Exercise 9. Underline the correct word or word combinations in the following sentences.

1. Lack of information by the (inaccurate instructions | control tower), or delayed instructions, are major factors contributing to accidents.

2. The dangers of more powerful (positive lightning | faulty instrument) were not understood until the destruction of a glider in 1999.

3. The (icing | de-icing) of wings is another problem and measures have been developed to combat it.

4. Even in the 1940s, several Yakovlev Yak-9s experienced delamination of (wood | chip board | plywood) in their construction.

5. The use of(lacunas or misting systems |smoke hoods) were examined although both were rejected.

6. Bird strike is an aviation term for a (crash | collision) between a bird and an aircraft. It is a common threat to aircraft safety and has caused a number of fatal accidents.

7. An electrical fire on Air Canada Flight 797 in 1983 caused the deaths of 23 of the 46 passengers, resulting in the introduction of (floor level lighting | evacuation) route to assist people to evacuate a (survivability | smoke-filled aircraft).

8. The tests measure (flammability | fire bottles) and the (toxicity | survivability) of smoke.

9. Poisonous grass can be planted that is not palatable to birds, nor to insects that attract (high-bypass | insectivorous)birds.

10. As the failure develops inside the material, nothing is shown on the surface; (cyclic stress | instrument methods),often (de-iced | ultrasound-based), have to be used to detect such a material failure.