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| Date: | Tuesday 26 March 2024 |
| Time: | 11:30 |
| Type: |  Bombardier CRJ-100ER |
| Owner/operator: | CemAir |
| Registration: | ZS-CMK |
| MSN: | 7273 |
| Year of manufacture: | 1998 |
| Total airframe hrs: | 31468 hours |
| Engine model: | GE CF34-3A1 |
| Fatalities: | Fatalities: 0 / Occupants: 51 |
| Other fatalities: | 0 |
| Aircraft damage: | Minor, repaired |
| Category: | Serious incident |
| Location: | NE of George -
 South Africa
|
| Phase: | En route |
| Nature: | Passenger |
| Departure airport: | Johannesburg-O.R. Tambo International Airport (JNB/FAOR) |
| George Airport (GRJ/FAGG) | |
| Investigating agency: | CAA S.A. |
| Confidence Rating: |  Accident investigation report completed and information captured |
CemAir flight 5Z404, a Bombardier CRJ-100ER, was cruising at FL300 about ten minutes before the top of descent when the starboard cockpit window shattered. The flight crew promptly donned emergency cockpit oxygen masks and declared an emergency to air traffic control (ATC). They then descended to FL090. The flight continued and safely landed on runway 11 at George, with no reported injuries among the passengers or crew.
Probable Cause
Electrical arcing in the heating element, evidenced by the discoloured polymer interlayer, was a significant factor in the windshield failure. This arcing caused localised high temperatures and electrical stress. Extensive delamination between the outer glass layer and the interlayer on the heating element interface compromised the heating element’s effectiveness. The temperature gradient and stress from the malfunctioning heating element likely caused the delamination. The stress exceeded the tempered glass layer’s limits, which led to the fracture and further delamination.
Contributory Factors
1. Delamination of the windshield assembly: Prolonged exposure to ultraviolet (UV) rays, moisture and other environmental factors can cause the windshield assembly to delaminate.
This delamination increases the stress on the outer glass layer, which can compromise its integrity.
2. Ingestion of moisture: The delaminated zones allow moisture to enter and could affect the performance and safety of the windshield.
3. Arcing of the heating element: The increased moisture content within the delaminated zones could lead to electrical arcing in the heating element, potentially causing malfunctions or damage
Accident investigation:
 |
|
Sources:
SACAA
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 08-Apr-2024 19:37 | ASN | Added |
| 08-Apr-2024 19:38 | ASN | Updated |
| 17-Nov-2024 20:30 | ASN | Updated [Total occupants, Narrative, Accident report, ] |
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