August 14, 2012

Single Engine


Most of my flying during the past 18 years has taken place in and out of the same airport...an airport with which I am now quite familiar.  Like anything else, familiarity and routine can be both a positive and a negative thing.  On the positive side, it helps a pilot predict what is coming next and highlights unusual clearances, mistakes and anything else that might be out of the norm.  For instance, the normal climb out of DFW goes something like this…the initial clearance for jet aircraft is a climb to 10,000.  Typically, the first departure controller will clear you directly to 17,000.  The first center controller issues a clearance to FL230 and the first high altitude controller will issue a clearance to your filed cruise altitude, usually somewhere in the mid-thirties.

If you're familiar with what's normal, then you know that an initial clearance to something less than 10,000 is a good indication that there's traffic in the departure corridor that isn't usually there.  The absence of a clearance to 17,000 indicates conflicting traffic on the arrival.  A clearance to something less than FL230 might indicate that you are following slower traffic which would require a level off to avoid separation issues.  Pilots commonly use the term S.A...situational awareness.  S.A. is knowing what is happening around you at all times.  Not just with your flight, but with anyone around you.  We're all sharing the same taxiways, runways and airspace, and knowing and paying attention to what everyone else is doing only adds to the level of safety.  

Another byproduct of familiarity and routine is that it helps a pilot remember unusual events.  Many of the details in the story I’m about to share are seared into my memory more in relation to their departure from the norm, than anything else. 

The Captain was working the radios and I was at the controls as we took off from runway 18L on our way to Mexico for what was supposed to be a simple turn-around.  We had a full load of passengers and a heavy load of fuel in anticipation of poor weather at our destination, so the aircraft was well above maximum landing weight as we took to the air.  Our initial clearance altitude was 10,000, the first departure controller cleared us straight to 17,000, the first en-route controller cleared us to FL230 and the high altitude controller immediately cleared us to our cruise altitude.  So far so good.

As we passed FL230 we got a call from the First Class Flight Attendant who explained that she had our meals ready.  Yes, we get fed at meal time in the cockpit, but we usually get fed after the meal service is complete in the cabin.  Crew meals are a contractually negotiated perk that we have managed to hold onto over the years.  They’re a little like eating the same thing every day at a restaurant you don’t particularly like, but the food is free and pilots are cheap.

At any rate, the unusual timing of the cabin to cockpit chime highlighted the moment and the altitude in my mind.  As the Captain got out of his seat and stepped back to the cockpit door, the amber “Caution” light illuminated on the glare shield in front of me.  This light is designed to catch the pilot’s attention and direct him to an abnormal condition with the aircraft.  The overhead panel is a sea of lights, buttons and switches, but situated above the windshield and below the overhead panel is an annunciator panel.  Usually blank at this stage of the flight, the OIL STRAINER CLOGGING light stood out like a sore thumb.

"Master Caution" and "Master Warning" lights in the upper right hand corner.
MD80 Annunciator Panel as it normally looks during flight...dark, no lights
This is an issue I've handled before…on more than one occasion actually…but never in the real airplane.  It’s come up a few times in the simulator on a LOFT (Line Oriented Flight Training), something we do every nine months to stay current.  This time it was real and although the first thing we did was consult the emergency checklist, I knew what it said to do.

We were in communication with Houston Center at the time and the Captain requested a level off at FL240 because he too knew what was coming.  The Captain read the checklist as I performed the procedure.  After turning the auto throttle off, I added pressure to the left rudder pedal as I pulled the right engine to idle thrust.  I held pressure on the rudder instead of adding trim because I knew we would be starting down in a few moments and would have both engines at idle, negating the need for trim.

The warning light remained illuminated, but all other engine parameters appeared normal…oil temperature, pressure and quantity normal…EGT normal…N1 and N2 normal.  We were not required to shut down the engine.  It's much better to leave an engine running at idle if at all possible.  At idle, the engine is not providing any thrust, but it is providing air and electricity and is standing by to produce thrust if absolutely necessary.

I have declared an emergency on numerous occasions in my 25 year flying career and have always received prompt and helpful service from ATC.  Today would be no different.  I pushed the throttle up on the good engine in an attempt to control speed and asked the Captain to request a lower altitude.  Given the heat of summer and our heavier than normal weight, we weren't going to be able to maintain FL240.  The Captain declared an emergency and requested an immediate descent and a turn back toward the airport.  We were cleared to descend at our discretion to FL180, an altitude we could maintain on one engine, and were cleared directly to the airport.  We were now headed the wrong way on a heavily traveled departure corridor from one of the busiest airports in the nation, but ATC would clear the path for a straight in arrival with no delays.

 “Say souls on board and fuel remaining”

One of my jobs as the First Officer is to review the weight and balance data that the company sends us after we leave the gate.  This data must be received, reviewed and verified as correct before we can legally takeoff.  The closeout comes in the form of a short printout in the cockpit with all the information we need to verify the weight and balance of the aircraft.  Part of my personal routine is to write the flight number, draw a line from our planned flap setting to the stabilizer trim setting and make note of the number of souls on board in large enough print to be seen by old eyes…mine and the Captains.  (Pictured below is the closeout from another flight).  Souls on board and fuel remaining are typically the first two things ATC wants to know after a pilot declares an emergency.


“145 souls on board, three hours fifteen minutes fuel remaining”

After completing the checklists, the Captain was very busy keeping the Flight Attendants in the loop, making PA announcements to concerned passengers and coordinating our arrival back at the airport.  He delegated flying the airplane and working the radios to me. It was at this point that I remember making a conscious decision to make the arrival as normal as possible.  This goes back to the concept that know what is normal will highlight things that are not.  I wanted this arrival to look as normal as possible to help me identify anything else that wasn't.

As we descended with both engines at idle power, there was no differential thrust so the airplane flew normally.  I planned to pass abeam the departure end of the runway at 8,000 feet so I could make a power off descent to the final approach course.  We called the airport in sight and were cleared for a visual approach to runway 18R.  We could have had any runway we wanted, but 18R was the normal runway, so we stuck with normal.  We started our turn from the downwind leg back toward the airport as we passed through 5,000 feet and I didn't have to add power until we were almost over the final approach fix.

I slowed the aircraft and configured for landing as I would for any other flight with the exception of the flap setting.  We are required to use 28 degrees of flaps instead of the normal 40 degrees when landing single engine to help with climb performance in the unlikely event of a single engine go-around.  Less flaps...less drag...all good when operating on one engine.

At about 1,200 feet above touch down, I increased the power one last time on the good engine and stabilized our approach speed.  I'm not embarrassed to admit that the last 1,000 feet of the approach got my blood pressure up just a hair.  This was my first single engine landing out of the simulator.  We were over the maximum landing weight for the aircraft by almost 10,000 pounds and flying on one engine.  The approach needed to be perfect and in order to prevent damage to the aircraft, the touchdown needed to be smoother than normal.

I set the main gear smoothly onto the runway, lowered the nose until the wheel touched and raised the reverse thrust lever on the good engine as I applied the brakes.  We slowed to taxi speed on the runway and leisurely took the last high speed turnoff from the runway where the “safety vehicles” were waiting for our arrival.

 “Safety vehicles”

I may be letting the "cat out of the bag" here, but when making PA announcements to the passengers, there are many words we generally avoid…thunderstorm, tornado, wind-shear, emergency, engine failure, fire…just to name a few.  In this case, the words “fire truck” could strike fear into an otherwise calm and collected passenger.   Imagine if you will, a first time flyer sitting at the over-wing exit. He read the safety card in the seat back in front of him, so he's fully qualified, right?  After landing, the aircraft is surrounded by fire trucks with lights ablaze and a hand full of guys wearing full fire gear jump out and surround the jet. It isn't at all inconceivable that this guy might panic, pop the emergency exit and evacuate.  What a mess!  We want the passengers to be informed and we want them to know what is going to happen next, but certain words just cloud the issue.  We avoided stressful words and warned everyone ahead of time about the "safety vehicles."  No worries...please remain seated.

We stopped the aircraft on the taxiway just clear of the runway and shut down the right engine as the “safety vehicles” inspected our aircraft and gave us the all clear to taxi to the gate.  To be honest, the whole thing was a little anti-climactic.  I've trained for this sort of thing many times.  The Captain and the Flight Attendants were so good at their duties that most of the passengers hardly knew anything was wrong.  I stood in the door of the cockpit to say goodbye as everyone calmly deplaned.  I didn't notice single concerned face.  Most people said thank you and I even heard a few "nice flight" type comments.  I wondered to myself if they knew we weren't in Mexico.

An hour later we were climbing through FL240 for the second time that day, but with slightly more productive results.  On to our destination and back again, I was home within two hours of when my wife was expecting me.  I don’t think she even noticed.

4 comments:

  1. Great read!

    As a pilot wife myself, I would have noticed the two hour delay...unless you got in after bedtime. How did you break the news to her? I am anxious just reading this, I couldn't imagine if my husband were you!

    ReplyDelete
  2. I called her after the first landing and let her know I would be running late, but didn't tell her the whole story until morning. She would have worried all day.

    ReplyDelete
  3. Hi Brad,
    When aircraft fly in cruise altitude, say FL35, do many planes fly one behind the other or each plane has a separate track. Hope your writings appear in a book form in future. Rgds

    ReplyDelete
  4. Hello Pranesh,

    Really, we do both. We often fly on a jet airway that is very much like a highway in the sky, where we line up and fly 10-20 miles in trail of each other. But we often cross paths as the airways cross paths in the sky just like highways and roads on the ground.

    ReplyDelete