1950/51 a Pulqui II jet pilot with some kind of early H-1 pattern helmet modified with earphones outside, or maybe an Argentine version of the early rigid helmets for jets in the late 40s, early 50s. What is clear is the pilot's A-14 oxygen mask, which may indicate where the helmet is from. The photo was taken in the second of 5 constructed prototype jets. The second prototype was in an accident in 1951 causing the death of the pilot, Captain Vedania Manuwal. Having existed only one experimental helmet of this type, it is possible that it was lost in the accident. In other photos taken in other prototypes, the test pilots like Capitan Edmundo Weiss wore the leather type "C" RAF.
A screen capture from a February 8, 1951 film
USN/USMC type A-11 Flying Helmet with A-14 Oxigen Mask
RAF type C Flight Helmet with 10A/7063 Radio Receivers and the A-14 Oxygen Mask.
In the photo Captain Edmundo Weiss is with the Pulqui II. It was before the inaugural flight of the Pulqui II in 1950. Weiss was the leader of the Test Pilot Squadron. Weiss appears to have a WWII era parachute and a RAF Type C leather flight helmet with Mk.8 style flying goggles and E or G type oxygen mask.
Model LPK n101 Baumuster Netzkopthaube WWII Luftwaffe Flying Helmet (Bf-109, FW-190, Me262, etc). Gerät-Nr. 124. Werk -Nr - 1K His. Earphones marked Ln26602. Flight Goggles marked UVEX
WWII RAF Type "C" Leather Helmet (Spitfire, Hurricane, Lancaster, etc) with Type "H" Oxigen Mask. Electronics: 10A/7063 Receivers and 57 Microphone.
Luftwaffe LKP W101 (Winter ) Flying Helmet with goggles, Battle of Britain. Cap marked: Siemens. Earphones marked: Ln 26618.
Luftwaffe LKP S101 (Summer) Flying Helmet (M109, FW190, Me262 etc) by Siemens. Earphones marked Ln 26617.
1950s Soviet MIG Pilot Leather Helmet, KM-32 Oxigen Mask, Laryngophone Troat Microphone and goggles.
Type AN-H-15, H-4 Gentex Flying helmet Inner / liner made by General Textile Mills Inc Carbondale PA (GENTEX).
Receivers: (HS-38); CBRR ANB-H-1, Black Plug Maked PL-540.
Microphone: CBRD M6A/UR Boom Mounted Mic; MT-522 A/U Mic Braket, marked Joyce Telectronics Clearwater FL. PJ-292 Male Microphone Plug
USAF P-1B (Late 40s) Flight Helmet Upgraded to P-4A (1957).
Korean War H-3 USN Flying Helmet by GENTEXITE (GENTEX) with Tinted USN goggles made by Rochester Optical.
H-4 Type French Flying Helmet 403-M3 by SOCAPEX/GENTEX.
Early USN/USMC Flying Helmets: RAF Type "B" and Pre-WW2 training helmet for Gosport speaking tubes.
WWI - 1920 FLying Helmet with S&B NY Resistal Goggles.
Early Flying Leather Helmet by Eaglet
Early training cloth helmet by Eaglet for gosport tubes
WWII Army Air Force AN-H-15 Cloth Helmet
WW1, Argentine born pilot from the French 27 Squadron, Vicente Almandos Almonacid.