Air Canada 767 Problems at Madrid

[diffident]

Sky News have just reported that an Air Canada 767 is preparing to make an emergency landing back at Madrid, after parts of the landing gear fell off and was ingested by an engine.

The flight is this one - https://www.flightradar24.com/ACA837/23be1953

It appears to be burning fuel at the moment, but certainly quite a situation developing there.

[Airbubba]

Tire burst on takeoff perhaps?

Didn't Air Canada famously disable the fuel dump on their B-763's?

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/802x689/ac837_8232c197b26e7d47a6b96f65c3952cf72f2902fc.jpg

[theflyingbus]

I’m sure it’s having to hold, to allow the Iberia regional aircraft to land-that’s just taxing out at BCN!

[Lake1952]

An overweight landing could obviously be a major problem if there has already been some landing gear/ tire damage.

The flight continues in a hold at low altitude and 340 kts about a hundred miles southwest of MAD.

[diffident]

Here's a live video feed of arrivals into Madrid:

https://www.youtube.com/watch?v=O6M2TLL4_wc

[Airbubba]

The flight continues in a hold at low altitude and 340 kts about a hundred miles southwest of MAD.

Holding at 340 knots in a B-763 with a gear problem? That will burn some fuel. ;)

Delta had one of these B-767 takeoff incidents at Barajas with significant damage to the hydraulics a few years ago:

https://aviation-safety.net/database/record.php?id=20131205-0

[ETOPS]

Some early 767 models are not fitted with fuel dump - ask me how I know :rolleyes:

[evansb]

Flight Aware shows ACA837 holding at 7,600 feet ASL, groundspeed on outbound leg (southeast heading) of hold around 270 kts, on inbound leg (northwest heading) as high as 303 kts. The variation(s) are most likely due to winds.

[jewitts]

Circling for 4 hours. I wonder if they have informed the passengers about the predicament?

[diffident]

Circling for 4 hours. I wonder if they have informed the passengers about the predicament?

Someone on the flight has been tweeting, with a video of a Spanish fighter alongside inspecting the damage, so I would guess it would be difficult to hide the situation from the pax.

The chap said something about being told of a blown tyre. Here's some footage he's posted. His twitter is worth keeping an eye on as he seems to be continuing to tweet video from on board;

https://twitter.com/CarlosC97620547/status/1224376220147683329?s=20

Here's a view from the ground of the fighter with the 767.

https://twitter.com/pampaIIIlaborac/status/1224387206065938442?s=20

[568]

Didn't know if the gear was down, I assume it wasn't retracted after rotation, so my assumption is that the gear limit speed is 270 knots or m 0.82.

[foxcharliep2]

Circling for 4 hours. I wonder if they have informed the passengers about the predicament?

Passengers have been informed by crew at all times acc. to reports from pax in the a/c.

Tire burst and left engine u/s due to ingesting parts of gear.
Landing at 19:15 LT acc. to airport. On approach now.

[foxcharliep2]

Live broadcast here :
https://www.youtube.com/watch?v=_PaAAzkWE7M&feature=emb_title

[foxcharliep2]

Just landed
FF and ES on the runway behind it. Looks well...

[patrickal]

Appears to have landed without incident.

[Auxtank]

Some early 767 models are not fitted with fuel dump - ask me how I know :rolleyes:

Now, why did they do that? Genuinely interested to know.

Surely it wouldn't be a weight consideration. Was it part of certification - keeping it simpler, etc.

[NWA SLF]

Believe dump was eliminated when they added winglets but don't quote me on that one.

[Twitter]

Now, why did they do that? Genuinely interested to know.

Surely it wouldn't be a weight consideration. Was it part of certification - keeping it simpler, etc.

So that the schoolkids in Campo Real won’t get sprayed maybe?

[gearlever]

Now, why did they do that? Genuinely interested to know.

Surely it wouldn't be a weight consideration. Was it part of certification - keeping it simpler, etc.
A300 no fuel dump
A330, fuel dump system is an option

It has to do with the route network, flying mostly short sectors, no dump sys....

[ETOPS]

Not certain - caused me a couple of problems over the years.

Anyway congratulations to the Air Canada crew - good job!

[Mr Mac]

Well done AC but I would bet that was a long 4hrs for SLF and crew up there.
kind regards

Mr Mac

[tdracer]

Now, why did they do that? Genuinely interested to know.

Surely it wouldn't be a weight consideration. Was it part of certification - keeping it simpler, etc.
When the 767 was originally certified, it was considered a mid range (certainly not intercontinental - this was before ETOPS was envisioned) and there was little difference between the MTOW and the MLW, so it was decided that there was no need for fuel dump capability.
However, the MTOW gradually crept up (eventually over 400k lbs.), while the MLW stayed the same (320k if memory serves, but don't quote me on that). At some point in there the Feds said enough is enough and insisted fuel dump be added. Memory says it was basic on later builds but again don't hold me to that.
I don't know anything about it being removed...

[Spooky 2]

I flew a former Qantas 767-200ER and it did not have a jettison system installed. Later high gross weight aircraft such as the CAL/UAL 767-224ER all had the fuel jettison installed.

[Seat4A]

He was onboard AC837 and posted some videos and still photos. Great "front row" seat.

https://twitter.com/thelastfedor

[Catwalk Dweller]

Here's how SkyNews covered this "Breaking News" at 1616Z today (3 Feb): A screenshot from flightradar24.com was shown, showing the same holding pattern posted by Airbubba previously. Then came this voiceover:

The aircraft is holding over the airport, but before landing "first it must get rid of all fuel on board."

Well, it certainly will land after that, alright!

Anyway, made me laugh . . .

[Airbubba]

Didn't know if the gear was down, I assume it wasn't retracted after rotation, so my assumption is that the gear limit speed is 270 knots or m 0.82.

Yep, the claim that a B-763 is holding at 340 knots with the gear down is nonsense in my opinion.

Believe dump was eliminated when they added winglets but don't quote me on that one.

More nonsense, many 767's with winglets have fuel dump operational.

A300 no fuel dump

Wrong again, fuel dump is an option on both the B4 and the A300-600.

[568]

Yep, the claim that a B-763 is holding at 340 knots with the gear down is nonsense in my opinion.



More nonsense, many 767's with winglets have fuel dump operational.



Wrong again, fuel dump is an option on both the B4 and the A300-600.

As always, on point Airbubba.

[DaveReidUK]

Yep, the claim that a B-763 is holding at 340 knots with the gear down is nonsense in my opinion.

Quite so.

Averaging the GS around the hold would suggest a TAS of around 280-285 kts, after adjusting for wind, which at 7500' would equate to about 250 KIAS. So no surprises there.

I suspect the OP's 340 kts was a typo for 304 kts GS on the downwind leg of the hold.

[zerograv]

while the MLW stayed the same (320k if memory serves, but don't quote me on that).

Your memory serves you correctly !!!

145 tons is about 320k lbs.

Some older airframes do NOT have Jettison installed, and a glance at the remaining Air Canada 767 fleet seems to fit the profile of being older airframes.

[longisland]

I flew for a US carrier that had about 20 767-200s. They did not have a fuel dump system. 320,000 lb max tkof.

The 767-300s we got later had a fuel dump system from the center tank(s) only, as I recall. I think 407,000 max tkof weight.

[gearlever]

Wrong again, fuel dump is an option on both the B4 and the A300-600.

Yep, my bad.
Thx:ok:

[787PIC]

https://www.cbc.ca/player/play/1692914243975
Kudos to Air Canada crew!
They handled this emergency perfectly.

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1501x803/bbb0c256_e032_4d81_af62_2cd7e1ed95dc_1020808f3810b15b5c0485b def979753ac5efa31.jpeg

[Dropp the Pilot]

Ya think? I'll disagree. Landing after 35 minutes might get you a "perfect", but after 4 hours of shilly shally not so much. Engine failure on a two engine airplane? Land. There are no reasons for delay. Here endeth the lesson.

[admiral ackbar]

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[Airbubba]

YEngine failure on a two engine airplane? Land. There are no reasons for delay. Here endeth the lesson.

Well, one could argue that Air Canada has previously demoed more 767 glider time than all other carriers combined. :)

[Dave Therhino]

Now, why did they do that? Genuinely interested to know.

Surely it wouldn't be a weight consideration. Was it part of certification - keeping it simpler, etc.

I wrote the material below in a thread some time back to explain the regulation that contains the requirements that determine whether a jettison system must be installed. Hopefully this responds to your question. The earliest 767s with the dry center wing box were not required to have a jettison system. Whether subsequent variants were required to have jettison depended on their thrust rating and their max takeoff weight because, as discussed below, it's a quick return to land climb gradient requirement that determines if jettison is required. Whether jettison was actually installed on those variants could have been driven by it being required or by the customer electing it as an option. Here's my previous post:


The regulation that determines whether a jettison system is required is 14 CFR 25.1001(a). It has nothing to do with the relationship between max takeoff weight and max landing weight. The requirement for a jettison system is instead based on climb capability at a weight equal to max takeoff weight minus the weight of fuel necessary for a 15 minute flight consisting of a takeoff and return to land. If the climb gradient requirements of sections 25.119 (all engine climb in the landing configuration flaps down gear down) and 25.121(d) (engine out climb in the approach configuration flaps down gear up) cannot be met at this weight, then a jettison system is required by 25.1001(a).

The flow performance of the jettison system, if required by 25.1001(a), is required by 25.1001(b) to be able to get the airplane within 15 minutes to a weight that allows the airplane to meet the climb gradient requirements of 25.119 and 25.121(d).

The braking system regulation, section 25.735, sets the energy absorption capability requirements for the brakes. Landing at max landing weight at anticipated speeds must be withstood repeatedly as normal operation with no damage other than normal wear. Landing at max takeoff weight must be withstood without hazard, but parts can be destroyed or require inspection/maintenance. The structural regulations (25.473) set the landing loads that must be met by setting descent rates that must be accommodated as limit loads at max takeoff weight (6 feet per second descent rate at touchdown) and at max landing weight (10 feet per second descent rate at touchdown). A design can be limited by the braking and structural regulations to a maximum landing weight that is significantly less than the maximum takeoff weight, and whether or not a jettison system is required would have nothing to do with this. It's all design choice - how strong do you want to build your gear and brakes, and what climb performance do you want to provide.

Of course, performance information (climb gradient and runway distance) for landings in excess of the maximum landing weight up to the max takeoff weight is required to be provided in the AFM by 25.1587(b)(3).

So yes, as most of you pilots already know, you can theoretically land safely above the maximum landing weight, but you are going to at least have some inspections required afterward, and worst case could blow the tires and damage the brakes and wheels. I am not qualified to speak about the judgment of whether you should do this in a real world situation.

[tdracer]

Ya think? I'll disagree. Landing after 35 minutes might get you a "perfect", but after 4 hours of shilly shally not so much. Engine failure on a two engine airplane? Land. There are no reasons for delay. Here endeth the lesson.

I'm thinking they might have been reluctant to perform an overweight landing when they knew they already had a damaged undercarriage...

Anyone know if the engine was shutdown, or just run at lower power/idle? That's some pretty nasty fan blade damage.

[PJ2]

From the twitter feed linked to earlier in the thread, the engine appears to be running, (occasional compressor stalls accompanied by flames out the back, plus sound). The thrust level appears to be higher than idle, but we'll know when the data is read.

[lomapaseo]

I'm thinking they might have been reluctant to perform an overweight landing when they knew they already had a damaged undercarriage...

Anyone know if the engine was shutdown, or just run at lower power/idle? That's some pretty nasty fan blade damage.

Well the hp might be able to run at idle and drive some externals,but the lp is sure gonna screw up the flow into the HP seeing as the LP Turbine won't feel much load from the wide open fan blade tips. Any successful attempt to run at power is gonna cook the HP turbine as it tries to salvage the engine cycle. Hopefully in a worst case you can baby the engine until a worse case emergency

[fdr]

The regulation that determines whether a jettison system is required is 14 CFR 25.1001(a). It has nothing to do with the relationship between max takeoff weight and max landing weight. The requirement for a jettison system is instead based on climb capability at a weight equal to max takeoff weight minus the weight of fuel necessary for a 15 minute flight consisting of a takeoff and return to land. If the climb gradient requirements of sections 25.119 (all engine climb in the landing configuration flaps down gear down) and 25.121(d) (engine out climb in the approach configuration flaps down gear up) cannot be met at this weight, then a jettison system is required by 25.1001(a).

The flow performance of the jettison system, if required by 25.1001(a), is required by 25.1001(b) to be able to get the airplane within 15 additional minutes to a weight that allows the airplane to meet the climb gradient requirements of 25.119 and 25.121(d).

The braking system regulation, section 25.735, sets the energy absorption capability requirements for the brakes. Landing at max landing weight at anticipated speeds must be withstood repeatedly as normal operation with no damage other than normal wear. Landing at max takeoff weight must be withstood without hazard, but parts can be destroyed or require inspection/maintenance. The structural regulations (25.473) set the landing loads that must be met by setting descent rates that must be accommodated as limit loads at max takeoff weight (6 feet per second descent rate at touchdown) and at max landing weight (10 feet per second descent rate at touchdown). A design can be limited by the braking and structural regulations to a maximum landing weight that is significantly less than the maximum takeoff weight, and whether or not a jettison system is required would have nothing to do with this. It's all design choice - how strong do you want to build your gear and brakes, and what climb performance do you want to provide.

Of course, performance information (climb gradient and runway distance) for landings in excess of the maximum landing weight up to the max takeoff weight is required to be provided in the AFM by 25.1587(b)(3).



DTR, quite so.

Many oddities on a takeoff will result in the sort of decision that this crew had to make, and it is definitely in the realms of decisions made under uncertainty.

The F18 off the wing is notable, assume that an airborne inspection was requested by the Captain, or accepted if offered by ATC. That may have provided the crew with the information that would otherwise be missing to them after the entertainment of a clunk-bang event on the takeoff above V1. A tyre failure can result in an engine failure, sometimes, not all that prevalent. the first failure may not be determined to be a tyre failure, the crew may only known they have an engine failure with hints of severe damage, until someone looks out a cabin window and sees excess tinsel and stuff (maybe). The potential for one engine to damage another is relatively low in a pylon mounted engine case from one wing to another. engines on the same side have been damaged by a single failure on a number of occasions. Across the aircraft a HPT/LPT letting loose has caused damage to the other engine on occasion, with a ricochet off the ramp.

So, chance that both engines are damaged is not high, it is also not zero, but it is not high. An immediate landing is possible, but is compromised in this case by the tyre failure, depends on the availability of Edwards or similar maybe, as your stopping is dependent on variables outside of certification. A single flat tyre, not a problem, but if it takes out the other 3 on landing, the things are awkward, 1/2 TRs, 1/2 braking, control authority etc... becoming a bit interesting, and a lot of unknowns, stuff that the OEM pays TPs to play with, without pax.

When would a multi engine failure be an elevated risk?

birdstrikes, with large flocks. The larger fans deal with birdstrikes better than small donks, there is a smaller relative area of intake air to the core and that is protected by larger roots of the blades, birds tend to be centrifuged, still happens though.

An unknown cause to pilots:

contaminated fuel. bad fuel can result in losing any or all engines, but isn't a high prevalence, and contamination appears to affect engines more at lower power than higher power.
Fuel icing. BA038 sort of deal. Happens later in flight after cooling of a system, and needed the power to be low first up to cause buildup.
Airframe icing: SAS MD80 style. not much of a choice left to make. failure is going to be prompt and more or less symmetric for an aft engined aircraft with undetected ice on the wings that sheds into the intakes.

Once the crew know the failure is a tyre, then the urgency to land overweight is reduced. Even on a small jet, such as a Gee whizz, or a Lear, a tyre/wheel/brake disk failure may well cause damage to the flaps, and possibly to the same side engine, but is not likely to cause bilateral damage, unless... a disk happens to spit its dummy at the same time, which is unlikely. A fan blade or two going cross country is possible, but the disk has the energy to hurt and is not likely to part ways. It it does, your decisions are going to come up rather quickly and be made for the pilot.

The OEM on the topic had a single comment of note, that the Autoland function is not certified for the overweight landing. The logic that they operate under would not change due to being a bit heavier, it is a relatively simple geometric progression, and that doesn't care about the start conditions so much. However the suggestion was to manually land. aiming for lower than 360FPM around the touchdown which would rattle teeth anyway. (ground effect is dependent on CL, so a reduced flap setting is going to result in a lower ground effect in the flare, so the flare needs to ensure a reducing in sink rate from pitch change in the flare process. As we always do.... or try to anyway)

[InSoMnIaC]

holding for 4 hours on 1 engine due to overweight landing/tyre damage. I havent done the landing perf assessment but I doubt it would have been a major problem to bring it right back

[Dropp the Pilot]

If you have departed from a runway you can safely land on that runway with one engine, or safely go-around after a single-engine approach to that runway. This assessment can be done in one half of a second. It is unclear what proportion of the four hours was occupied by this assessment.

[George Glass]

Don’t know about the B767 but on the B737 if the engine runs surge and stall free at reduced thrust and engine indications are stable there is no requirement to land at the nearest suitable airport. Suspect they did a good job.

[Say Mach Number]

Bringing it straight back may be ok In terms of performance and distance etc but tyre speed limits may be a factor at very high weights and certain ambient conditions and light winds.

Can’t speak for 767 but on 738 it’s 200mph and that can be achieved on touchdown at certain high weights and the right ambient conditions.

Losing more tyres on landing due to exceeding tyre speed limits may have been a consideration.

ps especially if planning less than normal flap settings for landing after tyre damage to engine or flaps etc

[Auxtank]

I wrote the material below in a thread some time back to explain the regulation that contains the requirements that determine whether a jettison system must be installed.

Thanks Dave and to all above who posted such informative responses to my query.

[SaulGoodman]

on avherald it is stated that they had one MLG tyre blown and they shut down the #1 engine. The info of the one tyre came apparently from the f18.

I am purely wondering, not judging, why did they continue for so long on one engine?
This is a sticky situation. Continue with only one engine or land at high Gross Weight with (at least) one tyre damaged. I think given the info I probably would have landed “at the nearest suitable airport”. In any case, they landed safely so kudos to the crew.

[Landflap]

This moves into the "multi fail" scenario. One engine out, land. Yes , Drop the pilot . We would all love to live in your easy world . But these guys faced potential of gear problem too . Burn fuel to lowest LW. Now, two scenarios tied together and you see why we are paid all this money eh ? Very good co-ordinated decisions led to safe outcome. Are we asked for anything more ?Tough job well done indeed.

[twochai]

This moves into the "multi fail" scenario. One engine out, land. Yes , Drop the pilot . We would all love to live in your easy world . But these guys faced potential of gear problem too . Burn fuel to lowest LW. Now, two scenarios tied together and you see why we are paid all this money eh ? Very good co-ordinated decisions led to safe outcome. Are we asked for anything more ?Tough job well done indeed.

AMEN! Would that all should have such a successful outcome.

[A320LGW]

Well done AC but I would bet that was a long 4hrs for SLF and crew up there.
kind regards

Mr Mac

As long as a sim session :E

[Ancient Mariner]

Was on a SK B767 having one engine go bang climbing out of PEK heading for CPH. They turned around and landed ASAP, no damage anywhere else though.
Per

[widgeon]

From Flyertalk

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as a matter of interest what are the green thingies next to the wheels

[Beamr]

as a matter of interest what are the green thingies next to the wheels
brake cooling fans

[InSoMnIaC]

If you have departed from a runway you can safely land on that runway with one engine, or safely go-around after a single-engine approach to that runway. This assessment can be done in one half of a second. It is unclear what proportion of the four hours was occupied by this assessment.


An overly simplistic approach to a complicated scenario.

[discorules]

I will be interested to understand the sequence of events which led to the failures observed.
As the MLG is quite far aft of the intake for the engines, although plausible, is it likely that a burst tyre, especially one on the rear axle, would eject debris far enough forward to be ingested?
I know that the engine intake danger areas extend around and aft of the intake itself, especially at high-power settings, and that forward speed of the a/c at the time of the tyre failure could influence this scenario, however, is it possible that the engine damage was caused by other debris, which in turn led to the ejection of shrapnel into the tyre causing it's subsequent failure?

[jantar99]

As the MLG is quite far aft of the intake for the engines, although plausible, is it likely that a burst tyre, especially one on the rear axle, would eject debris far enough forward to be ingested?

The upper part of the tire moves at twice the speed of the AC, so yes, the debris can fly forward enough.

[BRE]

The upper part of the tire moves at twice the speed of the AC, so yes, the debris can fly forward enough.

You have chosen a strange reference point for that statement. Let's just say the upper surface moves away from the aircraft at the aircraft's speed.

[Twitter]

You have chosen a strange reference point for that statement. Let's just say the upper surface moves away from the aircraft at the aircraft's speed.

Having had this happen at Vrot, I can assure you that the tyre doesn’t give a monkey’s about the reference point. It goes Bang and bits fly in all directions.

[hans brinker]

You have chosen a strange reference point for that statement. Let's just say the upper surface moves away from the aircraft at the aircraft's speed.

And in the same direction (otherwise it could be just lying on the ground).

[Beamr]

The upper part of the tire moves at twice the speed of the AC, so yes, the debris can fly forward enough.
I'm terribly sorry but I don't follow;
if ground speed is 100knots, the tyre outer skin is rolling at exactly 100 knots against the tarmac.
if it would go faster or slower, you would be burning rubber.
If the tyre it self would be going faster than the AC, you'd have a bit of a rush to catch it.

[cats_five]

I'm terribly sorry but I don't follow;
if ground speed is 100knots, the tyre outer skin is rolling at exactly 100 knots against the tarmac.
if it would go faster or slower, you would be burning rubber.
If the tyre it self would be going faster than the AC, you'd have a bit of a rush to catch it.

And the entire tread is rotating at 100 knots around the centre. So, the very top is moving forwards at 100 knots

[Beamr]

And the entire tread is rotating at 100 knots around the centre. So, the very top is moving forwards at 100 knots
Very true. Not 200 knots.

[MichaelKPIT]

And the entire tread is rotating at 100 knots around the centre. So, the very top is moving forwards at 100 knots

Not true. The AXLE is moving forward at 100 knots. The top of the wheel is moving forward faster than that. (But no, not at 200 knots.)

[Beamr]

Not true. The AXLE is moving forward at 100 knots. The top of the wheel is moving forward faster than that. (But no, not at 200 knots.)
How come the top of the wheel moves onwards faster than the axle? To put it other way round, does the bottom of the wheel move forwards slower than 100 knots?

[lomapaseo]

I love it when we get arguments like this I use to bet my wallet on being correct but I lost everything over the years :)

Yup the top of the tyre is going forward at the same speed that the bottom is going aft aft so it nets out as zero as long as it's attached to the aircraft,

But if a piece now leaves the aircraft it simply maintains the last vector that it was on when it was release (Forward, Aft or Up). That vector is made up of ground speed against the surface speed of the released fragment.

No bets until you work out the numbers. Of course one can always add in a moving runway like a conveyor belt or maybe an aircraft carrier to work your brain

[MichaelKPIT]

How come the top of the wheel moves onwards faster than the axle? To put it other way round, does the bottom of the wheel move forwards slower than 100 knots?
Yes it does. It moves forward at precisely 0 knots. Otherwise it would be skidding. In fact my previous statement about the top NOT going 200kt is actually wrong. Assuming the wheel is perfectly circular, and the axle is dead center, then yes, we have a 1:1 lever so the top IS actually going forward at 200. My apologies.

[Beamr]

Yes it does. It moves forward at precisely 0 knots. Otherwise it would be skidding.
so you are saying that the bottom of the tyre stands still.
yet at the same time you are saying that the top of the same tyre moves forward faster than the AC.
I really can't argue with that.

[MichaelKPIT]

Relative to the runway that's precisely what I'm saying. The very bottom of the tyre tread is moving at 0kt relative to the runway with which it is in contact. If not it would be skidding. The axle, x feet up from the runway is moving forward, relative to the runway, at 100kt (in this example.) The top of the wheel, 2x feet up from the runway, is moving forward, relative to the runway, at 200kt. The whole complete wheel, as a component piece, is obviously traveling forward at 100kt, however it is rotating, so the top has a forward velocity (speed in a given direction) greater than the axle or the bottom, and while the bottom is in contact with the runway, and is not skidding, it has the same forward velocity as the runway, which is obviously 0kt.

[wiggy]

so you are saying that the bottom of the tyre stands still.
yet at the same time you are saying that the top of the same tyre moves forward faster than the AC.
I really can't argue with that.

What ground speed do you think the bottom of a tyre of a moving vehicle is doing (any tyre, any vehicle....aircraft, car, bicycle ) when it is in contact with the ground ?

[MichaelKPIT]

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/634x237/3_s2_0_b9780750651318500099_f08_50_9780750651318_1aa02f19ad4 33a47d730873d01a92389a2d5c549.gif
A picture is worth a thousand words.

[Airbubba]

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/634x237/3_s2_0_b9780750651318500099_f08_50_9780750651318_1aa02f19ad4 33a47d730873d01a92389a2d5c549.gif
A picture is worth a thousand words.

And the curve plotted by Point P is known as a cycloid. But all I know as a pilot is that a tire burst can sure FOD an engine on takeoff (or landing). ;)

[Beamr]

What ground speed do you think the bottom of a tyre of a moving vehicle is doing (any tyre, any vehicle....aircraft, car, bicycle ) when it is in contact with the ground ?
there is a difference in horizontal speed and rotational speed.
take any car, a drag car for instance: the wheels are warmed up before run, and the rotational speed is significant, but the wheel isn't going nowhere.
on the other hand, an airplane, after take off, the wheels stop spinning, but the wheels are moving just as fast as the AC.

so, regarding the circumferential speed: it is constant at every location on every spot with identical distance from the center, neverminding the speed or direction of the wheel.

What I understood from the message above is that a vehicle moving at constant speed N would have a rotating tyre of which the top section is moving onwards with the rate of N*1,1 and bottom section with the rate of N*0.

What I am trying to explain is that the wheel it self is really moving onwards at the horizontal speed N, and the rotational speed is a different factor that really does not affect the actual horizontal speed of the wheel.

[MichaelKPIT]

there is a difference in horizontal speed and rotational speed.
take any car, a drag car for instance: the wheels are warmed up before run, and the rotational speed is significant, but the wheel isn't going nowhere.
on the other hand, an airplane, after take off, the wheels stop spinning, but the wheels are moving just as fast as the AC.

so, regarding the circumferential speed: it is constant at every location on every spot with identical distance from the center, neverminding the speed or direction of the wheel.

What I understood from the message above is that a vehicle moving at constant speed N would have a rotating tyre of which the top section is moving onwards with the rate of N*1,1 and bottom section with the rate of N*0.

What I am trying to explain is that the wheel it self is really moving onwards at the horizontal speed N, and the rotational speed is a different factor that really does not affect the actual horizontal speed of the wheel.

I think you may be confusing angular velocity with linear velocity. You are absolutely right that every part of the wheel is ROTATING at the same angular velocity. The wheel as a component part of the aircraft is also moving forward, relative to the runway, at the same speed as the aircraft. However it is also rotating. The bottom of the wheel, in contact with the runway, and not moving relative to said runway, therefore has a LINEAR velocity of zero. Take another look at the image I posted above. It shows the linear velocity of a point element of the wheel as 0 when it's touching the runway and 160 km/h when it's at the top.

[Beamr]

I think you may be confusing angular velocity with linear velocity. You are absolutely right that every part of the wheel is ROTATING at the same angular velocity. The wheel as a component part of the aircraft is also moving forward, relative to the runway, at the same speed as the aircraft. However it is also rotating. The bottom of the wheel, in contact with the runway, and not moving relative to said runway, therefore has a LINEAR velocity of zero. Take another look at the image I posted above. It shows the linear velocity of a point element of the wheel as 0 when it's touching the runway and 160 km/h when it's at the top.
true, I got fixated with the term forward speed.

[hr2pilot]

ATC audio:
(Sorry if this is posted elsewhere in this thread)

https://youtu.be/z44W_S5skis

[ACA856]

https://scontent.fybz2-1.fna.fbcdn.net/v/t1.0-9/84049418_2551343834963252_3338336469814083584_o.jpg?_nc_cat= 1&_nc_ohc=Ze1T8U7emTQAX-sM6lr&_nc_ht=scontent.fybz2-1.fna&oh=ea04f111a28d97727cc7fafd757bb17a&oe=5ED5DA9C

Looks like a pic taken from the F-18 surveying the damage.

[Airbubba]

ATC audio:
(Sorry if this is posted elsewhere in this thread)

Thanks for the link, good job as usual by VASAviation.

I'm wondering why Air Canada chose to retract the gear with the fighter observing? They had known tire damage and needed to burn off fuel.

They said the left side brake temps were 8's after landing, hopefully the junior ground engineer was able to place those fans in time to prevent the fuse plugs from blowing.

I thought all B-763's had brake temp indications. Tower Dog and others set me straight that this was an option that some carriers like American did not order.

Seems like Air Canada disabled all 767 fuel dump systems years ago to save maintenance costs.

[Airbubba]

Looks like a pic taken from the F-18 surveying the damage.

Sure does. Is this flaps 5?

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1440x1028/84049418_2551343834963252_3338336469814083584_o_f18f10c86dbd 183fdd1545bb8e5904453d1014f6.jpg

[ACA856]

Airbubba - Appears to be Flap 5, and not all AC 767's had the brake temp indication IIRC. I was not aware of the fuel dump disabling on the AC 767's but I am old and memory is the second thing to go.

[Chu Chu]

Anyone still doubtful about wheels throwing debris forward should ride a bicycle through a mud puddle and then look at the back of their shirt. Fenders ruin the effect, of course.

[YRP]

I love the use of YouTube for transferring serious aviation safety info. :)

[Commander Taco]

Seems like Air Canada disabled all 767 fuel dump systems years ago to save maintenance costs.

Airbubba - you’ve said this before on a different thread and on that thread I informed you that Air Canada had quite a mixed bag of 767’s after the takeover of Canadian Airlines. In point of fact, AC began a campaign of reactivating the fuel jettison system on all its 767 aircraft. The MAD 767 was not original to either Canadian Airlines or Air Canada, but was brought into the fleet as a lease aircraft by Robert Himself. It was an earlier model 767-300 and as noted above in previous posts, quite likely never had a fuel jettison system installed.

[Airbubba]

In point of fact, AC began a campaign of reactivating the fuel jettison system on all its 767 aircraft.

Thanks, so the installed fuel jettisons were deactivated at one time, that's what I thought. :ok: I've sure struggled through different configurations in the same aircraft fleet from leases, mergers and model updates.

The MAD 767 was not original to either Canadian Airlines or Air Canada, but was brought into the fleet as a lease aircraft by Robert Himself. It was an earlier model 767-300 and as noted above in previous posts, quite likely never had a fuel jettison system installed.

Are you sure about that? C-GHOZ is listed as a B-767-375(ER). The 75 Boeing customer code indicates Pacific Western/Canadian.

[DaveReidUK]

The MAD 767 was not original to either Canadian Airlines or Air Canada, but was brought into the fleet as a lease aircraft by Robert Himself. It was an earlier model 767-300 and as noted above in previous posts, quite likely never had a fuel jettison system installed.
Are you sure about that? C-GHOZ is listed as a B-767-375(ER). The 75 Boeing customer code indicates Pacific Western/Canadian.

All 5 of ACA's 767-300ERs are ex-Canadian/Canadien and of a similar vintage (built 1989-1991).

[Jorge Newberry]

The F18 pilot talks about his role here (in Spanish but google/deepl should do the trick for those unversed in the language of Cervantes)

https://www.europapress.es/nacional/noticia-piloto-18-asistio-air-canada-hice-inspeccion-conciencia-vi-me-tranquilizo-20200205134433.html

[admiral ackbar]

Thanks, so the installed fuel jettisons were deactivated at one time, that's what I thought. :ok: I've sure struggled through different configurations in the same aircraft fleet from leases, mergers and model updates.



Are you sure about that? C-GHOZ is listed as a B-767-375(ER). The 75 Boeing customer code indicates Pacific Western/Canadian.

Yes this is an ex-CP bird and I have no idea what Robert Milton has to do with any of this.

[Longtimer]

History of the aircraft Source:
https://wwwapps.tc.gc.ca/Saf-Sec-Sur/2/CCARCS-RIACC/RchHsRes.aspx?st=1&hid=42511,&mh=GHOZ&rfr2=ADet.aspx?id=42511&rfr=RchSimp.aspx&print=y
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1083x168/history_22bc4731505e59d24d55a69694b936c04380ae43.jpg

[DaveReidUK]

History of the aircraft Source

A useful reminder that, for airworthiness purposes, the only ER 767s are the -400ERs.

[Airbubba]

Yes this is an ex-CP bird and I have no idea what Robert Milton has to do with any of this.

Commander Taco is very knowledgeable about the Air Canada fleet and my thinking that B-763 fuel dump was at one time deactivated by Air Canada is probably from an old ground school conversation in the pre-Y2K era. At least we know that fuel jettison still works on at least one of Delta's Triples. ;)

I once flew for an airline that operated over a dozen variants of the B-727-200. And some with mixed engines.

I am curious about the decision to raise the gear while holding with a blown tire and excess fuel to burn. Was this done for passenger comfort perhaps? I've always been taught to leave the gear down with possible brake or tire damage lest it jam in the well on retraction.

[Twitter]

Commander Taco is very knowledgeable about the Air Canada fleet and my thinking that B-763 fuel dump was at one time deactivated by Air Canada is probably from an old ground school conversation in the pre-Y2K era. At least we know that fuel jettison still works on at least one of Delta's Triples. ;)

I once flew for an airline that operated over a dozen variants of the B-727-200. And some with mixed engines.

I am curious about the decision to raise the gear while holding with a blown tire and excess fuel to burn. Was this done for passenger comfort perhaps? I've always been taught to leave the gear down with possible brake or tire damage lest it jam in the well on retraction.

More on that subject here:

https://www.pprune.org/tech-log/622300-tyre-wheel-damage-retract-landing-gear.html#post10508346

Collateral damage may affect the decision

[foxcharliep2]

The F18 pilot talks about his role here (in Spanish but google/deepl should do the trick for those unversed in the language of Cervantes)

https://www.europapress.es/nacional/noticia-piloto-18-asistio-air-canada-hice-inspeccion-conciencia-vi-me-tranquilizo-20200205134433.html

Very professional and factual statements - thank you for the link !

[Commander Taco]

History of the aircraft Source:
https://wwwapps.tc.gc.ca/Saf-Sec-Sur/2/CCARCS-RIACC/RchHsRes.aspx?st=1&hid=42511,&mh=GHOZ&rfr2=ADet.aspx?id=42511&rfr=RchSimp.aspx&print=y
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1083x168/history_22bc4731505e59d24d55a69694b936c04380ae43.jpg
Thanks for the correction, Longtimer. C-GHOZ is an oddball registration that didn’t fit in to any of the CAIL 767 registration sequences and I thusly assumed that C-GHOZ was not an original fin to either AC or CAIL.

[TwinJock]

Shocked when I listened to the ATC transcript. The crew sounded like a bunch of amatures. Cannot raise the landing gear initially with an Engine failure, but managed to raise it later. WTF?

Secondly cannot fly a radial to hold.

Holding for hours on 1 engine. And this is considered a safer option than landing overweight?

Always thought that Air Canada is one of the better trained operators, but I have been proven wrong.

[J.O.]

Shocked when I listened to the ATC transcript. The crew sounded like a bunch of amatures. Cannot raise the landing gear initially with an Engine failure, but managed to raise it later. WTF?

Secondly cannot fly a radial to hold.

Holding for hours on 1 engine. And this is considered a safer option than landing overweight?

Always thought that Air Canada is one of the better trained operators, but I have been proven wrong.

:rolleyes:

[Jet Jockey A4]

Shocked when I listened to the ATC transcript. The crew sounded like a bunch of amatures. Cannot raise the landing gear initially with an Engine failure, but managed to raise it later. WTF?

Secondly cannot fly a radial to hold.

Holding for hours on 1 engine. And this is considered a safer option than landing overweight?

Always thought that Air Canada is one of the better trained operators, but I have been proven wrong.

Yes I don’t understand why on a twin engined aircraft that can land overweight, a crew would decide to burn or dump
fuel for one or even two hours.

I have several friends now retired from Air Canada for several years that flew the 767 and Airbus and during their career there they tell me that the policy was to land immediately and they are dumbfounded by the last two events they read about (787 and 767) that the crew decided to stay airborne instead of landing immediately.

[cashash]

Yes I don’t understand why on a twin engined aircraft that can land overweight, a crew would decide to burn or dump
fuel for one or even two hours.

I have several friends now retired from Air Canada for several years that flew the 767 and Airbus and during their career there they tell me that the policy was to land immediately and they are dumbfounded by the last two events they read about (787 and 767) that the crew decided to stay airborne instead of landing immediately.

I dont think that is very fair. They crew had an undercarriage problem and an engine shutdown at the same time so taking your time to talk to Ops and Engineering and then get a fighter scrambled up to check out the damage seems quite sensible. After all there is no hurry to land and taking your time to be fully informed (or as informed as you can be given the circumstances) seems a reasonable option.

[tcasblue]

Shocked when I listened to the ATC transcript. The crew sounded like a bunch of amatures.

Holding for hours on 1 engine. And this is considered a safer option than landing overweight?

Yes I don’t understand why on a twin engined aircraft that can land overweight, a crew would decide to burn or dump
fuel for one or even two hours.

I have several friends now retired from Air Canada for several years that flew the 767 and Airbus and during their career there they tell me that the policy was to land immediately and they are dumbfounded by the last two events they read about (787 and 767) that the crew decided to stay airborne instead of landing immediately.

I suggest that both you and the retired captains are not analyzing things properly. I don't have a 767 FCTM but the 747 one likely has the same statement....."Boeing airplanes are designed so that the landing gear and remaining tire(s) have adequate strength to accommodate a flat nose gear tire or main gear tire. When the pilot is aware of a flat tire prior to landing, use normal approach and flare techniques, avoid landing overweight and use the center of the runway."

Why do you think that Boeing says this? Only three out of four tires are available on that bogie. The aircraft is overweight and it will have a higher touchdown speed. There is a significant chance that there could be more tires lost. How will that affect directional control and stopping capability. Even if the remaining tires are not affected, how will braking be? And, there is no reverse from one engine in this case. Don't you think that it would be higher risk to land overweight with both deceleration devices(brakes and reverse) degraded.

There seems to be this panic mindset that one has to land ASAP(airbus term)/at the nearest suitable airport because that is what the manual says. But this airplane was flying just fine. Why not burn off the fuel.

During the time that they were above their MLW, no airport in the world was suitable unless there was another overriding factor(which there was not) because the rest of the tires could easily blow out leading to significant directional issues or exacerbating deceleration issues. Once they were down to MLW, Madrid became their nearest suitable airport.

In fact based on their subsequent actions, it is a damn good thing they burned the extra fuel. Why? Because of the subsequent decision to accept a tailwind landing on a relatively short runway instead of landing into wind on the runway with the much longer LDA. Listen to the end of the ATC tape, they state that their brakes are very hot. Not good if hydraulic fluid is leaking, a distinct possibility in this incident, and evidence that they could have had an increased likelihood of an overrun

Finally from the FCTM, in part....

"Situations Beyond the Scope of Non-Normal Checklists It is rare to encounter in-flight events which are beyond the scope of the Boeing recommended NNCs. These events can arise as a result of unusual occurrences such as a midair collision, bomb explosion or other major malfunction. In these situations the flight crew may be required to accomplish multiple NNCs, selected elements of several different NNCs applied as necessary to fit the situation, or be faced with little or no specific guidance except their own judgment and experience."

Judgement and experience might lead one to decide that there is little risk in continuing to fly and reduce weight due to the significant risk that will be encountered on landing. The other engine is almost certainly not going to fail.

[megan]

If one is agonising about not landing immediately,you'd probably suggest removing any ETOPS approval as well. :uhoh:

[Twitter]

Tyre failure on TO often causes collateral damage. Apart from the fairly obvious popping or failed engine there can be damage to structure and flying surfaces.
Within the wheel well, apart from the gear itself, there are systems, position sensors and components which are also vulnerable.
Assessing the aircraft status takes time. Planning a suitable landing strategy takes time too. Which AP/RW? Any hydraulic leak? Paired tyre OK? Airborne inspection? Weight reduction?
Gear locked indicator? Foam? Arm the spoilers? Wind? Prepare the cabin? Do available checklists fit the case or would it be better to modify items? Public address, Company, ATC are also neccessary and take time.
Whatever you decide, you can be sure of criticism afterwards. Take your time to assess and sort it all out and you can expect complaints, that you should have got down sooner.
Rush to get it down and fold a leg or ground loop and apart from a crash, you will get the know-alls telling you you should have waited. Raise the gear and the engineering experts will criticise you, Leave it down and the performance experts will be after you. In this age of the smartphone and blog you will get criticised on line too - possibly with video "evidence".
Facit: You are the boss and you and your crew decide what is best and execute it as well as you can. If it all works out and no-one is harmed, the decision was a good one and blast the critics.
If it doesn't work out and you've done your best, it's still what we are paid for. Having been in a similar situation I sympathise with the crew and congratulate them on a good outcome.

[WillowRun 6-3]

Post just above by Twitter sketches out a situation in which lots of factors must be assessed and then acted upon - and I'm sure this SLF will be corrected if such understanding is not correct.

But some algorithm purveyor will replicate the airmanship, judgment and experience, and (sorry, resorting to abstraction) overriding concern for safety of passengers and crew - and deliver an autonomous system that will produce successfully safe outcomes just as reliably, if not more so. Right?....I mean, I read that on the internet, so . . .

[TwinJock]

I suggest that both you and the retired captains are not analyzing things properly. I don't have a 767 FCTM but the 747 one likely has the same statement....."Boeing airplanes are designed so that the landing gear and remaining tire(s) have adequate strength to accommodate a flat nose gear tire or main gear tire. When the pilot is aware of a flat tire prior to landing, use normal approach and flare techniques, avoid landing overweight and use the center of the runway..

Why do you think that Boeing says this? Only three out of four tires are available on that bogie. The aircraft is overweight and it will have a higher touchdown speed. There is a significant chance that there could be more tires lost. How will that affect directional control and stopping capability. Even if the remaining tires are not affected, how will braking be? And, there is no reverse from one engine in this case. Don't you think that it would be higher risk to land overweight with both deceleration devices(brakes and reverse) degraded.

There seems to be this panic mindset that one has to land ASAP(airbus term)/at the nearest suitable airport because that is what the manual says. But this airplane was flying just fine. Why not burn off the fuel.

During the time that they were above their MLW, no airport in the world was suitable unless there was another overriding factor(which there was not) because the rest of the tires could easily blow out leading to significant directional issues or exacerbating deceleration issues. Once they were down to MLW, Madrid became their nearest suitable airport.

In fact based on their subsequent actions, it is a damn good thing they burned the extra fuel. Why? Because of the subsequent decision to accept a tailwind landing on a relatively short runway instead of landing into wind on the runway with the much longer LDA. Listen to the end of the ATC tape, they state that their brakes are very hot. Not good if hydraulic fluid is leaking, a distinct possibility in this incident, and evidence that they could have had an increased likelihood of an overrun

Finally from the FCTM, in part....

"Situations Beyond the Scope of Non-Normal Checklists It is rare to encounter in-flight events which are beyond the scope of the Boeing recommended NNCs. These events can arise as a result of unusual occurrences such as a midair collision, bomb explosion or other major malfunction. In these situations the flight crew may be required to accomplish multiple NNCs, selected elements of several different NNCs applied as necessary to fit the situation, or be faced with little or no specific guidance except their own judgment and experience."

Judgement and experience might lead one to decide that there is little risk in continuing to fly and reduce weight due to the significant risk that will be encountered on landing. The other engine is almost certainly not going to fail.
You do make some valid points, but it seems you see the failures in isolation.

The crew was definitely aware that they had an Engine failure, and that should have been the priority. The possibility of tire damage, which was only confirmed hours later by sending up a fighter aircraft, seems to me to have became the focus of the crew.

I still maintain that "hanging" around for hours on a single engine is not the best option available to the crew. If it was purely a tire problem, with 2 engines turning, then they can stay airborne as long as they want, think about it, contact whoever they wanted to, and figured out how to intercept a radial.

If SE was not a problem as you stated, why didn't the crew fly for 4 hours towards destination and then land - if this is indeed the safest option. Twin with an Engine failure should land at nearest suitable airport in terms of time, and 4 hours sounds way excessive.....

We see the ETOPS argument being used more and more during EFATO and in the cruise. Whilst the aircraft is certified for 180 minutes ETOPS it gives you NO guarantee that the operating engine will last at least that long...

Any reason for not landing on the longest runway available, as the FCTM points out?

[megan]

What Boeing has to say.An overweight landing with an engine inoperative or a system failure may be less desirable than landing below maximum landing weight. Yet, delaying the landing with a malfunctioning system or engine failure in order to reduce weight or jettison fuel may expose the airplane to additional system deterioration that can make the situation worse. The pilot in command is in the best position to assess all relevant factors and determine the best course of action.An inability to calculate landing performance for overweight landing with the reduced braking capacity I'd humbly suggest as a SLF the crew did the right thing ie agree with tcasblue.

https://www.boeing.com/commercial/aeromagazine/articles/qtr_3_07/article_03_1.html

If SE was not a problem as you stated, why didn't the crew fly for 4 hours towards destination and then land - if this is indeed the safest optionI suppose you're suggesting they retract the gear then, people have run out of gas trying that, besides the fact the flying rubber may have caused untold damage to systems in the wheel well. Sticking near the airport was smart IMHO.The possibility of tire damage, which was only confirmed hours later by sending up a fighter aircraftI'd say the crew were well aware of the initiation of their problems, that's why they left the gear down. An inspection by the fighter was prudent to assess the level of apparent damage, one can never have too much information in such cases.

[Jet Jockey A4]

You do make some valid points, but it seems you see the failures in isolation.

The crew was definitely aware that they had an Engine failure, and that should have been the priority. The possibility of tire damage, which was only confirmed hours later by sending up a fighter aircraft, seems to me to have became the focus of the crew.

I still maintain that "hanging" around for hours on a single engine is not the best option available to the crew. If it was purely a tire problem, with 2 engines turning, then they can stay airborne as long as they want, think about it, contact whoever they wanted to, and figured out how to intercept a radial.

If SE was not a problem as you stated, why didn't the crew fly for 4 hours towards destination and then land - if this is indeed the safest option. Twin with an Engine failure should land at nearest suitable airport in terms of time, and 4 hours sounds way excessive.....

We see the ETOPS argument being used more and more during EFATO and in the cruise. Whilst the aircraft is certified for 180 minutes ETOPS it gives you NO guarantee that the operating engine will last at least that long...

Any reason for not landing on the longest runway available, as the FCTM points out?



I agree completely with you.

We are not talking about a situation here where the crew just went through the appropriate checklists then advise the cabin crew and passengers of the situation.

Take the appropriate time needed to get all the previously mention items done correctly (checklists, announcements), then come in for a landing.

They actually waited for an F18 to be available to them to fly up close enough to the aircraft to validate a blown tire.

Then they stayed up in the air for presumably 4 hours on one engine... I'm sure the passengers were very happy and stressed out for all that time.

What if another aircraft was not available to fly up to check their aircraft out to validate the blown tire?

The argument of ETOPS is not valid one in a scenario where a twin engined aircraft takeoffs and shuts down one of its engines for what ever reason and becomes a MAYDAY aircraft... Any modern turbine powered twin engine aircraft (whether ETOPS or not) can stay in the air for a long time on one engine, but this is not the point.

In any case there will always be pilots that see things differently and I believe this will be a ongoing argument... Land ASAP on one engine or burn off fuel to land under the max landing weight. Same thing with cross wind landings... some argue the proper technic is not to un-crab the aircraft prior to touch down and those that say yes un-crab, low wing into the wind and use the rudder to straighten out the aircraft prior to touch down.

[FlightDetent]

and I believe this will be a ongoing argument... Land ASAP on one engine or burn off fuel to land under the max landing weight. I do no think so. We've had it here for several times, with very good contributions. No one I remember managed to say more than the Boeing's AERO article.

My take on all combined is that with a fuel-jettison aeroplane (never flown one!) there is a certain logic to reduce down to max OEI go-around weight in case of inclement weather. Otherwise, if calculated landing distance allows, there is no justification to say airborne for the sole purpose of reducing weight.

[tcasblue]

You do make some valid points, but it seems you see the failures in isolation.

The crew was definitely aware that they had an Engine failure, and that should have been the priority. The possibility of tire damage, which was only confirmed hours later by sending up a fighter aircraft, seems to me to have became the focus of the crew.

I still maintain that "hanging" around for hours on a single engine is not the best option available to the crew. If it was purely a tire problem, with 2 engines turning, then they can stay airborne as long as they want, think about it, contact whoever they wanted to, and figured out how to intercept a radial.

If SE was not a problem as you stated, why didn't the crew fly for 4 hours towards destination and then land - if this is indeed the safest option. Twin with an Engine failure should land at nearest suitable airport in terms of time, and 4 hours sounds way excessive.....


This wasn't a twin with an engine failure. This was a twin with an engine failure and reduced braking capability, and the high possibility of more tire bursting on landing. I find it strange that you thing that I am the one thinking of the failures in isolation when you want to just land ASAP(or close to it) without serious considerations of the ramifications of further tires bursting and significantly reduced deceleration capability.

The crew could have flown four hours(or whatever time it would take to get to MLW-or less weight) but logic would make someone stay around Madrid due to potential further degradation of systems, the good weather and runways with a long LDA available. Too bad they didn't use one long runways into wind.

[tcasblue]

I do no think so. We've had it here for several times, with very good contributions. No one I remember managed to say more than the Boeing's AERO article.

My take on all combined is that with a fuel-jettison aeroplane (never flown one!) there is a certain logic to reduce down to max OEI go-around weight in case of inclement weather. Otherwise, if calculated landing distance allows, there is no justification to say airborne for the sole purpose of reducing weight.

I already gave the justification based on what Boeing states about not landing overweight with a blown tire. Do you not think that this is important. Can you calculate the landing distance for a blown tire. And then what is the landing distance if the remaining three tires blow out on that gear leg. Will the landing be smooth or accidentally firm. Will it be accidentally long....then what...go-around?

I agree completely with you.

They actually waited for an F18 to be available to them to fly up close enough to the aircraft to validate a blown tire.

Then they stayed up in the air for presumably 4 hours on one engine... I'm sure the passengers were very happy and stressed out for all that time.

What if another aircraft was not available to fly up to check their aircraft out to validate the blown tire?



Who cares if the pax were not happy and stressed about staying airborne for four hours. They would be a lot more stressed if the remaining tires had blown on landing and they had gone off the side or the end of the runway. Do you really consider the happiness of pax for serious decisions like this?

If no F-18, I suspect the same decisions would have been made.

Meanwhile for the scared of single engine operation crowd, I wonder how many commercial PC-12's were flying at the time.

Once again.....
"Situations Beyond the Scope of Non-Normal Checklists It is rare to encounter in-flight events which are beyond the scope of the Boeing recommended NNCs. These events can arise as a result of unusual occurrences such as a midair collision, bomb explosion or other major malfunction. In these situations the flight crew may be required to accomplish multiple NNCs, selected elements of several different NNCs applied as necessary to fit the situation, or be faced with little or no specific guidance except their own judgment and experience."

[FlightDetent]

@tcasblue I do not find my statement at odds with your logic, or vice versa. Anyways all I tried to say was there actually is an end to OEI overweight landing debate.

[pilot9250]

Maybe off topic but I guess I find this bit curious from an earlier post

"They actually waited for an F18 to be available to them to fly up close enough to the aircraft to validate a blown tire."

From the post in Spanish, the airforce commander seems proud it took only 40 minutes to scramble a QRA fighter.

Does anybody else find this ever so slightly ridiculous?
​​​​

[threep]

It depends where the fighters are based. Madrid is in the centre of Spain whereas I expect QRA fighters to be positioned to counter hostile external threats. Madrid is something like 350km from its nearest coastline.

[733driver]

The fighters are based next door to LEMD at LETO.

[DaveReidUK]

From the post in Spanish, the airforce commander seems proud it took only 40 minutes to scramble a QRA fighter.

Does anybody else find this ever so slightly ridiculous?​​​​

That was possibly the time needed to find an F-18 pilot whose first instinct wouldn't be to shoot down the 767 ...

[Luc Lion]

That was possibly the time needed to find an F-18 pilot whose first instinct wouldn't be to shoot down the 767 ...
Most F-18 pilots whose first instinct would be to shoot down the 767 have now retired after multiple ejections.
They had to eject after shooting down the KC46 that was coming to refuel their fighter jet.

[foxcharliep2]

Maybe off topic but I guess I find this bit curious from an earlier post

"They actually waited for an F18 to be available to them to fly up close enough to the aircraft to validate a blown tire."

From the post in Spanish, the airforce commander seems proud it took only 40 minutes to scramble a QRA fighter.

Does anybody else find this ever so slightly ridiculous?
​​​​

No. But your comment is ridiculous

It was known mechanical trouble and no QRA intruder.

[wiggy]

No. But your comment is ridiculous

It was known mechanical trouble and no QRA intruder.

:ok:

It doesn’t look like a standard “out of the box” Q mission... there was no threat and the passengers safety was at stake...

[pilot9250]

:ok:

It doesn’t look like a standard “out of the box” Q mission... there was no threat and the passengers safety was at stake...
​​​​​​
Always a mystery.

I guess I assumed that the Q in QRA means quick, and that 'go there and intercept that' is standard and included in "out of the box".

Fortunately it seems, while benefiting from an external visual, the Q part of QRA wasn't too critical.

[AlexGG]

​​​​​​
Always a mystery.

I guess I assumed that the Q in QRA means quick, and that 'go there and intercept that' is standard and included in "out of the box".

Fortunately it seems, while benefiting from an external visual, the Q part of QRA wasn't too critical.

Let's say one has an alert aircraft on standby to deal with an urgent threat, and something comes up that does not look really urgent or threatening. In this case, is in better to commit the alert aircraft, or wait for some other aircraft to be prepared to launch?

[Markos.]

Gents,

Please don’t assume facts that you don’t know anything about.

QRA a/c are airborne within 15 minutes max.
For this particular msn:
-767 reported its intentions to hold over 4hrs to burn fuel
-the Spanish Air Defence Command then offered the help of a chase a/c (F18)
-once the crew accepted the help, they called a pilot that was preparing another msn for that very afternoon and retasked him and his a/c

There was no need to rush or to scramble the QRA. QRA must be preserved for other defence related msns plus the QRA is armed with missiles and gun while this chase a/c was not.

Please always remember whenever you have an emergency that fighter a/c might help. Radio, navigation, etc... Portugal latest events come to my mind for instance.

[Twitter]

The idea of having a visual check on the aircraft in flight is not “just to verify a blown tyre” but to give a report on the overall condition of the aircraft.

I wanted a visual check of my ship done when we had a tyre blow with further complications on T/O, before planning our landing. Trouble was, they couldn’t get a fighter and wanted to vector a Fokker Friendship on to us. I politely declined. If you have someone in formation with you, you want someone who is in practice.
You also need someone who knows what to look for and can respond to queries from the cockpit, while assuming appropriate position.

[tdracer]

I says a lot about the state of PPRUNE that an incident where the pilots followed the recommended procedure, no one was hurt, and the aircraft suffered no damage other than what occurred during the initiating incident has generated six pages of discussion about why the crew (and others) did what they did. :ugh:

[Zombywoof]

Are we still talking about this? Geez...

[DaveReidUK]

I says a lot about the state of PPRUNE that an incident where the pilots followed the recommended procedure, no one was hurt, and the aircraft suffered no damage other than what occurred during the initiating incident has generated six pages of discussion about why the crew (and others) did what they did.

Well I'll admit to having enjoyed a healthy, albeit vigorous, debate which served as a reminder that professionals don't always agree about everything.

And if all else fails, you can always tweak your PPRuNe control panel settings and get it down to 4 pages. :O

[tcasblue]

I says a lot about the state of PPRUNE that an incident where the pilots followed the recommended procedure, no one was hurt, and the aircraft suffered no damage other than what occurred during the initiating incident has generated six pages of discussion about why the crew (and others) did what they did. :ugh:

There is no doubt one has to sort through a lot of posts to glean good information just like on many other forums.

Some Boeing designs have created much more than 6 pages of pilot discussion on Pprune in the last 18 months. I am convinced that if the Ethiopian pilots had thoroughly read the Lion Air crash thread, they would have had the info(not supplied by Boeing) to prevent the conditions that led to the second accident ie…….leave the flaps extended and there will be no MCAS activation. Can you believe it? The golden nugget to prevent a disaster(or the subsequent follow-on situation that led to the disaster) was on Pprune. Would have saved many lives and perhaps 20 billion for Boeing.

A pilot learns only the basics of aviating to get their license and has many gaps in knowledge even when completing a type rating. One can learn so much(but also gain so much bad info on places like this) but it takes initiative and time. Just like in so many other facets in life.