Here is my experience with full flaps in the Beaver. First, the Beaver I'm flying has the Baron mod with the 5370 upgross. The old flap placard has been replaced with a new one that reads:
Cruise - 0
Climb - 15
Baron - 25
Takeoff - 35
Landing - 50
I have tried around 15 or more landings at the "Landing" setting, or 50 degrees. I almost always land at or just a little farther down from the "takeoff" setting (35-40 degrees), which I believe is more than the "takeoff" setting on the old placard. The first time I landed full flap was during my checkout where I was warned never to use it but we did a full flap landing just to get a feel for it. The landing was uneventful, flew a stabilized descent down to the water around 70 mph and kept the power on until I was flared level a few feet over the water. I have never landed full flap with the airplane anywhere near gross. Maybe that is where guys find themselves in trouble? Also, never tried it with gusty winds of any kind. Maybe the solution is maintaining the speed (65-70 mph) with power right into the roundout??? Like I said I've never had any bad experiences with full flap but I've just had a healthy respect for the full flap landing because of what I've read on this forum and from being cautioned by my chief pilot. It's not something I'm going to use in day to day ops but my feeling is that if you can't fly your aircraft in every configuration you don't have any business flying it in the first place.
The 40 Degree Flap Question
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Cat Driver
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Lets all take a trip back to flying kindergarten and review how an airplane flys.
Regardless of flap position the wing will produce a constant lift as long as airspeed remains constant.
There are two basic means of maintaining a constant airspeed.
(1)Power.
(2) Gravity.
If a Beaver were at 10,000 feet lets say and at the recommended speed for that flap setting the lift produced using full flap will remain constant as long as you maintain an attitude that gives a constant indicated airspeed at zero thrust from the propeller.
Generallly where pilots get into a iffy control response and rate of descent problem is when transiting from a steady state, constant attitude, constant airspeed flight path will be in the flare and hold off portion of a landing.
That can be taken care of with proper training and practice.
When using full flap I almost always complete the last portion of the approach and landing from around 200 feet with the throttle closed, the idea is a short approach path and short landing...therefore using power defeats the whole purpose of using full flaps.
Regardless of flap position the wing will produce a constant lift as long as airspeed remains constant.
There are two basic means of maintaining a constant airspeed.
(1)Power.
(2) Gravity.
If a Beaver were at 10,000 feet lets say and at the recommended speed for that flap setting the lift produced using full flap will remain constant as long as you maintain an attitude that gives a constant indicated airspeed at zero thrust from the propeller.
Generallly where pilots get into a iffy control response and rate of descent problem is when transiting from a steady state, constant attitude, constant airspeed flight path will be in the flare and hold off portion of a landing.
That can be taken care of with proper training and practice.
When using full flap I almost always complete the last portion of the approach and landing from around 200 feet with the throttle closed, the idea is a short approach path and short landing...therefore using power defeats the whole purpose of using full flaps.
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
cat, could you please address this comment?
"I know if you have take-off flap, you can go as slow as possible, almost flaring over those last trees, with power off, and when you clear the trees, duck the nose down, re-flare over the water and when you touch down, push forward a wee bit on the column for brakes. "
I don't think I can respond without getting overly colorful.
"I know if you have take-off flap, you can go as slow as possible, almost flaring over those last trees, with power off, and when you clear the trees, duck the nose down, re-flare over the water and when you touch down, push forward a wee bit on the column for brakes. "
I don't think I can respond without getting overly colorful.
Drinking outside the box.
In my outfit, pilots are trained and required to maintain proficiency at pretty much everything the AOI(POH) says the airplane can do. Try these numbers on for size.
Basic weight: 27,000 lbs
Max AUW: 45,000 lbs
Engines: 2 x 3060 SHP
Take-off at 37,000 lbs (SL, ISA, calm, firm, level)
7 deg – 93 KIAS – 1400’ grd roll – 2200’ dist to 50’ AGL
30 deg – 67 KIAS – 800’ grd roll – 1200’ dist to 50’ AGL (STOL)
Landing at 37,000 lbs (SL, ISA, calm, firm, level)
17 deg – 93 KIAS app – 750’ grd roll – 2150’ from 50’ AGL
40 deg – 83 KIAS app (no chart but probably around 600' grd roll)
40 deg – 72 KIAS app – 500’ grd roll – 1100’ from 50’ AGL (STOL)
In STOL ops, VMCA is disregarded. If you lose an engine on take-off below VMCA, power to idle, level the wings and die like a man. If you lose one on a STOL app, an attempted overshoot will cost up to another 700’ descent before climbing.
Dragging it in under high power is a no-no, thus approaches get steeper for greater flap settings. Power is moved to idle at 50’ for normal landings. For STOL landings, power to idle AFTER roundout. Other than for speed, flaps are limited for weight and crosswind component.
The SOP? Whatever it takes to get the job done safely in the given conditions.
The airplane? DHC-5 Buffalo
Basic weight: 27,000 lbs
Max AUW: 45,000 lbs
Engines: 2 x 3060 SHP
Take-off at 37,000 lbs (SL, ISA, calm, firm, level)
7 deg – 93 KIAS – 1400’ grd roll – 2200’ dist to 50’ AGL
30 deg – 67 KIAS – 800’ grd roll – 1200’ dist to 50’ AGL (STOL)
Landing at 37,000 lbs (SL, ISA, calm, firm, level)
17 deg – 93 KIAS app – 750’ grd roll – 2150’ from 50’ AGL
40 deg – 83 KIAS app (no chart but probably around 600' grd roll)
40 deg – 72 KIAS app – 500’ grd roll – 1100’ from 50’ AGL (STOL)
In STOL ops, VMCA is disregarded. If you lose an engine on take-off below VMCA, power to idle, level the wings and die like a man. If you lose one on a STOL app, an attempted overshoot will cost up to another 700’ descent before climbing.
Dragging it in under high power is a no-no, thus approaches get steeper for greater flap settings. Power is moved to idle at 50’ for normal landings. For STOL landings, power to idle AFTER roundout. Other than for speed, flaps are limited for weight and crosswind component.
The SOP? Whatever it takes to get the job done safely in the given conditions.
The airplane? DHC-5 Buffalo
The probability of survival is dependent on the angle of arrival.
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Cat Driver
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- Joined: Sun Feb 15, 2004 8:31 pm
Yah, 32a but you have the best training one can get....now if only commercial aviation had the same level of training these discussions would not be going on.
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
Re: The 40 Degree Flap Question
Jesus Mary and Joseph, that was quite a read!
Only enough time on this Earth to scratch the surface...
Imagine a time when a life's knowledge can be extracted onto a memory stick and uploaded onto a new platform, or a fresh brain, before heading to the final pasture.
Gives new meaning to stemming the "Brain Drain".
Only enough time on this Earth to scratch the surface...
Imagine a time when a life's knowledge can be extracted onto a memory stick and uploaded onto a new platform, or a fresh brain, before heading to the final pasture.
Gives new meaning to stemming the "Brain Drain".
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Loon-A-Tic
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- Joined: Sun Mar 29, 2020 12:51 pm
