Glasgow CTA change from Class E to Class G

Closing date 24 March 2009


Please note that in addition to responding by letter you can email your views to  This is not listed in the consultation document


NATS has proposed that the Glasgow CTA between Glasgow and Edinburgh which is currently Class E between 2500 ft and 6000ft amsl should be changed to Class D.  You can see their proposal here


In class E airspace IFR traffic has to obtain a clearance and is given separation from other IFR traffic but VFR aircraft can fly in Class E airspace without clearance.  The VFR limits are 5km and 1000ft/1500m clear of cloud but as there is no VFR at night in the UK class E effectively has the same rules as class D during the hours of darkness.  During daylight hours when the weather is suitable for VMC flight public transport aircraft do not necessarily have separation from VFR traffic although ATC may provide separation when they can.


Class E airspace is not common in the UK and the CAA does not like it.  But elsewhere and especially in Europe it is widespread and is found around many regional airports.  Airline pilots will be well used to flying in class E.  That said, where an airport has a large number of public transport flights it should be able to offer the additional level of safety found in class D airspace during VMC conditions and that is the basis of the LAA position.  We agree that public transport flights should have the safety provided by class D airspace.


However, there are a number of ways that Glasgow could keep its traffic inside class D airspace without changing the class E CTA and these have not been explored.  Moreover the effect of changing the CTA would be significant for the safety and operation of non-commercial aircraft but that has not been considered.  Importantly, the consultation document is based on substantially false data which we expose in the LAA response and a letter sent to Director Airspace Policy.


Once you have reviewed the consultation document and the LAA response, please consider giving NATS your personal view on this.  We offer the following themes that you might like to cover if they are relevant to you:


  • It is clear that this change has the potential to isolate the Highlands from the south for aircraft which cannot obtain or accept a clearance through class D airspace. 


  • Members who use the existing airspace regularly report that obtaining crossing clearance has been often been difficult. 


  • Alternative routings are daunting; fly below the Glasgow CTA, base 2500ft amsl through a corridor blocked by the Cumbernauld ATZ and with terrain rising to 1738 ft in the north, fly east around Edinburgh crossing the Firth of Forth or fly west and cross the Firth of Clyde and inhospitable terrain. 


  • Forcing many GA aircraft, microlights and gliders below 2500 ft will have environmental and safety consequences which are not addressed.


  • The consultation is based on significant false and misleading data, perhaps the most important is the statement that “all flights using Glasgow have to pass through class E airspace” when about 70% go nowhere near it and the other 30% only need fly in it at all if NATS vectors them through it, the procedures all being drawn in the existing class D airspace. We list the main issues in para 3 of the LAA response for your reference.


  • Traffic levels have not increased but remained broadly constant for 10 years and have fallen off significantly in recent times.


  • The size of the Glasgow airspace is covered in para 10 of the LAA response.  It seems to be already much larger and less used than other similar airspace.  The CTR is more than 3 times the size of Gatwick but with one third of the traffic.  It is 2½ times the size of Birmingham with only some 80% of the traffic.


  • Although there is a section headed “impact on other airspace users” it does not even mention the subject.


  • The design options do not include real alternatives and it is not credible to assert that boundaries cannot be changed, proved by a late offer to change some boundaries by a relatively minor amount.


Finally you should offer your view on how NATS should proceed. 


The LAA thinks that the proposal will force aircraft lower bringing environmental and safety disbenefits.  However, it clear that this airspace is seriously under-utilised.  NATS could review all the airspace in that area to provide a realigned class E or even class G corridor that would meet the needs of all airspace users, commercial and GA, and without an environmental impact.