Videos from TheFlightPractitioner are educational, comprehensive and interesting. I fly with Cary when in Florida, and have found his instruction to be top notch. Our 13 year old granddaughter and her best friend both did their intro flights with Cary in August, and loved the experiences. They each flew for 20 minutes on separate flights, and other than initial takeoff and the last 200 vertical feet of final approach to 28J, they each flew the entire time with Cary's instruction and guidance.
Thanks for the question!. To properly answer it though, I would need to know why you think it is a bad idea. I'll try to explain my rationale. I was assigned a "direct to the numbers" approach by the controller in order to put me in front of a landing corporate jet. While that made me number one for landing, I was still mindful of the following traffic which was faster than me and closing. For that reason, I elected to fly a faster than normal approach (but within my limits) and defer final flaps. I usually use 25 degrees for a final flap setting in the Cherokee when runway length and other circumstances are not a factor. By selecting 40 degrees flap at the end of this approach, however, I was able to adjust my VREF speed down a few knots to reduce the landing roll and make an easier runway exit onto Runway 13/31 or taxiway Echo.
For one, the pitch down moment of adding full flaps close to the ground could easily have elicited an involuntary addition of back pressure that could easily induce a stall. Long runway, 2 notches, you were stable. You became focused on the plane in trail and your strategy for vacating the runway before you even crossed the threshold. The Citation could and would (I hope) go around if warranted. Obviously, you are not a novice. That said, a low time pilot should never do this.
Great discussion points! You are correct that any destabilizing factor on an approach within 200' AGL is cause for concern. With regard to the pitching moments on the tapered wing PA28s, flap extension will usually cause a nose up force due to the airflow change over the stabilator. This is most noticeable at higher speeds (closer to VFE), and usually on initial extension to 10 degrees (it is why I like to see PA28 pilots slow to VFE - 10 KIAS before extending flaps to 10 degrees). However, when extending flaps from 25 to 40 degrees at or near VREF, there is no noticeable pitch change whatsoever, and no requirement to retrim. It is a quite common practice in the PA28 to defer the final flap settings, such as after breaking out on an instrument approach to a contaminated and or short field. For this reason, I do not consider a flap extension from 25 to 40 degrees below 200' AGL in the PA28161 to violate the stabilized approach criteria. Your point about consideration to traffic in trail is also important. I see many pilots become obsessed with traffic behind them, to the point where it affects their approach. As I said, in this instance, I was "mindful" of (not focused on) the jet traffic. In such circumstances, if I am able to help maintain separation without introducing risk I am open to do so. That being said, and as you point out, a pilot's decision to deviate from any procedure must be carefully thought out.
Videos from TheFlightPractitioner are educational, comprehensive and interesting. I fly with Cary when in Florida, and have found his instruction to be top notch. Our 13 year old granddaughter and her best friend both did their intro flights with Cary in August, and loved the experiences. They each flew for 20 minutes on separate flights, and other than initial takeoff and the last 200 vertical feet of final approach to 28J, they each flew the entire time with Cary's instruction and guidance.
Why did you yank in full flaps just outside the threshold? Seems like a bad idea that late in the approach.
Thanks for the question!. To properly answer it though, I would need to know why you think it is a bad idea. I'll try to explain my rationale. I was assigned a "direct to the numbers" approach by the controller in order to put me in front of a landing corporate jet. While that made me number one for landing, I was still mindful of the following traffic which was faster than me and closing. For that reason, I elected to fly a faster than normal approach (but within my limits) and defer final flaps. I usually use 25 degrees for a final flap setting in the Cherokee when runway length and other circumstances are not a factor. By selecting 40 degrees flap at the end of this approach, however, I was able to adjust my VREF speed down a few knots to reduce the landing roll and make an easier runway exit onto Runway 13/31 or taxiway Echo.
For one, the pitch down moment of adding full flaps close to the ground could easily have elicited an involuntary addition of back pressure that could easily induce a stall. Long runway, 2 notches, you were stable. You became focused on the plane in trail and your strategy for vacating the runway before you even crossed the threshold. The Citation could and would (I hope) go around if warranted. Obviously, you are not a novice. That said, a low time pilot should never do this.
Great discussion points! You are correct that any destabilizing factor on an approach within 200' AGL is cause for concern. With regard to the pitching moments on the tapered wing PA28s, flap extension will usually cause a nose up force due to the airflow change over the stabilator. This is most noticeable at higher speeds (closer to VFE), and usually on initial extension to 10 degrees (it is why I like to see PA28 pilots slow to VFE - 10 KIAS before extending flaps to 10 degrees). However, when extending flaps from 25 to 40 degrees at or near VREF, there is no noticeable pitch change whatsoever, and no requirement to retrim. It is a quite common practice in the PA28 to defer the final flap settings, such as after breaking out on an instrument approach to a contaminated and or short field. For this reason, I do not consider a flap extension from 25 to 40 degrees below 200' AGL in the PA28161 to violate the stabilized approach criteria. Your point about consideration to traffic in trail is also important. I see many pilots become obsessed with traffic behind them, to the point where it affects their approach. As I said, in this instance, I was "mindful" of (not focused on) the jet traffic. In such circumstances, if I am able to help maintain separation without introducing risk I am open to do so. That being said, and as you point out, a pilot's decision to deviate from any procedure must be carefully thought out.