The Netherlands has a few Eurocopter EC135s for air medical services. (See Wikipedia.) How much clear landing space is required (either theoretically, practically or regulatory) for these?
What is the minimal landing area required for an EC135 air medical services helicopter?
3$\begingroup$ According to my experience on Flight Simulator X, roughly an area the size of a medium sized town - but I suspect I'm not the most talented helicopter pilot. $\endgroup$– Jon StoryApr 12, 2016 at 11:53
Theoretically the diameter of the rotor plus some room for the tail is sufficient. If it fits, it fits.
Practically, a bit of room for manoeuvring is required. Also special attention to the generated turbulence is needed in cramped spaces.
Regulatory I don't know the exact size required for the EC135 operated as air ambulance in the Netherlands. But I do know that the Dutch police helicopters are allowed to land on an area with a diameter of 1.5 $\times$ LOA (length over all) during daytime operations. They hit a lamp mast once which resulted in this investigation (in Dutch - or English text-only translation) by the Onderzoeksraad (Dutch Safety Board). Page 5 and 6 show some of the regulations in force at the time (2008).
I don't think there's a hard and fast rule for this, but it depends on a number of factors:
- Wind/ Weather conditions requiring safety margins.
- Effect of nearby objects/structures. If they are big I think they might cause unpredictable wind effects, again requiring compensation and space.
That said, I'm no helicopter pilot, so somebody else might be able to give a more detailed answer. YouTube is a pretty decent place to find some tight landings though.
1$\begingroup$ From what little I understand about helicopter operations, that's basically the deal: You can land anywhere you can fit (the biggest consideration being not smacking the tail rotor into anything). Various helicopter-related sites offer rules of thumb on landing area size and other considerations (that PDF from CALSTAR recommends 100x100 feet, or about 30x30 meters) $\endgroup$– voretaq7Mar 12, 2014 at 21:50
$\begingroup$ @voretaq7 that sounds pretty reasonable. $\endgroup$ Mar 12, 2014 at 22:20