Best Laid Plans Torn Asunder

The reward of suffering is experience – Aeschylus

The ancient Greek playwright’s observation can be applied to most life situations, and for my selfish purposes, to that of the slow process of gaining aeronautical wisdom. It follows that should everything always go according to plan and our Standard Operating Procedures handle every situation that fate can throw at us, we would all be bored out of our minds and our experience base would be non-existent.

A few weeks ago, I was easing back the right-hand front seat of an A340-200, having enjoyed a surprisingly decent bit of lamb, uplifted from Munich. You know you are hungry when airline food becomes appealing. My esteemed leader had taken a temporary leave of absence and was chatting to the cabin crew in the forward galley, leaving me alone on the flight deck, when what appeared to be a distant flash of lightning caught my peripheral vision. I leaned forward, surprised that a thunderstorm would be this far north. We were still over the southern Sahara, southbound for Johannesburg, having just step climbed to Flight Level 370.

The flash dutifully repeated itself, but it was apparent that this was not a meteorological phenomenon. There was a mini fireworks display taking place inside my front windshield, between the two thick panes of glass that sandwich the windshield heating element. After a brief mental pause, my few remaining brain cells collided, prompting me to think about doing something to stop this. I vaguely recalled something in the Airbus Quick Reference Handbook about windshield arcing, and I further moved my seat back to glance upwards to the computer reset buttons on the overhead panel. Before I could even start to locate the WHC button (Windshield Heat Controller), the heating element failed, causing the windshield to go from plus thirty degrees to minus fifty-six degrees in an instant and the outer pane shattered with the crack of a pistol shot.

I am sure there is still a chunk of the sheepskin seat cover missing on that aircraft where I bit a hole in it with my backside.

I had instant visions of that spider web-like crack pattern continuing its way to the inner pane, and with the assistance of 8.6 Pounds per Square Inch of cabin pressure, spewing the entire windshield outwards. This would have been followed by myself, with the contents of the forward galley in hot pursuit, making a mess of the desert floor beneath and leaving the now depressurised flight deck empty. Amazing how one’s mind can run away with oneself in a split second.

My immediate dilemma was – what first? Oxygen mask on, or strap in fully? I figured there was no point in being ejected through the front windshield with my mask on, so I rapidly secured the five-point harness and then donned the Scott oxygen mask, in anticipation of the worst. I can report that the masks in the aircraft smell exactly the same as the ones in the simulator – almost as if it had been previously used by someone who had been chewing old socks.

Now what? My heart was thumping, and my breathing rasped through the mask but apart from that, nothing disturbed the serene night atmosphere of the flight deck. We were still in the cruise at 37 000 feet, autopilot engaged, and no one on that aircraft, apart from me, was aware that anything was awry. My next concern was that the cabin pressure differential had to be reduced as a matter of urgency to prevent my imagination’s worst from materialising. I had another “deer in the headlights” moment, before coming to the realisation that I should get the Captain back and tell him I had broken the aeroplane.

Not wanting to sound like a bad Darth Vader impersonation, I momentarily whipped the mask off and called for the Captain to return to the flight deck over the PA. Needless to say, he was back in the cockpit like a scalded cat, closely followed by half the cabin crew. The simple process of communicating with a mask on to someone who doesn’t is futile if you don’t have your speaker turned up and intercom selected. Simulator basics. Now that the aircraft was restored to the correct two-crew operation, the chances of managing the issue successfully increased dramatically. I continued as Pilot Flying, and handling the communications (getting descent clearance from N’djamena) while the Captain located the correct checklist and began to action it. Our airline philosophy actually calls for our roles to be reversed, as I ended up monitoring the actions of the higher authority figure, and historically this has proven to be fraught with CRM issues. However, in this case, a hand over of control would have been inappropriate, so the process was modified accordingly.

On reaching FL230 (as per the QRH), I thankfully removed the mask and continued with the PF duties. This is where our actions finally coincided with our trained procedures. With me as PF, the Captain could assess the situation, and implement our Risk Management Model. The cabin differential pressure had been reduced to 5psi by using manual pressurisation control to raise the cabin altitude to 8200’, which according to the experts will allow the damaged windshield to hold up, or failing that, a less dramatic depressurisation event.

The biggest issue now was that at this altitude we did not have enough fuel to make our destination, with some seven hours of flying still ahead of us. Compounding this was the fact that we were now within the perfect (worst?) icing range, so we grudgingly spent quality time with the nacelle anti-ice system on, increasing our fuel burn, as we thumped through the weather at the equator. The auto-thrust system was not happy at this speed and altitude, and being unable to engage in “Soft Mode”, was hunting with excessive thrust changes, chewing up more fuel. I suggested disengaging the system and setting thrust manually for the rest of the flight, which seemed to work well. After all, this is a basic of flying, and we did it for years with the B747 SP.

Sod’s Law also kicked in, as the ACARS system had been on the blink since our departure in Germany. This system allows crew to communicate through a system similar to SMS, via satellite from anywhere in the world to our home base as well as uplink weather information for almost any airport. Useful indeed with the prospect of an enroute diversion looming, and our company wondering what on earth we are doing.

To cut a longish story shorter, when we were within six hours of Johannesburg, and had obtained the latest weather forecasts through HF radio communication, we nominated our destination as our alternate, which meant we could delete Durban from the flight plan, provided we were assured of reaching the threshold of the runway with 45 minutes of fuel in tanks. Thus we decided to try to continue to Johannesburg, having the bolt-hole of Lusaka or Harare as plan B when we passed abeam. As daylight dawned, the full extent of the cracking was revealed, and reaffirmed my initial imaginings of depressurised mayhem. Interestingly, the QRH caters for both windshields failing, and recommends an autoland, as forward vision would have been severely reduced.

We made it home, albeit almost two hours late as a result of our much lower speed at the low altitude. Undoubtedly, some passengers would have been moaning about missing connecting flights, unaware of how the best laid plans had been torn asunder, but then sort of restored through the use of trained procedure.

I was chatting to one of our Training Captains a few days after the event, and his comment was “Well, Mike. I hope the first thing that went through your mind was FLY!” (This is the essence of our latest abnormal procedure – Fly, Navigate, Communicate). My response: “No, sir. The first thing that went through my mind was F_ck!!” And I suppose this is where those “deer in the headlights” moments originate – when the nature of the events overtake the trained mantra that should lead us to a controlled, calm and logical procedure to resolve the abnormality. We got there, eventually, but the initial containment was not as per the trained plan. It was an event not specifically trained for in the simulator, as there is no Cracked Windshield function on the instructor’s station. More specifically, is the process of continuing the flight for many hours in a reduced capability situation. The latter was well managed through our trained procedures, and I can attest to the planning and prediction functions of the FMGS of the Airbus. It’s pretty damn accurate.

Much like being in the army, routine aviation is 99.9% boredom, with 0.1% panic. It is how effectively we are able to mitigate the effect of the panic, and get the procedures flowing that prevent the incident becoming an accident. This is where we need to have something – anything that gives us a solid starting point to get the ball rolling. For us, it is meant to be “I have control: Fly!”, whether it be verbalised or mentally used to anchor the situation.

Had the windshield let go entirely from the outset, I would not be sitting here in a wet and dull London writing this. Also the timing of the event, with me being the sole occupant of the flight deck at the time, could well have resulted in a hull loss had I rapidly exited through the window, along with our fruit tray. The likelihood of a total windshield failure, however, is remote due to the certification standards required for this important bit of primary structure, and de-laminations of this nature can and do happen, but not as a matter of course, thankfully.

The same Captain that I was discussing the event with afterwards mentioned that in his twenty-four thousand hours of flying, he has never seen this. In retrospect, I suppose I am in some way lucky to be able to add this to my pool of experience within the eleven thousand flight hours that I have survived so far. While looking forward to my next eleven thousand, I am hoping that the experience will only be useful to me while narrating it in the pub.

By | 2017-02-26T16:02:07+00:00 January 1st, 2015|Mike's Articles|0 Comments