NZ8800 From New Zealand, joined May 2006, 425 posts, RR: 2 Posted (7 years 11 months 2 weeks 4 days 22 hours ago) and read 1727 times:
I noted with interest when researching a project on RNZAF Station Whenuapai/Auckland Airport; that though the Britannia carried more people than the DC-7C (up to 139, compared to 86 - 103); it had an LCN of 40 - exactly the same as the airport's runways; and the DC-7C had a LCN of 55. This made CAA very hesitant about allowing them into Whenuapai at all, but they were allowed to land there twice weekly as of 1960.
Question - if the DC-7C had 10 wheels like the Britannia, rather than the five it had, would this have made its LCN lower?
To my mind it would, but I am not a professional pilot, or engineer, and there are probably other complicated factors involved.
(To add a little to the problem, Whenuapai's runways were/are made of intersecting hexagonal concrete blocks, which are not cemented together, although the main runway does have a tarmac overlay since 1962).
MDZWTA ~ Mobile Disaster Zone When Travelling Abroad
Jetlagged From United Kingdom, joined Jan 2005, 2594 posts, RR: 25
Reply 1, posted (7 years 11 months 2 weeks 4 days 16 hours ago) and read 1699 times:
It's all about how the load is spread across the concrete surface. That would depend on the aircraft weight, the number of wheels, how the aircraft weight is distributed between mains and nose, and the tyre pressures. You are probably right in that if the DC-7C had more main wheels its maximum allowable LCN would reduce. Reducing tyre pressure would have increased contact area and so spread the load more too.
A civil engineer would be able to answer this question in more detail.
The glass isn't half empty, or half full, it's twice as big as it needs to be.