Tuesday 13 February 2018

THE ONE BOUNCE RULE

Acknowledgements: Thomas P. Turner (Mastery Flight Training Inc.)

The pilot of a Mooney M20J “bounced multiple times during landing, then experienced landing gear collapse,” according to an FAA preliminary accident report this week.
The pilot, alone in the airplane, was not hurt. The extent of damage to the airplane is not yet reported; however, high performance retractable-gear airplanes rarely fare well following a gear collapse.

Pilot-induced oscillation (PIO) occurs when the airplane begins a departure from the desired flight path, and the pilot applies inappropriate, excessive or mis-timed corrections that result in ever-increasing excursions which threaten to force the airplane out of control. In short, the pilot is “behind the airplane” and his/her attempts at regaining control only make matters worse.

PIO can occur in any phase of flight, but it is usually associated with pitch excursions on landing and can rapidly develop to catastrophic proportions, even in the hands of an experienced test pilot. Airline pilots can enter a PIO; even test pilots flying the first glide tests of the Space Shuttle bounced and entered a PIO (at least I doubt that it was a pre-programmed flight test manoeuvre!).

Stresses can rapidly damage landing gear and other airplane structures. It can force the airplane off the runway, or out of control in roll or in a stall. Propeller strikes are common in propeller-driven aircraft.

Bounce a landing and PIO becomes a real possibility. Once a PIO begins your best option is to power up and go around (well, not in the Space Shuttle!). So:
  •        Add go-arounds after the main gear touches the ground to your recurrent training regimen.
  •        Be well-practiced in establishing the right pitch and angle of attack, while firmly  holding the proper attitude to prevent PIO.

There are two kinds of go-around, but some instructors only teach one. It’s comparatively easy to power up, pitch up and clean up from a point a couple of hundred feet above the runway lights. It’s quite another task to go around once the mains have touched, the speed is low, and the angle of attack is very near a stall.

My first instructors presented touch-and-goes as pseudo go-arounds; it wasn’t considered a touch-and-go if the nose-wheel of the Cessna touched the ground. We were learning the skill of aerodynamic braking, because some of us would go on to fly Air Force fighters.

But we were also learning the art of the on-runway go-around, with a lift-off in a condition that necessitated a firm push forward on the controls with power application, then finesse as flaps were retracted and flying speed restored. In short, we learned how to recover from PIO.

After my Air Force experience, and after seeing what my early students did after a bounced landing, even on a very long runway, I developed what I call The One Bounce Rule. Basically, The One Bounce Rule is this:
  •          If you bounce a landing, make a snap decision
  •         Immediately decide whether you have the speed (no less than five knots below your final approach “VREF” speed) and angle to attack to recover into a second flare
  •          Immediately decide whether there is sufficient runway remaining to come to a stop from the point you’ll touch down a second time, given the airplane and environmental conditions that exist at the time
  •       If the answer to either is “NO” or you have any doubt, go around immediately. PUSH and HOLD to acquire the proper airspeed, angle of attack and coordinated wings-level heading
  •          If the answer to both is YESand you elect to do so, PUSH and HOLD into a second flare
  •         If you bounce a second time, go around immediately. No hesitation, no questions asked. PUSH and HOLD to acquire the proper airspeed, angle of attack and coordinated wings-level heading

If a propeller strikes the surface it’s another story. Prop strikes can cause immediate, catastrophic engine damage or propeller damage that makes a go-around incredibly risky. They can also cause internal over-stresses that will become a catastrophic failure at some point in the future, usually without warning.

Most engine manufacturers recommend engine tear-down inspections after a propeller strike. One manufacturer considers a tear-down mandatory if the propeller speed is seen to drop any amount at all when the strike occurs, and even if a prop strike occurs when the propeller isn’t turning (for example, a towing accident).  If the damage is substantial enough the propeller must be removed from the airplane for repairs.

Attitude is everything, at least where PIO recovery is concerned. Practice so that you are proficient at hitting the proper attitude required to fly out of a bounced landing into a second flare if it’s advisable, or to initiate a go around as you add power and gradually clean up the airframe (retract flaps and landing gear consistent with type-specific considerations).

if you’ve bounced a second time, or if there is any doubt about being able to re-flare and land on the remaining runway after the first bounce, FOLLOW THE ONE BOUNCE RULE!


FLY SAFE!

Wednesday 7 February 2018

RISK MANAGEMENT

Acknowledgements: AOPA/Dan Namowitz & Tom Horne

TRAINING TIP: 'NO UNNECESSARY RISK'

SCENARIO:  
Pre-flight weather report

“A warm front is advancing toward the area with its first effects expected during the time-period of a proposed VFR cross-country flight to visit family in another state. Ceilings are not expected to go down for several hours, but throughout the period there is a chance of marginal visibility and freezing rain from precipitation falling from the warm layer aloft into colder air at lower altitudes”.

Hmmmm?

A pilot considering a VFR flight might well feel torn between making the relatives happy by showing up for holiday fun or staying put and missing a chance to see loved ones and enjoy warm cider and three kinds of pie. Meanwhile, family members, well-intentioned but unaware of the weighty decision the pilot faces, are texting, emailing, and calling, eager to know when the flight will arrive.

Everybody loves pie and no one wants to disappoint, but there are times when it would be unwise to rely on luck where capability (be it naturally-inherent or experience-gained) is lacking.

Thanks to a strong educational effort, numerous widely publicised accidents, and an abundance of common sense among the pilot population, the number of fatal icing-related accidents has been trending downward over the past decades.

But, typically, every year there are still four to six fatal general aviation accidents attributable in some measure to icing. The reduction’s good to see, but this is no reason to let our guard down. Besides, as new generations of pilots join our ranks, it’s important to continue to drive home the basics of icing avoidance. Seasoned pilots, with fat logbooks and ratings galore, also should be reminded!

Not only does freezing rain, or even freezing drizzle, pose a serious threat of structural icing, but a warm front, with its widespread low clouds and restricted visibility, is nothing to tangle with, especially for a non-instrument-rated pilot flying a basic aircraft. Unfortunately, not all pilots are deterred.

Here are some important thought-traps to avoid:
·         It’s just rain. Let’s say you are instrument-rated and current and are flying in light rain. It’s tempting to believe that the rain will persist, but you may be flying in a temperature inversion. This occurs when flying at lower altitudes below a warm frontal surface. The advancing warm air rides up and over a retreating cold air mass, causing rain to fall. Problems crop up fast when the rain becomes supercooled as it falls into the cold air mass. Clear icing or freezing rain may soon be in the offing!
·         No problem, I have weather radar. This does a great job showing areas of precipitation, and the bigger the droplets, the brighter the radar returns. But unless it shows clouds it’s of little use in avoiding most icing conditions!
·         It’s OK, I’m on top. That’s a nice place to be, but eventually you’ll descend for a landing. And it had better be at an airport not affected by icing conditions. Otherwise, a descent through a cloud layer, or layers if you’re between layers, could mean that you’ll pick up ice on the way down!
The FAA’s Airman Certification Standards Concept introduced in 2016 and revised in 2017 is intended to ensure that an applicant possesses the knowledge, ability to manage risks, and skill required under the certification to be able to act as Pilot-in-command (PIC). It includes the requirement for a private pilot applicant to master task-specific knowledge, and to demonstrate understanding of each task’s risk-management elements.

“The goal of risk-management is to proactively identify safety-related hazards and mitigate the associated risks” (FAA Pilot’s Handbook of Aeronautical Knowledge). It goes on: it is important to remember the four fundamental principles of risk-management:
  •         Accept no unnecessary risk. If you are flying a new airplane for the first time, you might determine that the risk of making that flight in low visibility conditions is unnecessary.
  •         Remember that you are pilot-in-command, so never let anyone else - not ATC and not your passengers - make risk decisions for you.
  •       Accept risk when benefits outweigh dangers (costs). A day with good weather, for example, is a much better time to fly an unfamiliar airplane for the first time than a day with low IFR conditions.
  •     Because risk is an unavoidable part of every flight, safety requires the use of appropriate and effective risk-management not just in the pre-flight planning stage, but in all stages of the flight.

IDENTIFY HAZARDS-ASSESS RISKS-ESTABLISH CONTROLS-IMPLEMENT CONTROLS-
MONITOR RESULTS

Remember: While poor decision-making in everyday life does not always lead to tragedy, the margin for error in aviation is thin.


FLY SAFE!