HPK SP-1 explained

The HPK SP-1 a.k.a. "Some Pisser-1" is a single seat homebuilt aircraft.^[1]

Design and development

Engle Flying Service members, Harold Hayden, Art Payne, Robert Kinney, and Norman R. Benner developed the HPK SP-1 over the course of five years. Plans for a two-seat side by side, and four seat variants were not completed.^[2]

The SP-1 is a single-place, all-metal, low-wing aircraft with conventional landing gear and partial span split trailing edge flaps. The cowling is from a Piper Tri-Pacer.^[3]

Operational history

The aircraft was built and tested at Three-M airfield in Pennsylvania, home of Kaiser-Fleetwings Company.^[4] The prototype has been registered for over 50 years.^[5]

Notes and References

1. Web site: Abandoned & Little-Known Airfields: Pennsylvania - Northeastern Philadelphia area. 17 June 2011.
2. Sport Aviation. February 1959.
3. Book: Jane's all the world's aircraft. Frederick Thomas Jane.
4. Web site: Abandoned and little known airfields. 17 June 2011.
5. Web site: N65X. 17 June 2011.