Crash of a Cessna 560 Citation V Ultra in Fairoaks

Investigation indicated that there was no technical reason for the aircraft to overrun the runway. One factor outside the crew's control was that the APAPIs were not set at the glideslope angle described in the Jeppesen approach charts. However, the error was one quarter of one degree and should not have affected the touchdown point of the aircraft. Additionally, the crew stated that the APAPIs showed 'two whites' when first acquired and made no mention of them during the approach; it seems likely that the commander was flying his approach to land close to the threshold. Prior to departure, the commander checked the landing distance required for the expected weight of VP-CKM at Fairoaks and calculated that he had 30 to 40 metres longer than required based on zero surface wind. This calculation was subsequently confirmed as reasonable for a landing on Runway 24. However, the initial approach into Fairoaks was for Runway 06 which has a landing distance some 53 metres less than Runway 24. Therefore, the landing distance available on Runway 06 was less than that required by the Flight Manual by at least 13 metres. The commander was unable to land on Runway 06 because of the into sun visibility and so landed on Runway 24. For the approach to Runway 06, the surface wind was reported as 060° less than 5 kt and, for the subsequent approach to Runway 24 the surface wind was reported as calm. The landing distance available on Runway 24 was more than that required by the Flight Manual on a dry runway with no wind. However, the reported surface winds indicated a possibility that the aircraft could experience some tail wind component during the landing and the co-pilot also noted that the FMS displayed a tailwind of 5 kt as he deployed the speedbrakes. The presence of mist could indicate a runway surface other than dry and the co-pilot also noted that the runway was damp and seemed "shiny". Against these factors, the commander would have considered the added advantage of using thrust reversers. Nevertheless, since the commander was not applying any recommended safety factors, it would have been prudent for him to ensure that his approach and touchdown were accurate. He considered that his speed was close to that required as he approached the threshold and that the landing was just beyond the threshold. However, the co-pilot considered that the touchdown was just past the APAPIs positioned 142 metres from the threshold. Outside observers noted the touchdown as between 1/3 and 1/2 way down the runway and this view was corroborated by calculations from the CVR and radar information. The speed on touchdown, as assessed from the recorded information, was close to that required. From touchdown to leaving the paved runway surface, took a period of 11.5 seconds. Thrust reverse was used for three seconds and deselected some 6 seconds before the aircraft left the runway. As thrust reverse was deselected, the commander called "we're going round". This would indicate that the commander became concerned during his landing roll that he would not be able to stop in the distance available and deselected thrust reverse in preparation for a Go-Around. However, the Flight Manual warns that a Go-Around should not be attempted once thrust reverse has been selected. Since there was no evidence from the CVR that power was subsequently advanced, it seems likely that the commander immediately decided against this option. However, the action of deselecting thrust reverse reduced the aircraft rate of deceleration as the runway end approached and resulted in a longer overrun. The commander subsequently stated that he cancelled reverse thrust to enable him to shut down the engines and reduce the risk of fire in what was, by then, obviously going to be an overrun.