Why didn't Cessna planes in Bicol, Isabela incidents send distress signal?

Jacque Manabat, ABS-CBN News

Posted at Feb 24 2023 12:38 AM

MANILA — It took aviation authorities three days to confirm that the wreckage near Mayon Volcano was that of the Cessna 240 that went missing on February 18, while it has been over a month since a Cessna 206 went missing in Isabela.

The search for these planes could have been quick if only these aircraft were able to send a distress signal. 

However, the Civil Aviation Authority of the Philippines (CAAP) confirmed it did not receive any distress signals from both Cessna planes the day they went missing.


A distress signal is sent through the Emergency Locator Transmitter (ELT) activation. The emergency beacon device should automatically send a distress signal to alert rescue authorities and indicate the location of the aircraft. 

Once the ELT detects a sudden drop in altitude, changes in the plane's movement, or gets submerged in water, the device automatically sends a distress signal to the air traffic systems. 

This signal would be received by CAAP's Communications, Navigation, Surveillance/Air Traffic Management (CNS/ATM) in Pasay and as far as mission controls in Hong Kong and Japan, prompting air traffic controllers to alert rescue authorities and pinpoint the aircraft's location in real-time.

The pilot could also manually activate ELT through a red remote switch and control panel indicator in the cockpit.

The ELT is encased inside the tail part of the small aircraft and connected to an antenna. Aviation experts said that the tail is sturdy enough to protect the ELT, and it's the part that usually survives a crash.

CAAP said small aircraft would only pass the regulatory body's annual inspection if the ELT is present or functions. Only then can CAAP grant small aircraft operators an Air Worthiness Certificate. 

In the case of the Cessna 206 missing in Isabela and the Cessna 340 that crashed in Bicol, CAAP maintained that the two aircraft are airworthy.

“Equipped sila ng ELT," CAAP spokesperson Eric Apolonio said. 

"Naisyuhan po yan (ng Air Worthiness Certificate) because unang-una, nabanggit natin yung ELT - meron sila nung time na tine-test namin, nagfa-function po 'yung ELT.”

("The planes are equipped with ELT. They were issued Air Worthiness Certificates because their ELTs were functioning at the time of inspection.")


Most flying schools use Cessna planes to train their pilots and maintenance engineers. Among these schools is the Alpha Aviation Group, which operates the most Cessna planes in the country, with over 30 stationed in their training centers in Pampanga and La Union. 

The flying school said Cessna planes are safe to use as long as it is properly maintained. A part of their protocol is to check the ELTs in their aircraft. 

“As long as you follow what is prescribed by the manufacturer, it is (safe)," AICAT Alpha Aviation group Aircraft Maintenance Manager Renz Jayson DIlag said. "Parang sasakyan. Kung mine-maintain mo 'yung sasakyan, kahit luma yan okay lang."

("It's like using cars. If you ensure it is well-maintained, it's OK.")

Dilag also explained that there are two possibilities why the ELT will not function: a discharged battery or its antenna fell off. 

“Dapat talaga automatic siya (ELT), kaya meron tayong check every year na nilo-log natin. Kasama siya sa annual inspection na inaaprubahan ng CAAP para ma-lessen yung chances... maging remote 'yung chance na hindi gagana yung ELT," Dilag added.

("ELTs should function automatically, that's why we have yearly checks which we log. It's part of the annual inspection approved by CAAP to lessen the chances that the ELT will not work.")

Aside from the ELT, there are other tools or protocols for pilots in cases of distress. They are trained to send an emergency code through a transponder device found in the Cessna cockpit, which then sends a signal to air traffic control. All these and other emergency responses are part of a pilot's training.

"For instance, if the Cessna is experiencing mechanical failure engine failure, it is not to panic or to follow the procedure. Here, we train the cadets to react calmly even in worst-case scenarios," Capt. Gimby Cervania, head of training of AICAT Alpha Aviation Group, said.

CAAP is still trying to determine why there were no distress signals sent by both Cessna planes. The regulatory body, which also acts as investigators in plane crashes, will include this in its investigation. CAAP has said must examine the wreckage up close to determine why the planes went missing.


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