davidjohnson6; Could someone explain what benefits would be achieved for DND with a wider runway ? I'd like to understand what exactly the airport wants to achieve (ie which aircraft types will be able to fly to DND which can't now) by doing this work.
Not saying it shouldn't happen - just think there should be more info on the scheme to allow debate on the topic
It's not just a case of widening the runway. There are regulations that require specific distances between an active runway and aprons and this varies according to the type of aircraft. Then there are issues such as RFFS category (Rescue and Fire Fighting Services), PCNs of relevant parts of the runways, taxiways and aprons, ACNs, wingspan, undercarriage width etc.
Detailed technical info for DND is available on the NATS website via this link;
NATS | AIS - Home
Dundee currently meets RFFS category 4 which is aircraft with fuselage length from 18m up to but not including 24m and a fuselage width up to 4m. RFFS categories 5 and 6 are available by prior arrangement. Cat 6 is aircraft with fuselage length from 28m up to but not including 39m with a fuselage width of up to 5m. Cat 6 would cover an A320 but not an A321. RFFS category is probably one of the easier aspects to upgrade if the economics justify the investment.
PCNs might be a bit more of an issue. The PCNs of the aprons and taxiways at Dundee are not clearly defined in terms of strength of subgrade, method of assessment etc. but the runway is PCN 27/F/D/Y/T. Taxiways A,B and the main apron are PCN 27 according to NATS data for Dundee. I'm guessing that they are probably PCN 27/F/D/Y/T but can't be certain. That would be enough for an Avro RJ85 or similar but not enough for an A319 or B737. For comparison LCY's runway has a PCN of PCN 30/R/C/Y/T. The C strength subgrade and the 30 strength top surface mean that LCY's runway is about 20% stronger than DND.
Runway length is another factor. According to the article, the runway at DND can't be extended. The existing runway is 1,400m x 30m. This is the same width as London City but 108m shorter. Even if the PCN and runway width were to be increased, an A319 or B737 would have little or no payload / range from such a short runway.
At the moment, I'd have thought that most aircraft that can operate from LCY could also operate from DND but with a payload / range penalty compared to LCY due to the shorter runway and weaker PCNs. The only reason I can think to widen the runway at DND would be for operating aircraft from A319 size upwards but, given current traffic demand, how could this be commercially viable especially given the significant payload / range restriction that would apply? In an earlier post in this topic, I calculated the payload / range of a B738 from DND using detailed performance data and charts from Boeing's website and concluded that, although it could take off in 1400m, it would have little or no payload / range.
There are plenty of other factors to take into account and which may impact on the suitability of DND for larger aircraft. CAP168 contains the official CAA regulations on the licencing of aerodromes. It is available via this link;
https://www.caa.co.uk/docs/33/CAP168.PDF