A B737-800 crew exceeded flap speeds and deviated from the departure track when distracted by flight director problems during a departure in difficult weather conditions.
Synopsis
A B737-800 crew exceeded flap speeds and deviated from the departure track when distracted by flight director problems during a departure in difficult weather conditions.
Narrative
Departing with heavy rain and strong winds; a line of weather was moving through the area; wet runway. Aircraft are departing with reports of occasional moderate turbulence. Departing Runway 28L aircraft are given heading 210 or 290 from Tower. We were given heading 290. Late on takeoff I told the First Officer my flight director is not working. He said his was not either. After lift-off we were in heavy rain IMC and moderate turbulence. At 1000 FT the First Officer is trying to get the flight directors to engage; selecting heading; vertical speed; level change the flight directors were not engaging. At 1500 FT we were momentarily VMC but still with moderate turbulence and we requested a 210 heading and 1500 FT to remain VMC and were given clearance from Tower to do so. We leveled off and pulled the throttle back and called for flaps up but we had a flap overspeed. Shortly after; we were able to engage the flight director in heading first then altitude hold and it remained working throughout the flight. We notified Dispatch of the overspeed and Flight Director problem and put it in the logbook upon arrival. While losing flight directors during a critical phase of flight in severe weather may not constitute an emergency; it certainly reduces the level of safety. With the option of maintaining VMC; I feel that increased the level of safety during this critical phase of flight. It is unfortunate that I was not able to reduce power and retract flaps fast enough to avoid an overspeed but with the turbulence and thunderstorms and system problem everything happened very quickly.
Second reporter narrative
On rotation we saw we had no pitch guidance on the Flight Director; all other instrument conditions were normal. At 400 FT AGL; I engaged heading and twisted in 290 per the clearance and was looking to see why we had no pitch guidance. At this stage; Captain rolled to a head of 200 degrees and stated he wanted to go in that direction for weather. I called Tower to let them know we were turning to 200 versus 290 due to weather an obvious concern was departure traffic off Runway 27. Tower asked that we pick up a northerly heading versus 200 to avoid the weather due to departure traffic. At about this time the warning system sounded with 'don't sink.' Looking in the cockpit I saw we were no longer climbing and had started a descent and advised Captain accordingly. He leveled aircraft. I relayed to Tower that we needed the 200 heading for the weather. Shortly thereafter I saw we were accelerating through 250 KTS and we still had flaps 1 extended. I advised Captain accordingly; put the flaps up and hit speed on the mode control panel and set 1350. With all that occurred I could not tell for sure when the flaps were up but I would guess about 260 KIAS. At about this time Captain slowed the aircraft to 250 KIAS and continued climbing to 5000 FT and Tower rolled us to departure. I checked in with departure and told them of the 200 heading for weather avoidance; they vectored us around to the North West as weather allowed and we picked up the departure.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.