As I am off to Malaya this month I thought it wise to do some homework on on the airfields over there. This is what I found:
In 1939 the following airfields existed:
Seletar (Singapore) - ovoid grass airfield 1000 yards minimum and 1,100 yards maximum dimensions permanent hangars (type

plus a watch office with tower. Extended c.1940 SSW 1,400 yards, SE 1,250
yards and WSW 1,200 yards
Tengah - grass airfield 950 yards by 800 yards - temporary hutting. Extended c.1940 E-W 1,200 yards, N-S 1,165 yards, NW-SE 1,150 yards and NE-SW 1,100 yards.
Sembawang - grass airfield 1,080 yards by 1,050 yards with temporary and permanent buildings. Extended c.1940 NW-SE 1,380 yards, NE-SW 1,300 yards.
Woodlands - Fuel Store (15,000 tons). Extended c.1940 as Woodland North with additional 6,500 tons of aviation fuel.
Kallang (Singapore) - temporary accommodation adjacent to the civil airport. Extended c.1940 NE-SW 1,400 yards.
Ipoh - two grass strips 700 yards and 600 yards
Batu Pahat - grass strip 900 yards long
Kuala Lumpur - grass strip 800 yards long. Work started c.1940 on a combined engine repair depot about six miles north of the town.
Port Swettenham - two 1,000 yard grass strips
Sitiawan - one 800 yard grass strip
Taiping - rectangular grass field 950 yards by 750 yards
Penang - grass airfield 800 yards by 1,000 yards with tarmac runway 950 yards long.
Alor Star - grass airfield 900 by 1,000 yards with tarmac runway 1,000 yards long.
Kota Bharu - grass airfield.
Kluang - grass airfield constructed c.1940 1,100 yards in diameter.
Kuantan - constructed c.1940 grass airfield 1,100 yards in diameter.
Kahang - constructed c.1940 on a grass satellite with runs of 1,100 yards.
Source: Works