B737-300
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 241; Flight Crew Type 7300
Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Gate; Flight Crew Rejected Takeoff; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft; Human Factors
After being cleared for takeoff; the Captain called for takeoff thrust to be set. I set the takeoff thrust which took a little extra time being that we were operating an older model airplane (no autothrottles). Once power was set; I took a quick scan of the engine instruments which were all in the green and then took a quick glance outside to see that we were tracking down the center line. At this point I usually also take a quick look at the magnetic compass to verify runway heading. I came back inside to scan the flight instruments and get ready to make the 80 knot call when I realized that something was missing. It took a second or two for me to realize that the missing info was no airspeed indication. I instinctively looked at the Captain's airspeed indicator to see if it was indicating properly and I did see needle movement; but had difficulty reading the actual indication. I came back and took another look at my airspeed indicator to verify what I was seeing when I noticed the airspeed flag. At this point I stated to the Captain; 'I have no airspeed;' and 'you have to call it.' With the second statement; I was referring to the V1 and rotate call outs. Unfortunately; the Captain may have thought I was prompting an abort decision; which added some complexity to his decision. Either way; it was probably too ambiguous of a call out. By this time the airspeed was probably over 100 knots and the abort was initiated around 120 knots approximately. (V1 was 142 knots.) The rejected takeoff went smoothly and we easily stopped the aircraft on the remaining runway.After exiting the runway and notifying ATC that no assistance would be needed; we computed the brake cooling and reviewed the Rejected Takeoff Checklist in the non-normal section of the QRH. We held out from the gate for 30 minutes. It is unclear when my airspeed indicator became inoperative; but it was probably sometime before we took the runway. More vigilance in scanning the flight instruments before taking the runway is needed on my part. As Pilot Monitoring; the call out of the failure should have been more timely and clear.
The weather was misting to a slight rain and engine anti-ice was required. I taxied out onto the runway for takeoff after all checks were completed. When I pushed the power up; the configuration horn sounded. It was checked before and all was set correctly. I bumped the trim switch twice and the horn silenced. The configuration had been rechecked and the takeoff continued without any configuration warnings. At approximately 80 knots; the First Officer announced he didn't have airspeed. While maintaining aircraft control; I started analyzing the problem by glancing at my airspeed indicator and saw approximately 90 to 95 knots. Instinctively; I glanced over to the First Officer's instrument panel and confirmed what he had stated. I confirmed the pitot heat panel was not illuminated; indicating the anti-ice system was functioning properly.While I was analyzing; the First Officer announced that I have to call the speeds since his indicator wasn't working. I was aware the aircraft hadn't used more than 4000 feet of the 9500 foot runway; and our stopping margin was 2500 feet. In the interest of safety; I elected to reject the takeoff knowing we were going into icing conditions. I then commanded the First Officer to tell the Tower of our reject. Knowing that the airspeed indicator is directly linked to the #2 air data computer system and the #2 pitot static system; I was aware other instruments could be affected. As the reject was started by closing the throttles; I noticed the airspeed was approximately 120 knots; which was 20 to 25 knots higher than my last glance moments prior. I was always well aware that I was far below our computed V1. I continued with the rejected takeoff procedure; pulled the speedbrake lever up; and deployed the thrust reversers. The reject was uneventful. Exiting the runway; I had the First Officer compute brake cooling. I notified the Passengers of the situation and requested that they remain seated. Dispatch and Operations were notified; and we performed the QRH checklist for rejected takeoff. The calculated hold for brake cooling was 30 minutes. Once the 30 minutes expired; we continued into the gate where Maintenance was waiting.If I had rejected takeoff when the First Officer announced that he had no air speed; the aborted takeoff would have been initiated approximately 20 to 25 knots sooner. Instinctively; I glanced at his instrument panel and pitot static panel to analyze the problem. After I confirmed his instrument had indeed malfunctioned; I immediately rejected the takeoff. I would have aborted sooner. I have gone over this situation a thousand times in my head. When; where; what; how; why.....In the end; our training is spot-on in all of the parameters with primary concern for safety. No one can train for that split second decision of what. As I mentioned; just in those few seconds of analyzing the situation we gained 20 to 25 knots. We could have noticed if the air speed indicator was inoperative earlier in our preflight; however that being said; I believe it was functioning properly at the time. After returning to the gate; our mechanic noted that the indicator was intermittent. Do not reject a takeoff for anything above 80 knots unless it's an engine failure; fire; or fire warning; predictive windshear warning; or if the aircraft is unsafe or unable to fly.
B737-300 flight crew reports discovering that the First Officer's airspeed indicator is inoperative above 80 knots when the he calls it out. The Captain takes time to analyze the situation and initiates a reject at 120 knots.