amonty
pm me if you wish. I have both a Mk3 and a Mk4 helmet.
The Mk4 is lighter...and doesn't cover so much of your neck as the Mk3.
If you are doing lots of G, you may find the lighter helmet a better choice. For me personally, I find the Mk3 more comfortable. The weight is not a problem as my stomach often tells me that I have had enough of aeros well before my neck muscles do.
Re the comms - I struggled for a long time to get this right.
The amp on JPs is on the aircraft, so any boom mic needs to be un-amplified. Racal sell them. The mics in the mask - oxy assembly will normally be un-amplified.
Dave Clark boom microphones will not work in JPs - because the Dave Clark mics have amplifiers built in.
IMHO, you should get whatever helmet you choose professionally fitted. A wrongly fitted helmet may not be a problem from an ejection point of view if the seats are not live....but inappropriate pressure on your forehead, or the visors not properly sitting in your field of vision, or not being able to close properly over the oxy mask will detract from your enjoyment of flying JPs.
Last edited by D SQDRN 97th IOTC; 23rd Apr 2010 at 12:33.