Aviation regulator Directorate General of Civil Aviation (DGCA) on Friday issued guidelines for all airlines staff including pilots informing them of the risks posed by locust swarms hitting aircraft on landing or take-off and how to avoid flying through a swarm.
“As locust swarms fly along with 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 can detect Locust swarms. 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,” read the circular issued by DGCA.
The circular cautioned that 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 pilot and static sources lead to erroneous Instrument indications, especially unreliable airspeed and altimeter indications. Though an individual Locust is small in size, the impact of large numbers on the windshield is 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 wind shield,” the DGCA said.
The circular further said that 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. 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,” circular reads.
“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 the release of aircraft for next flight. Ground handling agencies should be aware that Locust swarms pose risk to parked aircraft, where possible air inlets and probes should be covered,” the DGCA said.
The airline regulator’s circular said that the only favourable aspect is that locusts do not fly at night, thus providing a better opportunity to sight and avoid them.
DGCA said that the level of presence of Locusts witnessed this year was last seen more than 20 years ago.
“Locusts are potentially very dangerous pests as they have the ability of swarms to fly rapidly across a great distance. Locusts swarms fly with the wind at roughly the speed of the wind, therefore, covering distances up to 200 kilometres per day and are known to have reached heights of 2000 meters above sea level,” it said.
Flight operations commenced since May 25 since it was suspended from March 25 following worldwide coronavirus pandemic.