Accident Lockheed C-130H3 Hercules 94-6706,

ASN Wikibase Occurrence # 319167

Date:	Monday 8 June 2020
Time:	22:05
Type:	Lockheed C-130H3 Hercules
Owner/operator:	United States Air Force - USAF
Registration:	94-6706
MSN:	5398
Year of manufacture:	1995
Engine model:	Allison T56-A-15A
Fatalities:	Fatalities: 0 / Occupants: 26
Aircraft damage:	Substantial, written off
Category:	Accident
Location:	Al Taji Army Air Field - Iraq
Phase:	Landing
Nature:	Military
Departure airport:	Ali Al Salem Air Base (OKAS)
Destination airport:	Al Taji Army Air Field (ORTI)
Investigating agency:	USAF AIB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
The Lockheed C-130H3 Hercules departed Ali Al Salem Air Base, Kuwait at approximately 20:53 local time. After cruising for approximately 59 minutes, the aircraft began its descent into Camp Taji, Iraq. During descent, the crew leveled off at 3700 feet mean sea level (MSL) and reduced throttles to flight idle. The copilot slowed and configured the aircraft for a night vision device (NVD) approach and landing with flaps set to 100 percent. The aircraft's highest recorded airspeed during this approach was 157 Knots Indicated Air Speed (KIAS), although the maximum recommended airspeed with the wing flaps set to 100 percent is 145 KIAS. At approximately two nautical miles (NM) from the airfield, the aircraft was 1000 feet above the recommended glideslope for runway 34 and at 150 KIAS, and remained above glideslope until landing. The reported tailwind for runway 34 at Camp Taji was 10 knots, with a temperature of 34 degrees Celsius. The aircraft crossed the runway 34 threshold at a ground speed of 161 knots (151 KIAS); the recommended calculated landing velocity for the aircraft at its weight (122,000 pounds) was 105 KIAS.
The crew attempted to land the aircraft at higher than optimal speed with a nose-down attitude. The aircraft's excessive air speed continued to generate lift on the aircraft and caused it to porpoise upon touchdown, which prevented the aircraft's braking system from engaging due to a lack of proper weight on the wheels. Thirteen seconds after touchdown -eight seconds of which were spent
porpoising- the aircraft began to slow as expected, once the engines were placed in reverse and when the wheels then received adequate weight to engage the anti-skid brakes. However, by that point there was insufficient runway remaining (less than 1000 feet) and the aircraft departed the prepared surface, whereupon it came to a stop only when it struck a 12-foot-high concrete barrier approximately 600 feet past the end of the runway, at approximately 22:05 local time. All 26 individuals onboard the aircraft survived the mishap and egressed, with only relatively minor injuries to two individuals.

CONCLUSION by AIB President:
After a comprehensive investigation into this mishap, I find, by a preponderance of the evidence, the cause of the mishap was the aircrafts excess indicated airspeed on approach, which developed into the subsequent floating and "porpoising" of the aircraft after touchdown, further resulting in continued lift and insufficient WOW to apply braking action.
Additionally, I find, by a preponderance of the evidence, that the crew's failure to adequately assess risk, failure to follow proper procedures, and poor communication were all substantially contributing factors to this mishap. The crew failed to recognize, and appropriately respond to or correct the aircraft's excess airspeed on the approach, or to take control of the aircraft and call for/conduct a "go-around" once the approach and landing was deemed untenable.

Accident investigation: