King Air belly landing at CBG

[STN Ramp Rat]

BBC News - 2012 Olympics plane forced to land at Cambridge (http://www.bbc.co.uk/news/uk-england-cambridgeshire-19036183)

[His dudeness]

hmmm...emer gear pump handle stowed after pumping the gear down?

From the PTM:

Remove the hand pump handle from the se- curing clip and actuate the hand pump until the three green gear position lights (NOSE–L–R) illuminate. Place the pump handle in the down position, and secure in the retaining clip.


If the green gear position lights do not illuminate, continue pumping until heavy resistance is felt to ensure the gear is down and locked. Then leave the handle at the top of the stroke.

[merlinxx]

:{Only charts & compass !!!!

[megle2]

What no Ipad on board to nav with

[mmitch]

Unable to communicate. Was it in the restricted area?
Was it intercepted?
mmitch.

[Flaymy]

Cambridge is just outside the Atlas airspace. That might be why he landed there.

I wondered if he checked his starters.

[Expressflight]

Looking at the slot allocations for Cambridge it would appear that the aircraft was based there for the duration of the Games.

[Trim Stab]

There are lots of rather cocky and smug comments on here, who seem to have no idea what they are talking about.

If the B200 was using additional certified equipment to relay pictures, it probably had its "normal" electrical system heavily loaded, though within certified limits. The operator seems to have just followed SOPs in recovering to their home base after an electrical overload.

[megle2]

Trim

"lots of rather cocky and smug comments on here"

9 posts so far, only 2 tend towards cocky and smug
Hardly class that as "lots"

Your post is the most interesting opening up the implied suggestion that external equipment ( certified of course ) linked to the aircraft electrical systems may of caused an overload

[His dudeness]

The operator seems to have just followed SOPs in recovering to their home base after an electrical overload.

If so, why did they end up in the news? Equipment failure or...? (not trying to lay blame..)

Complete elec failure as it was said to be by the guy from ASL just from `an electrical overload.?` Hmmm. one would guess that if they have an extra equipment, that it would be correctly protecting the elec system (aka CB/Fuse). Now how could a simple overload then get you a complete elec failure?

If you care to explain that to me, then I will retract my cocky and smug comment.

I wear a been there, done that T-Shirt when I talk about the emer extension of a B200, though it wasn`t because of an electrical failure. Just the motor on the hydraulic pack that went AWOL. Same problem one faces then, although we had our lights.

[Trim Stab]

I don't know the B200 electrical system, but have flown two other types commonly used in surveillance and video-relay role. On both types, we operated with the electrical system under continuous load that was higher than the load typically encountered in (say) night IFR flight in icing conditions, but which was still under the certified load limits. On both types electrical anomalies were not uncommon after extended ops, eg alternator imbalances going outside of limits, or popping CBs.

Certification limits are not black and white - they are set at parameters which give a good probability of successful operations in normal circumstances - if you push outside of normal circumstances you increase the chance of failure.

[Piltdown Man]

Just exactly what has a possibly overloaded electrical system got to do with a collapsed landing gear?

PM

[MungoP]

I had a similar problem after taking off from Bucharest for Dusseldorf last year... operating single crew. First thing I noticed was #1 Altimeter failing..didn't realise immediately that I'd suffered a dual gen failure, (the annunciators dimmed rapidly due to the load on the battery) trying to trouble shoot the problem while fending off ATCs questions as to why they'd lost mode C, I noticed that the torque indication remained the same as I applied power in the climb and so suspected an AC failure but swapping inverters didn't help..I kept the climb going until at FL220 all the radios/nav, everything just died...totally dead cockpit.. I'd been in IMC since climbing through FL100 but no big deal as I had the vacuum horizon as a back-up. Problem was where to land.. After flying the SID I had a vague idea that Bucharest was to the south about 60 miles but didn't want to go blundering into their airspace.. Romania is a bit short on airports.. I found a small airport used for basic training that looked a bit on the short side for a flapless B200 but after flying around for an hour couldn't find anything else so made my way back to it.. turned out to be Ploiesti..Had to pump down the gear and without any display of three greens had to keep pumping throughout the landing and roll-out.. It felt as though I was back in the FlightSafety Sim..
This was just one of the many issues experienced with the a/c inc blowing current limiters/failing pressurization plus a number of smaller irritations.. The aircraft had been sitting around for several years at our ops base in Kabul with very little flying.. never good for an a/c... they believe that as I selected the icing on going through FL100 the extra load caused the #1 genny to go off-line and the extra load taken by the #2 was rejected by the GCU which took the other genny off-line...it had proved problematic in the past.. the battery was in pretty poor shape and very quickly died under the load.. annunciator panel faded almost immediately the only indication visible was a very faint master warning light flashing but nothing bright enough on the MWP to read..
It would have been nice to have someone else along for the ride.

[Flaymy]

Trim Stab

The generators are pretty good on the 200; if everything is working correctly you never get to 50% with normal kit, even with full anti-icing on, so a single generator is enough to supply the load. Obviously if there is a problem with some kit, or extra equipment, and one generator goes offline then that is a different matter.

I have heard of a small number of total electrical failures on King Airs. The only one that the pilot could have done much about was caused by the starters being switched on which stopped them working as generators (for those unfamiliar, the King Air has starter generators). It is thought that sun glare stopped the crew seeing the warnings on the annunciator panel. That was why I asked about the starters, as they might also know that pretty quickly.

[His dudeness]

@PM: the gear is hydraulically lowered and latched by an hydraulic power pack which receives its pressure not from engine driven pumps, but one electrically motored pump.
No electrics means emergency extension and no lights. You need to pump quite a while (no freefall and hydr. pressure required to lock) to get the thing locked (IME) and if don´t get it locked or cant verify it locked (e.g. no lights) then the book tells you to pump as long as there is resistance that you can´t overpower and LEAVE the pump handle at the top of the stroke. IF you stow it, you`d take the pressure off the system, pressure that had been supplied to the extend side of the actuators.
No having pumped long enough and having stowed the pump handle COULD cause the gear to retract. When all 3 gear retract that would be a plausible thing IMO, but of course there is always the possibility of say a failure in the valve or so...

In preparation to pump the gear down one has to put the gear handle down and has to pull the control CB. That way the pressure from the handpump can enter a small pilot hole and shuttle the valve to the extend side. Failure to do so could lead to a valve that electrically 'creeps' back (with the remaining low voltage, its just a magnetic coil...) and releases the pressure also. (pure speculation on my part)

One thing in the electrical system of the 200 is critical and thats the current limiters and their checking... an item I´ve seen often omitted and I was told by the chief technician of the shop we had our KingAir maintained, that they - relatively - often find them blown. Now, if both GENs are working, you won´t see anything amiss, but if there is e.g. voltage drops or the like on the faulty side, then you don´t have the battery to dampen these out, which in turn can cause further problems to e.g. the GCU.

I had one GEN shadding its parts and in the event sending voltage peaks into the system throwing out the other side as well. We were on a sharpish ILS approach in a snow storm going into an Ukrainian Airport - nothing I recommend for recreation...
On a side not, B200s have 250 Amp Gens or optional 300 Amp ones.

[kirkbymoorside]

Some possible similarities to this incident reported in France?:
http://www.bea.aero/docspa/2011/f-po110107.en/pdf/f-po110107.en.pdf

[Flaymy]

klirkby

That was not the incident to which I was referring, which was a UK-registered aircraft. I know of others who have left starters on and found the problem, or have had the same problem in the sim. So if you fly a King Air remember this!

[MungoP]

Interesting point that.. In two and a half years instructing in the sim I never saw anyone select the starter on by mistake except during an in-flight restart after flame-out.. on a few occasions someone would forget to take the start-switch out of 'start' and then discover that they couldn't bring on the genny.. the rest was fun to watch as the second genny hopelessly overloaded would burn itself out after five minutes or so.. Making this mistake with both starters before flying would create havoc and it would be impossible to even get airborne.

[silverknapper]

Making this mistake with both starters before flying would create havoc and it would be impossible to even get airborne.

I'd be interested to know how you reach this conclusion. Mu understanding is its very possible, and the major contributory factor to the G-PCOP accident.

[MungoP]

I'm not saying that it wouldn't fly.. but it's difficult to imagine anyone persisting in trying to get airborne with multiple 'failures' resulting from having no gennies online...

[His dudeness]

What I do before takeoff when switching on the AUTO IGN is calling '2 on' after having checked the advisory lights "Ignition" (green). Then I increase power till "2 off" and I do not elease the brakes before that 2 off call - props have spun to full RPM by then.... the igniton works continously below 400 ft/lbs of torque...
This should prevent the inadvertent selecting of the starters.

[MungoP]

Absolutely Dude.. The checklist calls for Auto-Ign to be on as part of the final items.. there's no requirement and no reason to turn them off until after landing. They're only 'armed' not sitting there wearing themselves out so it's difficult to see why anyone would need to play around with them in the air.

[His dudeness]

Before someone thinks I sound like I never made a mistake: yes I did. And I still make em...

And actually it would be no problem (IMO) to put a warning on that airplane if both gens are off. The 2 yellow ons can be overlooked more easily in a high workload situation.

[Flaymy]

MungoP

That is what I had always seen and done, both in TR training and company SOPs. However on the French report kirkbymoorside linked to it suggested that the company's SOP was to use them only in icing conditions (did not mention heavy rain). Seems odd to me; there is no cost to having them on 'AUTO' in flight.

[nopax]

I find it hard to believe that the starter-gen switches were both left in the start position, as there are two bright amber lights top left and right of the annunciation panel, which we should be checking a dozen times before takeoff (if a run-up is completed before departure).

Depending on the serial number of the aircraft it may have electric, chain driven gear, or electro-hydraulic gear, the procedures for emergency extension are different, and a gotcha if you are used to one, more so than the other.

Was the aircraft equipped with a Ni-Cad battery, or the more common lead acid?

Inverters need DC to turn into AC, so that would account for the compass and charts comment (no alternators). AC drives a lot of systems, such as instruments, autopilot, EFIS displays etc., and can be very distracting.

[Flaymy]

nopaxI find it hard to believe that the starter-gen switches were both left in the start position, as there are two bright amber lights top left and right of the annunciation panel, which we should be checking a dozen times before takeoffI would agree, except for having heard of two cases now where it occurred. I do think that the French aircraft might have had poor SOPs as a contributing factor, if they were switching auto ignition on in flight, but we don't know the SOPs for this operation.

[nopax]

Two things - first things first, thread related:

The aircraft was BB-1473, so did have electro-hydraulic gear.

Any ideas, what could cause a "major electrical system failure" on a King Air 200?

A scenario often presented in training is the blown current limiter, followed by loss of a generator - a multiple failure, but has occurred in the past. In that scenario, the battery supplies power to one generator bus, which may only last so long before a battery charge annunciation occurs with a Ni-Cad battery installed. The battery charge light would be a cause for alarm, due to the potential of a thermal runaway.

Loss of an inverter, and not following the memory item, would cause a loss of AC. AC powers EFIS instruments, autopilot, gyros and avionics. This in of itself wouldn't lead to a gear issue, but significantly increases the workload of the crew. When I'm rushed, I'm more likely to make mistakes, or omissions.

SOPs..
Switching auto ignition on or off in flight is not really a sign of poor SOPs - although I'm not at all familiar to the reference made. I flew for a King Air operator that insisted the auto ignitions be turned off during the climb checklist, and turned back on during the before landing checklist. Auto ignitions were to be turned on in icing conditions, turbulence or wind-shear, and moderate or heavier precipitation. The theory was that too many ignitor-boxes had been replaced from them being left on (all the time), with the power being brought to idle etc., so the operator wrote their SOP as above. Also, the manufacturer doesn't require the auto ignitions be on during the entire flight, on the King Air 200 and earlier models. The operator has a fleet of King Airs, of all types, heavily used (800-1200 hours per year per airframe) and has been in business for about 30 years. That was part of their SOP, and everyone followed them.

Recently, however, I have been flying with an operator that leaves them on during the entire flight, and doesn't care for the cost of replacing them if they fail, as the owner can well afford the aircraft, or to charter an aircraft if need be and the King Air is lightly used. One less checklist item keeps it simple, so I'm all for that.

[Flaymy]

What difference would it make turning the auto-ignition off during climb and back to auto before landing?

It would be unusual surely to have torque below 400 lb.ft. in that part of the flight, so they would not be doing anything. All you are doing is operating the switches more, shortening the life of the switches and increasing the chance of doing what might have been the cause of two serious incidents.