Corrections and additions, Jet Age Flight Helmets:

Page 8:
Helmet is a P-1A or P-1B, not a P-1. Most likely it is a P-1A as the picture is taken in 1954 and the edge beading and oxygen mask tabs are already darkened from exposure to light .

Page 9, upper right-hand photo:
Photo shows a factory-made P-1A, not one modified from a P-1. The clue is the tan-coloured edge beading and the sand-coloured chinstrap. P-1 helmets have black edge beading and when modified to P-1A they usually have olive-drab chin and nape straps.

Page 12, upper left-hand photo:
Caption should be changed from "...except for the addition of a nape strap" to "...except for the addition of a nape AND CHIN strap".

Page 13, upper left-hand and right-hand photos:
Photos show an (early? - OD chinstrap) P-1A. The P-2 was an experimental design with separate cloth inner helmet.

Page 13, lower left-hand photo:
Correct service designation for this helmet would be P-4A, while a collector would term it a P-1B that has been T.O. upgraded to P-4A.

Page 14, all photos:
This helmet has been upgraded with H-75 series comms as evidenced by the two screws, string, and rubber stud on each side of the helmet, and the larger type microphone plug cover on the lower left side. It is therefore in P-4 configuration. 
It looks as if it has been T.O. updated from a P-3. The small hole on the lower right side just behind the chinstrap attachment suggests, however, that it has been fitted with P-3 standard HS-38 or HS-38A comms. Correct service designation for this helmet would be P-4, while a collector would term it a P-3 that has been T.O. upgraded to P-4. 
The caption under the upper left-hand photo is wrong. The visor is an original P-3 feature from 1951, not a retrofit to factory made P-3s. The visor shown in the photos is in collector-terms called Type II, and it is typical of the P-4 helmet. It would have been more correct to show a P-3 with the so-called Type I visor which has a square metal flange protruding upwards from the centre of the visor yoke. The Type I visor is also characterised by its shorter J-arms on the sides making the visor lens hang slightly down into the pilot's field of vision.

Page 16, middle photo caption and lower left caption:
The MBU-3/P was not just a USAF re-designation of the MS22001 oxygen mask. The MBU-3/P is based on the MS22001 but it has been modified including changing the MC-3A oxygen connector to the MS27796 three-pin connector and CRU-8/P connection block.

Page 20, all photos:
The MB-4 does not have a visor. When an MB-4 has a visor fitted it becomes a P-4A. Correct service designation for this helmet is therefore P-4A, while a collector would term it an MB-4 modified to P-4A.

Page 23:
Around 1980 the designation of the single visor helmet based on the HGU-22/P shell became HGU-26/P like the dual-visor version.

Page 24:
The APH-5A is based on the same shell as the HGU-2 series helmets.

Page 29 and 38:
The correct designations for these headsets end on AIC, not A1C. It is an abbreviation of Aircraft Interphone Communications and is taken from the Joint Electronics Type Designations System (JETDS). The full explanation can be found at http://www.designation-systems.net/usmilav/electronics.html

Page 31:
The centre visor locking track of the Toptex 3BM helmet is not similar to the P-4B helmet visor. There are no locking holes in the Toptex visor track.

Page 35, upper left photo caption:
PRU-36/P is the designation of the complete double-visor, not only the visor housing.

Page 35, lower left photo:
HGU-22/P is not a helmet in its own right. It is only the designation of the helmet shell used for HGU-2A/P and HGU-26/P helmets.

Page 42, upper caption:
The HGU-36/P helmet is not an HGU-55/P derivative. Its shell is shaped like the HGU-22/P shell but it is ballistic. The MBU-12/P did not replace the USN MS22001 mask; the Navy use masks based on the MBU-12/P but they differ in configuration and therefore also in designation.

Page 44, upper photos:
This early HGU-55/P has the original thin leather edgeroll whereas the helmet shown on page 43 has the later thick edgeroll.. The EEU-2A/P nuclear flash protection goggles were used earlier on HGU-26/P helmets.

Page 46, upper right hand photo and both below:
Apart from the paintwork, modifications to the Thunderbirds HGU-55/P helmet include a black leather edgeroll instead of the grey standard, chrome-plated cast aluminium oxygen mask receivers and a US Navy standard EEK-4A/P single visor housing as used on e.g. HGU-33/P and HGU-34/P helmets.

Page 47, caption for upper left hand photo:
The correct designation for the night vision goggles is AN/AVS-6. They are also known as Aviator Night Vision Infrared System (ANVIS)

Page 71, lower right photo caption:
The correct spelling of the pilot's name is Iven C. Kincheloe.

Page 87, photo caption:
The H-1 helmet was superseded by the H-2 helmet, which was an integrated design like the H-1. The H-2 helmet shell was similar to the H-3 with reinforcing ridges. The H-3 and H-4 helmets were not integrated but had a separate cloth inner helmet with communications and an outer hard-shell protective helmet.

Page 97:
The APH-5 helmet is based on the same helmet shell as the HGU-2/P helmet.

Page 101:
The VTAS I system was later installed on helmets based on the PRK-37 shell. When the shell was drilled for the VTAS I system it became a PRK-41/P shell, and the complete helmet became an HGU-30/P.

Page 105:
The helmet in the photos is not a modified HGU-20/P and it is not designated HGU-15/P in the shown configuration. The HGU-15/P was a USAF forerunner of the USN HGU-20/P. The helmet in these photos is one of 16 HGU-15/Ps modified for a 1971 study on helmets for use under chemical and biological warfare conditions.

Page 111:
The first VTAS II helmet was designated HGU-37/P. It is unclear how the HGU-37/P and HGU-46/P differ from each other.

Page 113:
The correct designation for the night vision goggles is AN/AVS-6. They are also known as Aviator Night Vision Infrared System (ANVIS)

Page 143-147 and 153:
The manufacturer's name is spelled 'Gueneau', not 'Guereau'.

Page 155, lower caption:
The Polish helicopter helmet is designated THL-5CN.

Page 156:
This series of helmets can be called the Sh-50 series. The Z & L designators (ShL-50 and ShZ-50) simply differentiate between summer (L) or winter (Z). The winter helmets are lined with a heavy fur and the summer 
ones have no liner. Otherwise the helmets are identical. In order to be clear on these, there are four different primary types of helmets in this series.

- Sh-50
- Sh-61 (also called the Sh-50a)
- Sh-78
- Sh-82

The helmets shown on this page are either the ShL-78 or ShL-82 for the top two pictures and an ShL-61 for the bottom pictures. The ShL-50 did not have the foam ridge on top and had a double strap arrangement on the back. The ShL-61 added the foam ridge (to keep the ZSh-3 hard shell in place). Note the difference between the back of the ShL-78 or –82 and the back of the ShL-61. The ShL-78 or –82 has a single strap on the back.

The Sh-50 used the KM-15 mask exclusively. It had no additional clips or receivers to hold a mask. The –61 was upgraded for use with the KM-16 mask. This upgrade is notable in the addition of the forehead clip and cheek 
clips. This style of clip was also used on the later KM-32 O-2 mask (see page 157 upper right). The mask married up with the helmet as opposed to being held onto the pilot's face by means of its own straps.

Page 157: 
The goggles on the left, affectionately called "bug eyes" by Russian pilots have the designation of PO-1M.

Page 158: 
The ZSh-3 is formed by a Sh-61 or newer leather helmet. The original Sh-50 was not used with the ZSh-3 until after the foam ridge was added. Once the ridge was added and the O-2 mask clips put in place, the helmet was designated the Sh-61.

Page 159: 
The air bag is called an occipital bladder. It fits into a pouch in the back of the leather helmets – Sh-61, -78, and –82.

Page 160: 
The helmet shown in the lower left picture is the ZSh-3B – the B means Bronirovannyj or Armoured. The visor is a twin visor system – the first full face visor is shatter resistant and the second visor is a sun visor that covers only the eyes. The sun visor is a dark charcoal in colour.

Page 161: 
The wooden shipping container is for a ZSh-3M, Size 2 (1-small, 2-medium, and 3-large are possible), the serial number, the size of the O-2 mask (this one is size 3, sizes 1-5 are possible), the inner helmet (this would be an Sh-82) size of 57 (European hat size, roughly equates to size 7 U.S.), and the date of manufacture of September 1990.

Page 163: 
In the upper right picture, note the hood beneath the helmet. Two different hoods were issued with each helmet. One, shown here is the winter hood. The other hood was simply a cotton skull cap (shown on page 165).

 Page 165: 
The BMSK should read VMSK-4 flight suit. Also, throughout the section on Soviet/Russian helmets – the LA-3 and LA-5 throat microphones should be used interchangeably as they are nearly identical. The LA-3 is chamois and the LA-5 is leather.

 Page 167: 
The designation of ZSh-7LP should read ZSh-7AP.

Page 168: 
Caption stating BMSK should read VMSK. The KM-35 is also used in the Su-27N (naval variant). And note that not all KM-35 masks have "KM-35" on the outer shell. The primary colour on the masks is Grey. Black is rare. The hard shell used for the KM-34D Series II mask is the same as the shell used for the KM-35.

Page 169: 
Helmet designation should read ZSh-7AP.

Page 170-173: 
No comments (not enough information on the GSh-4 – although the designation of GSh-4AA might not be correct).

Page 174: 
The right side pictures show the sizes of the helmet (both hard shell and inner communications) as 2B and 2M. The GSh-6 comes in numerous sizes – sizes 1, 2, and 3, small (designated as M), medium (no designator letter), and large (designated as B).

Page 175: 
The helmet shown here is the GSh-6A. The orange skirt is used 
exclusively with the VMSK-4 flight suit, which is used during over-water 
flights. The Green skirt is used with the VKK-6M.

The –6LP has eight lugs. There is no such variant as the "AA".

Page 188-199:
British helmet designations use Arabic numerals, not Roman. They are therefore Mk.1A/M, Mk.2A, Mk.3A/B, Mk.4, and Mk.5 respectively.

Page 192-193:
The Mk.3A helmet was equipped with a microphone for helicopter use. Mk.3B had hooks for oxygen mask attachment

Page 197:
The Mk.5 helmet was used by Tornado-crews, and it was produced by M.L. Aviation.