DGCA warns pilots of locust risks

It says there is a need to avoid flying through a swarm

The Directorate General of Civil Aviation (DGCA) on Friday issued a circular cautioning all pilots, operators, ground handling agencies and air traffic controllers against the risks posed by locust swarms.

Stating that the country was witnessing an unusually high locust activity this year, which was last seen over 20 years ago, the DGCA said there was a need to avoid flying through a swarm.

“As locust swarms fly along the current wind, their path of travel changes with the change in wind direction. Pre-determination of their travel path is difficult to forecast as weather satellites and other satellites used to monitor the environment cannot detect locust swarms,” said the circular.

Generally locusts are found at lower levels and therefore, pose a threat to aircraft in the critical landing and take off phase of the flight. Almost all air intake ports of the aircraft will be prone to ingestion in large numbers, if the aircraft flies through a swarm. (areas like engine inlet, air-conditioning pack inlet, etc).

“Pitot and static sources can also get partially or fully blocked while flying through locust swarms. Blocked pitot and static sources lead to erroneous instrument indications, especially unreliable air speed and altimeter indications,” it said.

The DGCA said although an individual locust was small in size, impact of large numbers on the windshield was known to have impacted the pilot forward vision. “This is a grave concern during landing, taxi and take off phase. Use of wipers at times may cause the smear to spread even more. Pilot should consider this aspect prior to opting to use wipers to remove locust from the windshield,” said the circular.

Large swarms can also obstruct visual ground contact over a large area, therefore flights under Visual Flight rules also need to be aware of their presence. “Air traffic controllers, when aware of locust presence in the vicinity of their aerodrome, are advised to share the information with all arriving and departing flights,” said the DGCA, adding that it being a day time phenomenon, the pilot is also expected to keep a keen eye for any such observations.

“All pilots are also required to share information of locust swarm location if they have sighted any during the flight. As far as possible, it is strongly advised that flights should be avoided through any known locust swarm. The only favourable aspect is that locust do not fly at night, thus providing better opportunity to sight and avoid them,” the circular said.

Post a flight through a locust swarm appropriate entry in the pilots defect log should be made giving details of any malfunction experienced and the engineering crew should conduct checks as mandated prior to release of the aircraft for next flight. The ground handling agencies should be aware that locust swarms also pose risk to parked aircraft. Therefore, wherever possible, air inlets and probes should be covered.

Locust swarms fly at roughly the speed of the wind, cover distances up to 200 km per day and are known to have reached till 2,000 metres above sea level. Locust swarms can vary from less than 1 to several hundred square kilometres. There can be at least 40 million, and sometimes as many as 80 million locust adults, in each square kilometre of swarm.