Aircraft technical Basics: Introduction to Airplanes - Navy Training Courses Edition of 1944: Chapter 11 Aviation Seamanship

CHAPTER 11 AVIATION SEAMANSHIP

HANDLING BOATS AROUND PLANES

AVIATION SEAMANSHIP relates to the WATER HANDLING OF SEAPLANES AND AMPHIBIANS   in all aspects - and to the OPERATION OF SURFACE CRAFT, large and small, in connection with such airplanes. Ordinarily there'll be a regular coxswain available for the job of handling small boats around water-borne aircraft, but you never can tell when EMERGENCIES are likely to arise, and YOU may be elected to take over. So it behooves you to absorb as much "savvy" of aviation seamanship as you can.

There are certain HABITS, common to the whole seaplane family, which you'll have to take into account whenever you're handling them - whether in independent operations or in operations involving the use of surface craft - such as towing, hoisting aboard ship, or lowering from ship to water.

Here's a list of these FUNDAMENTAL CHARACTERISTICS of seaplanes

On the water, with engine IDLING, a seaplane normally HEADS INTO the wind.

On the water, with engine STOPPED, a seaplane drifts quite rapidly before the wind and HEADS INTO (or very nearly into) the wind.

A seaplane, when anchored or moored to a buoy with no current in the stream, rides HEADED INTO the wind.

When anchored or moored to a buoy with current running, a seaplane will be CARRIED DOWNSTREAM by the current but will also tend to HEAD INTO the wind. The position which it assumes will depend on the combined effects of both wind and current.

Watch that boat, when approaching a seaplane. The construction of seaplanes, particularly of the wing and tail surfaces, has to be LIGHTWEIGHT. So they're liable to suffer severe damage if bumped against the ship's side or into contact with small boats. In your mind's eye, always look on sea-planes as if they had "HANDLE WITH CARE" signs plastered all over them.

In the normal course of operations, LIGHT-DRAFT boats which have a Low FREEBOARD and are easy to maneuver should be used in going alongside sea-planes. The boats best suited for the purpose are 26-foot MOTOR WHALEBOATS and 24-foot MOTOR-LAUNCHES, but in a pinch you can use ANY type of boat, as long as it has good backing power.

WHY BOATS ARE NEEDED

There are a lot of reasons why you'll be using boats for duties in connection with seaplanes. For instance, there's the job of TOWING a plane, perhaps to a new location, or to a ship to be hoisted aboard, or away from the side of a ship. Boats are also used for placing crews aboard planes, or removing them to shore. Maybe you'll have to go alongside planes that have crashed. Or you may be detailed to help REFUEL a seaplane from a boat.

As coxswain of a power boat tending planes, you have to be thoroughly familiar with the MANEUVERING qualities of your craft. There's as much difference between types of boats as there is between a tin lizzie and a fire engine, when it comes to maneuverability. Small boats used around sea-planes should always be equipped with soft fenders or "puddings" around bow and gunwales. These are usually made of canvas stuffed with kapok, or of tubular rubber.

Figure 37. - Small boat approaching a seaplane. Inset - Method of approaching a drifting seaplane.

What's the best method for approaching and going alongside a seaplane if you're in a motor whaleboat or motor launch? The answer to that one depends upon the condition of WIND, SEA, and TIDE. There are some good general rules to follow, with an eye to these factors. You approach a DRIFTING seaplane from windward as in figure 37, so that it won't drift down on you. A plane drifts more rapidly than a boat, as it has a greater surface exposed to the wind. But a MOORED or ANCHORED seaplane should be approached AGAINST wind or current, depending upon which has the most influence. Always approach in such a way that your boat. will tend to drift AWAY from the plane in case your engine stops.

You'll keep your record clean every time if you follow orders carefully and AVOID CONTACT between boat and seaplane. Seaplanes are delicate.

Use MINIMUM power on your boat engine. Don't approach drifting seaplanes from the stern.

Make sure that the men in your boat fend off by HAND - NOT with boathooks.

Stay clear of planes until swells from passing ships have SUBSIDED.

Avoid unnecessary DELAY when transferring personnel between boat and plane.

Never go alongside a seaplane which has its engines running unless ordered to do so by the pilot, and then KEEP CLEAR OF THE PROPELLERS.

If it is ever necessary for you to tend a seaplane with a large power boat that is difficult to maneuver, it is a good plan to anchor AHEAD of the plane and allow the boat to DROP BACK by veering the necessary amount of chain. If the seaplane is small, it is possible to anchor the boat and pull the seaplane up to the boat.

TOWING SEAPLANES

TOWING A SEAPLANE on the water presents some special problems, but they'll usually solve them-selves if your remember those fundamental habits of water-borne aircraft that were pointed out earlier. Varying conditions of wind and sea, the available gear for the towing operation, and the type of towing craft will all affect the choice of tactics and methods for attacking the particular job.

Old-timers will tell you that towing operations usually fall into one of two classes

The towing of SMALL, FLOAT-TYPE SEAPLANES by small boats for relatively SHORT distances.

The towing of PATROL-TYPE SEAPLANES by large or small surface craft for comparatively GREAT distances.

Why? Because all capital ships, cruisers, and carriers of our fleet are equipped to hoist aboard small types of seaplanes and to stow them properly. Small boats can handle the necessary towing, as the hauls are short. On the other hand, only a FEW aircraft tenders have facilities capable of hoisting LARGE patrol seaplanes aboard, and even then can do so only under VERY favorable conditions. What's the answer? LONG hauls whenever towing of patrol planes is necessary.

The operations of small seaplanes with the fleet are such that, if there is a forced landing and towing is required, there is almost always a near-by ship which is equipped to furnish a boat for towing the plane alongside. Patrol planes, however, operate over large sea areas, and ships equipped to take them aboard are SELDOM available.

TOWING GEAR

Ship-based seaplanes are commonly towed by means of line - or lines - secured around the FORWARD float struts and led through the cleat at the Bow of the float, as shown in figure 38. Most planes of this type do not carry their own permanently installed towing gear, so it must all be provided by the towing boat. This gear includes a 21-thread manila TOWLINE which is 20 fathoms long (120 feet), TWO WING LINES, also 20 fathoms long and equipped with heaving line, and CHAFING GEAR (for seaplanes not equipped with towing shackles at the base of forward float struts).

Whichever approach you make, the boat must be kept directly to WINDWARD of a DRIFTING plane and - as soon as the towline is passed - maneuvered to head into the wind straight AHEAD of the aircraft. If towing is to be done across wind, the seaplane should then be pulled up near enough to the boat to pass wing lines. Here's a tip to the wise - DON'T HESITATE TO USE WING LINES, as in figure 39. They are mighty useful in steering a plane that's in tow, and are especially important on the windward wing to prevent yawing when towing across wind. But don't put the strain of towing on the wing lines. They are not meant for such use.

Figure 38.-Securing a towline to a seaplane.

A 20-fathom towline is long enough to allow an approach to a drifting seaplane - bows on - from windward, to pass the towline, and to turn and head into the wind before taking a strain. In LIGHT winds, sometimes it's better to approach the seaplane from abeam and turn into the wind just ahead of the plane, passing the towline as the turn is made. The approach in figure 37 is being made that way.

Figure 39.-Small boat towing a seaplane.

It is best if the ship to which a seaplane is being towed is also kept to WINDWARD. Such a position not only permits an up-wind tow, but also provides the protection of the LEE. When you reach the ship, pass the towline and wing lines up to the deck so the plane can be hauled under the hook.

TOWING PATROL PLANES

What about towing the patrol-type plane? When water conditions are smooth, these bigger craft may be towed by means of the anchoring and mooring pendant, with the aid of steadying lines. But if you have to tow a loaded plane a long distance - or through a rough sea - you'll be needing a TOWING BRIDLE.

All patrol planes are equipped to accommodate a towing bridle. Rings for the purpose are provided in the leading edge of monoplane wings. The rig you use will depend upon the circumstances, and the particular practices of your operating unit.

DISABLED PLANES

If a seaplane is DAMAGED OR DISABLED on the water, what's the first thing you'll do ? Right. Look after the PERSONNEL aboard the plane. Make sure they're safe and not in immediate danger. Next, the RESCUE VESSEL should proceed to a spot alongside, where a line can be thrown to the plane. If that's impossible a boat must be lowered to tow the plane to the ship so that efforts can be made to hoist it from the water.

The HOISTING SLING, located above the upper wing of seaplanes, is almost always the best place for attaching the hook suspended from the boom on board ship. Damaged planes, however, don't behave the way you would like, most of the time. Often it's necessary to fix up a JURY RIG for hoisting.

The PROPELLER HUB, the ENGINE MOUNT, the ARRESTING HOOK or SLING EXTENSION (On carrier-based airplanes), or the JUNCTION OF BRACES in the fuselage (where the arresting hook is fastened when installed), are useful points for attaching a jury rig. If you can't use these strength members as attaching points, then STRAPS (wide ones) can be passed through a fuselage bay and led to the hook or a common junction point for hoisting. Chafing gear, and spreaders to hold the straps in place, should be employed to prevent further accidents or damage to the plane.

As the plane is raised slowly from the water, openings must be made in the fabric of wings and fuselage to release the water that has entered. The easiest way to make them? Slit the fabric with your jack-knife. If the hoisting gear still can't handle the load, you may have to punch a hole in the bottom of the hull or floats to let the water run out. But remember, that's only a LAST RESORT.