Twin Proficiency: Missed Approach: The First 400 Feet

Twin Proficiency: Missed Approach: The First 400 Feet

Twin Proficiency: Missed Approach: The First 400 Feet

screen-shot-2016-12-01-at-1-50-52-pm300 feet to go…hand on the throttles (you’re going to have to pull them back if you see the runway, or push them forward if you don’t). 200 to go…localizer centered, glideslope centered. 100 to go…still nothing but gray outside. Missed approach point: no runway environment in sight, miss the approach….

You’ve now entered what is arguably the highest workload phase an instrument pilot can face—the missed approach. There’s a lot you have to do to transition from a descent to a safe, consistent climb. How can you minimize the workload and manage a safe missed approach?

The first 400 feet

The standard missed approach is designed around a 200 ft/nm climb gradient. The minimum rate of climb you’ll need to maintain this gradient depends on your ground speed.

Ground Speed (kts) 90 100 120 140

Vertical Speed (fpm) 300 417 500 583

Minimum climb rates required to achieve 200 ft/nm climb

For pilots of most twins these climb rates are easily achievable. But if your airplane is heavy, density altitude is high, or engine power is reduced, you may have to decide before beginning an approach if you’ll have the climb capability to miss the approach. In fact, the minimums for many approaches, especially in mountainous terrain, are driven not by obstacle clearance for the approach inbound, but the need for terrain or obstacle clearance on the missed approach.

At the minimum 200 ft/nm climb gradient you’ll be two miles from where you initiated climb before you’re at 400 feet. There’s a lot going on in the first 400 feet climbing out from a gray hole so close to the unseen ground.

Fighting denial

Pilots are, by nature, can-do people, and this manifests itself in an expectation that we will be successful in flight operations. We tend to expect we’ll be able to land out of every approach, and may not think much about the possibility of missing the approach until we find ourselves at minimums with no runway environment in sight. “Missed approach denial” will cause indecisiveness and delay exactly when you don’t have time to dawdle.

We need to redefine “success” in completing a trip as safe arrival at a destination that meets minimum standards of weather, fuel and personal safety margins. Most times, that destination will be the one originally planned, but on any given flight “success” may mean landing somewhere else. A mindset that successfully flying an approach means flying the procedure to FAA and personal standards (including the missed approach if needed), and not landing on the runway at the end of the approach, will go far to fight missed approach denial.

Set-up for success

Missed approaches are risky when workload exceeds the pilot’s immediate capability, so by reducing pilot workload we have a much greater margin of safety.

Think about what you need to do at the missed approach point if the runway environment is not in sight. At the very least, you need to:

Advance power

Begin a climb, initially straight ahead

Configure the airplane for climb

Prepare to navigate the published or assigned procedure

Report the missed approach (and, if you’re a stickler for regulations, the reason you were required to miss)

Let’s look at each of these requirements, and consider what can be done to reduce workload.

Advance power: If possible, set the propeller controls for climb power before reaching the missed approach point. That way, if you need to climb out you have effectively made your engines a single-lever power design: move the props to climb before final let-down.

What about mixture control?  Many pilots fly at lean-of-peak (LOP) at least some of the time. Common LOP practice is to set mixture for cruise and leave it there through landing. A mishap trend is emerging, however, where LOP pilots are having power failures at the beginning of a go-around or missed approach. If the mixture is very lean, advancing the throttles (adding air) causes it to go leaner still, reducing power output on a fairly steep curve. If the mixture is not advanced sufficiently the airplane will continue to descend, and the engines may quit altogether when you need them most…in IMC only a couple of hundred feet above the ground. Sure, some instructors teach advancing the mixture first, then throttle, when missing an approach. The principle of workload reduction suggests, however, that you advance the mixture controls before beginning your approach, so there’s one less thing to do if success mandates flying the missed approach.

Climb straight ahead:  Many missed approach procedures are quite complicated, but they all begin the same way: climb straight ahead before turning. Keep the wings level as you advance power. If the airplane is properly trimmed, pitch attitude will trend toward that needed for climb. “Proper” trim would be one that results in an indicated airspeed close to optimum for climb. There are any number of reasons to fly this airspeed or that for an instrument approach. The best rationale (in my opinion) favors flying at the speed at which you’ll climb on the missed approach. That way, when you advance power and reconfigure the airplane for climb, it’ll already be trimmed for the missed approach airspeed. It’ll tend to do exactly what you want it to in this high-workload operation.

Configure for climb:  Once power is up and attitude is right, begin reconfiguring the airplane for climb. Some airplanes require retracting flaps right away, especially at higher density altitudes. Others will climb just fine with partial flaps out. Some, like the Beech Barons I often fly, have a decided pitch-down tendency with flap retraction which suggests the pilot not be in any hurry to bring flaps up in the first 400 feet of a missed approach. Experience or a little instruction in the airplane you fly will teach what’s best for you.

After you’re on attitude and speed for climb and you have a positive rate of climb, retract landing gear and retract any remaining flaps as needed. Don’t forget to open cowl flaps if your engines require a lot of cooling air at high power/high angle of attack, but this can wait until you’re at least 400 feet into your climb.

Prepare to navigate:  After you’re climbing in trim with the wings level, navigate the missed approach. You reduce workload and increase success by having most of the missed approach navigation prepared before you ever start the approach. When you review the approach chart make a note of the initial direction and altitude called out in the missed approach procedure. I like to write these on a “sticky note” and put it somewhere where it’s in my primary scan. That way, I won’t have to try to find it in the fine print later on; writing it down also helps me memorize the information for when I might need it.

With many GPS navigation systems, there’s one more task to perform; hit the OBS button to exit SUSPEND mode so you’re able to navigate toward the holding fix when you have reached the altitude where turns begin.

Report the missed:  Lastly, you’ll need to tell controllers you missed the approach so they know you’re flying the procedure. This can (and must) wait until you have everything else under control. As a simulator instructor most of the missed approach “accidents” I saw were prefaced by the student’s call of “missed approach” to ATC. Think about what happens when you make the call:

N12345:  “N12345, missed approach.”

ATC:  “Roger, 345, climb runway heading to 2000, then right turn direct Bingo, contact departure on 120.575.”

N12345:  “Runway heading to 2000, right to Bingo, departure 120.575.”  You now retune to departure frequency.

N12345:  “Departure, N12345 at 1200 climbing to 2000.”

ATC:  “Who’s calling departure?”

N12345:  “N12345, 1300 climbing to 2000, missed approach at Wichita.”

ATC:  “N12345, negative radar contact, are
you squawking…..”

You get the point. A lot of talking starts when you call missed approach, distraction you don’t need in the initial moments of a miss. You were already cleared for a missed approach direction and altitude as part of your approach clearance. So, fly what you were told to fly until you have everything under control and are ready to accept any changes ATC may require.

What we’ve all been taught about flying applies to a missed approach as well:  aviate, navigate, then communicate.

The first 400 feet

The first moments of a missed approach are among the highest workload you’re likely to encounter. You’ve got a lot to do to turn a descent into a climb, while you’re very close to the ground you cannot see. Successfully flying the transition into missed approach climb is greatly enhanced by the proper mindset and preparation, so when you reach the missed approach point and nothing but nothing is outside the windscreen, there is a minimum number of things you need to do to get the airplane pointed safely skyward.

Autopilots and the missed approach

It’s common practice to fly autopilot-coupled approaches in low IFR conditions. There’s a very strong argument that this increases safety significantly by keeping the airplane within very tight instrument tolerances all the way to the missed approach point, and enabling the pilot to maintain the “big picture” while monitoring the autopilot-flown approach.

But everything changes if the runway environment’s not in sight at the MAP. Following horizontal and vertical guidance, the autopilot doesn’t know what to do next. You’ll have to hand-fly the first portion of the missed approach. True, many installations have a “go around” button, but in virtually all cases “hitting the button” disengages the autopilot and puts the flight director command bars in a straight-ahead climb position—but you have to manually make the airplane follow.

Further, autopilots have the ability to hold a little control force against trim. This is why it’s common for an airplane to pitch up or down when you click off the autopilot—the system was “pushing” or “pulling” against the trim. When you reach the MAP on a coupled approach, then, not only will you have to take over manually and hand-fly at least the transition into climb, but you may have to do it with a slightly out-of-trim airplane. Anticipate the possibility the nose will want to go up or down from its desired pitch when you click off the autopilot to begin the missed.

Missed Approach Checklist

When beginning a missed approach:

Missed approach…COMMIT. Once you decide to miss, don’t try to “salvage” the approach or circle to land if you subsequently break out. If you start the miss, fly the miss.

Autopilot…DISENGAGE. Use the flight director “go around” feature if equipped.

Power…ADVANCE. Smoothly advance power to the recommended missed approach setting

Pitch…ESTABLISH. Establish the recommended pitch attitude or, if no recommendation exists, the same initial climb attitude you use on takeoff.

Wings…LEVEL. Fly runway heading to at least 400 AGL before making any required turns.

Flaps…AS REQUIRED. Begin flap retraction as required or recommended in the flight manual or POH.

Positive rate of climb…CONFIRM.

Landing gear…RETRACT as applicable.

Cowl flaps…OPEN as recommended, if equipped.

GPS…SUSPEND or OBS MODE as applicable.

Navigate…AS REQURIED once established in a climb


About the Author

Leave a Reply