DHC-8-4 in landing accident @ CYEG [Archive]

PT6Driver

8th Nov 2014, 19:29

With the first SAS incident the props went through the aircraft, injuring pax on the left hand side. The crew of the second incident learned from this and shut down the engine prior to landing, there were no injuries from prop blades.
The question is why didn't the crew shut down the right hand engine?
One blown tyre should not cause gear collapse, a dash q 400 has landed safely when one wheel parted company from the aircraft.
Therefore if the blown tyre story is correct then it must have caused quite substantial damage when it blew. Did the crew get the chance to inspect the damage before making an approach?

noclue

8th Nov 2014, 19:58

Some guidance from the Q400 FDEM regarding a single main gear landing.

"If the Flight Crew elect to land with one main gear unsafe, they must assume and prepare for the gear to collapse on landing.

In this situation and in addition to the AFM procedures given in Paragraph 3.16, the following is offered for consideration:

� Reduce landing weight through fuel burn.
� Passengers to be moved from seats in the plane of the propellers and re-seated elsewhere in the cabin. Priority to be given to passengers seated on the side with the indicated unsafe main landing gear
� Crosswind (if any) would be advantageous from the side with the un-affected main landing gear
� Land with flap 35 degrees
� Fly the appropriate Vref for the landing weight
� Giving due regard to the specific approach to be flown, flight conditions, and possible missed approach; prior to commencing the final approach, feather and secure the engine on the side with the indicated unsafe main landing gear.
� On touchdown, maintain maximum wing down lateral control on the side with the unaffected main landing gear
� Should the indicated unsafe main landing gear collapse, in an effort to reduce the aircraft turning moment in the direction of the failed main landing gear, apply maximum braking and reverse thrust as required on the side with the main landing gear down and locked
� Feather and secure the operative engine
� Be prepared to action an engine fire"

Jet Jockey A4

8th Nov 2014, 20:12

Could it be the gear collapsed only after they left the runway due to lost lateral control from the wheel with the blown tire?

ehwatezedoing

8th Nov 2014, 21:31

The question is why didn't the crew shut down the right hand engine?
One blown tyre should not cause gear collapse

You probably answered your own question.

germanflaps

8th Nov 2014, 23:10

I was actually reading about the SAS incidents before this thread got posted... gotta love these "coincidences".

Anyway the pic with the blade penetrating the cabin doesn't look reassuring at all. I'm probably going to sit away from the propeller next time I fly the Q400 as pax.

Lost in Saigon

9th Nov 2014, 02:29

Could it be the gear collapsed only after they left the runway due to lost lateral control from the wheel with the blown tire?

No. it looks to me like the wingtip was in the dirt before the gear(collapsed gear?) left the runway.

http://i2.photobucket.com/albums/y17/msowsun/photo%20stuff/Photo15/_q2.jpg

http://www.avcanada.ca/forums2/download/file.php?id=9791

http://www.avcanada.ca/forums2/download/file.php?id=9790

Row7

9th Nov 2014, 20:17

Given the multiple incidences of gear failure and the possibility of a prop blade entering the cabin isn’t it up to the FEDs to ground the fleet until the engineering is rectified? Should Q400 pilots start polishing up their resumes?

Tu.114

10th Nov 2014, 05:43

Should we not rather wait for the official investigation report before jumping to such far reaching conclusions?

The landing gear incidents at SAS were traced back to corrosion and on occasion O-rings that were in a place and in a hydraulic system where they had no business were found as well. So upon extension, the gear leg just fell out of its bays and hit and broke some stops vital for downlocking. It then just dangled outside unable to take any load. The problem has been solved and since then, no more such accidents have been noted.

For now, it seems that the accident discussed in this thread involved leaving the paved surface before the right leg failed to bear the load placed upon it. There is no word out that the crew did not achieve a full 3 green downlock indication before the approach. So I am not surprised that they did not follow the procedure posted above by Noclue - also in my company, there would have been no reason to do this.

Furthermore, I would not be surprised if the "failed" leg was the one still equipped with two wheels. When braking after landing, there would have been one wheel braking on one side and two of them on the other side; consequently there would have been some imbalance causing a yaw to the good side.

ManaAdaSystem

10th Nov 2014, 06:27

Should we not rather wait for the official investigation report before jumping to such far reaching conclusions?

A picture of a prop blade penetrating the fuselage (again) indicates a "minor" weakness in the design, IMHO.
Are there any design criteria regarding the protection of passengers in this area?
I don't find myself around prop aircraft very often, but with six main landing gear failures (for whatever reason) that I know of on the Dash, finding a seat away from the prop area seems like a good idea.

readywhenreaching

10th Nov 2014, 08:35

A picture of a prop blade penetrating the fuselage (again) indicates a "minor" weakness in the design, IMHO.
Are there any design criteria regarding the protection of passengers in this area?
thats exactly my concern as well..and it happened before.

Didnt Bombardier built another fuselage "ring" around the hull in the area of the propeller axis to prevent things like this ?

Well, somebody might get to get back to the drawing board again.
Same for the blades which shouldnt break apart like wooden sticks when they came into ground contact. Frightening, as they supposedly operate below their max RPM setting at the time.

I definetaly will avoid any seat in the "smashing area" on my next Dash trip.

Miles Magister

10th Nov 2014, 08:52

Guys,

This is not a design flaw but a know potential issue with propeller strikes. I educate all my co-poilots to this potential danger in prop aircraft.

Many years ago a good friend of mine, who is a pilot, was a passenger in a similar aircraft type, in Canada by coincidence, and the crew taxied onto the mud and tried to power out. As my friend felt the aircraft sink he evacuated the rows of passengers by the engines just in time as when the last fellow passenger was clear a propeller blade came through the fuselage and right through the seats they were sitting in. He was expecting the incident as soon as he felt the crew try to power out of the mud.

This potential problem has been known about since the aircraft were invented and should be taught in type rating and recurrent training.

I once had a main u/c red for landing so feathered both engines as I came over the threshold. Worked a treat, no asymmetric to deal with. Came to a stop nicely in the middle of the runway.

The only thing that will catch you out is the unexpected, plan for as many problems as you can when on the ground and then there will be very few unexpected things to catch you out.

Prior Planning and Preparation Prevents a Poor Performance.

DaveReidUK

10th Nov 2014, 12:26

Didn't Bombardier built another fuselage "ring" around the hull in the area of the propeller axis to prevent things like this ?

No. Any reinforcement or increased skin thickness will have been intended to protect against ice being shed from the prop.

No amount of structure will prevent a liberated blade from penetrating a fuselage if it's headed in that direction.

phiggsbroadband

10th Nov 2014, 16:00

On the Private Flying Forum someone asked where his Cessna Prop bit had gone, after it suffered a detachment. The general consensus was that if it were a perfect projectile, and starting at 2400 rpm on a radius of 0.8m, then it could have gone up to 6 km.
I wonder where all the blades are of this DHC-8 ? It has a larger radius, but the rpm is not known.

bratschewurst

10th Nov 2014, 20:54

There was a virtually identical incident in 1984 or 85 with a Republic (ex North Central) Convair 580; went into a snowbank on landing and shed a blade that penetrated the cabin and killed a passenger.

As a non-engineer, I'm always amazed that the blades stay attached at all. I assume that the blades on the Q400 are composites; would that have any implications for their sturdiness in this scenario?

Lost in Saigon

10th Nov 2014, 21:26

Air Canada crash landing in Edmonton was more serious than first reported - The Globe and Mail (http://www.theglobeandmail.com/news/national/air-canada-crash-landing-in-edmonton-was-more-serious-than-first-reported/article21516648/)

When the right landing gear deployed, Ms. Kurylo saw that the tire was “shredded and flapping.”

Ms. Menard said the landing initially seemed normal and passengers hadn’t been told to brace into a crash position.

Then the plane suddenly started rattling as they went down the runway. The right landing gear collapsed and the plane started tilting to the right. Ms. Menard felt as if she was in a car about to roll over

This quote seems to point to a possible bad wheel shimmy die to the blown tire. Bad enough to cause the gear to unlock maybe?

The Dash 8 is known for landing gear shimmy. We used to call it the "Shopping Cart Shimmy".

Aerozepplin

10th Nov 2014, 21:29

The photos and video of the Eagle Air (Air NZ) B1900 that landed gear-up showed quite nicely the path the props took.

The CAANZ safety magazine used the picture on the front cover of one edition. A nice shot of the 1900 on the bottom on the page, with a prop blade flying past the title at the top.

NutLoose

11th Nov 2014, 12:02

Prop hit a pax in the head :eek:
but ok

Plane propellor smashes through fuselage and hits passenger (http://www.msn.com/en-gb/news/world/plane-propellor-smashes-through-fuselage-and-hits-passenger/ar-AA7sH4R)

Bell212noise

12th Nov 2014, 20:06

I was on this particular flight and can def clear up how i watched the incident play out from my seat. Which happend to be 6F one row in front of where the prop came through the cabin. I am a Heli pilot so I dont have much knowledge to fixed wing emergency procedures. Yes on take off from YYC right before the roll i was awoken to a large bang and then some violent shaking through the AC. The pilots did the right thing got us in the air asap i am sure at that point if we had not the end of the runway was coming up soon. About 10 mins into the flight the captain told everyone we blew a tire and that it was no emergency and that plane can land no problem in Edmonton. This is where I am kind of curious as to why we weren't briefed on emergency procedures by flight crew or as you guy have mentioned cleared of the rows next to the prop. Not that it would have done any good as the plane was full of pax. I also and wondering why we didnt choose to burn off any fuel to reduce the gross weight of AC as we were full of PAX luggage and I am assuming enough fuel to make it to Grande Prairie. I was also surprised to not see the captain or co pilot come back to check on the gear and tire. I did see stewards try to see if we had a tire. Clearly we did but it had a large piece missing from the back side of it.

long story short plane descended and pilot put us down very slowly and smooth. Unfortunately this is where it gets a bit crazy once the weight of the plane was put on the gear the large vibration from the blown tire shook the plane violently then the gear collapsed. As the same time i was hit with pieces of the AC as the prop had blown out the area behind my head and also my window. at that point all i could see was sparks and ducked for cover.

to be honest I think the pilot did well to keep the AC on the tarmac and not the ditch but I am concerned about how the emergency was handled before we got to that point

evansb

12th Nov 2014, 22:45

WHAT! "...right before the roll"? Do you mean "before rotation", or "at rotation" or "after rotation"? Surely not "right before the roll"? ? ?

Bell212noise

12th Nov 2014, 23:33

sorry iPhone auto correct was just before Rot

Jet Jockey A4

12th Nov 2014, 23:42

The questions to ask are...

Did the pilots know of a tire blow out prior to V1?

If so, were they on a short runway and decided to go anyway? A reject on a short runway with a blown tire is not recommended.

Was the gear raised for the flight to Edmonton?

BARKINGMAD

13th Nov 2014, 07:21

"I was also surprised to not see the captain or co pilot come back to check on the gear and tire."

Post 9/11, flight crew are feeling inhibited from going back into the cabin, mixing with the SLF, in case they are attacked.

This is probably due to the wrong message being perceived as a result of DaFT and UK Transec and other Western Gov rules rules where flight crew are of course instantly subject to attack by crazed SLF with boxcutters etc blah blah.......

Alan Quaeda 1 - Common sense nil. :ugh:

9 lives

13th Nov 2014, 11:21

Bell 212 noise has told us that when the wheel spun up upon touchdown, the whole aircraft shook violently. Is it possible that it shook the gear leg so much that the downlock was shaken undone, and the "leg lock" arrangement unlocked to allow the collapse?

PT6Driver

13th Nov 2014, 14:59

Bell 212,
Thanks for that. I hope you and the pax behind are ok.
Depending on the conditions in a Dash v1 is normally the same as vr or within 1 or 2 knots.
As can be seen on the debate about birdstrike continuing to destination, the Fo went back and had a look. When the wheel came off another dash I believe one of the crew went back as well.
Presumably dark so it would be quite hard to see the extent of the damage, however as I said before, just a blown tyre, should not have caused such vibration and subsequent gear collapse. It is possible that visual inspection by flight deck could have identified the extent of the damage with different decisions. There again maybe not.
Obviously the gear would still have collapsed but with a shutdown engine maybe not so much damage to pax.
It is perfectly ok for flightdeck to leave the cockpit so long as correct procedures are followed. I for one would probably want to go back myself and look.

F-16GUY

13th Nov 2014, 20:01

The manual for most types I have experiance on (military) clearly states that landing with a blown tire that has not separated completely from the rim can lead to gear collapse due to heavy vibrations. It does not state if the collapse is due to the downlock actuator beeing shaken into the unlocked position or due to the failure of the entire landing gear structure.

lincman

13th Nov 2014, 20:25

Great picture, Dave.
I believe at least one of the injuries was due to being hit by the prop blade. I was most surprised to see that pax are seated in the prop plane. I have flown on a few prop jobs (DC-3, Viscount, Brit, and Vanguard) and none had seats in the prop plane. In fact, I dont recall any of these even had a window in the prop plane. Different regs. for different folk?

pattern_is_full

14th Nov 2014, 04:59

Interesting point.

Hard to check every commercial prop airframe design ever certified - but it seems as though the only "basic" propliner with seating in line with the props from the get-go is the ATR 42 (one row).

The original versions of the DHC-8 and Fokker 27/50 have the props just (barely) ahead of the seating - but in stretching them, seating moved into the prop plane. As also the ATR-72.

Could be an oversight, or could be someone decided a prop separation was a low-probability risk. At least against the return from all those lovely extra revenue seats.

(Lots of designs have cabin space in the prop plane, but devoted to galleys, bogs, bulkheads between first/cattle class, etc. If you choose the wrong moment to get your coat from the stowage closet on an F-50....)

evansb

15th Nov 2014, 03:23

A passenger was killed when a Trans Canada Airlines Viscount threw a prop on a flight from Chicago to Toronto, back in 1956. The aircraft landed in Windsor.

RatherBeFlying

15th Nov 2014, 13:38

Back in the propliner days, my father was quite strict that me and my sis did not sit opposite the props.

My memory is that there was uninterrupted seating from the front to the back in Douglas, Boeing, Lockheed, Canadair and Vickers products.

lomapaseo

15th Nov 2014, 17:51

It is considered impractical to stop a released prop blade from going into/through the cabin walls. However some degree of minimization of the hazard to aircraft critical systems need be shown. (redundancy, duplication etc.)

Nowhere in the regulations does it specifically state passenger seating.

Most aircraft designers eliminate the view of the prop plane from a window line. (I guess that is a calming means when it comes to bird and ice splatter)

9 lives

16th Nov 2014, 14:25

Nowhere in the regulations does it specifically state passenger seating.

They were thinking about the pilots though....

Sec. 23.771

Pilot compartment.

For each pilot compartment--
..... and
(c) The aerodynamic controls listed in Sec. 23.779, excluding cables and control rods, must be located with respect to the propellers so that no part of the pilot or the controls lies in the region between the plane of rotation of any inboard propeller and the surface generated by a line passing through the center of the propeller hub making an angle of 5° forward or aft of the plane of rotation of the propeller.]

pattern_is_full

16th Nov 2014, 18:36

Does the Vickers Viscount have uninterrupted seating? Yes.

Is any of the seating in the prop plane? No. It starts behind the props and goes back from there.

http://www.flightglobal.com/airspace/media/civilaviation1949-2006cutaways/images/8920/vickers-viscount-701-cutaway.jpg

DC-6 - same thing: http://www.the-office.com/470/douglasDC6.jpg
DC-4 - same: http://ipm.comxa.com/alkva/pic/ac/prop/DC4-cw.jpg

Vickers Vanguard; washrooms in the prop plane - http://www.airliner-models.org/_fr/20/4715464.jpg

Lockheed Connie - washroom in the prop plane: http://www.flightglobal.com/airspace/media/civilaviation1949-2006cutaways/images/8831/lockheed-1649-starliner-cutaway.jpg

Lockheed Electra - ALL the seats (uninterrupted) AND the cockpit behind the prop plane: http://atallguy.com/Simple-Multi-View-Plans/L-images/lockheed_electra_3v.jpg

Lockheed 188 - http://lessonslearned.faa.gov/ElectraWings/Lockheed%20Electra%20L-188%20wireframe.jpg

Boeing 377 - galley and washroom in prop plane, no seating: http://www.airlinereporter.com/wp-content/uploads/2013/05/1950s-pan-am-strat-cutaway-ad_672.jpg

Boeing 314 - galley and radio operator in prop plane - no seating: http://socks-studio.com/img/blog/b-314-cutaway-interior.jpeg

Father's advice was no doubt good - but unnecessary, since it was virtually impossible to disobey. At least back then.

RatherBeFlying

17th Nov 2014, 00:06

PIF, I complement you on your research.

It's been some decades since I've been in these airframes, but do recall seeing pax seating in line with the props on occasion.

I might caveat that not every interior hewed to that in Flight's excellent cutaways.

evansb

18th Nov 2014, 22:16

Sitting in-line with the props gives you the noisiest, most vibration prone seat in the aircraft. As cited, a Viscount threw a prop and killed a passenger. Safety? One in a quad-rillion chance of a failure. Sit away from the engines for the most obvious reasons. Geeeze...reeeeally? Does it take me, a 11,480 hour punter, to point that out?

1.) Tire failure. Resulting in..

2.) Gear failure. Resulting in..

3.) Prop Failure. (they are frangible, by the way..) Six-blade composite construction, individually replaceable. Slowest turning props in the industry..They are quiet. Very quiet.

4.) Buy a lottery ticket. Odds of winning are similar to prop failure..

In the old days, prop driven airliners sat the first-class passengers in the aft cabin. Jetliners seat first-class passengers in the front cabin, ahead of the engines. Go figure..

DaveReidUK

19th Nov 2014, 06:39

Would that make sense?

See post #10.

Cantiflas

19th Nov 2014, 18:40

Talking DHC aircraft,props and "region"of protection for the flight compartment,which was compromised in this case by severe external forces on landing:

AAIB 8/83 DHC-6 Twin Otter

1.15 Survival Aspects

.......the most significant hazard was caused by failure of the right wing.
When this wing detached,the propeller of the engine cut through the
aircraft fuselage between the cockpit and passenger cabin close to the
co-pilot's seat.In so doing the propeller severed the pilot assistant's
upper torso restraint harness behind his back,WITHOUT TOUCHING
EITHER THE SEAT OR ITS OCCUPANT.
My italics!