I find lots of confusion in the PA46 world concerning flaps. When should they be deployed? When should they not be deployed? Are there rules that must be followed concerning the flaps?

It’s a broad discussion, and there is rarely a one-size-fits-all answer to the use of flaps. There are lots of variables in the decision-making process, and good judgment is expected and assumed by the pilot. Runway length, crosswind component, type of PA46, airframe icing, pilot experience and knowledge, ceiling and visibility, and whole host of other important factors play into the final decision of when to use flaps.

Let’s lay some groundwork about flaps, and hopefully answer some of the questions. Concerning flaps on a PA46, here’s some info that needs to be understood:

Deploying flaps add lift and drag – Duh. This one is easy. But, it does need to be said for this statement is elementary and important. Lesser amounts of flap deployment usually add lift and little drag, and large deployment of flaps increase drag significantly. But adding flaps adds both lift and drag, which can both be helpful (or hurtful) in certain situations.

Deploying flaps increases the approach angle (assuming all other variables remain constant) – I train engine-out landings with all of my clients, and the flaps can be your friend in an engine-out scenario. If you are high on approach, add flaps; if you are low, don’t add flaps.

Adding flaps creates a nose-down moment, and a subsequent need for greater negative lift with the tail – Adding flaps pitches the nose forward, and the tail must produce more negative lift. If the airplane is loaded with ice, then making a change in configuration (adding flaps) can create a stall with disastrous results.

The electric flap motor on most PA46’s can “stop in place” if overloaded – There are four conditions that can cause resistance in the deployment of flaps, and cause the electric motor to be overloaded:

1. Flaps being deployed at too high a speed: All of the OPs adhere to a mantra that I teach, “lead with the gear.” The landing gear on the PA46 is robust and strong, and should always be deployed before the flaps to slow down so the flap speeds (Vfe) is respected.
2. Flap tracks that are dirty or misaligned: This happens frequently. Make sure your maintenance provider checks for properly aligned flap tracks at annual.
3. Icing on the flaps or flap tracks: Deploying flaps puts the flaps tracks into the slipstream, and if the slipstream has ice the ice can bog down the movement of flaps, especially flaps that are to be retracted.
4. Flap transmission that is worn: The 90-degree transmission that is just below the flap motor can wear on the inside and bind. Especially on older airframes, this flap transmission can require replacement.

Anything within the flap system that could bog down the flap motor can cause the flap motor to “stop in place.” You will get a FLAPS caution advisory light, and the only way you gain control of the flaps is to reset the flap electronic circuitry. Since shutting off the electrical system for the airplane is not practical in flight, the best way to reset the circuitry is to pull out and reset the FLAP WARN circuit breaker. Once accomplished, the flaps will again respond. The FLAP WARN circuit breaker is one of the CBs that should be collared so it can be found easily in flight.

The increments of deployment are important –The first notch of flaps is 10 degrees, the second is another 10 degrees, and the third is 16 more degrees. So moving from “flaps up” to “first notch” is a lesser move than moving from “two notches of flaps” to “three notches of flaps.” So, be intentional when you deploy to full flaps, as the third notch of flaps adds more, with a greater effect of lift and drag.

G1000-equipped PA46’s have a flaps issue – There is a small device called a _________ that is behind the front seats. This device signals the position of the flaps to the G1000 system. This device only works if the flaps are in an exact position, meaning that the G1000 will only signal 10 degrees, 20 degrees, or 36 degrees. The G1000 will not signal “in between” position of the flaps. So, if the flap handle is placed “in between” (for example, 15 degrees), then the ______ will receive signals from both the 10 degree indicator and the 20 degree indicator and cause an over voltage condition inside the ________ and it will literally char the ________. This will cause the flaps to stop in place (at whatever location the malfunction occurred), and the flaps will not work until the __________ is replaced. It will be a $2,000+ mistake. For those that operate non-G1000 airframes, this problem does not exist.

Flaps at 20 degrees or greater cause the GEAR WARN light if the gear is not down and locked – I like using 20 degrees of flaps or greater on a “normal approach” because of the potential of activating the GEAR WARN light and audio. The OPs were created to use 20 degrees of flaps (or greater) to ensure this safety feature is triggered.

ˆThe landing attitude with no flaps is a higher pitch angle than with flaps, creating less visibility on landing. It is quite doable, but still a different perspective. All pilots should practice landing with different flap settings in initial/recurrent training to ensure comfort with landing with each flap setting.

Too many pilots are scared of full flaps – I’m not sure where it came from, but there seems to be a minority of PA46 pilots that were taught that 36 degrees of flaps creates a “dangerous” or “undesirable” flight characteristic. This is simply not so. It is just as easy to fly a PA46 at 36 degrees of flaps as with flaps up. To me, a “normal landing” is 36 degrees of flaps, and I then reduce flaps on a landing potential for outside factors such as icing, strong crosswinds, not seeing the runway until 200’ AGL, or other factors.

The flaps in the M600 is completely different than all other PA46s, and requires a different OP – The wing on the M600 is completely different than all other PA46s, so don’t confuse the two. When moving from a piston PA46 to a Meridian/M500/JetPROP, the use of flaps is identical. The M600 has a completely different wing with completely different flaps, and the operation of those flaps are different. Expect a small (but very surmountable) learning curve when moving up to an M600 from any other PA46.

A “stabilized approach” is the goal, and no changes to the configuration should be made at less than 500 feet AGL – I see this violated all the time. Recently, I had a pilot fly down the glide slope at 10 degrees of flaps, add 20 degrees at 200 feet AGL, and then add 36 degrees at 100 feet AGL. It was a disaster of an approach. The best approaches are made with no configuration changes below 500 feet AGL. While not a “hard rule,” for the pilot always has the prerogative to do whatever is needed to create safe flight (especially in an emergency), a stabilized approach is always the goal, and not changing the configuration creates stability on an approach.

Don’t add flaps to slow down in turbulence – As John Mariani teaches so well in M-Class, “Your enemy in turbulence is lift.” So, if you anticipate a rough ride, don’t add flaps. Do reduce power and do use the gear to slow down. While flaps will add drag, which will slow you down, flaps also add lift. Never ever add flaps in a PA46 to slow down in turbulence.

Flaps require pitch trim use – Actually, the amount of pitch trim movement required in a PA46 is FAR less than some other airplanes (the King Air B100 is probably the worst), but there is still a need to re-trim when flap changes are made. This re-trimming changes the stability of the approach. I see some pilots turn off the autopilot and immediately add flaps (for example, on approach to landing). A better way to add flaps on an approach is to add the flaps while the autopilot is ON and allow the pitch trim to null out the load change. When the autopilot is then turned OFF, the pitch trim will be set perfectly.

PA46 flaps are “effective, but weak” –The flaps are a huge percentage of the length of the wing, and as such they are quite effective. They do a great job. But, they also have a fairly weak mechanical setup. The weakest link is a bracket under the wing, visible in the wheel well. This bracket can bend or break under load on very rare occasion creating a “split flap” condition. The bottom line is to respect Vfe. Vfe 36 is violated more than any other flap setting, so make sure you get below Vfe 36 before adding that last notch of flaps.

Concerning icing and flaps, there’s some additional info that needs to be understood:

The older airplanes have much poorer verbiage concerning icing in the POH: In the 1980’s there was a lesser discussion in the aviation world about icing than there is today. We’ve learned much about icing in the last 30 years, and the verbiage in the more modern airplanes is far more robust. To bolster the discussion in the earlier model PA46s, “Section 9 – Supplements” has been added to the POH, and this provides a broader discussion of icing for a particular airframe. Make sure you read your POH all the way through and pay particular attention to Section 9 when considering icing.

The newer airplanes have MUCH better icing verbiage in the POH –The M600 has excellent guidance concerning flight with airframe icing, and the Matrix has better guidance than the Malibu. If you operate an earlier PA46, make sure to become a student of icing and apply modern practices. The icing discussion and limitations presented in the M600 POH is excellent, far better than any of the other PA46s. Being the most recent, the M600 icing verbiage is better than all other PA46s. The M600 POH provides clarity and leaves no room for doubt about how to handle icing on approach. All of the other PA46’s have varying excellence in terminology, usually commensurate with date of certificate approval.

The verbiage “Under no circumstances should full deflection of flaps (36 degrees) be applied until landing is assured.” comes right out of the Matrix POH, and the Matrix has better icing verbiage in the POH than other piston airframes –My fingerprints are all over the OPs listed on this website, and the other fingerprints are six other PA46 instructors that discussed, sweated, and negotiated the best ways to fly a PA46. I thought it best to include that statement because it provides a warning against deploying 36 degrees of flaps with ice. It does NOT advise replying 36 degrees of flaps…it provides a warning against adding 36 degrees until landing is assured. Part of this is due to the dire circumstances of performing a go-around with ice on the flaps, especially full flaps.

Icing and flaps don’t mix well – Every icing situation is different, and there’s no way to know for sure how the airframe icing will impact an approach without appreciable experience by the pilot that looks out on the wings in flight. It’s a subjective analysis, at best. If an approach must be made with ice on the airframe, increase the speed slightly and plan to use less flaps.

by Joe Casey