How can the pilot determine, for an ILS runway equipped with MALSR, that there may be a penetration of the obstacle identification surfaces (OIS), and care should be taken in the visual segment to avoid any obstacles?

Explanation:

Dissolve 2 -naphthol in ethanol in a round bottom flask.

Add sodium hydroxide pellets and boiling chips. Attach a condenser.

Heat under reflux for 20 minutes, until all the base dissolves.

Add 1 -bromobutane and reflux for an additional hour.

Pour the contents fo the round bottom flask into a beaker of ice

Collect the precipitate by vacuum filtration on a Bachner funnel

Rinse the product with cold water and dry it on the filter.