FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1949
1949 - 1441.PDF
AUGUST I8TH, 1949 FLIGHT 205 Preslwick Pioneer Progresses Advances- ijf--Power, Load and Perform- ance of the Scottish Specialist Type The exceptional take-off and landing characteristics of the Pioneer are largely responsible for its distinctive appearance. WHEN Scottish- Avia-tion, Ltd., producedthe first Prestwick Pioneer (Flight, October 2nd, 1947) it aroused a consider- able measure of interest as a result of its extraordinary performance. Originally powered with a de Havilland Gipsy Queen 30 Series engine of 240 h.p.—and so designated Mk 1—the Pioneer has now been modified and equipped with an Alvis Leonides, in which guise it is designated Mk 2. Naturally enough, the Leonides' take-off rating of 520 b.h.p. has made a considerable difference to the aircraft's take-off performance and, more particularly, to the payload which can be carried. In that the gross weight has increased by 48J per cent, however, the fact that the payload has in- creased by 56J per cent means that the payload/gross weight ratio has altered very little—in point of fact, it is improved by 1 per cent. Alternative power units such as the Cheetah 25 and the Pratt and Whitney Wasp Junior are envisaged as being suitable for the Mk 2 Pioneer. The inherent structual design of the aircraft remains un- changed in the latest version, although a few deviations from the original have been made. Span has been in- creased by the fitting of rounded wing tips, and this has incurred a concurrent increase in wing area. By the same token, the fact that the elevators have been furnished with horn balances at the tips has led to an increase in tail unit span. In the original aircraft, the tailplane incidence was adjustable by means of an electric screw-jack so that an angle could be selected to compensate the extreme nose-up attitude of the aircraft when flying at its ultra-low speed, and so obviate the onset of tailplane stall. This system of tail adjustment is still employed, but the range has been reduced from 14 to 9 deg, so giving movement from a positive incidence of +4 deg to a negative of —5 deg. In view of the increase in all-up weight to 5,400 1b, the stalling speed has gone up to 37 m.p.h. T.A.S. (although Genera/ arrangement of the landplane and floatplane versions. Data (given overleaf) are generally similar. for both, although the gross weight of the floatplane is SOIb greater. ,, ... \ B 27
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
