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An interesting article on Helipads for our voracious readers.
(Keywords: Helipad meaning, History of helipads, Sizes or dimensions, cost of construction, ground conditions, heliports, helipads)
Do you know that the world's highest helipad is built by India and that it is located on the Siachen Glacier at a height of 21,000 feet (6400 m) above sea level?
Helipads seat a heavy, flying, moving, spinning hunk of metal and support it at ease while still hanging out by the side of a high-rise skyscraper. How cool is that? Anything that is designed and engineered is interesting in itself. And helipad is an engineered piece of rods and nuts and bolts. Helipads enable us to safely land and facilitate the take-off of many million dollars worth of flying machines off the ground without any damage and hazards.
What do you call a helipad?
So a helipad is a designated area where a helicopter is supposed to land safely. They are found at hotels, private residences, hospitals, and even superyachts… But it isn’t as simple as that. We will find out more as we go along.
Tell me the difference between Helipads and Heliports
Well, the difference is basically that a helipad is only a small landing place for helicopters, denoted by a large "H" while a heliport is like an airport, except for helicopters instead of planes. Similarly like airports it allows for civilian passengers and military personnel to avail air travel through helicopters. A heliport has a large number of helipads along with all the necessary service facilities.
Quick trivia: There are around 1,141 heliports in India, while there are around 1,071 helipads in the country.
First of all, why do we need helicopters and helipads when we have airplanes and airports…?
The instant answer to that is that a helicopter can do a vertical take-off and a helipad requires significantly less area than an airstrip.
The broader answer is that a helicopter can do things that a plane can't do. The helicopter's ability to travel long distances at high speed, take off and land without a runway, and maneuver in tight spaces makes them far more useful for a wide range of applications, including search and rescue, VIP transfers, air ambulances, and more.
And while helicopters can land on almost any flat surface, just like a man can live anywhere where there is land, it is not always practical or safe to do so. That is where helipads play an important role in the safe landing of the helicopters.
History of Helipads
Let's take a quick step back in the history lesson to learn about helipads. It is cool to know that the first purpose-built helipads were made for the military. It was constructed by the US Army. It was wartime, the Korean War, in the 1950s, and the need came for a designated area easily accessible to military personnel to board and dismount out of a helicopter. Early helipads were used to evacuate soldiers injured on the frontline in the mountainous terrain of North Korea. The helipads proved so successful that their use was expanded for use in another war, albeit an infamous one, the Vietnam war. Here again, the helipads allowed for troops to be moved quickly around inaccessible jungle terrain. How awesome and game-changing is that! The logistics support that helipads and helicopters provided outmatched any mode of transportation in that war zone. Today, there are estimated to be more than 15,000 heliports and helipads in use around the world
Quick trivia: The airspace surrounding the heliport is also considered part of the heliport itself. Together, these two areas are known as the Primary Surface.
Materials used in constructing helipads
In the early days, steel and concrete were used to construct helipads, but in recent years, this has been superseded by aluminum. Now you can see a helipad sticking out of a highrise by the side, like a strong arm reaching out to the air, to seat the hovering choppers. And what a sight that is, right? Those helipads are mostly made of aluminum or steel.
Essentially we can make a helipad from any hard surface; even grass. However, the material we have chosen should be suitable for the type and size of aircraft in use. There is no point in making a helipad if the helipad is eventually going to get weathered, corroded, or sunk into the ground. The helipad should be able to carry the load of the helicopter during take-off and landing and should preferably last for a long period.
Size of a helipad
The ICAO SARPs classify the levels of safety needed for elevated helipads by classifying them into H categories according to the size of the helipad.
H3 is the biggest type of helipad and measures a diameter of 24m to 35m.
While H2 helipads measure up to 24m in diameter and the smallest type of helipads, H1 , has a diameter of up to 15m.
Quick trivia: The largest heliport in India is located in Noida
Some technical stuff:
God is in the details. They said it right.
Here we have some technicalities about the design and construction of a helipad that needs to be considered beforehand. As engineers, it is interesting to know that economics go hand in hand with the feasibility of a project, what are the sort of parameters we should analyze before even sanctioning the project…
Design procedure for Helipads construction followed in INDIA
In India, helipads' design guidelines are based on Annex 14 of ICAO. CIVIL AVIATION REQUIREMENTS SECTION-4, AERODROME STANDARDS AIR TRAFFIC SERVICES SERIES 'B', PART III provides detailed guidelines about the helipad/heliport design.
To talk details, we will see that there are various aspects to consider in the planning and construction of a helipad.
The purpose for which the helipad is needed to be built.
How frequently the helipad is going to be used.
The largest helicopter size will be landing on the helipad.
How near is the helipad to an airport, heliport, or another helipad
Availability of land, Adequate land should be available for the construction of the helipad, for a touchdown and lift-off area, final approach and take-off area, Safety area, clearways, parking of vehicles, and wind direction locator.
The type of surface to be used.
Any obstructions present around the helipad.
Accessibility to the helipad platform for passengers, refuelers, fire tenders, and ambulances.
The proximity of Prohibited, Restricted, and Danger areas.
Meteorological/ weather conditions like wind direction during different seasons of the year.
Design
The design of the helipad is based on the owner and regulatory requirements. The measurement of the helipad will be based on the largest helicopter which is likely to use the helipad. The pathway leading to the helipad and for towing the helicopter to the parking space in the hangar will be designed most conveniently to ideally suit the requirement. The design will also include easy accessibility of the helipad for passengers, refuellers, ambulances, fire fighting vehicles, etc. The design will take into consideration the ideal location for a touchdown and lift-off area, final approach and take-off area, safety area, and clearways keeping in mind the slope of the surface and location of obstructions around.
Helipad lighting, if required, will be incorporated into the design. The position of the windsock will be based on its visibility from the air and accurate display of wind direction under all weather conditions.
If required, the location of the hangar will be decided for easy towing in and out of the helicopter from helipad to hangar and vice versa.
Construction
The size of the helipad will depend on the type and number of helicopters likely to operate on the helipad. A minimum 6-inch concrete structure is required for the operation of small to medium-class helicopters. However, for heavy-lift helicopters, the requirement will vary according to the weight of the helicopters.
The slope of the helipad should be just enough to drain out the water without any waterlogging on the helipad and proper drainage of the water should be constructed to keep the area in the close vicinity of the helipad clear of the water. Proper marking and lighting if required will be incorporated during or after construction as per the regulatory requirements. The position for the windsock will be constructed based on the obstructions in the area and wind pattern.
The final approach and take-off and safety areas will be level and preferably on hard ground. The access roads and parking areas etc will be constructed to provide sufficient strength to bear the weight of the passenger vehicles, ambulances, refuelers, fire tenders, etc.
Hangar and access roads if required will be constructed as per the requirement of the owner keeping the regulatory provisions in mind. The security fencing will be constructed at a suitable distance from the helipad if required.
You also can have a look at the helipad construction video from start to finish
Cost of construction of Helipads
The cost of constructing helipads on the ground is significantly lower than that of a helipad constructed on the rooftop of a building because of the various levels of complexities involved.
Normally in India, the cost of construction of helipads ranges from 2 lakhs rupees to 5 lakh rupees while the cost of construction of helipads on top of a building would cost around 3.5 crore to 5 crore rupees.
Additional notes
Portable helipads
A portable helipad is a mobile structure with a rugged frame that can be used to land helicopters in any area with slopes of up to 30 degrees. These can be used in difficult terrains such as hillsides, riverbeds, and boggy areas. Portable helipads are easily transported by helicopter or powered-lift to place them where a helicopter needs to land, as long as there are no insurmountable obstructions nearby.
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