In todays safety concious environment you woul have thought that the CAA would automatically put some sort of controlled airspace (i.e. class D) around the airport. Unfortunately this is not the case and can take up to 2 years to implement, that is if the military do not fight it.
The requirements for obtaining new airspace classification are detailed in the UK Airspace Charter. As the CAA is the regulator and arbiter of UK airspace allocation, it is not for them to decide on the need for any airspace. That responsibility lies with those who use the airspace or provide services within it.
If Doncaster thinks it has a case for airspace, then it has to provide the justifications and consult with other airspace users as part of its case. It needs to reach an agreement with other users so that their needs are also addressed. Only then can it make an application.
The airport did not just open up overnight, it had been planned for for many years. It was mooted as far back as 2001 I think and was given the go ahead in 2003. That's more than enough time for any planner to have made all the appropriate airspace cases to other users, so that when it did open the formal case could be presented to the CAA. It could perhaps even have been presented before opening if the CAA accept predicted traffic figures as part of the submission (I do not know if they currently do).
Is it 'dangerous' in the meantime ? Not necessarily. There are millions of aircraft movements in Class G airspace every year. Yet the number of 'airprox' in Class G is very low when compared to the total number of movements. That isn't complacency, just an acceptance that there is a risk in anything we do balanced by the probability of anything happening being extremely low. The judgement call has to be made by every pilot who operates in Class G. It comes with being in command of the aeroplane and accepting the responsibilities that brings.
A major factor I see is the lack of awareness on the part of airline pilots about Class G airspace and how it is supposed to work. How many of them keep a good look out continuously (an integral part of airmanship) ? How many assume that the radar controller knows about everything and will keep them safe, and so continue with a 'heads in' operating technique ? How many apply the Rules of the Air for avoiding collisions in Class G airspace ? If the airliner is on the ILS at 2500' descending and a light aircraft is approaching from the right, it doesn't give the airliner any special rights or priority. The Rules say it is for the airliner to avoid the light aircraft. And why not ? It's Class G airspace, it's see and be seen, and it's a freedom we enjoy in the UK and is part of our heritage. If airlines can't cope with it then there are two choices. Don't operate in Class G ... or else have a robust and justifiable case for Controlled Airspace which is put to the CAA.
I am not fully aware of the traffic levels for Doncaster currently, but would be surprised if they meet a critical mass to justify a Class D Control Zone. A handful of movements every hour shouldn't disadvantage an extremely large number of GA, gliding, and military operators without good reason.
The nanny state we now unfortunately live in will no doubt argue otherwise !!!