Seasprites Get New Teeth
F/S Rob ‘Baden’ Powell
F/S Powell with the Seasprite's new mount and gun. (WN-08-0037-33-tn).
Since the introduction of the SH-2G Super Seasprite, No.6 Squadron has been using the M-60 Machine gun to support the Navy during boarding operations and other tasks.
The M-60 gun and associated M-25 gun mounting system has proven to be unreliable in support service limiting operational effectiveness. Problems include spent cases which can bounce out from the attached catch box and back into the gun working parts, causing gun stoppages. Even when working properly, the catch box can only hold a maximum of 150 spent cases, which does not match the ammo box which holds 200 rounds. Finally, the gun is fitted with open sights which are too inaccurate for use in these days of minimising risk to innocent parties on the ground/at sea.
In late 2007, the weapon users (No.6 Squadron Operations) raised a user requirement to have the gun replaced with the Belgian Fabrique Nationale (FN) MAG-58M gun. This is already in use in the NZDF on the Huey, and has been well proven. It would give us an opportunity to standardise NZDF helicopter-borne machine guns, introduce more accurate laser targeting sights (also in use with No.3 Squadron) and sort out the gun mounting system once and for all. An ambitious target time for introduction of service for the new gun and mount was set for April 2008, as HMNZS Te Mana was to go on operational deployment, ideally with the new gun.
Being an Aircraft modification, certain set procedures had to be complied with. At no stage were we prepared to accept shortcuts to meet the time line. This meant extensive consultation had to be made between users, (No. 6 Sqn Operations and Armament) TS Arm, 485 Wing, and Base Auckland MSS (particularly the Skin Bay, Metal Working and Machining sections and Base Armoury).
An original FN retractable gun mount was obtained and taken to No. 6 Squadron. Much head scratching and brainstorming ensued. As the gun mount has to be retracted inside the cabin to allow faster transit speeds, the FN mount was deemed unsuitable. It was decided to secure the base of the mount to the cabin as per the M-25, and adapt the original gun cradle. After test fitting, the cradle evolved to its current shape and a new top limit stop was also made by Machine shop to prevent the gun shooting off the nose of any missile that may be fitted to the weapons pylon (unlike the M-60!).
Following the Modification schedule, we had to write new draft maintenance and user procedures, produce engineering drawings and raise engineering concessions to allow test flying with a prototype system, all with heavy support from TS Arm. Once this was done, we could proceed in accordance with the trial proforma, starting off with testing the gun mount in an airframe for proper fit and ease of use, then progressing to ground test firing on the flight line with blank ammo, then a full day into night flight with live ammo.
Immediately trials began, it was apparent that the gun system was leaps and bounds ahead of the M-60. The new catch box can hold in excess of 500 rounds, and only one stoppage was encountered in over 1200 rounds. It was noted that the beaten zone around the target was much tighter, the gun was more easily controlled, and combined with the new laser sight, it was far more accurate than the old gun.
Once the trials were complete, the nod was given to put the mount into production. Professionalism came to the fore as all parties finalised the design and paperwork, and built the new production mount in just over a week. The afternoon we received the brand new mount, we used it on a gunnery sortie, firing 800 rounds without a hitch. The very next day, it was on board Te Mana, ready for her deployment three days later.
Through professionalism, integrity and teamwork, all agencies mentioned above, (plus others) proved that the RNZAF can introduce important items of new operational equipment in a very tight time frame - without having to take shortcuts - and for that they deserve commendation.
With good fortune, Te Mana will not have to use the new gun, but if they do, they can be assured that they are using the best gun system ever fitted to a Seasprite. All here at No. 6 Squadron wish Te Mana and her crew smooth sailing and an operationally effective and safe deployment.