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Constant Airspeed Climbs and Descents

Pitch holds the airspeed, power sets the rate, and your eyes keep coming back to the attitude indicator. A small set of habits, and the ones that get you out of cloud you never meant to enter.

Basic Instrument Maneuvers — FI.XI.B

Why you fly it

Three situations account for most of the cloud entries VFR pilots never planned, and all three are avoidable long before the panel becomes your only horizon. Night VFR near clouds you can no longer see against a black sky. Weather deteriorating ahead until the horizon quietly stops being a horizon. And fog, forming as the temperature slides toward the dewpoint — a spread that keeps closing across successive reports is the plainest warning you get, and it sits in every METAR you read. The cloud base calculator turns those same two numbers into an estimated base for convective cloud above the reporting station: a figure for deciding whether to go, not a figure to descend on.

Climbing and descending by reference to instruments is not a first step toward an instrument rating. It is there so that if you end up inside cloud without meaning to, the airplane keeps doing what you ask while you get back out.

Getting out begins with a level 180-degree turn back into the air you just flew through. That is the FAA's first answer for a VFR pilot in inadvertent instrument conditions, and the reasoning is hard to argue with: the weather behind you is the only weather you know was flyable. If that turn is not available — terrain rising, the way home closed in behind you — the next move is to climb to an altitude that clears everything around you and tell someone. Descending to break out underneath is a last resort, and it is a plan only when you know the ceiling from a reliable report, know the terrain and obstacles beneath you, and have ATC or an instrument approach involved. Every one of those moves is a pitch change made without a horizon, and pitch changes are where disorientation bites. That is what you practice here.

Practice it with someone beside you. Flying a real airplane by reference to instruments means a view-limiting device, and 14 CFR 91.109 requires a safety pilot in the other seat — at least a private certificate with category and class ratings for the airplane, working dual controls, and enough forward and side vision to keep watch — or an instructor. This is not a maneuver you take up alone.

What you are looking at

Six instruments do the work, and knowing what drives each tells you what fails together. Airspeed, altimeter and vertical speed run off the pitot-static system. Attitude, heading and the turn coordinator are gyroscopic, but they do not share a power source: in the typical training airplane the attitude and heading indicators are vacuum-driven while the turn coordinator runs on the electrical system, which is exactly why a vacuum failure still leaves you a working turn instrument. A glass panel swaps the gyros for solid-state sensors with their own power and data paths, so what dies with what comes out of your own POH and avionics supplement.

Layout follows the same rule. On the PFDs most trainers carry — the G1000 arrangement and the panels that copy it — the attitude display fills the middle, with airspeed on its left, altimeter and vertical speed on its right and the HSI beneath. Other manufacturers arrange it differently, so learn yours on the ground. Power lives somewhere else on every panel, which is exactly why pilots forget to look at it.

Scan hub and spoke. The attitude indicator is the hub: out to one performance instrument, straight back to attitude, out to the next, back again. You do not wander around the ring, and you do not stop anywhere.

Control and performance

Attitude plus power equals performance. The attitude indicator and the power gauge are your control instruments — the two you set directly. Airspeed, altimeter, vertical speed and heading are performance instruments; they report the result. Set an attitude, set a power, cross-check what you got, correct in small amounts.

In a constant-airspeed climb the power stays where your POH puts it, so pitch holds the airspeed: nose higher, the speed decays; nose lower, it builds. A constant-airspeed descent is the same trade with the power pulled back — the setting chooses how fast you come down, and pitch holds the number on the tape.

Flying the climb

1. Raise the nose to the climb attitude on the attitude indicator.
2. Add climb power smoothly, holding the heading with rudder as it comes in — in most training airplanes that is right rudder, and yours will show you which way it yaws.
3. Trim off the control pressure once the attitude is set.
4. Cross-check airspeed, then adjust pitch — not power — to hold it.
5. Keep the heading on the HSI and the ball centered throughout.

Trim matters more here than in visual flight: an airplane you are physically holding drifts the moment your attention goes to the altimeter, and it has to go to the altimeter. Corrections are measured in bar widths on the attitude indicator, not handfuls. Vertical speed lags what you just did by a few seconds, so a big input followed by an impatient second one is how chasing starts. Turning while you climb, hold the bank at or below standard rate — the turn instrument shows it directly, and at trainer climb speeds that lands somewhere near 15 degrees. There is no reason on instruments to go beyond about 20.

Level off before the altitude arrives. Lead it by about ten percent of your rate of climb, so 500 feet per minute wants roughly 50 feet of lead. Lower the pitch to level, let the speed build to cruise, then bring the power back and trim again.

Flying the descent

Entry runs in the other order. Reduce power to the setting your POH gives for the descent you want, hold altitude with pitch while the speed bleeds off, and as the airspeed reaches the target, lower the nose to hold it there. Trim, then cross-check vertical speed — if the rate is wrong, the fix is power, because pitch is busy holding the airspeed.

Level off with the same ten percent lead, and let the speed you are leveling at decide the order. Leveling at a cruise speed faster than the descent speed, power comes in first and the airplane flies out of the descent as the speed builds; raise the pitch to level, then trim. Leveling at the descent airspeed, pitch and power change together. What you want to avoid is the unplanned version, a handful of each at whatever moment you noticed the altitude, which leaves you high and fast with no clear idea which one to fix.

What goes wrong

Fixation is the big one. You catch the altimeter 80 feet low, you stare at it while you correct, and by the time you look away the heading has gone 20 degrees. Nothing gets more than a glance before your eyes come home to the attitude indicator.

Trend vectors invite a subtler version of it. A trend vector is a prediction, not a measurement. Fly the actual altitude and airspeed, and let the trend tell you only whether the correction is working.

Then the omissions. Power gets set once and never looked at again, because it is on another page. Heading drifts in the climb because the rudder came off with your attention. The ball sits out to one side for the whole maneuver, which nobody notices under a hood until the instructor points at it.

And your inner ear will lie to you. A gentle, sustained turn stops registering, so rolling out of it feels like rolling into one the other way. When what you feel and what the instruments show disagree, the instruments are right.

If the panel quits

Learn what failure looks like on your airplane before you need to know it. On the Garmin systems most trainers carry, lost data shows as a red X where the numbers should be, and the answer is reversionary mode, which puts the essential display on the screen that still works. Other manufacturers annunciate and revert their own way, so the button and the wording come from your avionics supplement rather than from a friend's airplane. Know which instruments survive a vacuum failure or a blocked pitot line, and use the autopilot only if you know what mode it is in.

Then use the resource that costs nothing: tell ATC unable VFR, request vectors, and say it early. If you are in cloud, unsure of the terrain, or need an altitude or a heading nobody has cleared you for, declare an emergency and squawk 7700 — that is the step that unlocks priority handling and whatever deviation getting out requires. Controllers have kept a great many pilots alive with a heading and an altitude, and every one of them had to be asked.

Where you meet it next

On the practical test the examiner hands you a view-limiting device and asks for climbs and descents at a constant airspeed, straight and turning. The tolerances are 100 feet of altitude at the level-off, 10 degrees of heading and 10 knots of airspeed, flown smoothly with the cross-check visibly working.

None of it is a separate skill from visual flying. It is the same pitch and power relationship you use on every climb out and every descent into the pattern, with the window taken away and the scan doing the horizon's job. The tasks either side of this one build the rest of the escape: instrument straight-and-level, turns to headings — where that 180 back into clear air actually gets flown — and recovery from unusual attitudes, with systems and equipment malfunctions taking partial panel on its own terms. They are all in the Learn library.