin t e sted at NASA-La R C i n an e ff o rt t o impr o ve t he stall / spln cha r a ct e r is t i cs o f thi s c la ss of airplanes. The S e a ir - p lane s a r e equippe d with t ail-moun t ed spin r ec o v ery para c hute S y st e ms in th e ev e nt t ha t the s p i nnin g cann o t be stopp e d b y t h e n o r m al airplane Co nt r ol s . I f b ot h t he ai r plane c o n t r o l s and t h e r ec o ve ry pa r a c h ut e f all to stop t he s pin, t h e pilot w ou l d have to a b and o n t h e airplane. O n e a ir plane c u rr entl y be i n g r e adi e d fo e sp in t est in g h a s a s in g le d oo r On the right s ide with n o o pti o n for egress on th e left sid e . B ai lo _ t w o u ld r eq u i re the pi lo t t o m o v e ac ro s s the ai r c r a f t t o ope n the ex i st in 0 d oo r, possi bl y a g ain s t centrifugal lo a ds ; this t s d i ff i c u l t t a s k a t best. A l e f t -si d e e gr e s s Opening would mi ni m ize th e pi l o t' s bailo u t e f f ort and ti me.
A py r o t echni c -ac tu a te d eg_ e _s opening wa s d_ velo pe d b ecause it p _ oved to _= be m ore advan t a g eo u s t ha n s mechanical s y stem on the bas is of str u ct u ral m od- i f i ca ti on , p _ rf o rm an ce , and t he po t en ti al f o r s uoc e _ s. A m e c h a n ic_ l system :: would re qu i r e con s id e r able str u c tu r al mod if ic a ti on and reana ly si s t o incorpo- r a t e a d oo _ and r e l ea s e me chan i_s . A p y_ o t echn i c ap pr oa c h would be an add- o n syst e m , ba s ed on p _ ev i o u_ experi e n ce g a i n e d i n t h e P- _11 a s d B- _ esca pe m o du le s .
i - _ 73 : T h _ p yr ot e o h n La 8 y_t o m d_ v e l o p e d in t h i _ e f _ o r_ u_ o _ _ _m all - qu _n t & t y, _ n lly o o n t_ £ _d , e xplo _w - _h_pe d Oh _ ge to _e ve _ _n d Je t _ l _Q n a l e _ C- _ d e p an e l _r o m _ he a t rpl e n e. Th e _ yee o m ie i n i_i ute d m e O hani e ell y by a bo ll c_a nk pull e d by the pi lot. ¥_ o m Ch at p oi n t, the BySt e m f un ot i o n_ a utOmuCle al ly.
_ h e d e a i _ an d d e v _l ot _menC O a p _C al i eod on oxt _ .t ng p y r ot e chn ic t ec h n olo g y , u_ e ft _ l Q , a nd c_ po n e nee , _ ,d em ph as ized p_ vL ng a ll a_ po o te o_ f un oti _ n _ l per e o r man ee . T h is proo f o £ pe r f or m an ce was a o, _ o m pli _hed a n a l yt i c a ll y en d _ u n O t ionally t O s ho w m ar g i ns of c e_ bl l i ty gre at e r _ . _an t l _ for es , _tre n gth, o c e n e r g y =_ q u i r o d , T hi s pap er d escr ib es the d e S . i gn , d e v e L o_e n t , a nd fun c t io n al test i ng o f th e py r o te chnic-act u a te d _er_e noy i n- f l ig h t e g re ss opening fo_ a _ k S_ -La _tC g ener al a vi ati on r e S ear C h a i r p lane.
This s e cti on describes t he eli - t he-sh e l f co m pone n t s.that were qua l ified under p r e v ious ae r o s pace p r ograms and t he test fixtures used in this p rogr am .
Fle x i b l e Li n ea r- Shaped Charg e (FLSC) F_ gC has been widely appl i e d by t he a er o s pace commun it y i n su c h applica- ti ons as r ocke t veh lc le S_ ag i n g a n _ a irc ra ft e sc ape s ystems . Fi g u r e _ shows a t ra n s ve r se cros s s e c t io n o f FLSCo The ma te c i a ls us ed i n this app l l c at i_ n a r e he x an ltros tilben e II (oE _ anic-preclpi t a ted HNS I _ ) e x p l o sive (3. _ 9 g / m (35 g r ain s / it)) in a silver sheath. This e xp l o siv e c an o nly be initi a ted b y a high explo si ve input ( grea t e r than 5.5 x 1 09 N / m2 (80 0 000 p al ))7 it cann o t b e init i ate d b y g u nfi r e , l ig htnin g , e l e c tromag n etl c - ln d u ced radi a ti o n , or p h ys - i c al hand l ing. I t wi ll bu rn in a fire , b _ t c annot a c hieve its cu t ting fu nc- ti o n. O n initiati o n , t he _ at e z ia l detonat e s a t a li n e a r velocity o f 7250 _ / s e c (23 80 _ it / se t ), generating 2.0 x 1010 N / m 2 (3 x 1 06 p si ). The expanding gas e s and s h e a t h mate ri al s a re fo cu sed in t he chevr o n to eff e ct a m e tal penetra ti on and d ef o m a ti o n / b re akin g acti o n .
• FLSC Bo os te r Tips T o a ssure tellabl e i n iti a tion o g t h e F L _ C and t o s ea l the e xp ose d e xplo- siv e a t the ends of _h e si x l e ng t h _ of FLSC , b ooste_ ti p s we r e installed. Thes e tips a re cups (4.83 _ (0.190 in.) i .d., 8.89 _ (0. 3 5 i n.) hei g h t ) st a m ped from 0 . 1 5- _ ( 0 . 00 6-1n.) 302 stainles s steel (con d it io n A) a n d lo a de d wi t h he x anltr o stil b ene I (HNS i) at 2.20 x 1 08 N / _ 2 (32 00 0 p si } to a height of 3 . 8 _ _ (0 .]_ 0 i h.). The cups w er e p o t ted o n t h e e n d 3 o f t h e _ LSC with a , o n- so lven t str u c tu r a l a dh es iv e (Sc oto h-W eld B r an d St r u c tu ral A d h es iv e 22 _ 6 B / k_ ).
1p_ od uct o f 3 M company.
17 4 _any a _A ot U_d D etO n_ o _ _h o dot a na_ o r u s e d _: e initiat e the F_ ¢ t a a h O. n i n _ig_ o 2. A 1 . 2 7 - _ (0. _ - in .) a t _ O _ O Comp r e s s e s t h e _I no a r _ ing to 09 X (20 ib_ ) t o _ t a tanoo at rele as e o _ t he a o _ . Th e r i c ing p in a aa o _ l y i a _l vo n _ n _ o th e po _ o _ o a _ on p_lm o _ to i n i t iat e t he _ o a _ a _l do / _ 8 Z ox p i o_i vo m a t e ri a l s I n t he OU tp , t o , _ .
_ he loa _ _zid o pr ov i de s _ n i n t e r face to d evelo p _ ho i n itiati on _ ia _ o _ o de c on n _i on wit h i n a 2 .54 - _ (0.1-in.) co l . m n t o pr o p e rly i niCi u t o th e _ ¢, ! wh i oh in t u r n i n i t i at e s an _ u sc b oo a t e _ t ip.
_ani fo ld_ TO p r o perl y l o _ate_ s e ou _: e, a n d p_ o t e o t th e F L _ C boo ate_ tips , fo _ t 6061- T S alum i nu _ m ani f old s _ e a tt a c hed t o t he skin and ai r c r a ft .t r u c tur e s , on e above a nd below _ he C e n tra l s tr ing e_ a t th e f o rw a r d a nd af t ex t r emi.ties o f the egre ss, a_ ea. The af t man if old s con t a i n e d a clos e - t ol er anc e g r oov e t o s e cur e t h e r i v e. H o w ev er, t he fo r w a r d m an if o l d s c o nt a i n e d not on ly a g roo v e l : b ut also a t h r e aded po rt t o re O ei ve t he l an y a r d-aC tu a te d detona t o r s a t t he co r r e ct r ela ti ve po s i ti on t o the tips ( _i ni m um gaps of 0.50 rm (0.020 i n.)) to a ss u r e r el i ab l e e x plos i v e i n iti a t io n .
Intern al Con tai nmen t D e v e l o p me n t Fi x tu r e T o d e vel o p t he i nt er nal s t r uctu re re q u i t e d t o c ont ain the expl o siv e b la s t I' : O f t h e FLSC , a t ea t f i x tu re was d ev elo p ed t ha t w ou ld demon s t r a te per f or m ance margi ns. The fixt u re was an e x act mo c k -u p of a t y p i c al a i r c ra f t S t r u C tu r e , b _t t o d e monstrate a co ntain m e nt m a rgi n _ the e xpl o s i ve l o ad was i nc r e ase d t o I_ 0 pe rc ent o f th e requi re d am o un t an d th e mo c k -u p o f th e air cr af t skin t h ic k- n e ss wa s increas e d to p re ven t any se v e r an c e an d venting of t he exp l os ive pres- sure. Further, the internal fre e v o lu m e within the c ont a i nme n t s t r u c t ure , a s i : w e ll as t he cle a r an ces Of t h e FLSC t o t he St rO ct Or e , were r ed u ced t o the mi n i - !_ mums e_ o t e d i n t he a ir craf t .
S m a l l - Panel Teat Fixt u re W ood - fr a m e d panel s , m eaaurlng 45,7 b y 45.7 c _ ( _ 8 by _ 8 in . ) were u s e d aS moc k- u p s o f a lrc r af t - r e pr e s en t a t ive s t r uct ur e s fo_ e xplo s ive s e v e r an c e tests.
. The mock-up akin wa s attached to t he f r ame , a n d t h e r ep r e s e nt at i v e full-Scale st r uc tu r a l ele m en t s, W i t h e x p l osive c om pon e nts , w _r e mo u n t e d t o t h e ski n.
s tr uctu r e s We ro m o c k e d-up i n w ood- fr ame d , f lat-panels t o e v alua t e the e g r e s s if : Full-sOale_ flat-panel test fixtu re s . - Two fu l l - s_ al e , l lg h t -al rp lane sys t em p e r f o r m an c e . All m a t e t lals (Al cl a d 2 0 24-T4 ) , mat er ial t h ick nesse s ( i. 02 _ (0.04 i n.}), a n d str u c t ur al layo u t s , i ncl u d i n g a 3.]75- _ (0 .] 25- in. ) t hi ck p l e xi g l ass wln d ow _ w e r e mo c ked - up . A 3 . 8-c _ ( _. 5-in.) sq u a r e- m esh s taln- l e ss w _re (0.5 n _ ( 0.020 in.) t hick) was use d on t h e secon d t e st t o p re v e nt th e p i e x i_ las s fr_ moving in t ernally . A c ow, p l a te a ss e m bl y, e xc 0t go t t he initia- tion sys tem , w a s t e sted .
O, _ : ov iding m _x i mumo V _ om ..4 : o _ . _ a bl_ i t_ ) he p y r o te ch nic m_ o r i a l B _ n d t_ o h niq u e o uoe d i n _ hi o eg_ oo o oy ot_ wor e _ oloO tod on t h e I m_ Lo o £ _e v i o u o aocoop _ e e d o _l_ e _ pec i o n oo _nd p _ ovto _ oly q_a li E ie d _ pon ent , e n d e y_t_ .
lni tia_i on- _ y e_a Dev e lo _nt _ h e ini t ia ti on su b s y sta wa s d e si gn ed an d d _ v e lo pe d w i t h s a fe ty con si d _ a- ti on _ pa ra mo u n t. _ he _ eloO tl O n _ d de v e lOp _en_ o5 t he i n iti a tio n _ y st e m we r e based on t h e f olZow.tng oh _ra e teristi e _ l .. Inde p e nd e n t syst em, i s o l a te d f r om onboa _ ys te ms 2. Hanagea b l e _ c t ua ti o n £ c c e e !
_ 3. Ful l y s e c u re in fl i gh t 4. Add iti ona _ S afe t¥1 n g _e a S u res o n t he g r ound S. P o s i t iVe _ e t ops" to a _ u _e t ha t t he ac t u ati on is co m p lete _ . &c e es s i bi lit y and re l i a bil i t y The c om ple t e i ni tiati on e_ sy st em aO t ua t o r (no de t on at or s ) w a s ao u n ted on a _ la t - p la t e b r eadboa r d _ o e val u a t e t h e a ct ua ti on fo r ce s re q uir ed t o over c om e i n t e r nal St a ti c a nd k i ne tic fr leti On . The 8g-N (20-lb f ) _ ax i mum. resisti v e f o rc e o f t h e l a i_ ¥ ar d-a ctuate d de t ona t o r w a s a p plied t o t he c a b l e , and t h e pul l f o _ e es necessary t o overc o me f_i e ti on were me asu re d.
Exp l osi ve Se v er anc e end Con t a i n m en t O e vel oime n t _ he de velopm e n t of t he expl o s i v e se ve r anc e te chn o lo g y p r o _e s _ sd t h ro ugh s e v e ra l , p h ases t 1 . S i z _ t he f l e xibl e li n ear- s h ape d cha _ge a nd d et_ m ine se v e r a n ce pe r fo r - m a n ce m a r g in s u n de r worst -ea s e cond iti ons (a double t h i ck n e ss O f alu _l n _ a n d i nc r ea si ng t h e t h i ckn ess be y ond t he exp ec te d i iml ts ). AlS o, de t e rNi ne t h e c ut - tl_g p e _ foma n Oe o 5 t h e FLSC a n d boos t e _ -Ou p comb i na ti o n i n si d e t h e man if o l d s .
Past e x pe _len e eIn d i Oa te d t ha t an y fore i gn materi al such a a p otti ng i n t h e
1 77
c h e v ron a r e a _ f th e 9 _ C d estr o y s th e c .¢LL n_ e fE tQi a n ay . T es t a wer e _ ru _a t e d O N 4 o n h l e - _ h lQ kn e ee pZ _ e a ( 1 .0 1_ n _ 1 ,0 1 6 _ (O.04Q on O,d4 0 i n,)), &_a_ n _ _al_ L _ n0 1 _ o _ _l X tu_ o _ _ o _ o u_ o _ t o _ o m on nt_a_ o t he l oO al_r o a _or g o _man oo.
4. _ ovo l o pa _ o t h o _ o f c o n tai nt n ¢ t ho oxp l o _ ivop _ o duo t o ia o id o _h o e uoo _ l a go, a aou _ in9 a po r_ o man oo ma_g i n . _y usi ng t h o i nt e r nal c o n ta i nm e nt d ovol= o_ o n_ f ix c ar o dooc _ i _d i n _h o A pp ae atu_ ooo t ton , oon t ai _ o nt t, o _t_ wo e o con d uo t o d un d o _ w o _at ®o a a ocon dit iono o f, a . 1 S O po _ oo nt o _ t he r oq uir od ex p losive l o ad was u s e d , 3.19 g / m (15 g rain o / f t ) RDX (oy Olo t¢Im o t h y leno tri n lt r _i n o ) i n ,t o a d o f 2.13 g / m (10 g _ atn _ / _t ) _' b. No e xpl o _i ve p r ess ur e ven tin g c. _inl_um v o l u me s d. F_ l li n g t h e v o l u m e w it h C losed -ce ll , flex i bl e f oa m .( uaed t o prec l ude c on t a mi na ti on o £ t h e c on t a i_ en t v o lum e ) e . P_ ox tm i t y of the ? _ C t O t h _ aircra f t a nd c o n tai_ n t str u Ct u r_ P ul l- S c al e , Pla t -Pa nel T eSts _ To d e v el o p a n u n d _rSt ahd in g o f sy s tem- l e v e l perf o rm a nce , t e s t s we re c on - _ : du cte d on the fu ll-Sc a l e, fl a t- p an e l t est m o c k-up _ d esc r i bed i n the Ap p a r atus _ " se c ti o n . P e r f o rm ance par am e te r s t o b e e v aluated were c omplete se v e r an ce , nea t n ess / u ni fo rm it y of Se v ered e d g es, effect on a i r cr a ft s tr uctu re d u r i ng ½ se ve r an c e, c a p abil ity o £ t h e c on t a i nmen t st ru ct u r e (pa rtic ul ar l y a t t h e _ strin g er ) t o st op e x p los iv e produc t s i n t e rn all y , Je tti son ve lo citi e s and dyna mic s o f t he seve r ed p a n el , a n d c a pa b i l ity 0 £ th e window m esh t o prevent _. i n t e r nal e ntr y of th e ple xlg l a_s W i nd o w f r a gm e n ts on pane l J e ttis on .
i : Ai rCr a f t P u sela ge _ o c k- up T e s t ., m ock- u p te s t wa s c on ducte d. This t es t in clud e d a ctuat i ng t he m e c ha nica l Ini - _ ' ! T o de m o n s tr at e t he fi n al sys te m d e s i gn , a ful l-sc al_ . ai c cr a f t f u se l age t a ln m eh t sys t em (par tic ularl y a t t he s t ringe rs ) Wit h c losed- ce ll f o am t o pr e - vent vol u m e o o n t a m lna tio n , and t he 3.8 - ¢ m (1.5-in.) p E o te c tlve w i re m e s h o n t h e _i' tl a tlon s u b system wi th b ot h d e to n a t o r s i nst alle d , t h e £ 1 nal design of t h e co n- • i ns i de o f t h e W i ndow t o p r e ve nt t he plex lg la ss fro m m o vi ng i n t ernally. In t e r- t h e e n ti re egres s area.
I! na l explos ive d e b ris and p re ss ure were mo n itor ed w it h a p l ex lg l a ss p an el a c r o ss _ ' 178 The mech ani c al _ y _to m _ pp _ o _ o h wo u1_ r oq _r O _ 1_r_ o _tru o _ur a _ m _i_ tO _ - _ on and do _ pn o_ o _ _ o _n oo _ po ra_o a d ooc _ r _m O an d d_r . Thi o wou_ b e _ o _lo wo _- by o _ 01 o_o o _ ¥ o _ o m, _uo h _o p u_l t n 9 h _ no o p _no _n_ a o _u_ n _ _ h o l _ o ho_ , w h i c h co u l d _ oq u l _ o oo n o t do _ a _ l _ pllo _ e g b e rt an d _l_ e . The r oloao o_ _oo_ m ay t hen r o _ro { _o o o e dln O _ o _ l l_ h _ oO n _l_l o n o) m a nu_ l _nd _ O r o _yn o _lo ]o_tlo on. _ l n_ ll y , • o o n_l dO r_ b _ ,o o_ o r_ m_ y be _o_ ui rod t o voll d _o t h e otr u o_ura l dool O n of _ h o m od i fi e d atr o r_£t under _ho h fo h - o_r oO _ , o 9 1n -p u ll ou_ cond i _ on _ .
T ho py _ o t o o hn l o _ y _tom ap_roaoh _ o Uld u _ o a _ lox i b l . e l i_o_ -oh apo d cha rge ( _ LSC) t o savo r t h e exis t in g akin a nd S tru c ture , _ oZlowi ng p rove n p r i n e i plo _ , appli _ lon _ , an d m_ to ria l _ . A minimal atc e c a E tm od i fiea _ion co uld expected, t h at l_, atta ch i ng tho OXploo ivo _ nd c o n t a i n m e nt to t he e xi stin g ot e uO tu r e . A p Lr o _e o hn i e sy o t_ n w ould r e .ire lt tt Z _ e f f o rt t o i n iti a t e a nd, a_ a Ocx _p lO tel¥ i n dependent On O_ g _ BOU r C e, wo u ld pr OduO0 a h ig hl y r o _ h _i v e _ eV e c a nOo a nd _ e tt i son ing ca pa b ility , S i n c e t he ex pe c ted o truot u ra l c ho ng e _ w o uld b e mi nJ. _al , no now l oad pa_ h _ o r str u c tural a n alyti c W o u l d b e e xp _ o t o _ o: nec ess a ry . Base d on t h es_ eono i de _ a ti ono , _ hO p y r o te chn i c 8y o t e _ wa_ _o le ote d £or d_ v e lop me n t .
Mater ia ls S e l e otlon / S yB_ o _ Qua l iE i cat l o n The _ lexibl e l i nea _ - s h a p _ d o ha _ g e (FLSC) ha s been _pp l i ed t o several a er o - s pa ce s y e t em s_ includ i n g t hO _ -11 1 ( r e _ . 1) and t he B-1 al r c r a £t, i n w h i ch t he co c kp i t i_ se v e r e d E r om t h e £ use lag e . T he _ LSC ma te r talP _ o= g an i c-p r ectp _t at ed h e xani t roetl l bene (l _ IS IX) i n a s i lve r sheath, wer e deve l op e d s pecifically _ or t he rm al a n d ag e st a b il i ty (ref. 2 )) a p p li ca tl oh s i n cl ud e the F-1 4 , F-16 , and AH- _G (Cobra) a lror a £t. T he bo os t er tip m a teri al s , I_S I i_ a s t ee l c up , a re applied al _ o st unive r sally to a lr o r a£t _ xplo si v e tr ansfe r s ystems . Th _ lanya r d-actuat e d detoha t o r wa s qualified for the F-14, F-15, an d the Space S hu t tle Orbl t e _ . Th e capabil i t y o £ th e _ LSC to withstand severe envi r onm e n t s is d e mong tr a _ed b y its _ any ap p l i cations. Th e E u n otl onal q ualif i ca t io n wa s ba a ed on o _ ponen t and u y s t em develo _ en t , e _ pha s iztn g p erf o r m an c e m a r g ins de s cribed i n s ubs e quent se m itonE, Inlti a ti on-S y s t e m D e ve l op _e H t Th e in l ti a_ i o n 8 yst e _ d e v e l c pe d r n th l s effort I s shown i n f i gur e 4 . & 40° rotational str oke o£ the handle a ss e m bly (9.9 c m ( 3 .9 i n,)) p r oduc e s 4.95 c_ (1.95 in,) p ul] ey _ ota t lon and cab le w ith drawa ls . The ca bl e s t h r e ad th r ough gu i de tubes to p r ov l do 90° r e d i r ected pul l s on th e l an y a _ d _ oE t h e d _t ona t o rs . Si flce a 1.27- _ (0.5-. I n.) _ t r oke _ requi r ed _ o act u a te the deto n a t o r , a ma rg i n of a t le a s t 3 t o I ex ists. E ach cab l e is fitt ed wi th a , 179 (0.06 _ - in, ) ch i ck aQ I,d -; oll ed s t ee l Co verp i ate ( 3 .6 1 c_ ( 1 .5 0 in .) W i de0 aa cequ i ced _ __ _e pa ra t a d f_ o _ the s k in by a 3.t5-m ( 0.1 2 S-in.) _ LU mi nu m_p lat e s t a n dof f . T he _n C- do wn por t i on cl _e_ th e c a v i ty and _mc_ a Ctmth e au _fa oe, reduu i n9 ae _ O d y n_mi o d c _ . T h e O _ v l W be tw ee n t_ ote e_ a nd t h e Skl_ was n e o e s_r ¥ , t o a a _e _ e _te do CleO ti o n of a d oUbl e - tht o kn ea _ ak i n to a llo w .
r e l ia b le sov er ano eL _ r _ ot u r e . _ _ .60- . n (0.0 6 3-1n.) O- _ ViCy allOwe d only pa c t_a l e evocan ae . The fina l des ig n of t h e ox t e c r m l cont a i n ment is shown In fig u _ 7 o n _h e a _r o ra_t f um e lage m oo _ -up of th e e g _ o s_ Sy stem .
To r eli ab ly Seve r t h e Oe nt ca l str in g er , two len gths o f explo si ve were _ eed. On e l e n g t h was lai d a long th e ski n , t h ro u g h a hole in the s tr i n g e r (i ns i d e th e ben _._ adi us o f the chan n el), and ac r oss t he l e g o f t he ch a nn el _ t he o t he r leng t h w a s l ai d a roun d t he strin ge r and m a _ ohed i nto oO _ n boos t er t ip s a _ e a c h en d . This a rrange me n t I n t rodu c ed tw_ proble m st de t e rml n l n g t he r elia b il it y of severin g _he do u ble- t hi o k n S s sma t erial ( st r i nge r and skin) with t he la r ge r st ando f f t o avoid the st rin g er radium, and de t er mi ning how to m anage the s _ ruc _r al damage and d efo r m iti es o _S ed by t he doubled q um nt i ty o f explo- sive. S eve ral t ea t s w ith lar_ er s t a n do ff s t ha n req ui r e d i nd i c at ed suffici en t ene rg y e xi s t e d to sev e r and te ar the m a teri a l wit h an adeq u a t e m ar _ in, The do _ bl e d q _ an t Lty o f explos i ve requ i red doub l i n g t he st ruct ur al attach m ent bol ts (2.54-c m (_ .0- 1 n.) c ente _ ) an d usi n g steel l_t e rn al oo nt a i n _ en t structure on t he s evered panel.
The £ nt e r na _ con t ainmen t s truc t u re t o p rot e ct the p il o t fc o _ explo siv e p ; od _ c t s is sh o wn in fi g ur e 8. The cc o s a- _ al lines_indic at e the l oc a - tions of sub S eq _ en _ s t ru et u r a l v i ews.
The p_I nC l p l es o f th e i _t erna l exp l os i ve c o n t a inm en t ac e s h o wn i n f i gu r e 9 ( s e cti on A-A). The skin i s severed b y th e expl o sive , c ausin g the stru c t u r e t o t he rig h t t o _ e Jet ti s o n e d fow nwa r dwi t h the panel. The explosive p ro d _c ts a r e co ntained wi t hin the free vo l um e f o r m ed b y the St r in g e r, t he an g le t o the _ i g h t , a nd the c o ve r c hannel. &c o ve r chann e l is _sed to prevent a-l e ft r o tati o n o f t he c o ve r pl _t e and str in g e r d ue tO t he explo si ve p _ess u r e. The t w o c o ver pl at e s ab o v e t he cha nn el Stiffen th e chann e l and cover t h e gaps a t t he cov e r- c h a nnel i n t er f a c e s . The r einfo rc em e n t angle prevents s hear i ng damage from the close p ro xi m i t y o f the explosive. The c l o sed- cel l f o a _ (95-p er cent al e ) p r e- ven t s _ on _ a m i n a t io n o f t he f E e _ v _ i m ae. Z f thls v ol_ n _ awere f i ll e d with w a t er (no f oam), con sid era b le d e fo rm a t ion o f _ he co ntainment s tr uc t ur e c ou l d occur, pos si b ly cauml n _ pilot i nj ur y.
T he sam e app ro ach a s desc ri bed abov e is shown in fi g u r e _ 0 (section B- B ), exce p t a co v er angle a _t a c hed t o th e ai r c r a ft r i bs i s used t o p re v ent r o t a ti on r a t he _ t han a channel. Th e co ve r angle is cu rved to m a tc h t he a ircr a ft cO _ - t o u_ The S eve re d / _ e tti eon e d po rt ion o f th e s tr uc ture i s b e low t he s t rin_ e r .
F ig u re _ (s e ct ion C-C ) and f i gure $ show the c _ mpl ic a te d welded s tai nless - Steel con t a inme nt s tr uc ture use d at t he f_r wa r d an d af t s e cti on s o f t he c entr a l stri ng e r. T he str_ot u _e a tt a c hes t o t he f r ame s a b ove and below t he stri nge r .
In orde r t o m ain t ain a n i n ter nal fr e e vol Um e t o d is s ip a t e t h e ex plo si v e e n e r g y o f t h e f l exi bl e li n ea r - s haped c ha rge a r o u nd t h e stri n g e r , t he s tructu r e had t o i projec t i n b o a rd i nt o the cockpi t . ALSO , this s t r uctu re had to aooo _ oda te the po st -aSse _ bly i n s t alla ti on o f t h e d et ona t o rs and i ni ti ati on - c ab le g uide tu bes.
_ 8 _ _n _ p pr o _ c h st m lla_ to _ oati O n I _ -g Is sh o wn i n _i B _e 1 2 ( se c t : _ on D -D) e xce pt , t . l _ t _h o aov e_ an g le i S _ . t .aa he d to t h e _r_e , F u r th erm o re , t h er e l e n o need £ o _ _ rel n f o e aenm n t an Bl e l the e xpl osiv e w a . nO _ m oun ted _galn st t be f_ ame .
F ull -Sea , e, Fl a t - P_ n al T e_ t 0 -- The gu ll- sc al e , f la t - panel t e sts c o nf i r med a nlm_ O £ s y stem p t lno ip tes a s w ell as d etec ting s_stem p r oble _ a re a s. Th e e x p lo si v e ly Severe d e dg es o f th e s ki n and _ettls on e d pa ne l were sm o ot h a _ u nifor m . The d y namias of t he I se v e r ed p an el s we r e u n iform and p r edic t a b l e . Th e panel wa s s m oo t hl y relea s e d i a n d pitched ho r iz on t a lly! t he b ase of the pa n e l sw u ng u p w a r d i n t he di r ecti o n of m o tio n. H o weve r , _ h e exter nal O On t ai n_e n t stru c t u re and skin de t ache d fr om _
t
the pa nel i n t he a r eas be n e ath t he d o ubled FLSC ar ou n d t h e c e nt r al s tr ln ge r , ] allowing e xpl o sive g a s e 6us prO d u C ts to ente r t he f us e la g e.
The g ases, c r e a te d on d e t onation o f t he e xp losive, s ha rp ly load t h e entire area wi thi n t h e i n t e r na l explos i ve c on t ain m en t , c a u s in g th e skin t o d eflect between t he b o l t at t achmen ts t o exhaust th e gas e S . The S e gas e s a r e h ig hl y visible a S flame a nd s m o ke. The fl a me i s a sec o ndary burn ing o f the u n _ eacted ca r b o n o n m ixin g wi th t he a z: . The flam e d u ration in bot h te s ts wa s appr o xi- ma t ely 2 1 me e o , an unlikely i g niti o n s ource o g e ve n t h e m os t r ea ct ive mate ri al s .
Th e m a n ifol d atta c h me nt s a nd the pleX ig la ss wind o w retenti o n wer e ina d e- q u a t e o n t he fi rs t test an d were c or r e ct e d on t h e s e C o nd test. The m an i fol d s (at tac he _ o n ly t h r oug h the Ski n) p u ll ed loos e; at t a chm ent s th ro u gh t he f ra m e .- ....
pr e v e nt ed d eta ohm e n _ . The Wind ow b r ok e u p du e t o pan e l / f r a me o ilo a nn i n g , t o s s in g sev e ral p iece s inbo ar d. A 3.8- b y 3.8-c m ( _ .5- by _ .5-in.) Wire mesh w a s st r etched a cro s s the wind ow and a t t a c h ed t o t he i nte r nal o o nt a lf _e nt struc- ture t o e li m in at e internal debris.
The J et ti so n c apab illtl e s dem o ns tr a t ed in the f l at- p ane l t ests (s m a ll and ful l s ca l e) are s _ - _ a r l zed in t a bl e llI. A l th oug h the syste m we i g h t i _ . _ e ased , t h e amo unt _ ofi.en e _._d e li # e r e d p e r u n it W ei g h t w a s consi s t ent.
A i rcraft M oCk- u p Test F i g u r e s _ 3 and _ 4 s how t h e n e a t , p _ edl ct abl e, s e ver e d _ d g es of the skin .................
and the f ram e a ro und t he o penin g c reat ed by th e int er nal Co n t ainment. N O inte r nal deb r is was detect e d by t h e witness pan e l Or hi g h- sp e ed c am e r a c o v er - a g e (4000 _ppS ). The int e rnal pr e ssures mea s u r e d w e re 3 4 . 5 k N / m_ (5 ps i) an d 17.7 k _ / mZ (2. 5 p al ) w it h a du ra t i o n O f less than _ .0 mac e. Th e s e p_ essu _ e l e vel s c om pa r e fav o rabl y with me as u reme n ts made on the B riti S h a i r cr a ft J e t P _ Ov o s t Mk .5, Wh iC h e mpl oy s a n e xp lo s l ve co r d -actua ted o v er h e ad- c an o py se v e r - anc e s y s te m . _ e a sur_me n t a a t t he ches t level of d_ ies ind ic ated p r e s su r es of _ 0. 3 t o _1 7 k N / _ 2 (7.3 tO _? p si) . H oweve r, p re ss u re l e vel s a t t he d _ u w y ears (in Si de th e h e lm et ) wer e appro xl matel y 26 . 2 k N / m 2 (3.8 ps i ).
The fl ame du ra ti on a nd je tti son v e lo city we re c o n si de r a bly i m pro v ed by t he r oo m tem pe r a t u r e-v u lcan l z l ng (RTV) c o mpound ap p l i c ati o n on t he ex ter na l co n t ai nme nt. Th e a ctu a l d ur ati o n of t h e f lam e Wa s l e ss than S m e et . Th e i mpr_ v e t ue n t o _ the con tai mnent: prevent _ed carbon p art i cl e a n d s ic mi x i ng and _ - _, be r i n g . F uc the mo | :e, th e :J e t:t: i eon ve l O a £ t y (t _ ab ] . e ZZI) J i n cre a _ ed 28 p e rc ent: d ue t o t:h e i m p s : eyed- s e a ling o f t he exp lo e _ J.Ve- ga a p_e e sur e wa ve. _ h e _ ev o r e d pane l w e igh ed 6 _ 62 k9 ( 1 4.6 ib) _ h d _ mm _ _ _ v e l ocit y _f I_ . 7 m / s e e (4s i t / s ee )..
: T h e s ev e r e d p a n el wa s c o mple t el y ln t: _ ct, e x cep t: foc the wi n d o W , fo l l o wJ . n g _ e te s t: (f i g s . 1 5 an d 16). Th e wlc e me s h pr eve n te d a n y w in d o w f r a gm en t: , fr om ente ring t h e fusela ge. T h e _ame cr ea t ed b y t h e e x tol' hal c on t a i n me nt w as s m o o t h and un i fom, a nd t h e s k i n w as se c ure ly atta ch e d i n al l a _eas .
CONCL U SI O NS A py ro tec hn ic -ac tuate d , i n-fl ig ht egr ess ope ning ha s been de v elo ped and q u a li f i ed _ c use in a l ig h t , g e ne ral av i a ti o n re s ea rc h a i rpla n e. Th i s s y s t em w ill a l l Ow th e pi l o t t o ba i l o u t f ro m t h e left side o f t he a i rpl a ne.
Th e e gres s s y st e m is s imp l e and hi g h l y r es pon si v e , r e qu i ring m in i mal a ir- plane m od i f icati on s Co i n corpo r a t e. A comp lete , f ull -sc a le a i r cr af t f u sel age ": m o ck - up d em o n stra t ed the ability of the s y s t_ to c_ ea t e an ope n in g o f ap p ro x - l_t e ly 76 b y 76 c _ (30 by 30 i n . ) , i n cl ud i ng t he w i ndo ws i n t h e c ab i n si d e.
The t o t a l sy st em we ig h t w as 11.17 kg (24.6 l b). Th e open i ng wa s cr ea t ed by Sm all-qua ntl t y exp los ive s ( flexi b le l l n e a _ - _ ha pe d C ha rge ) w h i ch se ver e d an d Jet tis On e d a 6 .62-kg (14.6-Ib) p ortio n of the f u se : l a gs skin an d str u c t u re a t a vel o ci t y o f 13 . 7 m / se _ (45 it / s e t ). Th e explosive produ c ts are c o ntained , -- pre sent i ng n o d e b ris o r sound / p r e ssu r e ha za r d t o th e pi l ot. F u rt he r m o re, the _ op e ning c r e at e d iS n e at and sm o ot h , p r es e n ti n g a m in ima l I nterf ere n ce p ot ent i a l t o t he pilo t o n e g r es s.
'_ Syst e m reliabil ity ha s b e e n dem on st r a te d b y previous ae ro s pa c e sy stem _ ' a pp l i c a t io ns and by fun c tional tests. Th e py r ote c hni c co m po nen ts and po k ier- i :. m an ce p rl n c ip _ -eshav e be e n qu a l i f i ed on a ir c raft s y st e m s su c h as the F - 1 1 1 a nd a-1 e s cape m od u le S. A l l f u ncti onal pa tt erer s have b e en tested f or this a p p l l - _, ca t ion tO de m o nstra te S u b_t an tl al per f or m ance mar g ins (a g rea t e r c a pa b i l it y !_ than re qui red to a c c o m p li s h t h e desir e d fun c tion) . The s ystem wi l l req u ir e n o -, mai nt e na nce , ex c ept go t a 5 - yea r rep lacem ent c y cle o n t h e det o n ato r.
i_ ' This egr e s s sys t e m tec hnolo g y i S appl i cabl e to a ny a i rc r a f t of si m i l ar _ :. _o fl S tru c tion .
i , _., _ 183 !
i
1 . 8 c M . me l , M. L., _ e F- I _ C _ew Ho dU l a, Ma_ o : Ch allen g e _ o _ ' _ h e_mall y s _ .able uxp losLveu. HODonnell _p ei: p_ sent:ed a_ . _ B y m_B L u m on ' l ' hemall ¥ S t able _p loo L ven o , t: _ _ val Or _ nco L e, bo a :a t O _ ¥ (Hh _ . t o O _ k, H a_ y _aL l d ) ,_ _ Tuno23-29, 1 9 70. (AvaJ, l ab :L Q - _ HDC70-01 9 . )* 2. a_ en l ;, _ , _uJ : ence 3 . _ Ai _ l:l , oat:ion 0 £ T_ . U pera t :u J : e-ResJ.s _ , n t: _xplosives t:o H h S k M l _ £ons. NkSA pa p e _ p[esen t e8 at: I:he SympOsJ. _ b n T hec _ lly S _ : _ ble ] _ x p ] . os£ve _ j_ t he HavaL O _ d n arme T , abo _ al: o_¥ (Whl _ e Oak, M a _y Ian8], 3 , u ne 23-25, 1970. •..................
_ e4 E x p lo s iv e o L _l ng / se V o r _n c e tes t s . . . ..... . ...... . . . . _ . . 23 Man i fold d _ v o lOpmen t ............................ . . 5 COn t a£nmen t . • • . -- _ ...................... . .............. 2 9 Full-scale moc k-up S = To t al t e st s pe c imens .............. .............. 6 e TABLE II.- E XPLOSIV E SEV E RANCE TESTS AND COMPARISON (a) _ xp los i v e s ev era n ce tests M a teri a l se v e r ed, w m ( i n. ) g xplos l ve _ / m (gra l ns / f t ) 1.016 on 1.016 1 .016 on 1.60 i 1.60 on 1.60 _ 0 _ 040 o n 0.040) (0. 0 40 o n 0.06 1 ) [ (0.063 o n 0.063) 1.48 8 (7) RDX Yes No 2.125 (10) RDX Yes Y e s No (b) E xp l o s ive se v e ranoe _ , anpa riS on (2024-T4 ta pe r ed pla t e s ) 2.i25 g / m (10 g r a i ns / f t ) R DX Wil l OU t 1. 5 3 ,UU (0.0602 in.) _ 131-pe rc en t 3.188 g / m ( 1 5 g r a i n s /g t ) HH S l! w i ll out 2.00 m (0.0788 i n.) J increase TABL L / II.- P _ L J E TT I SON _ AR _ S ON S Weight of Vel oc it y o £ E ne r gy per u n i t weig ht Type t es t s evered panet _ 8eve n ed pane l , of S eve r ed pane l k g (i b ) m / s ee (f t / se¢) J / k _ (f t -l bf / ib) , ,, , , , , ,,, • Sma il -s e _l e 0.34 (0 . 76) 9 _ E-(32) ...... 48.2 (15.9) (n o con t ainm e n t ) S m a ll -s c a l e 1. 0 0 (2.2) 1 0.4 (34) 53.2 ( 1 7.9) ( _t h co.tainment ) Fi _ e t m o ck-up 3 _ 40-(7.5) 1 0.7 (35) 58.8 (19.0) (f l a t pa n e l ) S e c o nd moc K -up 5 . 94 _1 3.1) 10.7 (35) 57.2 (18 . 9) (flat panel) FuS ela ge moc _ -up 6.62 (14.6) 13.7 (45) 94.0 (31.4)
O RI GI NAL PAO_ iS
_ OO R QU^LI T Y
0 .76 m R Sh o a t h - __ Exp l osi.v e _ t
/ _ff'K_\ ( 0 . I! I n. )
co re / A_l_'_ ' q_R_ \ 2,7 9 _g _lmm
9 0° ± 30 _ 5 .0 8 mm H (0. 2 0 in.)
F i g ure I.- Cro ae s e otl o n o f s i l ve r - s h e ath e d I WS II £ 1ex ibl e l in e ar -sh ap e d c h a z g e .
ACTU A TION DIREC T ION
t
REL E A SE SE AR C O M PRE SSION SPRING (I .27 -C M ( ,5 IN. ) S T RO KE) 7 0 N / CM ( 4 0 LB / IN.)
F I R IN G P IN ASS E MBLY P ERCU S$10 N PRIM E R O U T PU T C UP Fi gu r e 2.- C r os s sec ti o n o 5 la ny ard - ac t ua t e d d e ton a to r .
IB7
O.R I GINA . _ P A_ I_
OF POOR Q _A[,!T_
u , _IGINA L PAQ_ I8
L - 80 -_ 2i Figure 15. - E xt e rnal v ie w o f S ev e r e d pane l .
L- 80- 1 22 F i gure 1 6. - Int e r n al view o £ severed pa n el .