Check Flights and Pulling Circuit Breakers
 

Check Flights and Pulling Circuit Breakers

Industry thoughts/rulings/legislation on pulling circuit breakers to fail systems on high performance aircraft during check flights in aircraft (not simulator flights)?

No harm at all. Simulates that "'what-the?" factor we need.

Yep, Sounds sensible. Why not expand the policy to allow a check pilot to turn off a hydraulic system or trip a genny offline to give the crew a real world handle of a non normal?

Why not take it one step further and set fire to one of the engines, give the guys real world training...../s

You answered your own question, a high performance aircraft. Something described as high performance and that has capacity for hydraulics and generators should have a simulator, and that’s where failures are practiced, not in the real aircraft.

One of the considerations which most either forget (or never knew) relates to what is on the service end of the C/B. Just because it is labelled "XYZ" doesn't give you any guarantee that it doesn't also provide power to "ABC" and "RST". The electrical engineering folk who do the ELA work will make a point of finding out and knowing and the OEM procedures can be presumed, likewise, to be based on knowledge, rather than well-intentioned guesswork.

You pull C/Bs at your potential peril unless you either have done all the homework or are following OEM or specialist electrical guidance.

Well it depends on what's being checked, now doesn't it? Are we checking the crew or the plane?

Wasn’t a Westwind lost on departure out of Sydney, when the circuit breaker was pulled on the A/H and the turn and balance indicator was wired incorrectly?

It not 1960 just say no !!

Take a moment to Giggle “National Airlines Flight 27” in November 1973 before doing anything like this in flight!

The company I work for specifically does not permit this to happen - my understanding is that it is partly to allow deliniation between an actual issue and simulated. The discussions ive had from checkies with regards to failures/circuit breakers out etc have all had the same benefit as them pulling a breaker.

However, imagine the situation - they pull a circuit breaker on the pressurisation control as part of a check, its identified and reset... but the system faults out. It'd be a bit hard to explain that in the report.

I wonder what the paying travelling public would think if they knew the folks up front were purposely disabling perfectly good equipment.
It's kind of similar to requesting a Non-Precision Approach when a Precision approach is available. Although safe, the safer option is the ILS.
Our jobs are to get the fare-paying passengers from A-B in the SAFEST manner possible. Pulling cb's would not be included in this job description.
There is a fantastic tool called a simulator for this sort of thing.

Short answer NO !

We have two levels of training and testing for good reason.
The simulator is where we train for abnormal and emergency operations with degraded systems.
Line checking SHOULD be focussed on SOP and normal operations.
It is fine to explore technical discussions in the post flight debrief, but in every operator with whom I have flown this is strictly forbidden, and believe that underlying this are regulations stating such.

From a purely professional perspective, where is your defence should an incident occur for a deliberate act of this nature ?

There is no defence, you would be toast for doing it, and toast for allowing it to happen as an aircraft commander.

TR

VH-IWJ, in 1985

https://www.pprune.org/pacific-gener...l#post10767811

Early BOAC days of the "real" Boeing 707 - i.e. not the simulator at that time, the Stabiliser Runaway drill was to shout "Runaway Stabiliser" then first stop the rapidly turning wheel situated on the sides of the centre console, maybe breaking a finger nail, or even a wrist (!) in the process, cut the adjacent switches on the console, and call for the circuit breaker situated on the overhead panel to be pulled by the Flt. Eng. then raise the handles stowed in the wheels and manually re-trim by hand.

At around 5,000 ft over the Severn Estuary the Trg.Capt. ran the stabiliser nose down. The trainee co-pilot stopped the wheel, cut the switches and called for the CB to be pulled. " Very Good, now recover" said the Trg. Capt. The trainee pulled back on the control column to try to reduce the rate of descent, re-engaged the switches, and called for the CB to be re-set, but .... pulling back on the column was creating so much "G" force that the Flt. Eng. couldn't raise his hand high enough to reach the CB. By now the aircraft was seriously descending, and the force over the stabiliser was such that both pilots together were unable to turn the wheel with the manual handles, of course the answer would have been to momentarily push further forward to relieve the load, and then wind back but with the ocean rapidly filling the windscreen, who would ? Eventually, with the Flt.Eng. bracing his feet against the forward panel, and a hand on each control column, all three managed to pull hard enough to stop the descent - about 500 ft above the water apparently.

Following that CB's were not pulled, until the simulator sessions took over.

Murphy is always with us.

Can you imagine the feverish moustache twirling over a warm pint at the local ale house that evening? :oh:

In the airline I spent most of my life flying for, unless the check list called for it, we were not allowed to pull or reset any circuit breaker until we received permission from Maint Control.
Either via HF or ACARS.

Pulling a CB on a system that is working perfectly fine will nullify the insurance coverage for the flight. Try explain that to the passengers.

Early BOAC days of the "real" Boeing 707

.. getting on to 30 years ago. A sobering result of doing things which are not appropriate to do in an aeroplane.

Big no no! I know it was pretty common practice in GA years ago by a selected few checkies. If it isn’t in the AFM or SOPs, you’re on your own.

I recall an event that occurred a few years ago in PNG, where a very experienced Captain decided to intentionally disable a primary rudder hydraulic system in a Dash 8 to demonstrate something to the FO. He demonstrated that he was an idiot!

It went pear shaped although they recovered and the Captain was subsequently sacked, and quite rightly so!

It’s also an offence against the regs to do this type of stuff, hence if proven guilty one could end up in a world of pain.

Never pull a CB in an aitcraft in the air. If you do you are looking for trouble. If you look for trouble you may find it. There was a line check full of pax, being carried out in Asia somewhere and the country shall remain nameless. On final the check pilot pulled the A/P CB. the outcome was the P/F couldn't manage the situation and caused an incident.it shouldn't have but it did.

The time to play games, is in the simulator.

Section 20A of the Civil Aviation Act is pretty clear........

20A Reckless operation of aircraft
(1) A person must not operate an aircraft being reckless as to whether the manner of operation could endanger the life of another person.
(2) A person must not operate an aircraft being reckless as to whether the manner of operation could endanger the person or property of another person.

There is a certain irony in the fact that recklessness often leads to a wreck.

HA HA HA....
Did not some 'check' pilots in 'the dept of many names' HS-125 do exactly 'that' to stop the 'infernal noise' from the U/C horn whilst doing circuits?
And the result was..........................

Take a guess....only 1 guess per person allowed.....

NO cheers 'ere.......

Licensed Engineer's opinion;

High Performance or not, If technicians pull a CB for a test on the ground its because we are either following a procedure in the Type Certificate Holder's data, or we've analysed the wiring diagrams to be aware of the implications.

My advice to a pilot would be that, if its not a procedure in the POH or an approved Test Schedule leave it the f@ck alone! Whether you have pax on board, or not, is immaterial.

Don’t even do it on a bugsmasher these days. If it has electronic injection, sophisticated lithium batteries and an EFIS you may have just made a terminal mistake. Even more if it has autopilot, an electric CS Prop and other stuff.

‘’Please note it is illegal to shut down an engine in flight for training.

Thanks for your wise words of wisdom, Captain Sunfish

Another reason not to pull a c/b is that they have a finite life. If everybody does it, one day it might not reset.

With regard to maintenance isolating items of equipment....dodgy. I once picked up an S-76B from a maintenance base on an IFR day, very early in the morning. It had been placarded for a failed VOR/DME without us being told about it. The c/b had been pulled and collared. Our MEL said we could go, so we departed, into rather challenging weather, as it turned out, worse than forecast. On getting airborne, on trying to tune an essential VOR, which couldn’t be received on the ground at the maintenance base, we discovered that neither of the VOR/DME boxes would receive. Things got a little complicated quite quickly, so we made a crew decision to put the breaker back in. BOTH VOR/DME then worked normally!

Most probably is not allowed by local CAA
 

Depending on where you are, for example in Austria/EASA it is forbidden to pull CB during examination flights.
https://cimg2.ibsrv.net/gimg/pprune....53504c0d9e.jpg
https://www.austrocontrol.at/en/pilots/pilot_licenses/examination/examiner

This is 2021. Failures are practiced in simulators, not the aircraft, period, In flight, CBs are tripped when, and only when, the check list specifically requires it.

Modern aircraft are so electronically complex you rarely know just exactly what systems mat be affected as a side effect of the system you are trying to electrically kill.

R22 Key out auto
 

I seem to remember during my helicopter training twenty years ago a tale (which I think is true) that an instructor had the habit of turning off the engine and throwing the key on the floor, one way of entering an auto !!!!
I think it was an R22, in the States, or the UK.
Last time he did it the key was discovered on the floor of the wrecked helicopter.
Couldn't find it on a Google search, but I'm sure someone else will have been told about it.

During my training a few instructors had a habit of pulling the C.B's

Airbus
 

Wasn't there a new big one having a pre acceptance engine run up at Toulouse that ended up broken over the blast deflectors after some bright spark pulled a CB to silence the take off warning?

Did not some 'check' pilots in 'the dept of many names' HS-125

Dear old CAO.

There were some extenuating traffic circumstances at the time. Nonetheless, a crew foul up.

On the other hand, the then DCA Flying Unit (which was the operator at Essendon) had been trying to get the OK for some time to upgrade the aircraft mod status without getting any funds vote. The wheels up sorted that little administrative problem out and we ended up with the desired model out of the bingle.

ASD-51-7-67 HS 125 VH-CAO.pdf (airwaysmuseum.com)

How else can you practice a manual gear extension? Pull gear motor cb, select gear down, nothing happens, pump gear down manually. Not that you need to do this every check flight but it’s nice to know that it works.

Isn't there a CVR comment of the captain saying " Shut-up, Gringo" as he silenced the horn before making a wheels up landing? Some accident report that I forget.

LEARNING TO BLEED

(the 1985 Westwind crash at Sydney)

1457:31 PIC states he's going to introduce some emergency..
1457:59 PIC states you've lost these... ######
1458:24. END OF RECORDING

1.16.1.1 The Pilot 1n Command

Comprehensive Interviews were conducted with all the company [] pilots and various management personnel. Mr [] was evaluated by other company pilots as having average manipulative and instrument flying skills for his level of experience. However, they considered that he excelled as an Instructor by virtue of his personality, lecturing technique and thorough knowledge of the aircraft and its systems. He was a loyal and hard working employee who disliked inefficiency and laziness, and expected nothing less than 100% effort from other company personnel. Several company pilots reported that on check flights, Mr [] in his role of check and training pilot, would introduce simulated systems failures at any stage of the flight. Which systems were Involved and the extent of the failure was mostly graded to take into account the experience of the pilot undergoing check. A point made by almost all of the company pilots was that Mr [] could be relied upon to Introduce a unique or obscure failure that had not been covered previously with the candidate. It was also his habit to require the candidate to handle simultaneous systems failures but this was also graded to the experience of the particular pilot. An example of the types of simultaneous and complex failures given related to the loss of various navigation and attitude Instruments, coupled with an engine failure, while the pilot was carrying out an instrument approach at night.

Mr [] expected the company co-pilots to demonstrate their ability to safely control the aircraft by reference to the emergency FAI, following simulated failure of the FAI on the right Instrument panel. Some command pilots were expected to make use of the rate of turn indicator, following simulated failures of both FAIs on the left panel. To prevent the pilot obtaining attitude information from the co-pilot's FAI, this Instrument was covered, or the cockpit lighting on that side was extinguished. Some of the company pilots had been expected to cope with this emergency exercise immediately after a take-off at night.


---------


So, starting at 240 KCAS in a climbing left turn, they get to 420KCAS and the water, 4700 feet lower in 12 seconds.

The PIC of this saga was the chief pilot and chief instructor/checker and, was the guy who had reported the turn indicator was displaying in the reverse sense, some 350 days previously, and which had been reported a further 3 times without being rectified. He was also the product of his 9000 experience, and the practices were not alone in the industry at that time, however failing the attitude systems at night, at low level, and on a fleet of aircraft that have had known anomalies with the instrument that would be expected to be used was... "courageous, Minister... ".

Just say "No".

I would be interested to know why the question about C/Bs and check flights is being asked in the first place.

My thoughts exactly.

I'm guessing someone has had a checkie do it to him/her and is seeking validation here before 1. lodging formal complaint, or 2. hopping the checkie will read this and realise the error of his/her ways.

With thousands of pilots currently out of work, the price of being made redundant for speaking out and getting shafted for doing so is unfortunately much higher than it was 18 months ago.

Yes, it does seem like something of a "drive-by", firing off a single loaded question then running.

Another alleged CB-related event.

Dre, I often find your input somewhat droll however that one made me laugh out loud. Nice one.

Thanx 'JT'. I sorta remembered that it was 'CAO', but was not sure.

Re 'shut-up Gringo', # 35, that was (from memory) a South American '707' in South America I think, who was too low, got the 'voice' warning from the (GPWS) system, which was an American voice, being an American aircraft I guess, and did indeed utter the fatal words, and then the CVR suddenly STOPPED...as HE...CFIT!

Sad but true.

Sad but untrue. Yet another aviation urban myth. I doubt that any 707's were fitted with GPWS.

(wikipedia Avianca 011)