Air Nostalgia DC3 - the risk of unintended consequences?
 

imtVH-TMQ, an Air Nostagia DC3 sits forlornly at Essendon Fields aerodrome, facing the Matthews Avenue tram tracks. You can see it from the Tullamarine Freeway. It looks in good nick and its all natural metal finish looks lovely in the evening sunset. But there was something unusual I could not immediately pick about it. Then it struck me. It was the wooden cleats on each aileron designed to prevent the ailerons from being damaged in high surface winds.

It is a good few years since I flew Dakotas in the RAAF and old VH-CAN of the former DCA Flying Unit at Essendon. If I recall correctly, you had to fit the left and right aileron cleats carefully to avoid the wing flaps being damaged if they drooped with no hydraulic pressure to keep them in the fully retracted position. Put the starboard wing cleat on to the port wing aileron in error and you risk damaging the flaps. .

But I noticed that in the Air Nostalgia DC3, the aileron cleats were a different design from what I remember (allowing for fading memories). These Air Nostalgia cleats were designed to offset the control column wheel in the cockpit so that a pilot taxying the aircraft would instantly tell something was wrong because the control wheel could not be centred with the cleats in place.

However, ever since some DC3's crashed after takeoff because the control locks had been inadvertently left in place instead of being removed during the walk-around inspection, the rudder cleat was redesigned to deliberately offset the rudder by a few degrees when in place. I don't know if this was a CAA/CASA/DCA mandatory requirement or not. The theory being the pilot in the cockpit would notice during the before takeoff check, that the rudder pedals not respond to full and free movement. And even if he forgot that important pretakeoff check, he would have a real problem trying to taxy the aircraft with the rudder pedal offset which makes braking a bit tricky.

The elevator cleat in the Air Nostalgia DC3 when set in place forces the elevators into a slight stick back position. Again, whether or not that was a CAA/DCA requirement I do not know. I cannot recall the RAAF elevator cleat positions either.

Braving the occasional red back spider I found a wartime RAAF Dakota operating manual among other books in my shed. The front cover said: RAAF Publication No. 336 November 1943. Pilots' Notes - Operating Instructions for C47 Transport version of Douglas D.C.3.
Page 6 said there were three relief tubes installed in the aircraft. One beneath the pilot's seat, one beneath the co-pilot's seat and one on the aft bulkhead of the lavatory compartment. After all these years I never knew about the pissaphones under the pilots seats.

Paragraph g of page 6 says "SURFACE CONTROL LOCKS - Five surface control locks are stowed on the floor in the lavatory compartment." In other words they came with the aircraft and presumably to the manufacturer's specifications. Turning to page 16 para. (d) where the heading states: "Before entering the cockpit" it says: "Make certain that all surface control locks are removed." And finally at page 30 BEFORE LEAVING THE AIRCRAFT it says at para (3) 'Wing and empennage surface control locks installed." "Empennage" now that's a word you don't hear very often nowadays.

But the real purpose of this story is ask why the Air Nostalgia DC3 has changed the original design of the wing aileron cleats from something designed to lock the ailerons into a wings level neutral position on the ground, to an offset position that would roll the aircraft into an instant left turn after lift-off and eventually into the ground as the control wheel cannot be forced back into neutral?

Already the rudder cleat when inserted makes taxying so difficult that most pilots would twig something was seriously out of place and return to the tarmac. But what if someone removed the rudder and elevator cleats but was distracted and forgot to remove the aileron cleats?

Sure, the pilot would notice the offset control wheel when entering the aircraft, or when taxying or when conducting the controls full and free movement as part of the pre-takeoff check. But stranger things have happened in the flying game and checks have been missed for all sorts of reasons.

Are the design of DC3 surface control locks part of an airworthiness requirement? Certainly in all my previous experience in both RAAF and civilian DC3's I do not recall seeing off set aileron surface control cleats. I wondered who decided it was a good idea to have these type of cleats in place for the Air Nostalgia DC3?

Personally, I think it could be a trap for the unwary since getting airborne and suddenly finding the aircraft in a uncommanded left hand turn at 50 feet can only lead to one result.
The solution is to throw away the non-standard offset aileron cleats and replace them with standard shaped cleats that all Dakota and DC3 aircraft came equipped with since time immemorial.

Maybe it's time to throw away the DC3!

We call that part of EN.."The Corner of Shame!" There has been some celebrity aircraft there over the last few months. Two Challengers, a brace of Conquests, various spam cans sans engines. One doesnt know the true reason but I bet if that old DC3 had a soul it wouldn't want to be there. Behind concrete baracades or some other immoveable object suggests non payment of something or similar types of purgatory.

Lexair... wash ya mouth out !
The DC 3 is the all time enduring aviation artifact that should be around forever. And preferably in the air.
And strong. There is a story of the Berlin Airlift that one stalled out early just before touch down with a very heavy landing.
On checking the load , it was found that the aluminum girders had been replaced with steel ones. !
What stories that EN Dak could tell too, probably had a WW2 history in New Guinea and / or many other faraway places.
A thing of beauty is a joy forever.

Got to agree with Lexair. Yes, it's a beautiful aircraft but it has served its time. It's 85 year old design standard. It didn't even meet the 1950s airworthiness standards so they made a special reg for it. It might be strong in some areas, but that came at the expense of what we now call crashworthiness.

It should be kept for airshows and adventure flights. Artefact is an apt adjective.

I know that one can fly an BN3 with the aileron cleats in place.

https://cimg3.ibsrv.net/gimg/pprune....41967ff50b.jpg
It's always a thrill when the turbine survey ones arrive

Offset control locks, and VH-CAN
 

I flew VH-CAN in a later guise. Although I've handled the locks many times, and can picture them in my mind, annoyingly I don't recall enough detail to remember if the rudder lock was offset. I'm fairly sure the aileron ones were, but the mind is a funny thing and it's a good few years ago so I wouldn't be surprised to be proven wrong - Centaurus, fwiw they were red-painted aluminium channel, just in case they're the same as when you flew her?

Anyway it's a damned good idea. We were always careful with all our checklists and of course they were part of the pre-start list but having some sort of failsafe in case of distraction or whatever is good human factor engineering.

FP.

Thanks for triggering another of those trips down memory lane, Centaurus. Despite my brief (500 hrs) sojourn as P2 on the Dak, I well remember the attention that was given to the presence of "five locks and two pins" on board prior to engine start. (I think the two L/G pins were normally handed to the skipper.)

What I hadn't remembered (or perhaps never knew) was the secondary role of the aileron locks in stopping the flaps drooping in the absence of hydraulic pressure. I wonder if they all had that feature.

Merry Christmas,
Chris

Chris. Each aileron surface control cleat was specific to that aileron (left and right cleats) This was because one side stopped the flap on that side from drooping.

Yes, and I simply don't remember if ours were "handed" or not. Well, it has been half a century... :eek:

At least one of ours (G-AMRA) was still flying a few years ago with Air Atlantique and quite likely using the same control locks, so perhaps someone will pick up this point. You may remember it featured in a BBC documentary by Ewan McGregor and his brother Colin, called Bomber Boys. (I was going to post a link to the copy on YouTube, but it brings up a massive caption that might upset the Mods... If you find it, start watching at 10:20.)

I have only ever seen DC-3 aileron control cleats that allowed the flaps to drop when hydraulic pressure bled off.

The rudder cleat always centred the rudder. Since you used the rudder anytime the aircraft was moving I'd have a hard time picturing anyone taking off with the rudder cleat installed.

Elevator cleats locked the elevators in the down position so that snow and ice would tend to run off the surfaces.

The company I flew for also had both Yokes tied together with a bungee cord - procedure was to remove this as the aircraft was lining up then do a full control check prior to commencing take off. The cord would be installed again during taxi in after landing.

Gear pins and rudder lock were the last items to be removed prior to engine start and the first items to be installed after shut down.