div class=trans-pagebutton class=gotoPage data-page=1Page 1button div class=trans-imagea href=https:reader042fdocumentsusreader042viewer20220307115af9f6a17f8b9aff288dd865html5page1jpg target=_blank img data-url=document-20-sign-aerial-view-looking-straight-down-you-vlewlng-angle-si-dewalk-fig-21htmlpage=1 data-page=1 class=trans-thumb lazyload alt=Page 1: · Fig 20 Sign aerial view looking straight down you vlewlng angle si dewalk Fig 21 Fig 21 balloon viewing I angle 1000 m Fig 19 500 feet of string 3S0 15 ft3 min loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader042fdocumentsusreader042viewer20220307115af9f6a17f8b9aff288dd865html5thumbnails1jpg width=140 height=200 adivdivdiv class=trans-pagebutton class=gotoPage data-page=2Page 2button div class=trans-imagea href=https:reader042fdocumentsusreader042viewer20220307115af9f6a17f8b9aff288dd865html5page2jpg target=_blank img data-url=document-20-sign-aerial-view-looking-straight-down-you-vlewlng-angle-si-dewalk-fig-21htmlpage=2 data-page=2 class=trans-thumb lazyload alt=Page 2: · Fig 20 Sign aerial view looking straight down you vlewlng angle si dewalk Fig 21 Fig 21 balloon viewing I angle 1000 m Fig 19 500 feet of string 3S0 15 ft3 min loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader042fdocumentsusreader042viewer20220307115af9f6a17f8b9aff288dd865html5thumbnails2jpg width=140 height=200 adivdivdiv class=trans-pagebutton class=gotoPage data-page=3Page 3button div class=trans-imagea href=https:reader042fdocumentsusreader042viewer20220307115af9f6a17f8b9aff288dd865html5page3jpg target=_blank img data-url=document-20-sign-aerial-view-looking-straight-down-you-vlewlng-angle-si-dewalk-fig-21htmlpage=3 data-page=3 class=trans-thumb lazyload alt=Page 3: · Fig 20 Sign aerial view looking straight down you vlewlng angle si...