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Lowell, Michigan, United States
Dogs were born to run. I wasn't, but I do it anyway. :)

Thurman Munson the Pilot

posted by Andrew 02 August 2009 1 comments

Most people think of Thurman Munson as a baseball player, a talented and charismatic catcher for the New York Yankees during the 1970's. His success on the field was so impressive that Munson seemed almost certain to one day earn recognition in the Hall of Fame. Sadly, Munson's career and life were cut short 30 years ago today - August 2, 1979. It was his performance as a pilot, not as a ballplayer, that ultimately defined his legacy.

What
Munson was licensed pilot and on an off day during the 1979 season he took two of his friends, David Hall and Jerry Anderson, for a pleasure flight in his new Cessna Citation 501. During a series of touch-and-go's the aircraft descended too low during the fourth approach and crashed short of the runway, killing Munson and injuring his two friends.

How
Pilot error. Munson fell behind the power curve, both literally and figuratively. Literally because he flew his aircraft into a low speed, high drag condition that requires increased thrust as airspeed decreases. Figuratively because Munson failed to recognize a deteriorating situation and didn't take corrective action in time to avoid an accident.

Why
Preparation, execution, and luck. Most professional athletes excel because they are obsessive about their preparation and execution, and achieve greatness by being in the right place at the right time. My 7th grade teacher Mr. Pipkin was fond of saying: "Luck is when preparation meets opportunity." Munson was no exception and his baseball success was attributable to all three factors. Tragically, the failure of these factors - a lack of preparation, poor execution, and bad luck - led to Munson's death, one that was ultimately caused by his own judgement.

Lack of Preparation
Munson was a well-trained pilot with 516 hours of flight time, although just 34 hours flying Citation jets. While 500 hours is significant, the most experienced pilots measure their flight time in the thousands of hours. Some folks in aviation consider the 300-600 hour range of experience to be somewhat dangerous, the theory being that such pilots have enough experience to feel very confident in their skills, but not enough experience to fully appreciate the limits of their abilities. It's notable that John F. Kennedy Jr. had slightly over 300 hours of flight time under his belt when his fatal accident occurred, just to cite one well-known example.

Perhaps such confidence contributed to the fact that Munson never bothered to brief his passengers. This was especially critical as both of his friends were experienced pilots who Munson could've relied on for assistance; in fact, Hall was his former flight instructor (in a smaller aircraft) and was sitting in the co-pilot's seat. The NTSB report on the crash includes this quote from Hall:

"I was trying to convey to him my discomfort with the fact that we were getting a little bit low and that I was uncomfortable with the sink rate. I didn't want to come out and say 'I don't like this approach; please add power.' I was trying to feed that intormation to him in that fashion because, again, I had no experience in this type of aircraft."

A passenger briefing is required by FAA regulations yet Munson did not conduct one. As a result his friends were unaware of the specific aircraft configuration to expect for an approach, let alone the basics of emergency exits, etc. Notably, neither Munson nor Hall were wearing their shoulder harnesses (all three were wearing lap belts) and seatbelts are a part of any passenger briefing.

Further showing a lack of preparation was that Munson calculated the wrong target approach speed, Vref, which is based on aircraft weight. His jet was 1000 lbs heavier than he estimated and the resulting lower Vref gave him less margin for error as he flew into the "mush" regime of the power curve.

Lastly, choosing to perform touch-and-go's wasn't the safest way to demonstrate his new bird for his friends. Takeoffs and landings require a high workload for the pilot and to conduct them repeatedly while hosting friends on board increases the risk needlessly. A safer flight plan would've been to depart the airport traffic pattern and enjoy a pleasure flight at higher altitude in less congestion.

Poor Execution
During the flight Munson did not refer to any checklists. Even professional airline pilots with over 10,000 hours of flight time will always use their checklists. It's far too easy to forget a step, especially when unexpected events interrupt the series of tasks. During the accident approach Munson simply forgot to lower the flaps, an omission that reduced his margin for error by limiting the lift-to-drag ratio of the aircraft. He had even forgotten to lower the landing gear but his friends reminded him of that critical detail.

Compounding Munson's high workload was that he wasn't hitting his marks, and much like a pitcher not finding the strikezone and falling behind in the count, Munson fell behind the power curve. He wasn't holding the proper airspeed or altitude in the traffic pattern, forcing him to divert attention to make corrections while also communicating with air traffic control and his passengers.

Another odd choice was Munson's decision to deliberately fly the third approach (which was ultimately successful) without flaps and allow Hall to handle the controls. While it's possible to land without flaps, it is challenging and Munson decided to perform this maneuver spontaneously. Handing the controls to his friend was downright careless. Even though Hall was an experienced pilot, he had never flown a business jet and hadn't even been briefed on how to land in a normal configuration, let alone with a no-flaps setup.

Landing without flaps is analagous to driving a car without using first gear. Remember your first time driving a stick-shift and how difficult it was to start from a stop without stalling? That's what Munson asked his friend to do, while adding the challenge of starting in second gear.

During the fourth approach Munson forgot to lower the flaps but his friends assumed they were doing another planned no-flap approach and thus never alerted Munson. Being distracted by a change in traffic pattern assigned by air traffic control didn't help the situation, and Munson being poorly set up in the pattern further taxed his mental resources. Munson eventually realized that his jet was too low and still sinking so he began to add power, but only incrementally.

Jet engines require more time to "spool up" in response to a throttle change, and despite being aware of this fact - Munson had even cautioned his friends about it during an earlier approach - he was slow to react to the low thrust condition, perhaps due to his limited jet experience and high workload. By the time he realized that full power was needed, it was too late to stop the aircraft's momentum from carrying them all the way into the ground.

Bad Luck
In this accident luck wasn't much of a factor in avoiding the crash. However, luck played a critical role in the accident's survivability. The aircraft crash-landed into a field of small trees, skinny enough that they didn't result in any violent impacts as the aircraft skidded across the field... Except for the one huge tree stump four feet in diameter. The Citation slammed into the stump, spinning the jet 180 degrees before coming to rest. The stump impacted the left side of the cockpit, directly underneath Munson.

A few feet to the right and it might have been Hall who died; a few more feet in either direction and everyone may have survived. As it happened, both of Munson's friends were relatively unhurt by the impact. However, Munson's seat detached due to the force of the tree stump's direct hit, thrusting him into the instrument panel. The impact broke his neck, but Munson was alive.

Once the aircraft came to rest Munson asked his friends "Are you guys OK?" When they asked how he was doing, he replied "I don't know. I can't move. I can't move." With the aircraft engulfed in flames, Hall and Anderson struggled to free Munson but finally were forced to abandon their efforts when the flames became too intense. Both of Munson's friends suffered severe burns as they delayed their own exit while courageously trying to rescue him.

What If
As with most every accident, whether in aviation or any other discipline, a cascading chain of events eroded risk to the point that disaster was inevitiable. Breaking any single link in this chain would've resulted in a safe outcome, if not prevent the accident altogether. There were numerous opportunities for Munson change the tragic outcome of this flight:

What if Munson had...

  • remembered to lower the flaps? The approach likely would've proceeded uneventfully.
  • used the proper checklists? He wouldn't have forgotten to deploy the flaps.
  • briefed his friends of the flight plan? They could've alerted him to the forgotten flaps.
  • calculated the correct Vref? The aircraft would've carried more speed during the approach and required less corrective thrust.
  • flown a more stabilized approach? The reduced mental workload might have allowed him to react more quickly.
  • applied full thrust more quickly? The aircraft could've made it to the runway.
  • worn his shoulder seatbelt? It may have reduced the severity of his injury enough that he could've helped extricate himself.
    Indeed, this succession of pilot errors was cited in the probable cause of the NTSB's accident report:

    "The National Transportation Safety Board determines that the probable cause of the accident was the pilot's failure to recognize the need for, and to take action to maintain, sufficient airspeed to prevent a stall into the ground during an attempted landing. The pilot also failed to recognize the need for timely and sufficient power application to prevent the stall during an approach conducted inadvertently without flaps extended. Contributing to the pilot's inability to sufficient power application to prevent the stall during an approach conducted recognize the problem and to take proper action was his failure to use the appropriate checklist and his nonstandard pattern procedures which resulted in an abnormal approach profile."

    To err is human - all pilots make mistakes. The key is not going into a situation where a few simple mistakes can be deadly. Thus I view this accident as the result of a single failure: Munson's judgement.

    Munson exercised poor judgement by chosing to conduct a complicated flight in a high-performance aircraft in which he had little experience. He could have flown a more simple flight plan at higher alitude doing basic maneuvers, or even waited to demonstrate his new aircraft for his friends until he had accumulated more flight hours in the cockpit.

    I'm reminded of some advice my flight instructor once shared: "Takeoffs are optional; landings are mandatory. Sometimes the best flight is the one not taken."

    References
    NTSB accident investigation report (PDF)
    ESPN article from 2004

    Remembering Chris Tragna

    posted by Andrew 02 April 2009 5 comments

    Seven years ago today began like any other day... except for the crow.

    As I walked towards Hazelrigg Hangar where I worked as a flight test engineer, my gaze drifted above the building's distinct external truss roofline to marvel at the glowing purple pre-dawn sky over the Chesapeake Bay. Perched on the peak of a truss I noticed a crow and for some strange reason the deep purple sky behind the bird suddenly felt ominous. "Something is going to happen today" I found myself muttering; quickly I silently chided myself for being so superstitious.

    Soon I'd forgotten about that silly crow and was busy with the work of getting my F/A-18F Super Hornet ready for testing. I can't remember what we were testing or even if we flew that day, but I do remember when an image appeared that afternoon on the TV screen from a camera monitoring the runway at Patuxent River Naval Air Station.

    A small aircraft sat motionless on the runway with a white sheet covering the cockpit, surrounded by rescue personnel. We recognized the aerobatic aircraft as one of two Extra 300's being used by the Navy Test Pilot School (TPS). One of our colleagues was enrolled there and we all had trouble focusing on our work until we were able to check the schedule and confirm that our buddy wasn't flying at the time.

    Later that day our boss, test conductor Howard Gofus, got a phone call. The news wasn't good - he relayed to us that LCDR Christopher Tragna had died in the accident. "Trags?!" was my immediate reply; I can still hear the surprise in my voice.

    Trags had been one of the test pilots assigned to our group, flying the Super Hornets we tested before he moved on to become an instructor at TPS. He was the pilot for several test flights on my aircraft and our personalities were a good match; preflight and postflight briefings always went well when his name was on the flight cards.

    One of my favorite memories of Trags occurred during a test plan review. The plan was not very well written and I frequently proposed changes to improve the document. The plan's author became impatient with me, asserting that since all of the correct technical information was in the plan, why bother fixing the language?

    Most test pilots always seem to be in a hurry and would've sided with the author, eager to approve the plan and go flying. When the author lamented my attention to detail, Trags responded that he was happy to see an engineer who knew how to write. In fact, Trags had a long list of his own suggested changes! I replied that it was equally refreshing to have a pilot who appreciated good writing.

    Trags was a quiet and thoughtful guy - not your typical test pilot - yet he was also intensely intelligent. Unfortunately I didn't get to know Trags more closely; I began working at Pax River just six months before he transferred to TPS. Eight months later he was gone.

    As I walked out of the hangar after work I looked over my shoulder and was startled to recall the eerie premonition from the morning. If nothing had happened I would've completely forgotten about seeing that crow.

    The sun was setting and I thought about the advice my mentor, Chris Blundell, had given me about the culture of flight testing: "Remember that sooner or later, one of the guys sitting across the table from you in the preflight briefing won't come back."

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