Improper Execution Of Takeoff Checklist Leads To Stick-Shaker, Runway Overrun

Air Safety Week, Feb 21, 2005

The crew of a Lion Airlines B737-200, trying to take off from Sultan Syarif Kasim II airport (PKU) in Pekanbaru, Riau, Indonesia, on Jan. 14, 2002, forgot to extend the flaps or complete the takeoff checklist, preventing the aircraft from becoming airborne, investigators have concluded.

There was no indication of any malfunction in the flaps system components. Feeling the aircraft was unable to leave the ground, the PIC (pilot in command) aborted takeoff, the aircraft overran the runway, hit fences, and came to a halt 275 meters (900 feet) off the end of Runway 18. The aircraft, registered PK-LID, was departing for Batam as flight JT-386.

The PIC, with the first officer acting as pilot, decided to use "reduced take off power" with an assumed temperature of 35[degrees] C (95[degrees] F) -- the initial temperature was 27[degrees] C, or 81[degrees] F. The PIC opened the throttles and adjusted to the required takeoff setting. The aircraft rolled normally and there was no abnormal indication. The PIC called "V1" and "ROTATE" on the speed bugs and the first officer rotated to 15[degrees] nose-up. The aircraft attitude then reached 18[degrees] nose-up but the aircraft did not get airborne.

The PIC felt stick-shaker (stall warning). Realizing the aircraft had not lifted off, he added power. The speed increased and passed the speed bug setting for V2+15 (158 knots) but the aircraft remained ground-bound. The PIC decided to abort the takeoff and retarded the power levers to idle, selected reverse, extended the speed brake and applied the brakes. The nose went down hard and the crew turned the aircraft slightly right to avoid approach lights ahead. After hitting some trees the aircraft stopped 275 meters from the end of runway on heading 285[degrees]. One passenger had a serious injury and the rest had minor injuries, while the aircraft was a write-off. A passenger opened the window exit and most of the passengers departed there. A flight attendant opened Door 3, but no slides deployed. It was noted that the slides deployed after three hours and that none of the slides had any expiration date (or marked "last inspection" date).

The LH and RH flaps were found stowed. The flap selector was in detent 5, and the system was in good condition. The flap asymmetry system had been upgraded to an electrical component with a bypass valve. However, the flap aural warning circuit breaker was found tripped and would not remain engaged. The circuit breaker (CB) was found with a guard in place. The PIC felt the aircraft lift off for one to two meters about three-quarters of the way down the runway, then stall and drop to the ground. In his second interview, the PIC claimed he'd set the flap handle to 5, but did not remember verifying that with the flap position indicator on the panel. The channel from the cockpit area microphone is blank. Apparently, the cockpit area microphone was not working. Such a failure made it impossible to find out (from the cockpit voice recorder - - CVR) whether the flight crew carried out a proper takeoff checklist or to confirm whether there was any aural warning due to an improper takeoff configuration (i.e., no flaps/slats selected).

The Air Accident Investigation Commission (AAIC) of Indonesia's National Transportation Safety Committee (NTSC) concluded that -- because Boeing [BA] found no malfunction in any flap system components and the aural warning system remained unpowered due to the unresettable CB -- the crew had forgotten to extend the flaps or complete a takeoff checklist. Inspection of the report's R/T log shows that the first officer spent all the runway backtrack/line-up time chatting gaily over the VHF to his mate in aircraft callsign RI 071.

At the accident site, investigators found that the flaps were up. Should a pilot select the flap to takeoff configuration but the flap system fails and causes the flap to remain in the UP position, the crew would not see the green light illuminate, and the flap indicator would indicate a zero position. Therefore, had one of the above procedures been performed, the crew would have identified the flap's zero position, regardless of the failure of the takeoff configuration aural warning.

"The examination of the aural warning CB showed that the CB can not latch in due to wear on the latching mechanism. Such wear should be remedied by replacing the CB. This, however, was not done. Instead, for some reason, the maintenance crew of the previous owner/operator installed a pull-out guard over the CB. A basic failure to understand the problem contributed directly to this accident."

Same Cause Found In Separate Accident

The U.S. National Transportation Safety Board (NTSB) database shows that a similar accident happened to a Boeing 727 operated by Delta Airlines [DAL] on Aug. 31, 1988, at Dallas/Fort Worth Airport. Flight 1141 (registration N473DA) reported being normal on the takeoff roll. The crew stated that after rotation and main gear leaving the ground, they heard explosions and felt rapid deceleration. The aircraft had struck the ILS antenna 1,000 feet beyond the runway and came to rest 3,200 feet beyond the runway. The investigation found the flaps and slats were not configured to take off. Due to inadequate discipline on takeoff procedures, the crew failed to configure the flap and slat to a take-off configuration. The crew was not alerted to the improper configuration due to failure of the takeoff warning system.