Peter wrote:
The TBs have a good system.
The best I’ve seen around.
I used to secure the yoke with the seatbelt as per the PA28 POH, and I think the previous owners did too, as the pilot’s belt return has more play than the others. I now use an impossible-to-miss-red ‘remove before flight’ lock from Aircraft Spruce which ties the two yokes together and tethers to the throttle quadrant.
With single-door aircraft like the PA28 it’s impossible to get in without undoing the seatbelt, but on other aircraft it’s essential to only use the pilot’s seatbelt to block the controls. There was a fatal crash locally attributed to this; BEA report. Club practice was to tie back the Rallye’s stick to lift the elevator when pushing the aircraft into the shared hangar. It stalled shortly after takeoff, probably aggravated by the STOL design of the Rallye, and the towed glider lifting the tail up until the moment the tow cable was released.
Graham wrote:
We’ve all missed a pitot cover I’m sure, and if you can miss that then you can miss a control lock.
Yes, I have missed a pitot cover. It was not visible from the cockpit. I noticed this during the takeoff roll, as that was the first point in the operation of the airplane when this omission was detectable. A locked control will be detectable at any point when you first enter the cockpit – by moving the controls. Yes, an engine start guard is great, and a minimum to meet certification requirements – but it does not lock the controls – it just locks the control wheel/stick. For my experience, that is not enough.
In the case of both aircraft I flew which had control system damage, is was the result of the airplane sitting for a long time in the wind with the control wheel lock in. But yes, it is possible that someone could collide with the parked airplane, and damage it – I’ve have that happen three times. Each time that was detectable during my walk around (well, once, to make it easy, the two planes were at rest collided!). I would rather find during my walk around, a crumpled aileron trailing edge, and know I have a damaged airplane) than hidden damage inside the airplane because the control was defected far beyond its stop, and the mechanism damaged.
Hangaring can be a great solution, if a hangar is available, as long as hangar rash does not become a factor. Many airports (in my area anyway) have no hangars available.
Long term wind damage to airplanes is a reality. During my work to develop a repair kit for the current C 182 strut carry through bulkhead cracking, I spoke several times to the FAA Engineer (who was formerly a Cessna Engineer) about the cause and nature of this damage. Though Cessna and the FAA had originally suspected “aging aircraft”/long term operation of the airplane, reports that the FAA were receiving were pointing to just being tied down in the wind. Some very low time airplanes, which simply sat tied down in the wind their whole life had the bulkhead cracks.
A parked airplane maybe subjected to conditions which the manufacturer did not account for well. The pilot/owner can reduce these effects with good external control locks, and better tying down habits. And, the pilot is responsible for assuring that the airplane they are about to fly is externally undamaged, and has nothing attached to it which should not be there. Presuming that the airplane is effectively tied down, and the controls externally locked, I’m hoping that while the pilot is untying it, the control locks will be removed as a part of preparing the airplane for flight.
The TBs have a good system. The engine cannot be started with the lock in place, and the lock holds the controls (which apart from rudder and elevator trim are rods, not cables) in a neutral position, producing zero “lift” in the presence of wind.
Looking around, I see other planes have loads of other contraptions, and I am not surprised they cause problems.
Pilot_DAR wrote:
Based upon my experience, I see it very differently. Twice, after I removed the cockpit control lock, and checked “full and free”, I found myself airborne in an airplane with control system damage I could not detect without either a very close inspection of the flight control system, or more simply, it did not fly correctly. In both cases, external control locks would have prevented the damage. The forces imposed on flight controls when an airplane sits downwind in a strong wind can certainly exceed those created by pilot effort, and, go on and on as long as those conditions prevail, not just a few times during the occasional flight.
That sounds like an extremely rare occurrence to me. As I said if the winds are strong enough to damage it then it probably shouldn’t be outside in that weather. It the cases you reference I don’t suppose you can rule out other causes, like e.g. someone applying an abnormal force to a control surface somehow.
The TB10 I fly has lived outside for a long time, and thus I imagine through quite a few ‘normal’ storms, with its internal control lock. There’s never been any damage or issues with the flying controls. If strong winds tended to damage the flying controls because of the internal lock, I’m pretty sure it’d be known issue with the type.
Missing something during the pre-flight is by far the greater risk. External control locks on the tail especially so, because depending on the type you generally won’t be able to see them from the cockpit. We’ve all missed a pitot cover I’m sure, and if you can miss that then you can miss a control lock. I don’t buy the “this is so basic anyone who can’t do it shouldn’t be flying” type of argument, not for this or any other issue. If something can be forgotten then people will forget it, and if we assume that’ll never be us because we’re too competent for that then we’ve started down the road to complacency. Knowing my own limitations, I prefer the solution which makes it impossible to start the engine.
I use one of these, and there is no way you could miss it. It’s a bit of a hassle to get on and off, but seems to do the job, and holds all the controls “neutral”, including the rudder.
https://antisplataero.com/products/ultimate-gust-lock
They are for RVs, but I guess the guy running that company could be nudged into making them for other aircraft.
Graham wrote:
Loads the wind puts on the flight control system while cockpit-locked are no different from the loads on them in flight when the pilot holds them in a particular position in the airflow. It’s what they’re designed to do and surely better than banging around against opposite stops. If the wind (or other forces experienced while parked) are strong enough to damage restrained control systems then your aeroplane probably shouldn’t have been parked there.
Based upon my experience, I see it very differently. Twice, after I removed the cockpit control lock, and checked “full and free”, I found myself airborne in an airplane with control system damage I could not detect without either a very close inspection of the flight control system, or more simply, it did not fly correctly. In both cases, external control locks would have prevented the damage. The forces imposed on flight controls when an airplane sits downwind in a strong wind can certainly exceed those created by pilot effort, and, go on and on as long as those conditions prevail, not just a few times during the occasional flight.
There are times, I agree, when the control wheel/stick control lock is the “better than nothing” solution if there is no choice but to park an airplane downwind (a floatplane at the dock comes to mind). But for me, that will be as temporary as I can manage it to be, until I come up with a better external control lock solution, like at least parking it into the wind.
In the earliest Cessna POH’s, external aileron/flap, and a rudder control locks are depicted on the "Aircraft Tie-Down Procedure page.
If external control locks are hazard, then so is that pilot. If a pilot can’t manage to assure that the four corners of the airplane are present, and nothing is attached to the plane which shouldn’t be during a preflight inspection, they really don’t deserve to be flying that day!
Anyone who applies a control lock is bound (at least morally I suppose) to the regulation:
Sec. 23.679
Control system locks.
If there is a device to lock the control system on the ground or water, there must be a means to—
(a) Give unmistakable warning to the pilot when the lock is engaged; and
(b) Prevent the lock from engaging in flight. Quote
So assuring it’s red, and has a red flag is a really good idea.
I still haven’t got a control lock for the Bolkow Junior. I’m thinking of an external aileron lock. But the stick has to be full forward for the stabilator. With no-one in the cockpit C of G is very near the main wheels, and it’s easy to lift the nose. Fixing the stick forward is a problem – tie to rudder pedals?
At present I’m very cautious about wind speed.
The POH/AFM on my plane has no info related to locking the controls, in any way. Nor do I think at the time of it being written they would have had any understanding of the stabilator filling with water if you stored it outside with the stick fully aft. If they had understood I’m sure they would have added drain holes. Nor was the POH ever revised in this regard (only to reflect ADs). They only built 100 before moving on to other things. I don’t operate in a fully documented world 
It did occur to me that it would be very hazardous to fill the stabilator with water in that way, and then for it to freeze overnight making the surface highly out of balance. It’s one of many valuable things I’ve learned about my plane over time, some from other owners, some from my own experience, all good to know. I’m glad I stored it outside in the rain just once, to see water pouring out of the stabilator when I released the seatbelt.
I should build a control lock that locks the stick in a central position and at the same prevents one from sitting in the plane. If it folded up I could take it on trips.
Silvaire wrote:
On my type it can also result In the stabilator filling with water if it rains, to the extent that when you lower it the water runs out for some time. I only did that once and in any case prefer that the plane be parked inside.
I guess your type then doesn’t recommend it in the POH? (If it is recent enough to have a POH. 
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