Heme for: Director of Opcrations (Cont'd) 10 Sor 54 Beecure the overpressures listed xbove are essentislly acoustic, the effects care subject to acoustic aberrations such es diffraction ccused by te:purature inversions or wind shears, which could reduce th overpressurcs end associated gust velceitics below the velues listed, for nC distanecs involved. For examnle, althowsh ahout .7 psi wes anti- cin.ted at EVER for i IKE shot of Operation IVY, only .36 psi wos ex- pericnecd, 4. Throu,h the last two series of tests in hevada, ARDC i.s doen investigcting the effects cf atomic bursts on airerzft on the greund. fhe only people in this area who are well cequainted vith these tests cre tr. Fran: Janik, Structures Brauch, Aircraft ‘aborctory, WADC, and -ossrs Jovard 2worer ond Devid Mmoeel, of AlLlind Rescarch Assscictes, controcter to “ADC, here as cdvisors to Pro} cet 6.2, Conusecucntly, = Wes arranged with them to discuss thc »roebloms involved, conference Unfortunctecly there are no conics of the reperts on the Uovada tests avail: ble hrc, ‘invevor, on the besis of their experience, the believed thrt there wos no ris’: of dere ge et the overrressures anticip:ted, for tecticsl and e2rgo tyoe aircraft voried nose toverd Cround Zero, bet ore not cure of the effeets on licht airercft anc helicopters. As = resuit of discussion, the folloring list of norecautions was develoned, to reducetic ris!: of dvge to cireraft to the mininuns « - a. ALl cireraft must be sarced nose tovord Ground “ero j28tire the area in front of tiem crprefully cleared of possi'le minsilos, ehoe'ted, with their bralies set, cnd with fuel tanks fil or necrly full. They showld be ported far enoujh epart-so thet slight shifts in position wil’ not cause collisions between aircrort. Dd. Gust locks should be pleced on «11 coutrol surficcs. ce. “here comvenient, any tv-e of aizcraft should be ticd acu. It is sore importent to tie don aircraft such cs the C-47. whith cits a threc-nolnt attitude on the ground, d. doors, windows, hatches, bomb ‘sy dcors, etc. sh-ulc 22 e. 13's shod be stcred in the hing er vith their vines Poldoaec. ff, ‘@licontors siionld \e evecucted cr steered in oathe ‘bong povith ononed so th:t there are no scakd enclosures such cs ere’mits, c’bins or bomb “crys. rotors -folded and sccured. & vw WA -} “e eeTei3's ani heliesoters could be frrthir ~rovceted “xy see ene bem “lye ~ ; saa a ste Tee tring ther dwn ts send snes or piling send beacv cround tocde Vondins een,