3847 1913 Burgdorf 50c semi-official airmail stamp on PPC of pilot Oskar Bider & his plane, also franked 5c green, both tied by special violet cds dated "30 III 13", to Langnan with arrival cds. Superb. Mi IV cat €650 as loose stamp. Zum IV cat SFr1200 on cover. Moser cert (P) $400 $600
3848 1913 Herisau 50c semi-official airmail stampon colour flight PPC, also franked 5c green, both tied by special purple cds dated "30 III 13". Mi cat €650 as loose stamp, Zum V cat SFr1200 (P) $400 $600
3849 1913 Langnau 50c semi-official airmail stamp on PPC of pilot Oskar Bider & his plane with "Flugtag Langnau i E" red opt, also franked 5c green, both tied by special cds dated "4 V 13". F-VF. Mi VI cat €800 for loose stamp, Zum VI cat SFr1300 on cover (P) $400 $600
3850 1913 Liestal semi-official airmail stampon colour PPC for flight, also franked 5c green, both tied by special blue cds dated "27 IV 13". F-VF. Mi VIII cat €750 as loose stamp, Zum VIII cat SFr1100 on cover (P) $350 $500
3851 1913 Lugano 25c semi-official airmail stamp on PPC, also franked 5c green, both tied by special blue-black cds dated "8 GIUG 1913". F-VF, pmk bit affected by moisture. Mi IX cat €1700 as loose stamp, Zum IX cat SFr2850 on cover. Bohler VSPV photo-cert (P) $900 $1500
3852 1913 Sitten/Sion 50c semi-official airmail stamp on cover, also franked 3c violet blk of 4, all with special violet cds dated "18 V 13", to Chiasso with arrival b/s. Slight water stain around stamp & rough perfs. Mi X cat €1800 as loose stamp, Zum X cat SFr22,000 on cover. Significant Swiss airmail rarity, Biel VSPV photo-cert. (P) $2000 $3000
