Always Expect the Unexpected

Easy to say, but hard to do in real life. Sometimes it's nothing more than a bad feeling or an outlier in the normal arrangement of facts before you.

My daughter sent me this link to an article related to flying that we discussed. Much of this is also applicable to folks who operate boats, so I thought I'd post it here. Below is the link she sent me and my reply to her via email.

The Power of Mental Models: How Flight 32 Avoided Disaster

Interesting read. Thanks!

Yes, we trained in "shared mental models" so we'd all be "singing from the same hymnal." My standard was to always do things the same way so my mind was practiced at a certain flow of essential bits of data. If data points were missing, I'd notice. New data was cross checked against the norm and other sources. Any disparities were double checked and addressed. If one airspeed indicator read an unexpected speed, it was cross checked with the airspeed indicator on the other side of the cockpit. If they agreed, action was taken. If they disagreed, we sought a tie breaker...the emergency airspeed indicator, a groundspeed digital readout, a GPS source, the ATC groundspeed on the radar. lots of info available to validate the reading if you know where to look.

One of my toughest failures to diagnose and recover from occurred about 100 miles west of Oklahoma City in a town called Clinton Sherman. We were doing some early testing of GPS signals and were evaluating new flight testing procedures so we had some HQ folks aboard observing.

It was a simultaneous, dual electrical circuit failure that controlled most major systems. These circuits are powered from each engine's generator and batteries for quadruple redundancy due to the essential nature of the equipment powered by them. It's called the DC1 buss because it's the most important. The L and R DC1 circuit breakers popped and could not be reset. There was no emergency checklist procedure for this because it was never supposed to happen.

We lost electrical power to flaps, all powered hydraulics on spoilers, landing gear, and thrust reversers. All warning lights were diabled so we had no indications of which systems were impaired. Only basic navigation was available and all radios were dead. No lights, no electric trim, no nav displays on the copilot's side.

One thing in our favor was that were were working in good weather and we were VFR while talking with ATC when the failure occurred, so he knew something was wrong. We changed our transponder to the emergency 4 digit code of 7600 to tell ATC that we lost radios...just in case that box was working. (It was) We also transmitted our intentions in the blind over the ATC frequency just in case our transmitters worked but our receivers or audio circuits were the only dead portion. (the transmitters didn't work)

When the failures occurred, we learned quickly that we were unable to recover power, so we started taking inventory of what systems worked. We put all passengers to work calling out responses to the activation of systems as we tested them. Flaps? No flaps. Spoilers? No spoilers. We had no indicators on the systems so we didn't know what actually worked without seeing or feeling the change.

The plane was trimmed for 210 kts and any speed above that required excessive nose-down control wheel pressure to prevent a pitch up and climb. Below 210 kts, the nose would drop and start descending unless pressure from both of us was applied. I was left seat copilot (pilot flying) and the actual pilot in command on the flight was in the right seat. We turned toward OKC airport as we took inventory and formulated a plan. No flaps, no spoilers, high approach speed with no thrust reversers, possible brakes, but we won't know until we touch down. Manual landing gear extension, enter the traffic pattern like a Cessna and watch for light gun signals to land. As the plane slowed, Larry would pull back on the column between our legs (not the yoke) to assist in the flare while I would retain full authority for ailerons and rudders. I had the brakes alone just in case his activation would cause a loss of pressure.

As we entered the pattern on downwind with checklists exhausted and just about to start manual landing gear extension, I commented to Larry that there was one more thing we had not tried. There was a red EMER BUS switch that was designed to bypass certain circuits and direct battery power straight to L and R DC 1. Larry said, "Go ahead...we have nothing to lose."

I flipped the switch and many, but not all, the circuits came to life. Now we were hyper-busy in the cockpit trying to figure out our new operating inventory while we were about 3 minutes from touchdown. We had flaps. we had spoilers, we had electric gear extension, we had electric pitch trim, radios came to life and the emergency annunciator panel lit up like a Christmas tree. We still had no thrust reversers and brakes were questionable. We were cleared to land any runway. As you know, it turned out OK.

We had some system modifications on our Learjet 60 that directed engine bleed air through some pipes and hoses in the vicinity of a set of thermal-sensing remote circuit breakers in the tailcone section. When a bleed line let loose, the hot air tripped both sets of breakers (L and R sides) together. Learjet engineers never foresaw this occurring and had no emergency procedure for it. We consulted with them in detail and assisted in developing the DUAL DC1 BUS FAIL checklist that exists today.

On that day, it was the shared mental model, succinct and efficient communication between Larry and me (and the rest of the folks aboard), systems knowledge and a bit of good luck that saved our bacon. We trained every 6 months in the simulators for failures and they try to think up every possible scenario, but no one thought of this one until it happened to us. The training for this failure still occurs in the Lear 60 sims today.

We had 5 independent comm radio systems on that airplane...more than any other plane I've ever operated. On that day, all 5 failed simultaneously. I taught me a huge lesson to always expect the unexpected, even if someone says, "Oh, that could never happen!"

It can!

That sir is an awesome story!

Geez these guys sound amazingly cool in extreme pucker-factor conditions.

My take-away--should I ever find myself in a similar situation--is to look for a red button labeled "EMERGENCY."

Going back through aviation history there are some amazing feats of brilliance and coolness in unbelievable situations...there are also examples of colossal stupidity over the most simple things.

Lots have programs have come and gone...all trying to unlock the secrets of the mind and how teams work together the best.

Apollo 13 is an example of how a large, expanded team did the unthinkable.

Good story Al. One you'll never forget. My career was pretty mundane in comparison. Stuck flaps, precautionary engine shutdown, blown tire, unruly pax. Smoke in the cockpit and electrical failures (which can lead to smoke) were always my most concern.

3 other examples of exceptional airmanship:
United FL 232, a DC 10 that had an uncontained engine explosion resulting in control loss. Some loss of life but many survived inc the flight crew.

In 2003 an Airbus A-300 hit by a SAM shortly after takeoff from Baghdad, resulting in almost complete control loss. A more favorable outcome than the DC-10. https://en.wikipedia.org/wiki/2003_Baghdad_DHL_attempted_shootdown_incident

Qantas FL 32 an Airbus A-380 also experienced an uncontained engine explosion damaging many systems but the aircraft was largely controllable. The Airbus electronic emergency checklists designed for most failures had never been used in the multiple failures experience by this crew. Some people have argued that the checklist caused some confusion. Fortunately there were 2 check pilots aboard including the normal crew so work loads were shared between 4 instead of the normal 2.

Check Netflix's Smithsonian Air Disasters for more heroes and examples of stupidity.

Thank you Al.

That's a great story and link.

AL, thank you for the story and the tutoring.
I have faced 3 blowouts in oil rigs in my life. In two of them, I was brought to manage the situation when equipment was already on fire and the leak had to be stopped. In those situations, we always count with mother nature to help us.
On the third one however, there was no fire. It was what we call an underground blowout, extremely out of control as gas started to migrate to surface braking roads, houses and even a kinder garden school while threatening a small town 3 miles down the road. It took us 8 months to solve the problem but, now, thinking back, we only came to the final solution when we diverted our thinking for what could be done effectively instead what the books and the "experts" were saying. Once again, reactive thinking was putting us further and further away from the solution as time went by.


I had never thought about that!!!

FlyWright said:

...It taught me a huge lesson to always expect the unexpected, even if someone says, "Oh, that could never happen!" It can!

Click to expand...

It can and usually does.

Great story Al. Glad you're here to tell it.