I’m with Pilot DAR here. The aircraft is certified to obtain a certain amount of climb performance with flaps fully down, even at MTOW, as long as you fly the right speeds – you must’ve done this already when going around. Furthermore, from flying it in the circuit you also know that the aircraft flies perfectly fine straight and level with flaps down, and is completely manoeuverable. And it’s not like flaps ‘wear out’ when they’re deployed – you can fly around all day with flaps deployed if you want to, as long as you remain within the limits.
So… Make sure you are well below MTOW (don’t take passengers and the kitchen sink), take plenty fuel (at least double from what you’d normally take for that flight), watch your airspeed (white arc only, obviously), plan your turns like they’re all base-to-final (maximum 20 or 30 degrees bank) and a 40-minute flight should not be a problem whatsoever.
While I agree the TB20 has loads of power and will climb with full flaps, I also know (having > 2000hrs in it) that it doesn’t climb particularly fast like that and on a go-around one needs to get the flaps back at least a stage ASAP. With full flaps, the climb will resemble a PA28-141 with four Brits who have been eating fry-ups, and we have all read the accident reports on some of those 
So the thing to watch is obstacles. There really must not be any, because say +300fpm is really sod-all in terms of a climbout.
Have you tried full RPM power on while on breaks? (not sure how your are wired on electrics & mechanics)
You will be surprised that is enough to bring them up unless you have a serious mechanical defect, then few days waiting will do you as may not get a ferry permit or an insurance quote any quicker…
Ibra wrote:
Have you tried full RPM power on while on breaks? (not sure how your are wired on electrics & mechanics)
You will be surprised that is enough to bring them up unless you have a serious mechanical defect
Is that a suggestion that the combined application of full power and brake will cause a change in flap position?!
A reasonable airflow force from the prop will lift them without possibility of mechanical damange if nothing is in the way (I guess by design?)
I flew a PA28 (mechanical flaps) where they were stuck with flap down while cockpit mehanical lever is up, I could not lift them by hand but that power+break did work, I am not sure about TB20 electric ones but definitly having engine alternator running and propeller washing helps in that case as well…
The breaks is just to make sure you are not flying without a ferry permit ;)
Prop airflow cannot lift flaps under any circumstances, otherwise they would not usable in flight. In the PA28 case the mechanism must have been broken.
AFAICT this TB20 case doesn’t have a broken mechanism; the motor is just not being driven.
The TB20 flap mechanism is a worm drive – like a windscreen motor. You cannot overpower it, without breaking it.
I’m surprised you’re even thinking about it.
Yes, I have no idea how TB20 flaps works or the circumenstances of that aircraft, but for a PA28 there was “no smart reason” why flaps on that specific aircraft should not go up when you pull a mechanical stick (I was lucky to spot them visually stuck down on my ground checks as I flew the first leg and all was ok)
I am not sure about this TB20 but they could be lot of reasons why flaps are stuck, obvious one is drained battery in this winter? non obvious ones are from previous VNE landing?, one has to be creative from time to time and use his own judgement ;)
2greens1red wrote:
We’ve our TB-20 ‘unserviceable’ about 40 mins from our home airfield, with full-flaps stuck deployed, and engineers not available for a few days. s.
I don’t get your reasoning: you have no idea why the flaps are stuck (mechanism defect, motor burnt, switch corroded, cables broken, short circuit) and you are contemplating taking off with performance unknown to you versus waiting for someone knowledgeable? A systematic failure analysis has to be feasible for any aircraft mechanic.
What might your risk of a botched takeoff under normal conditions? 1:10000? Chances of a bad landing under normal conditions? 1: 1000?
What is your risk of a botched takeoff with full flaps? 1:100? Risk of a bad landing if by chance the flaps retract when you are in short final? 1:50?
You are weighting this vs. one or two, maybe three weeks without plane?
Ibra wrote:
I flew a PA28 (mechanical flaps) where they were stuck with flap down while cockpit mehanical lever is up, I could not lift them by hand but that power+break did work,
It’s bee a while since I flew a PA-28, but my recollection is that, like a manual flap Cessna, when the mechanical lever in the cockpit us up, the flaps are extended. When they are extended, it’s ideal that they remain that way, as the pilot desires, so “stuck” is likely a good thing. When the pilot wishes to retract the flaps, they push the position lock button at the end of the flap lever, and reposition the flaps as desired. If the flap position will change without the pilot pressing the lock button, or moving the lever, or, particularly with an application of power, the plane is very certainly NOT airworthy! Electric flap systems are entirely different.
Ibra wrote:
VNE landing?
How is this accomplished?
Peter wrote:
Prop airflow cannot lift flaps under any circumstances, otherwise they would not usable in flight. In the PA28 case the mechanism must have been broken
This.
The most serious risk which a pilot must consider when flap serviceability is in question, even more than performance in the case of a failure, is asymmetry. Some flap systems more than others are vulnerable to this, with Piper Twin Comanche’s and Navajos high on that list. I have had occasions of Cessna electric flap failures, where a ferry home was the only way, as a repair was not possible on site. this was never a problem, with risk management. A good understanding of your aircraft systems might help a pilot make a good decision.
I have had one occasion of flap failure during a touch and go, where they jammed at the point of retraction from landing position to takeoff position. As I was on the water on a remote lake in a Cessna 180 floatplane, staying could have created a big problem. The flaps jammed symmetrically, and takeoff was possible at 20, and I had to fly home that way. There was no problem doing this, though I flew very gently, and slowly – none of those Vne landings! Upon landing at the maintenance base, I found that a flap track had broken, and jammed that flap in a fixed position. This, of course, is critical, and had I known this was the cause when I was on the go, I might have stayed. But, I did not know the reason for the jam, and back in that day, a stay on that lake would have assured a night or two overnight on shore, a search for me, and then a distant fly in repair. It worked out okay, but was less than ideal from any viewpoint.
