Book on P-39 and P-63 in Soviet Service

[NZTyphoon]

I have just received a new book titled 'The Bell P-39 Airacobra and P-63 Kingcobra Fighters: Soviet Service during World War II'. Chapter 2 is titled "Testing and Mastering the Airacobra" which briefly details the tests carried out by NII VVS before and during the P-39's operational service: of note was the propensity of the Airacobra to enter a vicious spin, caused by...

Quote

"...the aircraft's excessive sensitivity to changes in the CG position. For example, with the ammunition expended, the CG position shifted aft considerably, causing the fighter to enter a spin at the slightest provocation. The same could happen as a result of minor piloting errors, especially excessive aft movement of the stick or excessive pedal inputs....

Even if the pilot managed to recover from a spin, there was another danger in store for him: high g-loads deformed the tail unit, causing the control surfaces to jam. Special investigations showed that abrupt manoeuvres sometimes led to warping of the rear fuselage....

NII VVS test pilots evolved a series of recommendations to service pilots in regard to the piloting of the  P-39: experienced pilots were sent to the air force units to demonstrate the safe techniques of flying the aircraft....Strict limits were imposed on the CG location; it was prohibited to perform aerobatic manoeuvres without weapons and ammunition or equivalent ballast in the nose."

The structural strength problems of the P-39 came to the fore in March 1944....An experimentally modified machine with reinforcement strakes on the rear fuselage was tested at NII VVS, whereupon similar field modifications were made to the Airacobras directly in the fighter regiments.

The Airacobra also had a fair share of minor deficiencies that had to be dealt with. For example, the bulletproof glass pane protecting the pilot's head from the rear had a tendency to fall out during violent manoeuvres. Fortunately, putting it back in place presented no problems.

One more nuisance was caused by the inward-opening direct-vision panel incorporated into the port side of the cockpit windshield. At high flight speeds the airstream pressed this panel into the cockpit, popping it off the hinges, and the transparency came flying straight at the pilot, hitting him violently in the face. Cases were on record that this caused loss of control and cost the pilot his life." (pages 35-37)

Apart from anything else, the book also goes into detail about the P-39's VVS aces and profiles many of their aircraft. 

Highly recommended.

Edited November 20, 2019 by NZTyphoon
'was' instead of 'is'