PS-89, ZIG-1 by A.Laville and A.V.Kulev

44k b/w image from "History of aircraft construction in the USSR", Vol.1 p.572

14-seat passenger all-metal (except control surfaces skin) aircraft with fixed landing gear in pants-style fairings. It was designed in the revolutionary moment in aviation history, when civil aircraft outpaced biplane fighters. Group of designers headed by A.Laville decided not to chase top possible speed, concentrating on reliability and safety of the aircraft for passenger flights:

• ability to sustain sufficient altitude with one engine cut off;
• minimal landing speed;
• reliable landing gear design;
• cockpit equipment allowing blind flight;

This is why fixed landing gear was chosen. Aircraft had long wing with large landing flaps. Skin was smooth, all aircraft was designed and built very clean.

Assembly was performed on the Aircraft Repair Factory named after Goltsman (Zavod Imeni Goltsmana, so comes designation ZIG-1). It was ready in Spring 1935. At the time A.Laville already left for France, and project was finished by engineer A.V.Kulev.

Factory trials proved good performance, but on November 27 tailplane broke off on landing approach. Aircraft nose-dived, killing 6 people (pilot Abliazovskij, A.V.Kulev and others). Crash was caused by manufacturing defects in the tail assembly...

Trials continued on the second aircraft, parallel with production of other six as a pre-series batch. At this final stage works were supervised by P.I.Berzin. Aircraft fulfilled all requirements in Spring 1937, and series batch (the first and the last one) rolled out in 1937- 1938.

All seven aircraft served for more than four years on passenger lines (Moscow-Simferopol and others), carrying normally 1160kg of payload at 250km/h. They spend few thousand hours in the air each, proving that trial accident was not a design failure.

No more production followed mostly because major specialization of Zavod Imeni Goltsmana was repair rather than assembly of new machines.