Ask The Pilot

[QF WP]

https://twitter.com/i/web/status/1615444009412878345

Just came across this video of a plane on final and at just above 200ft, has a bird strike. It hits the FO window and he exclaims, but the Captain (who must have been PF) doesn’t even comment - just lands the plane.

Have any of the pilots here had bird strikes?

 

[AviatorInsight]

Have any of the pilots here had bird strikes?

I’ve had a few. Nothing as bad as that but I’ve had it hit the nose, gear, engine and leading edge. More so at the outports. Luckily engineering was available to clear the defect in the tech log and we could continue.

It‘s one of the reasons why the windshield is heated. So if it’s not working we are limited to 250kts below 10,000ft.

 

[jb747]

Hey there JB747, from what I have read, the airline is not shy to max out passengers and baggage, etc. Hence my post was on the suspicion that they may have been overloaded, so the problems encountered were set up before the actual flight.

The speeds that are chosen as the minimum for approach are approximately 20% faster than the stall speed for that configuration. So, if the weight were wrong, it would have to be so wrong that it moved the actual stall speed by 20%. These speeds are related to the square root of the load factor (g), but that’s simply another way of describing weight. So, to get a stall speed increase of 20%, you’d need your weight to be out by 1.2 squared….about 44%. It wouldn’t have gotten off the runway in the first place!

That’s not to say that such an error is impossible, but not likely at the hands of the airline. I do know of one case where this almost happened. A Singair 747 was departing Auckland, and the crew did the take off numbers based on an incorrect weight. As the Captain had had recent experience on the A340, a number that was about 100 tonnes light didn’t set off any alarm bells. They barely got airborne, and managed to do so much damage to the tail of the aircraft that I think it was ultimately written off. But, having gotten into the air, and now listening to alarms from the damage done, they decide to return. Sadly they hadn’t realised the root cause of the issue, so they then proceeded to do the approach numbers still using the wrong weights. The aircraft weighed about 350 tonnes, instead of the 250 tonnes that they used. The actual weight was 40% heavier than the numbers used for the calculation. When they tried to slow to the calculated approach speeds the stall warning/stick shaker activated. I think the penny dropped about then.

And apologies for offerring an armchair opinion what is clear to me now as a "pilots" thread. I was just engaging in the thread, but realize that it is an inappropriate place for me to voice my arm chair opinions You are clearly a pilot, so will follow this with interest, but hold my tongue

If you have an opinion that you want to put out there as a question, we don’t mind telling you why you’re wrong. Or perhaps even right. This thread exists though, because many of the things that people think they know about aircraft are simply wrong.

 

[QF WP]

I’ve had a few. Nothing as bad as that but I’ve had it hit the nose, gear, engine and leading edge. More so at the outports. Luckily engineering was available to clear the defect in the tech log and we could continue.

It‘s one of the reasons why the windshield is heated. So if it’s not working we are limited to 250kts below 10,000ft.

Does having a heated window somehow lessen the impact damage of a bird strike?

 

[jb747]

...Wake turbulence tends to descend behind the airfoil.

I'm thinking simplistically an application of Newton's third law: a force has a equal and opposite reaction.
The force generating lift must have an equal force deflecting air in a downward direction.
Your Thoughts appreciated on this...

Is induced drag highest at wingtips?

Think winglets…. Wake tends to descend at about 500 fpm, which is one reason why it isn’t generally an issue for aircraft landing behind another.

Does having a heated window somehow lessen the impact damage of a bird strike?

If the window isn’t heated it will become more fragile in the cold air at altitude, and so the outer layer is much more likely to crack if hit by a bird.

( This from the QF engine shut-down thread)

In this case is there any impact on steering as the aircraft slows?

Reverse thrust provides very little actual reverse thrust. It does little more than counter the residual forward thrust from the core. The upshot is that the amount of force trying to turn the aircraft is probably an order of magnitude less than you might expect, and as such is easily handled by normal technique.

The most dangerous time with regard to steering the aircraft happens at the other end of the flight. As you apply power at the start of the take off roll, an engine failure during wind up could leave you with massive thrust asymmetry, well above the nose gear’s ability to control, and at a speed much slower than the point at which the rudder starts to be helpful.

Just came across this video of a plane on final and at just above 200ft, has a bird strike. It hits the FO window and he exclaims, but the Captain (who must have been PF) doesn’t even comment - just lands the plane.

Well done. He might have glanced at it, but it simply is not relevant to what he’s doing.

Have any of the pilots here had bird strikes?

Numerous. Even had one a little similar to the video. On approach to Jakarta, the FO made a comment along the lines of never having had a bird strike. Literally seconds later, he’d updated that status.

Worst was out of Perth in a 767. Hit a flock of birds, with a few going through the starboard engine. Smashed one of the flap fairings, punched a hole in the engine fan casing, and damaged the fan.

 

[SYD]

Worst was out of Perth in a 767. Hit a flock of birds, with a few going through the starboard engine. Smashed one of the flap fairings, punched a hole in the engine fan casing, and damaged the fan.

Apparently the 767 coughpit had to be respectively reinforced after a chook gun test on the development 757 penetrated the coughpit! (They shared similar design but the 767 was already flying ).

I was looking for the wonderful, if not possibly apocryphal story of a certification lab horrified that their chook gun testing of an aircraft was causing untold damage. The Boeing test engine enquired if they were defrosting the chickens first? Silence.

 

[NM]

Worst was out of Perth in a 767. Hit a flock of birds, with a few going through the starboard engine. Smashed one of the flap fairings, punched a hole in the engine fan casing, and damaged the fan.

Did that result in an immediate return to PER or did you continue to planned destination (MEL???)?

 

[jb747]

Did that result in an immediate return to PER or did you continue to planned destination (MEL???)?

I just had time to say "birds", and the engine note changed. They'd actually gone down both sides, but the engine display was showing much higher vibration on the right engine. We rolled that engine back a bit, cleaned up and climbed to a few thousand feet. Landed about 20 minutes after take off. Flew the approach as single engined (i.e. flap 20) but kept the right engine running at idle. It seemed happy enough there, and there was suspicion about where other birds may have gone.

The flight was Perth to Singapore. Rather impressively, the engineers removed the fan, moved two blades and replaced another two. Two of the 60 fan stators were missing but that was actually allowed under the MELs. Temporary repair of the hole in the casing and complete removal of what was left of the flap fairing. No hits on the other side. Four hours later we departed again, in the same aircraft.

The engine vibration display tells many stories, and is a major instrument to look at when working any sort of issue.

 

[AviatorInsight]

From the QF Engine Shutdown Thread:

Why would there still be hydraulic power on the engine if it’s shut down? At idle it makes sense, but shut down?

Because we never turn the pumps off. They are electrically controlled and hydraulically operated. During an engine shutdown, we don't pull the fire handle to "secure the engine". We only pull the engine start lever to cut off so the hydraulic engine driven pump continues to operate.

The number 2 engine uses hydraulic system B for thrust reverser actuation. Once on the ground, it'll allow us to pull both reversers to the first detent. The hydraulic system is what opens the sleeve. The EECs are then what drives the reverse thrust.

Because the start lever is in cut off, it electrically closes the fuel valve. No information is then being given to the EECs and so it won't allow us to pull the reverser past the interlock detent.

What would be the single engine altitude? I’d have figured mid to high 20s. Is there a pack limit that might impose FL200. I assume the APU can be started in the entire flight regime.

At normal weights, it'll be in the range of FL230 - 270. I initially stick to 240kts IAS and descend to FL240, set MCT, and then drift down. Once the aircraft is under control, I'll go into the VNAV page and select ENG OUT. Unlike other Boeing types (777), it won't complete the drift down for us. It's all manual. So the engine out page just gives us the information. We then go to the most appropriate flight level and speed for the phase of flight.

FL200 is actually part of the in flight restart checklist. If the engine is shut down for one hour or more or EGT is less than 30ºc, and a restart attempt is needed, then using a crossbleed start, fly at or below FL200 with airspeed above 220kts.

Using APU for electrical only can be used up to FL410 (service ceiling). A good technique we use in the sim for an engine failure is to call a Pan and then start the APU. This saves time when it comes to the checklist, and we can put the generator on the bus for an additional electrical source.

 

[flyer89]

e FO made a comment along the lines of never having had a bird strike. Literally seconds later, he’d updated that status.

Aeroplanes have an uncanny knack of dishing out Justice….

 

[flyingfan]

Sadly they hadn’t realised the root cause of the issue, so they then proceeded to do the approach numbers still using the wrong weights.

I’m interested in the troubleshooting/diagnosis parts and the CRM. Do you have other examples where pilots had a mystery which needed to be troubleshot as a race against the clock (low fuel, bad weather rolling in, hours)? Where if the root cause hadn’t been identified it could have ended badly?

 

[straitman]

Have any of the pilots here had bird strikes?

We had a situation many years ago (1975 maybe) when we had four Iroquois helicopters landing in Normanton. On arrival at the airfield there were so many large birds circling that any sort of 'normal' approach was impossible. Ultimately we went down to about 30 - 40 ft and did a fast hover taxi, one at a time, to the landing area. Diverting was out of the question as we needed to land there for fuel.

Doing that was bad enough but it would have been next to impossible in a fixed wind.

Other than that I only ever had a few small bird strikes in over 40 years of flying. You still react appropriately as you never know what damage may have been caused until after you have landed.

 

[jb747]

Because we never turn the pumps off. They are electrically controlled and hydraulically operated. During an engine shutdown, we don't pull the fire handle to "secure the engine". We only pull the engine start lever to cut off so the hydraulic engine driven pump continues to operate.

The number 2 engine uses hydraulic system B for thrust reverser actuation. Once on the ground, it'll allow us to pull both reversers to the first detent. The hydraulic system is what opens the sleeve. The EECs are then what drives the reverse thrust.

Because the start lever is in cut off, it electrically closes the fuel valve. No information is then being given to the EECs and so it won't allow us to pull the reverser past the interlock detent.

Interesting, I just don't recall any of the engines I've flown doing anything similar. Most were pneumatically powered, so they won't have a power source, but I think the 767-200s were hydraulic. Don't have that manual any more to check.

FL200 is actually part of the in flight restart checklist. If the engine is shut down for one hour or more or EGT is less than 30ºc, and a restart attempt is needed, then using a crossbleed start, fly at or below FL200 with airspeed above 220kts.

I wonder why they were at 200 then. I pretty much had a rule that I'd never attempt to start an engine that had snuffed itself out. And engine failures in the cruise are rarities.

Using APU for electrical only can be used up to FL410 (service ceiling). A good technique we use in the sim for an engine failure is to call a Pan and then start the APU. This saves time when it comes to the checklist, and we can put the generator on the bus for an additional electrical source.

APU was the 767s pilot's first port of call for almost everything. It gave you something to do with your hand for a few seconds, did no harm, and could fix many of the issues.

 

[RooFlyer]

Another from the QF mayday call thread:

Mayday to get an immediate altitude clearance, and then PAN once you’ve got what you need. An alternative anyway.

Just say that they didn't do anything in particular after the mayday call, other than things that didn't need ATC and say 5 mins later, changed to PAN (just being purely theoretical).

In an ensuing investigation, is it likely that that may result in a negative assessment of the flight deck's performance either by the airline (VA or QF) or regulator, (because issued Mayday apparently without a real need to do so), or would it be seen as a case of "Pilots in the air did what they thought best at the time, don't want to discourage that in the future, so no finding on this aspect") ?

 

[jb747]

Another from the QF mayday call thread:

Just say that they didn't do anything in particular after the mayday call, other than things that didn't need ATC and say 5 mins later, changed to PAN (just being purely theoretical).

In an ensuing investigation, is it likely that that may result in a negative assessment of the flight deck's performance either by the airline (VA or QF) or regulator, (because issued Mayday apparently without a real need to do so), or would it be seen as a case of "Pilots in the air did what they thought best at the time, don't want to discourage that in the future, so no finding on this aspect") ?

It is completely the Captain's call. There will be no come back from CASA or the company.

 

[jpp42]

Another from the QF mayday call thread:

Just say that they didn't do anything in particular after the mayday call, other than things that didn't need ATC and say 5 mins later, changed to PAN (just being purely theoretical).

In an ensuing investigation, is it likely that that may result in a negative assessment of the flight deck's performance either by the airline (VA or QF) or regulator, (because issued Mayday apparently without a real need to do so), or would it be seen as a case of "Pilots in the air did what they thought best at the time, don't want to discourage that in the future, so no finding on this aspect") ?

I'm only a private single-engine pilot, so not qualified to comment on jet operations, but I have read a lot of accident reports and am familiar with the "just culture" of aviation that is generally expected worldwide (although CASA isn't always totally onboard with this, but that's another thread). I would definitely say things should lean to the latter. If you as a citizen call 000 and say that there's an intruder banging down your door and then later find that it's just your neighbour repairing theirs, you don't get any kind of fine for misuse of the emergency system - as long as you notify them of the true nature of the incident when practical. Similar theory should apply here. If anything, I'd be questioning why Sydney Airport went with such a huge response (including notifying ambulances etc) when they should have understood the incident was not significant enough to warrant that, but IMO we don't really have enough detail to judge at this point.

 

[Hvr]

I'd be questioning why Sydney Airport went with such a huge response (including notifying ambulances etc)

I'll posit that SYD AP knew the true nature of what was happening and:
a) provided what the pilot asked for, and then
b) then used it as an 'exercise' (for want of a better word) to give the emergency services a real life training session.

Basically an opportunity too good to waste to see how things work when it needs to, it gives new staff a chance to 'roll for real', maybe gives trainee supervisors a chance to put their leadership training into practice, and so on.

it gives the firefighters and paramedics a chance to see if the much touted interoperability works.

The training/practice opportunities are too good to waste.

 

[RooFlyer]

I'll posit that SYD AP knew the true nature of what was happening and:
a) provided what the pilot asked for, and then
b) then used it as an 'exercise' (for want of a better word) to give the emergency services a real life training session.

Basically an opportunity too good to waste to see how things work when it needs to, it gives new staff a chance to 'roll for real', maybe gives trainee supervisors a chance to put their leadership training into practice, and so on.

it gives the firefighters and paramedics a chance to see if the much touted interoperability works.

The training/practice opportunities are too good to waste.

Sounds very likely and who knows, maybe they get to charge Qantas for this very elaborate training run

 

[justinbrett]

In an ensuing investigation, is it likely that that may result in a negative assessment of the flight deck's performance either by the airline (VA or QF) or regulator, (because issued Mayday apparently without a real need to do so), or would it be seen as a case of "Pilots in the air did what they thought best at the time, don't want to discourage that in the future, so no finding on this aspect") ?

Very much the opposite. We'd rather pilots over-declare their emergencies.

There is a myth in the GA community they have to pay for the emergency services (like back in the day you had to pay for the ambulance if you dialled 000).

This is completely false, you are not charged a cent for declaring a PAN PAN or MAYDAY.

I've seen quite a few pilots come back with very unserviceable aircraft that refused to declare an emergency. They got an emergency response anyway.

I'm only a private single-engine pilot, so not qualified to comment on jet operations, but I have read a lot of accident reports and am familiar with the "just culture" of aviation that is generally expected worldwide (although CASA isn't always totally onboard with this, but that's another thread). I would definitely say things should lean to the latter. If you as a citizen call 000 and say that there's an intruder banging down your door and then later find that it's just your neighbour repairing theirs, you don't get any kind of fine for misuse of the emergency system - as long as you notify them of the true nature of the incident when practical. Similar theory should apply here. If anything, I'd be questioning why Sydney Airport went with such a huge response (including notifying ambulances etc) when they should have understood the incident was not significant enough to warrant that, but IMO we don't really have enough detail to judge at this point.

You shouldn't be telling lies to ATC (ie MINFUEL if you're not MINFUEL), but declaring a MAYDAY for any aircraft emergency is fine, if the pilot feels that is warranted. ATC will never question it unless the pilot has been deceitful to get priority, which would be quite remarkable.

As for the emergency rollout, the Tower Supervisor usually makes the call on whether it is a Local Standby or Full Emergency. A Full Emergency for a MAYDAY is normal. Tower would have been advised very soon after the MAYDAY was declared, and they would have activated the AEP. When it was downgraded to a PAN PAN, ATC may not have downgraded to a Local Standby, or if they did, the individual components may have elected to maintain their posture (see next point)

For the record, if it were me and I was the Tower Supervisor in this situation, I would have maintained the Full Emergency.

I'll posit that SYD AP knew the true nature of what was happening and:
a) provided what the pilot asked for, and then
b) then used it as an 'exercise' (for want of a better word) to give the emergency services a real life training session.

Basically an opportunity too good to waste to see how things work when it needs to, it gives new staff a chance to 'roll for real', maybe gives trainee supervisors a chance to put their leadership training into practice, and so on.

it gives the firefighters and paramedics a chance to see if the much touted interoperability works.

The training/practice opportunities are too good to waste.

Close but not really.

No, they definitely wouldn't have declared it an exercise with a real aircraft emergency, whatever the severity.

Local standbys almost always end well. Still, ARFF will usually roll out, and the other components often roll out too in order to practice their procedures as if it were a full emergency.

They will usually run a CRASHEX once a year for full training, but routinely rolling out for local standby keeps everybody sharp. Those are the situations were they will use the words "EXERCISE EXERCISE EXERCISE" with everything so people know it's not real.

 

[RSD]

it gives the firefighters and paramedics a chance to see if the much touted interoperability works.

That must be a Sydney thing - I think that they have given up even pretending that interoperability exists in Melbourne