With 65 occupants a de Havilland Canada DHC-8-402Q was operating a scheduled passenger flight from Lima to Ayacucho (Peru). The flight passed by uneventfully until the flight was on the approach to Ayacucho. When the landing gear was selected down the nose landing gear failed to extend with a NOSE indication on the landing gear panel, indicating the nose landing gear was not down and locked. The crew decided to return to Lima, without detailing the reason for the return to ATC. The landing gear was retracted normally.
The aircraft on the runway in its final position on the runway
(Source: AVHerald.com © Michel R0mero)
While on the approach to Lima the crew selected the landing gear down again, resulting in the same NOSE indication as previously encountered on the approach to Ayacucho. The landing gear was selected up again before attempting an alternate gear extension. After performing the alternate gear extension the crew requested the tower controller at Lima to perform a visual check of the gear positions during alow pass. During the low pass, the tower controller observed that the nose landing gear doors were open, but the nose landing gear was not visible (still in the retracted position). Based on this observation the crew decided to make an emergency landing at Lima Aiport with the nose landing gear not extended. The subsequent landing resulted in sparks coming from the nose section of the aircraft as it slid along the runway surface. Attending firefighters applied foam to the aircraft and assisted with the evacuation of the passengers.
The aircraft shortly before touchdown (Source: AVHerald.com © Michel R0mero)
The CIAA (Comisión de Investigación de Accidentes de Aviación del Ministerio de Transporte y Comunicaciones - Peruvian Aviation Accident Investigation Committee) was alerted, and an investigation was launched. Under the supervision of the CIAA the aircraft was recovered from the runway with the aid of the operators' maintenance department. During the recovery, the nose landing gear alternate extension was operated and the nose landing gear extended to the down and locked position. Subsequently, the aircraft was towed to the operators' hangar.
During the investigation, it became clear that the dault had existed before departure and that a technician of the operators' maintenance department had cleaned a proximity sensor. After which the aircraft departed. The defect reported by the crew and the maintenance action were not entered in the aircraft technical log.
Location of the proximity sensors S11 & S12 (Source: CIAA © Bombardier)
Upon completion of the investigation, the CIAA concluded that the failure of proximity sensors S11 and S12 on the nose landing gear prevented the normal extension of the nose landing gear. The crew did not perform the alternate gear extension procedure completely, resulting in a nose gear-up landing.
A contributing factor to the accident was the limited experience on the DHC-8-400 aircraft by the operators' maintenance staff. The CIAA completed their report with several recommendations which can be read in the enclosed report. Click on the .pdf file below. (please note the report is in Spanish);
** Editorial note **
V2 Aviation - Training & Maintenance has not been able to obtain an investigation report in English on this accident. This blog is therefore based on an unofficial translation and several internet sources. Should there be inconsistencies in the blog don't hesitate to get in touch with us. There are two possibilities to do that, via the comments function at the bottom of this page or the contact page of the website.
Video of the landing (Source YouTube/Air Live)
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