Factors In Ice-Induced Hard Landings, Part 1 

Author submitted photo

The accident aircraft, an Embraer Phenom 100.

Credit: BEA/jetphotos.com

A charter crew approached Paris Le Bourget Airport in their Embraer EMB-500 Phenom 100 on the morning of Feb. 8, 2021. The wing and stabilizer de-icing system was not turned on when they passed through a layer of freezing clouds on final approach, and at 50 ft. above the runway, the airplane stalled. It descended rapidly and the recorders, FDR and CVR stopped when the airplane struck the runway. That happens when the G-load exceeds 5gs.
 
The crew did not forget to turn on the “Wingstab” de-icing system; they made a conscious decision to leave it off. Other Phenom pilots before them had made the same decision in similar circumstances, with the same results. One such accident took place in Germany in 2013 and another took place in the U.S. in 2014.
 
After those accidents, both the German BFU and the American NTSB made recommendations to prevent such accidents, but they weren’t entirely successful. The French Bureau d’Enquetes et d’Analyses (BEA) analyzed the Paris accident and came up with an additional insight that might be more helpful.
 
The accident flight departed Venice, Italy, at 0917 Paris local time and climbed to FL 340. The charter flight carried a two-pilot crew and one passenger. The co-pilot was the pilot flying. While enroute, the crew discussed the possibility of snow and a contaminated runway at Le Bourget and they tested the anti-icing system to ensure it was working. About 45 min. before landing, and before listening to the terminal information broadcast (ATIS), they briefed the normal clean-wing approach speeds. Those speeds were 97 kt. Vref, 102 kt. VAC (approach climb speed), and 121 kt. for VFS (final segment speed).
 
When they listened to the ATIS, it reported that the temperature was -1C (30F) and the dew point -3C and that there was severe icing between 3,000 ft. and 5,000 ft. The captain discounted this information, saying there was no snow and that icing was common near Le Bourget. The crew briefed the ILS approach to runway 27, planning to use full flaps and autopilot engaged. They did not consider any changes to the approach speeds.
 
Ten minutes before landing, the crew turned on the engine anti-icing and windshield demist/de-icing systems. As they intercepted the localizer, the crew activated the Wingstab de-icing system. Only 21 sec. later, after observing ice breaking off the wings, they turned that system off. They intercepted the glide slope, switched to the tower and were cleared to land on runway 27. They ran the before-landing checklist, and the captain turned off the engine anti-icing system.
 
The captain later stated that the cloud layer began just below 5,000 ft. and ended at 2,000 ft., and there was another thin layer at 1,500 ft. He did not see ice forming on the wing after he turned off the de-icing system.
 
At 300 ft. above the approach end of the runway, the airplane was stabilized at 100 kt. IAS and the autopilot was disengaged. Then the airplane began slowing and sinking, with the airspeed falling to 90 kt. and the angle-of-attack (AOA) increasing to 28 deg. The wings began to rock and the sink rate increased to 960 fpm.  The captain, saying the airplane was too high on the glide slope, took control. The “STALL STALL” aural warning sounded and the captain attempted to advance power for a go-around. The airplane stalled in a 10-deg. right bank and landed hard.
 
The airplane came down only 33 ft. past the runway 27 displaced threshold and slid 3,445 ft. before veering off the left side of the runway and pivoting around to a heading of 160 deg. The nose gear broke off and the right main landing gear penetrated the right wing and the right fuel tank. A fire broke out near the wing root, but the occupants were able to safely evacuate the burning airplane. Aircraft Rescue and Fire Fighting Service (ARFF) responded and doused the fire.

Part 2: Clues to why the Phenom crashed.
 

Roger Cox

A former military, corporate and airline pilot, Roger Cox was also a senior investigator at the NTSB. He writes about aviation safety issues.