Stable Approach
From my position, sitting behind the two pilots making their approach to land, I could see that things were not going well. The B737 was well above the glideslope, not yet configured for the final descent and with way too much energy. The airspeed was eye-wateringly high and they were only just inside the limit speeds to deploy the flaps. Needless to say, as their instructor I was more than a little curious about how they would handle the situation…
Surely, they would announce a ‘Go-Around’ soon, very soon… But no! The Captain called for “Gear Down, Flaps 15 and landing checks”, and the First Officer responded with the called-for actions. I noted at this point that they still had the speedbrakes out and the thrust levers closed trying to get rid of all that excess speed. At only three miles on finals, they were at least double the height they should have been, with 50+ knots more airspeed than the ideal. Still the engines remained at idle… They had received their landing clearance and I was now seriously concerned. I was mentally wishing them to Go-Around, climb away safely, retract the flaps and gear, to go for another approach – they continued.
We sailed over the runway threshold at around 200 feet, 30 knots too fast, but at least in the landing configuration with gear down and Flap 40, still no power from the engines, the speedbrakes had been stowed. The 1,000ft point (normal landing zone) whizzed past the cockpit windows and we were nowhere near maingear touchdown. The Captain’s right hand moved from the thrust levers and grasped the speedbrake lever*… I thought to myself, ‘Please God no!’ But then he thought better of it and put his hand back on the idle throttles. The synthesised Auto-Radalt Calls “FIFTY… THIRTY… TWENTY!” seemed unusually loud in the flightdeck, but as I looked over his shoulder, I could see we would land over halfway down the runway…
Suddenly, BANG! We were down! The mainwheels hit the runway and immediately the Captain’s righthand grabbed the reversers. He pulled them through the interlock and without a pause continued pulling them all the way back as the nosegear thumped onto the centreline. The N1 gauges soared as the engines roared their response to the command of Max Reverse. At the same time the Autobrake Disarm caption illuminated as his feet hit the manual toebrakes for maximum wheelbraking… I could see the end of the runway coming up fast now, but we were slowing. Oh yes, we were losing speed at a great rate and all three of us were thrown forward into our shoulder harness by the force of our retardation. The First Officer had been virtually silent throughout all of this, but now he came to life as he saw the continuous red lights of the runway centreline and shouted “THREE HUNDRED METRES CAPTAIN!” I looked at the groundspeed readout and it was still ridiculously high, although rapidly reducing. I could imagine those poor brakes and the steel discs glowing red hot under the strain.
Then, finally, we came to a shuddering stop with the Antiskid system kicking in and out over the last 100 metres. As the speed registered zero, the nosegear oleo bounced the cockpit back up to level, even as the thrust reversers were still roaring in protest. ‘Eww…’ I thought of those poor old engines re-ingesting their own exhaust gases along with all the dirt and dust from the runway threshold. The Captain and First Officer just sat there in silence; we all three noted that the concrete of the runway surface ended just 30 metres in front of the flightdeck windows. At this point I pressed the “Freeze” button on the Simulator panel next to me and the silence was total. The Captain sat very still for a moment, breathing heavily. Then he half-turned in his seat looking at the Co-Pilot. He swallowed and took a deep breath before he said very slowly in his deep baritone… “I think… we should… have… gone around!” The pale-faced First Officer nodded his assent. I smiled behind them both in the darkness of the Simulator and said “Yes indeed, Captain, I completely agree with you! Gentlemen, let’s try that approach again, shall we? Please remember… you can always Go-Around!” The lesson had been learned.
On another occasion, I was sitting on the flightdeck jumpseat for real. It was a night approach to land at Liverpool where I was the Base Captain for a scheduled airline. The aircraft was a B737-300 and although I was travelling on-duty, I was not part of the legally nominated crew. As such, I was very conscious of the fact that it was important that as an ‘observer’ I should make no input or verbal distraction to the crew while they performed their operational flying task. In airliner flying this is especially relevant at critical stages of flight. The First Officer was Pilot Flying (PF) and the Captain was carrying out the job of Pilot Monitoring (PM). It was a clear night and they had been cleared for a visual approach to land on Runway 27 by ATC. The First Officer elected to disconnect the automatics and fly manually. This was not unusual and a rare treat in our world of automated airliner flying. I noted that he turned in towards the final approach well above the ideal three-degree vertical profile and by the time we were on short finals (inside four nautical miles) the aircraft was nearly double the altitude for an ideal approach. The PAPIs were clearly visible as ‘Four Whites’, therefore the approach was far from stabilised. I imagined the thoughts of the poor Captain as he saw this unfold… “Oh NO! Not with my Boss in the jumpseat!” but he did nothing to prevent it and I sensed he was just hoping for the best. Finally, I had let it go as long as I dared. I slipped my shoulder straps and leaned forward, my head between them both. I said in carefully measured tones that they could both hear, “Captain… If you do not take control and execute a Go-Around from this approach, you will be suspended and probably dismissed from the company!”
THAT had the desired effect, immediately he sprang into action, “I HAVE CONTROL!” (his hands and feet on the flying controls), then… “GOING AROUND! FLAPS FIFTEEN!” simultaneously, he eased the nose up into a climb and advanced the thrust levers to the Go-Around thrust position. I sat back quietly and breathed more easily in my seat as I slipped my harness back on again. After an uneventful landing, he taxied in and shutdown the engines. They completed the after landing and shutdown checklists and sat in embarrassed silence. There was nothing more to say. I simply stowed the observer’s seat away and said, “Thanks for the ride, gentlemen, have a pleasant evening, goodnight!” and left the aircraft with the other passengers.
Statistically there are between seven and 11 factors which combine to form an ‘error Chain’ in the lead up to an aviation Hull Loss accident. Note that the removal of only one of these ‘links’ (by the operating crew for example) can break the chain. Without speculating as to the cause/s of the recent tragedy in Karachi with flight PIA8303, it is probable that the reportedly un-stabilised first approach to land was a major lost opportunity to protect the safety of the operation.
James McBride © 06 JULY 20, Athens, Greece.
*The extension of speedbrakes, otherwise known as (Lift) ‘Spoilers’ while airborne with flaps greater than Flap 15 in the B737, is prohibited by Boeing. The rate of descent would become extreme and its use to land the aircraft would result in structural airframe damage.
