Measure of Skill

Discretion and Precaution

August 1, 1997

The fine art of throwing in the towel

Pilot training places a great deal of emphasis on forced landings — and rightfully so. Being prepared to execute a successful emergency landing is an important part of a pilot's repertoire of skills. Of equal importance, however, is having the knowledge and judgment to be able to make the decision to perform a precautionary landing. Precautionary landings are procedures designed to avert forced landings or to prevent bad situations from becoming worse.

A reckoning

The decision to make a precautionary landing can be a tough one. Not because of the difficulty of the landing itself, but because of pilot reluctance to come to terms with deteriorating conditions. Just as there's a landing expectancy that can lull us into a commitment to land (when a go-around may be in order), so is there an expectancy that we can continue our flights to our planned destinations even though things are falling apart all around us. Problems crop up when unanticipated engine, system, or weather anomalies occur — and we still press on to that destination.

When this happens, pilots have to be willing to admit that potentially unsafe variables are at work. Then the pilot's job becomes one of accurately assessing risk and formulating plans to deal with it. Often the best plan is to land at the nearest suitable airport, and the sooner the better. This ends the potentially escalating level of risk and prevents abnormal or tense situations from developing into full-blown crises.

Assessing risk

Risk is a relative term. Much depends on pilot experience and qualifications. A low-time VFR-only pilot facing reduced ceilings and visibilities is one thing; a pilot with an instrument rating and 500 hours of actual instrument time in the same situation has a higher comfort level — and more options.

Often the issue of fuel reserves prompts thoughts of precautionary landings. Legal reserve fuel requirements (30 minutes for day VFR, 45 minutes for IFR and night VFR) can slice a thin margin of safety even thinner when unanticipated headwinds cut into an airplane's endurance. When doubts about your fuel reserves arise, ask yourself: What's better — landing soon and gassing up, or barging ahead with your original flight plan — your stomach churning, your eyes scanning the clock and the fuel gauges, and your ears listening for the engine's first stumble?

At other times, environmental factors enter into the decision to make precautionary landings. What's your comfort level with flying over mountains at night? Or on instruments in icing or around convective conditions? The bottom line here is to avoid these and any other personally stressful situations at their first suggestion.

You want an airport

The best thing about precautionary landings is that they afford you the luxury of a wider choice of landing sites. While it's true that a field may be the best option under certain circumstances, we'd all agree that landing at a nearby airport would be preferable. Finding one is a snap, provided you've done your flight planning well.

First of all, your route should be planned with alternate airports in mind. Ideally, your route will be flanked by airports that could serve as alternates should the need arise. If it's not, then it's time to reassess your risk tolerance, honestly evaluate your skill level, honestly evaluate your airplane's health and maintenance situation, and raise your personal weather minimums to offset any added potential danger. You may want to consider making the ultimate precautionary landing: canceling the flight.

Sorry, no airport nearby

Let's say that you're en route and that the nature of your difficulty — for example, an engine running alarmingly rough, but still running — demands an expeditious, but not forced, landing. Now's the time to look for a good landing site and to avoid some others listed with this article.

Enter a landing pattern as you would at an airport and use the airspeeds that you'd normally use. You'll probably need to perform a soft-field landing, so be sure to have that procedure firmly in mind. As you fly around the "pattern," keep a sharp lookout for wires, poles, and other obstructions. Also, get ready for a go-around should the field itself be obstructed or uneven. If that's the case, search for another, more suitable field and make another try.

Soft-field procedures

The pilot operating handbook for the specific type of airplane you fly is the final authority, but most soft-field landings call for:

  • A final approach using power to control descent rate
  • A steeper-than-normal approach profile, if obstacles are a factor
  • Full flaps
  • An approach airspeed of 1.3 times the stall speed (VSO) in the landing configuration.
  • A main-gear-first touchdown at minimum controllable airspeed
  • Holding the nosewheel off the ground as long as possible, using power as necessary

Practice, practice

Instructors should put greater emphasis on precautionary landings, and certificated pilots should always bear in mind a diversion to an alternate airport. Every pilot should make it a point to include more alternate airport information as part of preflight planning. At every stage of a flight, we should all be able to answer the following question: "Where's the nearest best place to land?" If you know the answer, you're well on the way to developing a proactive diversionary mindset.

GPS to the rescue

GPS makes finding the nearest airport a snap. Virtually all GPSs have features that let you call up several nearby airports — along with their ranges and bearings from your current position — in a keystroke or two. Another popular feature lets you check on a selected nearby airport's runway lengths, radio frequencies, and fuel availability. These kinds of "nearest" features alone justify buying a handheld or panel-mount GPS — if you haven't already.

Here are some popular GPSs and the ways to access their nearest airport feature:

  • Garmin GPS-90 (handheld): Hit the GO TO/NRST button twice.
  • AlliedSignal Bendix/King KLN 89B (panel-mount): Hit the NRST button. Hit the CRSR (cursor) button to highlight "Airport?"; then hit Enter.
  • Trimble 2000 Approach (panel-mount): Hit the APT/VOR button.
  • Garmin 155 (panel-mount): Hit the NRST button.
  • II Morrow Apollo 2001TSO (panel-mount): Hit the EMG button.
  • II Morrow Apollo Precedus (handheld): Hit GO TO/NRST twice.

Good and not so good

OK, so you have to make an off-airport precautionary landing. Here are some places to seek and avoid:

Good:

  • Golf courses (watch out for golfers)
  • Unplowed fields
  • Turf farms
  • Empty parking lots (watch out for poles)
  • Dry fields (light brown in color)

Not so good:

  • Highways (can have many obstructions)
  • Plowed fields (land with furrows to minimize damage)
  • Empty, fallow fields (often have rock outcropings)
  • Wet fields (dark brown)
  • Low ground (dark swales mark muddy drainage areas)

E-mail the author at tom.horne@aopa.org.


For further reading:

The following articles on this Web site provide additional information regarding this month's "Measure of Skill."