{{Short description|Polish single-seat gull-wing fighter prototype}} {{Infobox aircraft |name = PZL P.1 |image = File:PZL P1 II 2.jpg |caption = PZL P.1, second prototype |type = Fighter |manufacturer =PZL |designer =Zygmunt Puławski |first_flight =August 1929 |number_built = 2 |status = Prototype |primary_user = Polish Air Force }}
The '''PZL P.1''' was a Polish single-seat gull-wing fighter prototype, designed by the engineer Zygmunt Puławski, and manufactured by the PZL state aircraft factory. It remained a prototype, but was the first of the Polish PZL gull wing fighter series, leading to the PZL P.7, P.11 and P.24.
==Design and development== Among the first tasks of the newly created PZL aircraft works in 1928 was to design a fighter for the Polish Air Force. A team led by Zygmunt Puławski designed an all-metal monoplane fighter, designated '''PZL P.1'''. Puławski included a high gull wing, in an attempt to improve the pilot's visibility upward, compared to typical parasol monoplanes and biplanes of the era.
The first example first flew in August 1929, however the wing leading edge distorted in flight, but the test pilot, with Bolesław Orliński managed to land safely. In late 1929, after additional static tests, the prototype was modified and strengthened. In March 1930, the second prototype was flown, the '''P.1/II''' which introduced a revised rudder, similar to those used on later developments, along with numerous other detail changes.
The second prototype took part in a fighter contest in Bucharest in June 1930, where it placed 4th out of 7 competitors, after winning 8 of the 15 trials.
The P.1 remained a prototype, because the Polish Air Force insisted that its fighters be powered with Polish-built radial engines, resulting in the development of the PZL P.6. While this improved reliability and reduced cost, some modern authors have criticized this decision as the single-row radial engine produced more drag, and less power, while it also impaired visibility.<ref name=Cieślak>Krzysztof Cieślak, Wojciech Gawrych, Andrzej Glass: ''Samoloty myśliwskie września 1939'', NOT-Sigma, Warsaw 1987, {{ISBN|8385001115}} (in Polish)</ref>
In 1929 or 1930 an improved P.1 was developed, with the designation '''PZL P.2''', but this was abandoned after completing just the fuselage. Puławski was unwilling to abandon inline engines, and developed the P.8 with an inline in 1931.
==Technical description== thumb|First prototype after modification The PZL P.1 was an all-metal braced high-wing monoplane with fixed conventional undercarriage. The fuselage was rectangular in cross-section and built around a duralumin frame, skinned in smooth duralumin sheet.
The two-spar tapered wing was thinner and narrower at the roots and covered with corrugated duralumin sheet, braced with a pair of struts on each side. Most of the wing had closely spaced corrugations, while the outer panels had additional larger more widely spaced external ribs. The empennage was conventional, and unbraced and like the wings, was skinned in corrugated duralumin. The tips of all flying surfaces were formed from flat sheet. Two fuel tanks holding {{cvt|400|L}} of fuel between then were installed in the wings. The metal control surfaces were unbalanced and skinned with corrugated duralumin.
The open cockpit was fitted with a small windscreen, and faired in with a headrest that extended to the base of the fin. A fixed, but faired undercarriage had shock absorbers that were buried inside the fuselage.
The P.1 was powered with a {{cvt|630|hp}} Hispano-Suiza 12Lb water-cooled V-12 engine.
==Operators== ;{{POL}} *Polish Air Force
==Specifications (P.1/II)== {{Aircraft specs |ref=Jane's all the World's Aircraft 1931,<ref name=JAWA1931>{{cite book|title=Jane's all the World's Aircraft 1931 |editor1-last=Grey |editor1-first=C.G. |year=1931 |publisher=Sampson Low, Marston & company, ltd |location=London |pages=222c-223-c}}</ref> <br>Polish aircraft, 1893-1939<ref name=Cynk>{{cite book |last1=Cynk |first1=Jerzy B. |title=Polish aircraft, 1893-1939 |date=1971 |publisher=Putnam |location=London |isbn=0370000854 |pages=[https://archive.org/details/polishaircraft1800cynk/page/123 123-128] |url-access=registration |url=https://archive.org/details/polishaircraft1800cynk/page/123 }}</ref> |prime units?=met |crew=1 |length m=6.98 |span m=10.85 |height m=3.05 |height note=in the rigging position |wing area sqm=19.5|aspect ratio=5.97 |airfoil=Bartel 37/IIa (modified) |empty weight kg=1118 |gross weight kg=1580 |max takeoff weight kg= |fuel capacity={{cvt|400|L|USgal impgal}} in two wing tanks with a small gravity collector tank in the fuselage. <!-- Powerplant --> |eng1 number=1 |eng1 name=Hispano-Suiza 12Lb|eng1 type=V-12 water-cooled piston engine. |eng1 hp=630
|prop blade number=2 |prop name=fixed-pitch propeller |prop dia m= |prop dia note= <!-- Performance --> |max speed kmh=302|max speed note=at sea level :::{{cvt|293|km/h|mph kn}} at {{cvt|2000|m}} :::{{cvt|284|km/h|mph kn}} at {{cvt|5000|m}} |cruise speed kmh=250 |stall speed kmh=102 |range km=600 |endurance=2 hours at cruising speed. |ceiling m=8600 |ceiling note= absolute |g limits=13.5g |time to altitude={{cvt|2000|m}} in 2 minutes 40 seconds. :::{{cvt|5000|m}} in 8 minutes |wing loading kg/m2=81 |power/mass={{cvt|0.385|hp/lb|kW/kg|order=flip}} <!-- Armament --> |guns= 2 x {{cvt|7.7|mm|3}} Vickers E machine guns in a fuselage, with 800 rounds per gun (planned). }}
==See also== {{aircontent |related= *PZL P.6 *PZL P.7 *PZL P.8 *PZL P.11 *PZL P.24 |similar aircraft= |lists= }}
==References== {{Reflist}}
===Further reading=== {{refbegin}} *{{cite book|last=Cynk|first=Jerzy B|title=History of the Polish Air Force 1918-1968|location=Berkshire, UK|publisher=Osprey|year=1972|isbn=085045039-X}} *{{cite book|last1=Eberspacher|first1=Warren A|last2=Koniarek|first2=Jan P.|title=PZL Fighters Part One - P.1 through P.8. (International Squadron Monograph 2)|series=International Squadron Monograph|location=St. Paul, MN|publisher=Phalanx|year=1995|isbn=1883809126}} *{{cite book|last=Glass|first=Andrzej|title=Polskie konstrukcje lotnicze 1893-1939|language=pl|trans-title=Polish Aviation Construction 1893-1939|location=Warszawa, Poland|publisher=WKiŁ |year=1977}} No ISBN *{{cite book|last1=Krzysztof|first1=Cieślak|last2=Gawrych|first2=Wojciech|first3=Andrzej|last3=Glass|title=Samoloty myśliwskie września 1939|language=pl|trans-title=Fighter aircraft September 1939|publisher=NOT-Sigma|location=Warsaw, Poland|year=1987|isbn=8385001115}} {{refend}}
==External links== {{commons category|PZL P.1}} *[http://www.airwar.ru/enc/fww1/pzl1.html Photos and drawings at Ugolok Neba]
{{PZL aircraft}}
Category:1920s Polish fighter aircraft Category:Gull-wing aircraft P.1 Category:Single-engined tractor aircraft Category:Aircraft first flown in 1929 Category:Single-engined piston aircraft