No new ways to get it wrong

[John Farley]

I see that according to the initial NTSB report into the recent Spectrum flight test accident the aircraft took off with the aileron controls reversed.
A very sad gotcha, but I would bet good money that one day it will happen again.

[forget]

I read that - astonishing. Not only had the controls been disturbed but some related bracketry had been modified to allow a beefed up leg to be fitted. Then neither the guys who fixed it or the guys who flew it bothered to do a visual 'what moves what how' check.

[Genghis the Engineer]

Not a flight test accident, but it happened in the UK 3 years ago.

A colleague of mine arrived to perform a first flight on a different UK homebuilt about 4 years ago and found the ailerons reversed during his pre-flight.


It's very hard to actually make a point about this isn't it, without sounding incredibly obvious and patronising.

G

[forget]

Vaguely related. Many years ago at a Sumatran jungle camp with a couple of Wessex parked outside, and the sun well over the yard-arm, the evening Brains Trust was in session. Aircraft control was the subject and I suggested that rudder control was the reverse of the ‘natural’ sense. My argument was, if you took someone who knew all about vehicles and ships, stuck him in an aircraft for the first time and asked him which leg he’d push to turn the nose to the right - he’d naturally say left leg. I was ridiculed, but years later I discovered that RFC aircraft were rigged just so. The problem was that the control wires had to cross the fuselage, left to right and right to left. In several accidents it was found that they’d been routed directly - to the wrong side of the rudder. Their Airships decided to simplify matters and adopt the ‘reverse’ sense for rudder control. The French continued with the ‘natural’ sense for many years - which resulted in more losses of French aircraft in UK, until everyone started to agree.

[DVR6K]

And on aircraft where you can't see the controls move, who's to say the wiring for the EICAS/ECAM style display hasn't been rigged incorrectly so that when you move the controls, the surfaces move in the wrong direction but indicate correctly?!?! I'm sure I've heard of that being done before.

[Stuck_in_an_ATR]

I've heard of such case on a FBW Airbus - though I can't find any links, maybe it's just an urban legend. After some maintennance, the capt sidestick was incorrectly connected and gave reverse aileron signal. Fortunately the other sidestick was o.k. and they made it back. As for the old French planes - they also had reverse throttles - i.e. to get full power you needed to pull the trottles all the way back. I'm glad those mad days are long gone

[forget]

Here's the mis-wired Airbus link

http://catless.ncl.ac.uk/Risks/21.96.html#subj2

[Wader2]

Happened on a Shackleton in the '70s. The elevators had been wired up pull-down push-up.

Once the very experienced pilot realised what was happening - from take-off when the aircraft pitched forward when he pulled - he flew a circuit and landed safely.

Only thing I had not thought of, and do not recall being mentioned, what happened about the pre-take-off checks? Were they done? If they were why was this not noticed?

[slowrotor]

Actually happens more than you might think. (reversed controls)
I inspected a fatal crash in which the pilot/mechanic had reversed the aileron control cables in his DHC-3 Beaver. He did a slow roll on takeoff and impacted the nose almost inverted.
My theory is that because the ailerons were not installed on the day he got the cables reversed, he had no easy way to check his work. A month later the ailerons were installed by him. The ailerons use a pushrod control. So he may have thought the aileron pushrod could not be reversed and thought he was done and forgot to check the earlier work where he had crossed the cables at the control yoke.
Always check control direction before every flight.

[rodthesod]

Originally Posted by John Farley

I see that according to the initial NTSB report into the recent Spectrum flight test accident the aircraft took off with the aileron controls reversed.
A very sad gotcha, but I would bet good money that one day it will happen again.

This is so sad, when it is so very easy to make control linkages Murphy-proof at the design stage. (e.g. Male-female connector Left - Female-male Right)

[barit1]

Originally Posted by Stuck_in_an_ATR

...As for the old French planes - they also had reverse throttles - i.e. to get full power you needed to pull the trottles all the way back. I'm glad those mad days are long gone

Farm tractors also have a "reverse" throttle, and those of us who have instructed farmers have had the occasional "WHY did you do THAT???" mixup!

[Mad (Flt) Scientist]

Originally Posted by rodthesod

This is so sad, when it is so very easy to make control linkages Murphy-proof at the design stage. (e.g. Male-female connector Left - Female-male Right)

That would protect against a "maintenance" error but the NTSB preliminary report talks of a design modification being introduced prior to the accident flight. While it reads as if the modification itself was not the direct cause of the reversal of the controls, merely the cause of the disconnection/reconnection, nonetheless it's impossible to design a system that's 'Murphy-proof' against design changes, since one can always include a nullification of the Murphy-proofing in the design change .... design reviews can try to catch such things, but the final operational check of the system is the only sure defence.

[treadigraph]

I think one of the Gulf War One "Baghdad Hilton" survivors was subsequently lost in a Hawk at Valley due to mis-rigged ailerons... was it Dave Waddington?

I was at Chino a few years ago, walking around one of the restoration facilities admiring a Cessna Bobcat that was being rebuilt. They were testing the elevators, and the guy up front pushed and the elevators went up... ****! was the next word I heard. Better there I guess...

[cwatters]

I took off once with ailerons reversed. Noticed immediatly and flew a circuit using the rudder and small ammounts of aileron. Managed a rough cross wind landing that broke off part of the tail but otherwise ok ... bloody good job it was only a model!

[SCaro]

I worked for a company building flight simulators consisting of a real panel and yoke, but computer controlled. I used to do "Production flight test" on the simulators. Once I got one where the ailerons were reversed, which I noticed on take off (hard to do a preflight control check in a simulator). I realized what had happened before crashing, and flew around like this for a while, but I would sure hate to have this happen in a real airplane. One of the pilots in the Spectrum jet was a good friend.

[GlosMikeP]

Originally Posted by Wader2

Happened on a Shackleton in the '70s. The elevators had been wired up pull-down push-up.

Once the very experienced pilot realised what was happening - from take-off when the aircraft pitched forward when he pulled - he flew a circuit and landed safely.

Only thing I had not thought of, and do not recall being mentioned, what happened about the pre-take-off checks? Were they done? If they were why was this not noticed?

Actually it was about 1980/1, I remember it well. The outcome of the inquiry showed that the control wires (which were clearly visible inside the fuselage) had been put on the wrong way round - because the diagrams in the APs dated from the 1940s and the Lancaster! Needless to say, the figures weren't to any reasonable standard and very easily misinterpreted.

But as you say, how did the deflections not get noted as being in the wrong sense? Someone would have been standing in the astro bubble, as I have done many times, and should have been watching!

However, there's always a funny side to aviation. As the Shack got airborne and the pilots struggled to gain control (they quickly gave up elevator control and flew on the trim tabs) and the radio nav issued the Mayday on normal RT, the rear crew member per FRCs was heard to call 8 Ops on the selected radio "Octagon, Mayday, Mayday, Mayday, this is c/s...."; to hear the standard response that would have pretty much suited any other aircraft's return "Roger, Pan zero, transport booked........WHAT!".

Lossie to Kinloss 10mins. Hardly worth recording in one's log book eh?

[Shaft109]

617 Sqn incident

I remember reading the Dambusters book where one of the later pilots on the squadron (either Canadian or American) called Kurns? had the actual control surfaces reversed i.e. elevators fitted upside down on a lanc.

Apparently he "could no longer do his usual 3 point landings" or something like that and flew it a few times on raids in that condition before it was discovered!

[dakkg651]

Probably one of the most famous accidents caused by incorrectly connected controls was one of the prototype Avro Tudors which took off with the aileron control reversed. The aircraft rolled into the ground and Roy Chadwick, the famous designer of the Lancaster, was killed.

[blue up]

Shaft109. IIRC it was Nicky Knillans,Canadian, and when asked how the hell he had managed to fly so many successful missions in it he replied something like "I don't know, only God does".
The fact that it needed one specially long and one specially short set of control cables ought to have been a dead giveaway. I think it had done a large number of sorties and had been that way since leaving the factory. It was only discovered after Gibson (or Cheshire?) flew a circuit and refused to let it fly again.

Didn't Piper lose a Chieftan on test flight for reversed ailerons and then find the next 4 airframes rigged the same on the production line?

[Dan Winterland]

Treadigraph, no it wasn't Dave. Thesad thing about this accident was that you can't see the ailerons from the front seat of the Hawk, so the pilot relies on the groundcrew's signals to check control movement. In this case, the groundcrew saw the controls move, but didn't realise that they were moving in the opposite sense to the stick movement and the pilot didn't notice the groundcrew's hand movement were in opposition as well.