Trans RINA, Vol 161, Part A4, Intl J Maritime Eng, Oct-Dec 2019
Figure 3. Idealized flow over a backward facing step (Spazzini et al., 2001)
Even in the past, there have been certain rare exceptions of novelty in design of hangar-helodeck configuration as compared to back facing step configuration mentioned above, one example being Kashin-II class destroyers (Figure 4). An 80s' design of Russia, Kashin-II class has a submerged hangar which does not protrude in front of the helodeck, thus eliminating the recirculation zone completely and providing the helo with operating conditions very similar to the ones ashore. However, the possibility of introducing such novel designs are rare and can only be limited to certain ships, where space for stowage of helo can be allowed to be subsumed within the usable volume of warship.
render them unavoidable even in high seas. Having appreciated the indispensability of ship-borne helo operations, it needs to be clearly recognised that naval aviation is a complex integration of sea and air operations. By their very nature, ship-borne air operations, presently, are undertaken with safety margins much below those considered acceptable ashore. The process of Dynamic Interface Testing undertaken by experienced test pilots, to establish the operational envelope, is also associated with severe time implications and several constraints including the fact that the trials cannot be done at design stages rendering the findings unusable for design modifications. In order to improve the allowable limits of environmental conditions for safe ship-borne helo operations, several research agencies worldwide are undertaking structured research by utilising the available experimental and numerical resources for providing solutions for an improved design of helodeck-hangar configuration for modern ships without compromising on the aspects of stealth. In order to reduce the risk of accidents, such capabilities can further be used to provide information about the mapped flow conditions and probable critical zones for a given hangar configuration to pilots, especially prior to dynamic testing. Information available thus on the flow condition can act similar to road signage on a curvy road indicating danger zones which can be utilised by the pilots for ensuring safer operations.
Figure 4. Kashin-II class destroyer with submerged hangar (
https://upload.wikimedia.org)
Accidents are never acceptable, although they remain a very real and recurrent hazard in naval aviation. The money spent on aircraft, training and maintenance is simply too high for allowing accidents to occur. The human life, of course, is irreplaceable. However, notwithstanding the challenges, the range of responsibilities conferred on helo operations on warships
Considering the complexities involved in the problem, an attempt has been made in the following sections to holistically review the widely scattered and limited literature in this field. A good amount of literature on marine helo applications emerge from the offshore industry. Keeping in mind that the fields of warship design and offshore structures are dissimilar and have their peculiar problems, informed conclusions have been made in drawing lessons from available literature. Also an attempt is made to present a road map for future investigations in the area so as tomake the helo operations on warships as safe as possible.
©2019: The Royal Institution of Naval Architects
A-403
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166
