go here go site At the beginning of April 1931, the aerodrome at Alor Star (now Alor Setar) was opened to KLM aircraft. North Borneo availed to the Alor Star – Amsterdam airmail service by KLM in 1932.
source link A few interesting airmail covers appeared in eBay recently. These are airmails carried by the KLM (Koninkijke Luchtvaart Maatschappij or Royal Dutch Airlines) through the Alor Star – Amsterdam route. When mails from North Borneo were accepted for KLM services beginning September 1932, the air mail fee was 50 cents for every half ounce and was additional to the ordinary postage.
http://a4lions.ca/?iyted=diagrammi-forex-tempo-reale&86c=4f Beginning 7th of April 1933, letters for transmission by KLM were reduced to 45 cents per half ounce (additional to ordinary postage).The North Borneo Government were determined that as much mail as possible would travel by the Imperial Airways service, which is probably why the postal fees in Imperial was significantly lower than that of the KLM.
dating on earth tvxq wiki Despite higher postal rates, KLM service continued to be used considerably (at least at the earlier stage) because it was much faster. For example, a letter sent to Europe in 1933 takes about 16 days to reach its destination via KLM service but may only arrive a week later with Imperial Airline.
follow site Superscription, hand-stamp and airmail etiquette
In general, mails intended for KLM conveyance through the Alor Star – Amsterdam route must bear the blue air mail etiquette provided by the Postal Authorities. However, various other air mail etiquettes both adhesive and imprinted on the cover are used for these flights.
All letters must also be superscribed “ el metformin generico By Alor Star – Amsterdam Air Mail”. This is done both by handwriting or type-writing.
Mails intended for the service may receive transit markings in Singapore and Penang especially the earlier mails between 1932-1933. Based on existing examples, it seems that the practice of back-stamping the transit marks are largely abandoned from 1934 onwards.
Only letters from Sandakan may be hand-stamped with a special purple mark as shown in the cover above.
More about KLM airmail service here.