1928 Dansalan to Manila Aborted Flight

Postmarked DANSALAN, LANAO / FEB 28 6PM 1927
NOT FLOWN

The following AAMC listed 1927 Tour of the Southern Islands flights are relevant to the above cover:

#17g: MANILA to ZAMBOANGA, February 18.
Backstamped ZAMBOANGA, ZAMBOANGA, P.I. / REC'D /  FEB 25 2PM 1927 

#17h: MANILA to JOLO, February 18.
Flown via Zamboanga.  Received on front, FEB 26 / 10AM. 

#17p: JOLO to MANILA, February 26.
Flown via Zamboanga on same day, 4PM backstamped.  MANILA / MAR 4 cds on the side.

Fig 1: MANILA to MALANGAS, ZAMBOANGA
Flown via Zamboanga.
Received MALANGAS / P.I. / REC'D. /
FEB 28 8AM 1927

Fig 2: MANILA to DANSALAN, LANAO
Flown via Zamboanga.
Received DANSALAN, LANAO, P.I. / REC'D. /
MAR 4 4PM 1927
I assume that above cover was prepared but not flown because ofa change in routing. This assumption is based on the existence of an unrecorded MANILA to MALANGAS, ZAMBOANGA flight occurring on February 28 (Fig 1). We have now two covers both with February 28 postmarks. One is a receiver and the other is a dispatch.

The MANILA to DANSALAN flight flown via Zamboanga eventually was made although delayed on March 4 (Fig 2). To date, a DANSALAN to MANILA flown cover has yet to be reported. Logically, there has to be one. 
Edward Nocom Collection