aircraft crash in Stord, Norway
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No Spoilers on Landing
Reported today that the spoilers did not deploy on landing.
WOW switch + arming? (or something more arcane like wheel spin-up/nose-wheel on?)
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What are the pitfalls (if any)? Is it in the pre-landing checklist?
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- thrust levers idle + Weight-on-wheel + main wheels (left OR right) reach 'spin up' speed (33 kts), if fitted with autospoilers (avro RJ).
- idle + WOW + manual deploy if no autospoilers
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Spoilers not deployed on crashed Atlantic 146:
Norwegian investigators have discovered that spoilers did not deploy on the British Aerospace 146-200 which overran the runway while attempting to land at Stord Airport on 10 October.
Four of the Atlantic Airways jet’s 16 occupants were killed when it careered off the slightly-damp runway and down steep terrain, before coming to rest and catching fire.
Wreckage analysis has also revealed evidence that the aircraft suffered ‘rubber reversal’ as it tried to stop – a phenomenon where heat generated by the tyre vaporises the surface moisture and reduces runway contact.
But while ‘rubber reversal’ causes deterioration of the tyre condition, there is no indication any of tyres punctured or deflated.
Flight RC670 had been arriving at Stord, in western Norway, after a domestic service from Stavanger. It touched down on runway 33 with a 6kt tailwind.
While there was nothing unusual about the airspeed, touchdown point, flap-setting, landing weight or air-brake, preliminary analysis shows that neither of the two independent spoiler systems deployed.
One system controls a single spoiler on each wing, the other controls a pair, giving six in all. These systems are normally activated by the crew on touchdown, but a spokesman for the Norwegian Accident Investigation Board says the inquiry has yet to determine the reason for the failure.
“The crew did not feel it was appropriate to make a go-around,” adds the spokesman. “But in a last attempt to stop the aircraft they tried to put it into a skid. It was actually skidding down the runway at one point.”
Investigators are to examine the aircraft’s maintenance record as part of the inquiry. Atlantic Airways is based in the Faroe Islands and the Faroese ministry of trade and industry says that the jet had undergone a C-check in Sweden and returned to the fleet two weeks before the accident.
Courtesey ATI
Norwegian investigators have discovered that spoilers did not deploy on the British Aerospace 146-200 which overran the runway while attempting to land at Stord Airport on 10 October.
Four of the Atlantic Airways jet’s 16 occupants were killed when it careered off the slightly-damp runway and down steep terrain, before coming to rest and catching fire.
Wreckage analysis has also revealed evidence that the aircraft suffered ‘rubber reversal’ as it tried to stop – a phenomenon where heat generated by the tyre vaporises the surface moisture and reduces runway contact.
But while ‘rubber reversal’ causes deterioration of the tyre condition, there is no indication any of tyres punctured or deflated.
Flight RC670 had been arriving at Stord, in western Norway, after a domestic service from Stavanger. It touched down on runway 33 with a 6kt tailwind.
While there was nothing unusual about the airspeed, touchdown point, flap-setting, landing weight or air-brake, preliminary analysis shows that neither of the two independent spoiler systems deployed.
One system controls a single spoiler on each wing, the other controls a pair, giving six in all. These systems are normally activated by the crew on touchdown, but a spokesman for the Norwegian Accident Investigation Board says the inquiry has yet to determine the reason for the failure.
“The crew did not feel it was appropriate to make a go-around,” adds the spokesman. “But in a last attempt to stop the aircraft they tried to put it into a skid. It was actually skidding down the runway at one point.”
Investigators are to examine the aircraft’s maintenance record as part of the inquiry. Atlantic Airways is based in the Faroe Islands and the Faroese ministry of trade and industry says that the jet had undergone a C-check in Sweden and returned to the fleet two weeks before the accident.
Courtesey ATI
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No "Spoiler not Deployed" Alert?
A. So on the BAe146 if a pilot who usually flies an Avro RJ is in the RH seat, it's conceivable that he might have a brain unstart and just forget to deploy the spoilers? (because they're armed and auto-deploy on the Avro).
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B. Assuming that's possible, there's nothing to give anybody a heads up that this has happened? No alarms, alerts or whatever?
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c. Is it conceivable that spoilers were selected and just failed to (I imagine hydraulically) deploy?
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D. Are LH and RH spoilers on the same electrical bus?
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E. Any history of WOW failures on the BAe146 (or throttle at idle switch failure)?
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B. Assuming that's possible, there's nothing to give anybody a heads up that this has happened? No alarms, alerts or whatever?
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c. Is it conceivable that spoilers were selected and just failed to (I imagine hydraulically) deploy?
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D. Are LH and RH spoilers on the same electrical bus?
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E. Any history of WOW failures on the BAe146 (or throttle at idle switch failure)?
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1. Manual spoiler (lift dump) selection after touchdown (BAe146), normally done by the Captain (may depend on company SOP).
2. Non-flying pilot confirms deployment and calls ‘Yellow / Green’. A habitual call i.e. easily done without the spoilers deployed (human factors), thus it would be better to call any failure to deploy (threat and error management). Some aircraft are fitted with glareshield Spoiler Fail lights – spoiler not deployed when on ground + 6 sec.
3. Failure to position elevator controls at neutral; forward stick with excessive airspeed can delay main wheel WOW contact and prevent spoiler deployment. Forward stick technique is often used on rear engine aircraft (MD-80) and habit can surface during demanding, high workload operations. Check the crew’s previous aircraft types?
See post #71 re additional landing run required and crew precautions for spoiler failure. Is the 40% actual distance or factored landing distance required?
Contributions from a tailwind and wet (slightly damp) runway? ‘rubber reversal' = aquaplaning? Point of touchdown?
2. Non-flying pilot confirms deployment and calls ‘Yellow / Green’. A habitual call i.e. easily done without the spoilers deployed (human factors), thus it would be better to call any failure to deploy (threat and error management). Some aircraft are fitted with glareshield Spoiler Fail lights – spoiler not deployed when on ground + 6 sec.
3. Failure to position elevator controls at neutral; forward stick with excessive airspeed can delay main wheel WOW contact and prevent spoiler deployment. Forward stick technique is often used on rear engine aircraft (MD-80) and habit can surface during demanding, high workload operations. Check the crew’s previous aircraft types?
See post #71 re additional landing run required and crew precautions for spoiler failure. Is the 40% actual distance or factored landing distance required?
Contributions from a tailwind and wet (slightly damp) runway? ‘rubber reversal' = aquaplaning? Point of touchdown?
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The Shadow; On the Avro it is our company policy to deploy them manually anyway as a back up to the automatics. don't know what others do but this would eliminate what you suggest.
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The Backstick Braking Solution
backstick braking link
would probably have been a logical and effective solution - if they'd been familiar with the technique.
Search Pprune for backstick braking and you'll see what I mean. It works and works well. You'll find a reference in the link above to some BAe146 and Avro RJ pilots using it invariably. On wet runways it's a life-saver (or at least a reputation-saver).
would probably have been a logical and effective solution - if they'd been familiar with the technique.
PEI-3721 said:
Failure to position elevator controls at neutral; forward stick with excessive airspeed can delay main wheel WOW contact and prevent spoiler deployment. Forward stick technique is often used on rear engine aircraft (MD-80) and habit can surface during demanding, high workload operations. Check the crew’s previous aircraft types?
Failure to position elevator controls at neutral; forward stick with excessive airspeed can delay main wheel WOW contact and prevent spoiler deployment. Forward stick technique is often used on rear engine aircraft (MD-80) and habit can surface during demanding, high workload operations. Check the crew’s previous aircraft types?
backstick braking link
Belgique I think that you are mistaken in concluding that a particular technique would be beneficial based on the evidence in the link. My reading of the discussion suggests that operators should always follow what the manufacturer recommends.
In the case of the BAe146/Avro RJ crews are specifically instructed to place the control column at the centre position; this not only avoids the hazards of forward stick just after touchdown, but other problems that might result from back stick on wet / slippery runways where additional directional control could be required.
Instead of relying on a non-standard technique operators should concentrate on the simple standard items, such as landing into wind, correct approach speed and touch down point, selecting lift dump and checking correct deployment, using the appropriate braking level for the conditions, and checking thrust is at idle.
In the case of the BAe146/Avro RJ crews are specifically instructed to place the control column at the centre position; this not only avoids the hazards of forward stick just after touchdown, but other problems that might result from back stick on wet / slippery runways where additional directional control could be required.
Instead of relying on a non-standard technique operators should concentrate on the simple standard items, such as landing into wind, correct approach speed and touch down point, selecting lift dump and checking correct deployment, using the appropriate braking level for the conditions, and checking thrust is at idle.
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Nop, sorry. According to the company's website, the plane that were lost is OY-CRG, and on their fleet page, it states that the only RJ100 plane they have, is OY-RCC.
And to answer PEI_3721:
-Come on, all the eye witness accounts states that the fire started inside the cabin, after only a mere seconds after the impact, possibly before! And pictures of the aircraft shows that the fuselage is nearly purified:
(Images owned by VG)
That means only one thing: agressive fire. And, flammable insulation, cabin interiour etc, hazardous materials such as jet fuel, hydraulic fluid, etc, in close proximity to the cabin itself.
What you obviously didnt get out of my posts, were that I questioned the safety of the aircraft as a whole. And I still do.
-AnEvilTwiner
And to answer PEI_3721:
-Come on, all the eye witness accounts states that the fire started inside the cabin, after only a mere seconds after the impact, possibly before! And pictures of the aircraft shows that the fuselage is nearly purified:
(Images owned by VG)
That means only one thing: agressive fire. And, flammable insulation, cabin interiour etc, hazardous materials such as jet fuel, hydraulic fluid, etc, in close proximity to the cabin itself.
What you obviously didnt get out of my posts, were that I questioned the safety of the aircraft as a whole. And I still do.
-AnEvilTwiner
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What you obviously didnt get out of my posts, were that I questioned the safety of the aircraft as a whole. And I still do.
It is statistically the safest airliner out there, of it's era, and certainly a lot safer than the 737 has proven to be, so I think you may need to re-visit your logic!
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Backstick Braking
PEI_3721 said:
....but other problems that might result from back stick on wet / slippery runways where additional directional control could be required.
....but other problems that might result from back stick on wet / slippery runways where additional directional control could be required.
Suggest you acquaint yourself better with the technique (and the aerodynamics etc involved). Try the link provided. On there you'll find posts by BAE146 drivers who believe in and use the technique. It works. If it stops you going off the end and over a steep cliff, well it's gotta be beneficial.
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VG.NO yesterday reports that analysis of the cocpit voice recorder confirms the suspicion of malfunctioning spoilers. A representative of the Norwegian AAIB is quoted as stating that combined analysis of the flight data recorder and the CVR confirms what the cockpit crew had explained to the investigators.
In Norwegian:
http://www.vg.no/pub/vgart.hbs?artid=136019
In Norwegian:
http://www.vg.no/pub/vgart.hbs?artid=136019
Being familiar with the type I support his views on the need to follow aircraft specific procedures and concentrating on doing the simple tasks well before considering ‘exotic’ braking techniques. If you or any one need further convincing (particularly 146/RJ operators) then see the ‘incident’ report on an Avro RJ; apart from auto spoiler the BAe 146 systems in this respect are the similar. The relevant text is:-
The aircraft floated and the nose wheel touched down just beyond the lights which mark the end of the touchdown zone. After touchdown the control column was pushed fully forward. This action was contrary to advice contained in the aircraft manufacturer's training manual which contains the caution warning "After nosewheel touchdown, do not move the control column significantly forward of neutral". The warning was issued because if significant forward pressure is applied and held, lift generated by the elevators can reduce the load on the mainwheels to the extent that the 'weight on ground' sensors remain open. Without weight on the mainwheels the wheel brakes are ineffective, the ground spoilers cannot be deployed and the engines generate flight idle thrust instead of ground idle thrust. Consequently the landing ground roll distance increases markedly and heavy braking may be needed when the weight on wheels sensors eventually sense that the aircraft is on the ground and allow the ground spoilers to deploy. … the aircraft should have stopped without the need for fierce braing had the commander not held the control column fully forward.
Last edited by safetypee; 2nd Nov 2006 at 18:59.
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It is a while since I flew the 146 and all my manuals are packed away in the loft, but from memory, when the spoilers are selected out the green system spoilers (the inner one on each wing) will immediately deploy providing any two of the three squat switches are signalling on ground.
The yellow system (outer two on each wing) will not deploy earlier than 1.5sec after two of the three squat switches are signalling on ground.
In practice, If your observe a 146 landing, all deploy together as it is usual to wait for the nosewheel to touch before selecting the spoilers out and this usually takes a couple of seconds from mainwheel touchdown.
If the spoilers are selected out before the nosewheel touches there is a marked loss of downforce from the tail and firm arrival will occur if you are not quick with the elevator.
The yellow system (outer two on each wing) will not deploy earlier than 1.5sec after two of the three squat switches are signalling on ground.
In practice, If your observe a 146 landing, all deploy together as it is usual to wait for the nosewheel to touch before selecting the spoilers out and this usually takes a couple of seconds from mainwheel touchdown.
If the spoilers are selected out before the nosewheel touches there is a marked loss of downforce from the tail and firm arrival will occur if you are not quick with the elevator.
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VG.NO on Nov 4 published an interview with a Norwegian police lawyer who apparently speculates that noone will be charged. The Nowegian prosecution service now await the report from the Norwegian AAIB.
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Urr,
The yellow inner spoilers will always deploy slightly ahead of the green outer ones. The roll spoilers are yellow driven BTW, as are the flap. assymetry brakes next to them.
Landing on a short runway like that with a 6kt tailwind gives me a shudder...no thanks. If they floated and touched down late then stood on the brakes without giving time for the wheels to spin up, then they would have managed a pretty long skid! Spoilers are very good in braking, at anything over 1800m runway, I tend not to brake at first, and let the spoilers do the hard bit for a second or so, but then my little old kite has very snatchy brakes that take a good feel for smooth operation.
There's a lot of reasons this could have happened. The Norwegian CAA will let us know which one it was. The 146 has fantastic brakes, but like anything, if you use them hard without antiskid protection, you'll lock them right up. The spoilers and a smooth progresive pull back on the stick will press the wheels in nicely and both main and nose can take a fair old firm landing without any problems at all.
Short field technique requires a positive sit down and conformation of spoiler deployment then a good squeeze of brake. Tail wind is certainly not one of my requirements!
The IOM is about 1800m and we had a 6kt tail limit on wet runways with our 146-200...if I can remember right. We miss you G-MIMA!
If I got no spoilers, I'd be looking at a go-around, but hindsight is no good here. I am intrigued by the engine clue though. The FCU is purely mechanically linked from the throttles with a thick bowden cable and the TMS operates actuators right next to the FCU on the engine itself.
It does sound like the wing got ripped off though. Nasty.
The yellow inner spoilers will always deploy slightly ahead of the green outer ones. The roll spoilers are yellow driven BTW, as are the flap. assymetry brakes next to them.
Landing on a short runway like that with a 6kt tailwind gives me a shudder...no thanks. If they floated and touched down late then stood on the brakes without giving time for the wheels to spin up, then they would have managed a pretty long skid! Spoilers are very good in braking, at anything over 1800m runway, I tend not to brake at first, and let the spoilers do the hard bit for a second or so, but then my little old kite has very snatchy brakes that take a good feel for smooth operation.
There's a lot of reasons this could have happened. The Norwegian CAA will let us know which one it was. The 146 has fantastic brakes, but like anything, if you use them hard without antiskid protection, you'll lock them right up. The spoilers and a smooth progresive pull back on the stick will press the wheels in nicely and both main and nose can take a fair old firm landing without any problems at all.
Short field technique requires a positive sit down and conformation of spoiler deployment then a good squeeze of brake. Tail wind is certainly not one of my requirements!
The IOM is about 1800m and we had a 6kt tail limit on wet runways with our 146-200...if I can remember right. We miss you G-MIMA!
If I got no spoilers, I'd be looking at a go-around, but hindsight is no good here. I am intrigued by the engine clue though. The FCU is purely mechanically linked from the throttles with a thick bowden cable and the TMS operates actuators right next to the FCU on the engine itself.
It does sound like the wing got ripped off though. Nasty.
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VG.no reports that the head of Stord airport wants the remains of the burnt out plane removed as it frightens passengers using the airport.
Norwegian AAIB is considering the request, and do not think a report will be ready in 2007.
Norwegian AAIB is considering the request, and do not think a report will be ready in 2007.
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Backstick Braking
The spoilers and a smooth progresive pull back on the stick will press the wheels in nicely and both main and nose can take a fair old firm landing without any problems at all.
The best reference on pprune is: "Pulling a Stop to Runway Overruns"
but it gets a mention in five other threads also. Works in most jets for good aerodynamic reasons. However like most handling techniques, it's for Masterful Manipulators - and not Motor Morons.
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Families of the deceased has filed a notice with the police commissioner in the area demanding the police investigation into the crash be reopened. (It was closed with no criminal finding earlier)
The N-AAIB has not concluded, and according to Norwegian law, they and other s involved. (Airport owner etc) has not turned over any evidence to the police.
(Thankfully, Police has never done any good in aviation crash investigations IMHO)
No news in English yet http://www.aftenposten.no/nyheter/ir...cle1940010.ece
The N-AAIB has not concluded, and according to Norwegian law, they and other s involved. (Airport owner etc) has not turned over any evidence to the police.
(Thankfully, Police has never done any good in aviation crash investigations IMHO)
No news in English yet http://www.aftenposten.no/nyheter/ir...cle1940010.ece