CARGO DOOR LOSS IN UAF811-CASE STUDY

1. LOSS OF CARGO DOOR
IN
FLIGHT UAF-811
Varun K
144520,MTECH
EI,NITW

2. INTRODUCTION
• Happened on February 24th 1989 after the stopover
@ HONOLU INTER.AIRPORT ,HAWAI
• Door collapse  DECOMPRESSION
• DECOMPRESSION 10 SEATS blew out  Death of 9
passengers.
• Emergency landing on nearest runway after 15
minutes.

3. WHAT HAPPENED ???

4. UAF 811

5. • HONOLU INTERNATION AIRPORT
NEWZELAND
• 3 flight crew + 15 flight attendants+337 passengers
• 22000-23000 feet.
• Grounding noise with thunder from the business class
section.
• Cargo door blown away.
• Loss of seats(G and H rows ) + one seat from 9F
section along with passengers-9 peoples killed.

6. Artificial Oxygen System Flight Engine

7. • 4 engines E1,E2,E3,E4
• Severe damage to E3 and E4-flaming
• Shutting E3,Dumping fuel to reduce weight during
landing, Shutting E4.
• Emergency landing declaration
• Initial thought of BOMB.
• Partial deployment of flaps-190-200 knots landing
speed.
• Evacuation.

8. After emergency landing

10. OBSERVATIONS
• No air traffic problem, No weather issues
• Proper maintenance except door
• No pre-existing metal fatigue
• Overload at time of door opening –
decompression

11. Recovered door

12. Why DOOR opened????

13. How cargo door operates…….

14. Demonstration………
..United Airlines flight 811 accident Animation.html

15. Causes…………..
• If door cams are placed proper no chance of open
due to strong latch sectors.
• Placement of latch in partial or unlatched position .
• Forced to open electrically
• A)Partially closed doors
• B)electrically unlocked situations

16. PARTIALLY CLOSED DOORS
• Never closed fully before the door was locked.
• Back driven manually after the door has been
latched.
• Information from black box: Door latched fully.
• Manual driven back: Usage of screw driver -
No possibility.

17. ELECTRICAL SIGNALLING ON CARGO
DOOR
s2 switch-delivers the necessary control signal to latch sectors

18. IMPROPER ELECTRICAL
INSTALLATIONS
 S2 SWITCH
SHORT CIRUITS IN WIRINGS

19. Latch cam photos after
recovery

20. CONCLUSION
 main reason: electrical installation
 Cargo door in latched position  should be in over
latched position.
 Undesired electrical actuator of the laches.
 Airplane had not been maintained in accordance with
the provisions of AD-88-12-04:MANUAL INSPECTION OF
CARGO DOOR.

21. RECCOMONDATIONS
Removal of all electrical power from circuit
on the door after closure in order to
eliminate possibility of undesired actuator
movements.
Placement of secondary artificial oxygen
system.
Inspection of door after locking .