iii. An enlargement of the map or in certain cases a written

message may be dropped from the aeroplane giving the exact position of the target.

A combination of any two or of all these methods may be used.

=204.= _Observation of fire from aircraft._

1. For observation of fire from aeroplanes a different system to that ordinarily employed for ranging must be adopted. It is generally necessary to correct for line, range and fuze in succession, and not simultaneously.

As a rule single rounds are sufficient for observation, but it may sometimes be necessary in the case of Q.F. batteries to fire salvoes of two or more guns.

Salvoes may also be used when it is desired to carry out the observation of fire of one particular battery by aeroplane, and it is necessary to distinguish its fire from that of several others firing at the same target.

2. Shrapnel bursting in the air can be easily seen, but it is difficult to determine the height of burst, and consequently the position relative to the target. Bursts on graze are generally visible. In the case of 18-pr. guns, it is usually impossible to observe the strike of the bullets on the ground. The burst of lyddite shell from howitzers can be seen easily.

3. Very’s lights form the best means of signalling from the aeroplane to the ground, and white strips of cloth, 6 ft. by 1 ft., for communication from the ground to the aeroplane. If available a Klaxon horn in the aeroplane is also useful. For code of signals, _see_ Sec. =205=.

When possible, the observing aircraft should remain close to their own guns at the best height for observation, in order to facilitate communication. In some cases, however, it may be necessary to fly out further towards, or even over, the target in order to ensure accurate observation. In such cases much delay will ensue if the aeroplane has to come back over its own guns to signal the results; on the other hand, if it remains out in front the signals may not be seen.

4. The observer, having located the position of the target and conveyed the information to the artillery commander (_See_ Sec. =203=) receives from him the signal “Observe for line” (_See_ Sec. =205=).

The aeroplane now moves as in Fig. 32, keeping on that side of the battery furthest from the sun, so that the signals can be easily seen.

Shots can only be seen with ease when the aeroplane is moving out towards the target. If the distance A to B is about 1 mile, two rounds can be observed during each outward flight. As soon as line is obtained the signal “Observe for range” (_See_ Sec. =205=) is sent; the aeroplane now moves in an elongated figure of eight, as in Fig. 33, always turning towards the target. It will keep behind or in front of the battery according to the position of the sun. Shots can be seen at any time.

Range having been obtained the signal “Observe for fuze” (_See_ Sec. =205=) is sent, the aeroplane still moving as in Fig. 33.

Subsequent observation as to the general effect of the fire can best be made from over the target, the results being written out in a message and dropped at the battery.

When the signal “Land” is sent the aeroplane comes down at a place previously selected and not necessarily at the spot whence the signals are sent.

Two men should be detailed from the battery to watch the observing aeroplane, one with field glasses looking for the signals, the other with his naked eye keeping a continuous watch on it so as to make certain that no mistake is made as to the actual machine, since, when there are several aircraft out in observation, confusion between them is very likely to arise.

=205.= _Signals from and to aeroplanes._

1. With Very’s lights the following code of signals will be used for communication from the aeroplane to the ground:--

(_a_) Before fire is commenced--

One white light I am over the target. One green ” I am ready to observe fire.

(_b_) While ranging--

--------------------+-------------+-------------+-------------- Light used. | For Line. | For Range. | For Fuze. --------------------+-------------+-------------+-------------- One red. | Right. | Over. | Air. Two reds. | Far right. | Far over. | -- One green. | Left. | Short. | Graze. Two greens. | Far left. | Far short. | -- One red, one green. | Line. | Range. | Fuze correct. One green, one red. | Unobserved. | Unobserved. | Unobserved. --------------------+-------------+-------------+--------------

Succession of blasts on Klaxon horn Am about to fire two signals.

The signal “Far right” or “Far left” should be made when the shell bursts 8 degrees or more from the target. Any shell bursting 500 yards or more short of or beyond the target should be signalled as “Far short” or “Far over.” “Fuze correct” will be signalled when some of the shells burst on graze and others in air.

(_c_) After fire for effect has commenced--

Red, green Fire effective.

A white light fired at any time after fire has commenced means “Stop, am about to drop a message.”

2. Strips of white cloth 6 feet by 1 foot, placed on the ground, can be used for signalling from the ground to aeroplanes. The following code of letters formed from the white strips placed on the ground will be employed.

3. I } Direction of target. I } L Observe for line. X Observe for range. Z Observe for fuze. V Observe for general effect of fire. N Repeat last signal. T Land. F/ Fresh target on right.

The letters I, K or A may be placed immediately after the F to indicate to the aeroplane observer the nature of the target, viz., I for infantry, K for cavalry, and A for artillery.

All letters should be placed on the ground so that the top of the letter is towards the target.

=206.= _Observation of fire from kites._

1. When kites are available the results of the observation can be telephoned down to the guns and there is no waste of time, but they can only operate in a wind (_See_ Sec. =150=), and their range of vision and power to see behind cover is limited.

Kites require special consideration and the exact place from which they should be flown should be chosen by a kiting officer. Some of the requirements are:--