Sunday, 4 March 2012

Water Ops - Water Dams

Water Dam

Amphibious helicopters, both the Voyageur and Labrador exercised regularly and often in the water.  At times both variants conducted water borne procedures that necessitated opening the ramp and upper hatch.  To keep water from out of the cabin and from sinking the aircraft, a water dam was used.

In the beginning, Labradors would land on the water, dispatch the boat or dinghy all while the rotors were shut down.
As the air frames accumulated more hours they became more porous so the procedure evolved to the boat launch and recover.  Photo Boeing Vertol
In addition to hard points for securing equipment, the Voyageur and Labrador both had floor drains...if memory serves me, there were three of these. On more than one occasion the drains were left open causing the crew to react in haste to get back in the air and drain the water from beneath the floor boards, put the drain plugs in place and return to the water exercise.

In the 70's and into the 80's we used to conduct boat launch and recovery on a fairly frequent the late '80s we hardly every carried out the procedure. DND photo
The dam of each variant differed only marginally, and perhaps not enough for the modeler to notice.  Firstly, the dams were constructed of different materials and finished differently.  The Labrador ramp was made of lightweight metals and finished in the same gray as the interior of the cabin.  The Labrador dam, when in place at the end of the bench seats and ahead of the ramp was no taller than the box seats.

In the Voyageur, the ramp was made of wood and finished with a clear varnish or lacquer, so looked like a finished sheet of plywood.  Voyageur dams were slightly taller than that of the Labrador with the top of the dam above the top of the box seats.

Another noticeable difference between the dams of these two aircraft was their storage location when not in use.  It was common for the dam to be in place, especially when the aircraft was on SAR standby, however this was not a hard and fast rule.

While this is how I recall the Labrador's water dam, this is not the same storage location. Photo courtesy Jeff Wilson
On either bird, the dam was occasionally stored behind the stretchers at the rear of the cabin, however the more usual storage location was on the ramp area sidewalls, the Lab dam stored on the right side the Voyageur’s stored on the left side.  Since the Voyageur had a hydraulic hand pump at the forward end of the ramp on the right sidewall, placement of the dam in this location was impractical, so the same location on the left side was selected.

Towards the end of 113 service the dam was stored in the same location on both the Labrador and Voyageur.
The grey hydraulic pump handle located just above and slightly behind the ramp hinge prevented storage of the dam on the right side of the fuselage on the Voyageur where it was stored on the Labrador. Photo courtesy of Jeff Wilson
Despite practicing, several different waterborne procedures frequently right up until the late 1980s there are only a handful of rescues where the aircraft was actually put into the water to conduct the rescue. As an exclamation mark to the aging aircraft’s declining ability to conduct water ops, 424 Squadron Trenton almost lost a helicopter during a rescue because the crew forgot to put drain plugs in place…at one time an instinctive procedure for all crew members.!

The fact the door extension is on the lower dutch door and the door's position is near horizontal, indicates front door pickups of SAR Techs is underway. The water dam will be in place even though the ramp will remain closed. DND Photo
DND Photo
Front door pick up, note the aft upper hatch is open. DND Photo
Note the early style fuel dump tubes on the outside and back of the external tanks.
Front door pickup without any front door extension.
This is an actual operation after the FV Sisters Three sank off the west coast of Vancouver Island.

Front door entry. DND Photo

Note the lower dutch door while closed, still has the door extension attached.
SAR Mewasige, a 424 Squadron Trenton Voyageur picks up survivors from a grounded boat off Mississagi Island, Ontario. Photo Courtesy Ted Brown (424 Squadron Buffalo Flight Engineer)

MMMMarch 18 – 1978; Labrador 304 from 442 T&R Squadron, CFB Comox crewed by Major Mike Angelsey (AC), Captain Mike Clark (FO), Flight Engineers Dennis (BJ) B., Bob Ardelian and Rescue Specialists Don Lane and Danno Schut prepare to recover five survivors from the life raft of the fishing vessel (FV) Mothers Three. The crew of 304 was deployed to Tofino to watch the herring fleet when RCC diverted them to the Mothers Three. A Comox based Argus was assigned as top cover for the Labrador when it took the above picture.

Attempts to hoist the survivors from the raft were aborted. It was later learned the rafts’ sea anchor was not deployed causing the rotor wash to blow the raft aimlessly about the calm sea. Following a short discussion, it was decided that Rescue Specialist Team Leader Don Lane would swim to raft with rope in hand. Once on board the raft, the now six persons would pull themselves towards the helicopter’s right side door. After being adrift on the Pacific for five days, the crew of Mothers Three was returned to dry land via Port Hardy and a short hospital stay.

An interesting aside to the story is that the rope used to pull the raft to the helicopter was tied around the right spotter seat post and may have contributed to the seat breaking…and by extension perhaps a contributing factor in the reason Labrador seats were replaced with Argus seats?  Danno Schut provided details of the rescue. !

1 comment:

  1. Great pics. Brings back grand memories working as a SAR Tech. in 442 Sqn. Comox---"That Others May Live".