Do you always reach best true airspeed in cruise? You should know this step to use aircraft momentum from slightly above a selected altitude to accelerate into best cruise speed. The procedure has at least 3 benefits:
It’s a process check
No delay – you don’t wait on engine power
Cooler cylinder head temperatures
Here’s a process check using the GFC-700 autopilot in a Cirrus Perspective SR22TN Turbo.
In a full power climb from below, select an altitude 100 feet above the target cruise level, in this example 17,600 feet. Upon reaching 17,600 feet, reset the altitude select to 17,500 feet. Then touch the autopilot Vertical Speed (VS) and dial in a 400 foot per minute descent. This will set the plane in a slightly nose down position and use aircraft momentum to accelerate into best true airspeed (TAS). Continue reading “You should know this step if you fly Cirrus SR22 Turbo”→
Getting ‘on the step’ in a climb from below is easier with a Turbo Cirrus SR22 because the engine produces 100% full power all the way into the flight levels. Pilot work-load is reduced because no mixture adjustments are required and there are no cowl flaps. You just maintain full throttle and full mixture all the way up.
In a climb from below into cruise, you cannot always use the same procedure and get the same result. Powering to best cruise speed can be affected by a number of variables; such as, airplane weight, balance, and density altitude. Your time at full power may change if you have more fuel or an extra passenger or baggage in back (weight & balance) or hotter day (density altitude).
I know two pilots that have flown a Turbo Cirrus for about 3 years. And, they recently realized their Cirrus has not always been established in best performance cruise flight based on reading AOPA Pilot and letters from fellow aviators regarding Barry Schiff’s article “Stepping Along, ‘On the Step’ Fact or Fiction.”
Barry says, ” many pilots tend to prematurely and impatiently reduce power after leveling off. The throttle often is retarded before the airplane has had a chance to accelerate to normal cruise speed. In a sense, the airplane is established in a subtle form of mushing flight.”
When entering a selected cruise altitude from below, a Cirrus SR22TN Turbo may require up to 2 minutes at full power to pull the airplane into level cruise flight. But have you ever listened to a turbocharged TCM IO-550 engine at full power in level cruise flight? If you have then you understand why some pilots may pull the power back after about a half-minute. In less than a minute a turbo Cirrus will accelerate and appear to be in level flight. Continue reading “Two Turbo Cirrus pilots realize they have not always been in level cruise flight”→
The known definitions for the term flying “on the step” are summarized below:
Flying “on the step” definitions:
(verb) Getting “on the step” is a term used by the military. The military citations always involve using momentum from slightly above the selected altitude to accelerate the aircraft and lower the nose into best cruise performance. The procedure is an assist to formation flying by reducing process variation. The earliest documented origin for the term is found in the B-24 Liberator operating manual circa 1945.
(verb) A procedure used to set an airplane in level flight for best cruise performance. The procedure can be initiated properly from below or from above the selected cruise altitude. If flown correctly, the final cruise speed is the same regardless of entering the selected altitude from above or from below.
(noun) A condition or state in cruise flight that produces a higher cruise speed which can only be attained through a unique technique. Subject matter experts have asserted it to be a myth or old-timer’s tale.
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Getting “on the step” is a term and procedure used by the military. We’ve reviewed several aircraft noted for using the procedure. These include: the B-24 Liberator, Northrop T-38, and the Lockheed U-2 “Dragon Lady.”
The B-24 Liberator is the earliest documented reference we could find. We posted page 68 from the B-24 flight manual that includes illustration and instructions. Flying the B-24 Liberator “on the step” is standard procedure for establishing best performance in level cruise flight. The aircraft manual states to “always level off for cruising from the top in both speed and altitude.”
Charles Thornburgh wrote about flying the U.S. Air force Northrop T-38 “on the step” in his letter to AOPA. And, it’s also said that the Lockheed U-2 spy plane enters best cruise by using momentum from slightly above its selected altitude to get on the step in flight levels FL600 – FL700.
Getting “on the step” by using aircraft momentum from slightly above cruise altitude reduces process variation in establishing best cruise speed, which assists formation flying. Trying to climb into the selected altitude from below requires more process variation to reach best cruise speed, which can be a drag on formation flying.
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We’re continuing a review of articles written about flying an airplane “on the step.” These articles help us to better understand flying in level cruise flight. Simple right?
A number of expert instructors have pointed out that many pilots tend to prematurely reduce power after leveling off at their selected altitude, which creates a mushing along flight attitude with the nose slightly up and tail low. Cirrus pilots in normally aspirated SR22’s that reach higher flight levels have posted comments on this type of flight attitude.
At an altitude of 17,500 feet a normally aspirated Cirrus only has about 55% engine power. So, can a normally aspirated SR22 climb from below into flight level 17,500, it’s ceiling limitation, and use just engine power alone to accelerate into best cruise velocity? If the plane is set at full remaining power (55% of 310 hp), how long does it take to get the plane’s nose lower and accelerate into best cruise speed? Continue reading “How does a normally aspirated SR22 get into level cruise at FL17500?”→
David Rogers, a Beechcraft Bonanza F33A pilot, believes there is a step. He’s written about getting his normally aspirated airplane “on the step” for best cruise performance at 15,000 feet (FL150).
David mentions the problem some pilots can have when climbing and then “[rolling] the prop back to 2300 or 2100 rpm without allowing the aircraft to accelerate . . . .” Power reduction too soon can cause the plane to settle into less than optimal cruise speed. Other pilots describe the problem as a slightly nose high and tail low, which results in the plane mushing along in cruise. It’s not always obvious to pilots.
At higher altitudes such as FL150 it can be harder to get a plane into level cruise flight. Based on David’s article, the available cruise power for a Bonanza F33A at FL150 is limited to about 45% – 55%. He says, “Getting ‘on the step’ occurs when the aircraft is at the maximum velocity for the particular altitude and power available.” He believes using aircraft momentum from slightly above the selected cruise altitude is a best practice to accelerate the plane into optimal cruise speed. Continue reading “A Bonanza F33A pilot gets on the step at FL150”→
In a letter to AOPA Pilot, Charles Thornburgh says all airplanes are not equal in regard to flying on the step. His experience occurred on a cross-country flight in a T-38 in 1974. Here’s an excerpt from his description:
“We were flying from our home base of Holloman Air Force Base, New Mexico, to Homestead AFB, Florida, with a stop in Houston for gas. We were able to take off and climb with our two-ship straight to our cruising altitude of FL470 or FL490 (can’t remember which).
After we leveled off, the power was set for cruise. We spent a few minutes level at Mach 0.91, and then gently, without losing Mach, eased up 200 feet. We then nosed over and descended 400 feet, all the while not touching the power. As we then slowly returned to our cruise altitude, we noticed our speed was now Mach 0.93, where it remained. I thought it was pretty slick. Maybe you can borrow a T-38 and check it out!”
AOPA Pilot, “Letters from our May 2016 Issue,” Charles Thornburgh, Pooler Georgia, July 2016, pg. 12,
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In Fate is the Hunter, Ernest Gann described setting his airplane on the step after they departed from San Francisco bound for Honolulu in a DC-4A. The first and second officer onboard previously served as pilots in the Navy.
“We pass through ten thousand feet and for a moment steal an additional hundred feet so we can descend back through it. In the doing the ship can be set flying in a slightly nose-down position. Thus, “on the step” we will add better than ten knots to our air speed and also satisfy our sensual appreciation of flight. A mushing airplane, regardless of its speed, becomes a miserable contraption to any dedicated pilot. He absorbs this unhappiness through the seat of his pants. There is no reason to believe this will ever change regardless of aircraft design. A good pilot becomes morose and irritable in spite of what the most modern instruments proclaim unless his ship is “on the step.” He will work endlessly to achieve that delicate angle and for this once and only once will prove the instruments wrong and the hair tips of his sensory powers more honest. When the instruments finally admit additional speed, then the pilot is doubly content, for he has proof that the instruments are not his absolute master and he is not as yet altogether a mechanical man.”Continue reading “Ernest K. Gann cited flying on the step in Fate Is the Hunter”→
Could the origin to flying “on the step” have been drawn from water craft? Barry Schiff and another fellow pilot I know suggest it is a probable fountainhead for the term. But I have not located an original source document making this connection. Continue reading “Lexicon for flying “on the step” – Part 2″→