Another drone takes down another helicopter 12

[Sparweb]

Not the first time.
In its report, the NTSB noted that it has now completed three investigations where a collision with a drone has been confirmed, and gathered information on two other collisions where the evidence is consistent with a drone strike.

The drone was operating above 400 feet AGL in airspace that did not permit this, and at night when this is not normally permitted either. The type of drone that probably hit the helicopter (based on the damage) is not the kind that would be equipped with proper anti-collision lights that would make night flight possible.

Here is another example, probably not in the NTSB count - although a much more avoidable one that should not have happened.

http://www.sparweb.ca

 

[1503-44]

What is the idea behind the correction for wind speed within 3000 ft of ground? I've not heard about that.

 

[Alistair_Heaton]

Its for over mountains there is a pressure drop due Bernoulli as the air gets kicked over the top of it. It so we maintain a minimum safe separation from the ground when flying IFR rules.


So ATC take it into account when they set their minimum flight level for the day for a sector.

Its places like Innsbruck and Oslo etc in Europe it happens lower levels, although I am sure there is places in the USA that it happens as well. Air Traffic control deal with it for those flying controlled IFR like me but if you a private biz jet pilot flying off the controlled airspace system they "should" deal with it themselves. Airlines the ops department take it into account when they do the routings. If we are heading south into the med on low wind days we may go directly over the alps but when the wind gets up we will have to head round them to the east or west because if we have an engine failure our drift down to single engine cruise alt will take us into conflict with the ground. Its all set up so commercial traffic the decision is taken out of the cockpit because history has proved that if its done on the ground then it can be double checked in slow time, its safer. If its done in the air with time pressure then there is more likelihood of it being forgotten or mistakes made or commercial pressure will mean they do it anyway.

 

[1503-44]

Right. The Froude number. There's a lot of complex air here. Tenerife North is on a ridge at 2000ft elevation that runs 30miles or so before intersecting Mt Tiede, which gets up to just over 12,000ft. From its western side another 15mi 3000ft ridge extends to the NW corner. That cliff on the north side is nearly vertical. When the Froude number is <1,the air splits into 2 layers. The lower layer moves around the mountain, air above moves over the ridge, but above that layer it has to go around again.

 

[Alistair_Heaton]

Yep Tenerife requires a special briefing. We have started a rout down there with night stop.

Will let you know when it appears on my roster. Everyone is bidding for it so it's not likely soon.

Tenerife features heavily in commercial pilot training in Europe in several subject areas.

 

[1503-44]

Yes, the North Airport is the infamous record holder for most fatalities in a single incident and it can get foggy in seconds as well. I imaging strong winds are crosswise. I think most international flights use the south field. Ryanair caught a lot of labour related flack for eliminating their overnight base a couple of years ago.

 

[Alistair_Heaton]

There are 2 famous crm incidents there which every pilot knows about the KLM 747 and Dan Air.

We go to the south field but have to train for diversion to the north.

 

[1503-44]

KLM-PANAM

https://en.m.wikipedia.org/wiki/Tenerife_airport_disaster

I never read the details of the DAN incident. Good writeup of that here,
DAN

https://mayday365.wordpress.com/2015/04/25/remembering-dan-air-flight-1008/

 

[Alistair_Heaton]

We have a system called EGPWS mandated on all commercial aircraft these days. Which we train with every time we are in the sim. Its extremely good.

It started being developed after the Dan Air.

I have spent a lot of time flying under procedural rules and control. There are just so many ways it can bite you. Its still used a lot in various islands round Europe and in the med.

 

[dik]

Honeywell Enhanced Ground Proximity Warning System (EGPWS)

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

yep it really is extremely good. Much better than the old TWAS system.

I believe they are working on a new system which will give lateral guidance as well as vertical resolution.

There is a new approach method coming online which is called RNP AR approaches which using GPS will give you lateral and vertical guidance to a runway through high terrain it really is quite remarkable to watch the machine do it.

I am qualified and have done 20 or so of them in the last 2 months. We are fully certified for them now so the push to do them where ever possible has now gone. But to be honest I really like them in some ways they are easier than your normal ILS approaches. You just set the machine up and configure it and it does everything and no guidance wobbles from aircraft in front messing with the beams.

https://youtu.be/GYhJCTxHVGE

 

[1503-44]

I'm going to have to get used to that too. I'm not going to like turns after the flaps and gear go down. Thanks for the heads up. I'd be wondering what the hell is he doing.

Just for fun

https://m.youtube.com/watch?v=r_I3uZdH7nQ

https://m.youtube.com/watch?v=2sGunJcmA14

https://m.youtube.com/watch?v=pb7MFlYO01c

https://m.youtube.com/watch?v=c1aos1l_T3Q

https://m.youtube.com/watch?v=r_I3uZdH7nQ

https://m.youtube.com/watch?v=s4a2LzMCLhE

https://m.youtube.com/watch?v=K43JQkWd7L0

https://m.youtube.com/watch?v=Jb7M9PLH0Jw

https://m.youtube.com/watch?v=kI8fOZC7XN0

https://m.youtube.com/watch?v=xgE3Z_xjECA

https://m.youtube.com/watch?v=jS1UmmoxTxc

https://m.youtube.com/watch?v=Z6QIaTXXtHk

https://m.youtube.com/watch?v=M6LvaGNJ0f4

https://m.youtube.com/watch?v=TiqNpaKrZiY

https://m.youtube.com/watch?v=X-CZwfDYboc

https://m.youtube.com/watch?v=1sAAPLNK68M

https://m.youtube.com/watch?v=KLVa9r0MJNk

https://m.youtube.com/watch?v=OE2eFWcwbzg

https://m.youtube.com/watch?v=3swJpRh4geg

https://m.youtube.com/watch?v=rP-VJU0wqI4

https://m.youtube.com/watch?v=PT7FoLr8Cgc

https://m.youtube.com/watch?v=jnPT5SIDb68

https://m.youtube.com/watch?v=7Ax5PsgfHNs

 

[Sparweb]

...and no guidance wobbles from aircraft in front messing with the beams.

I didn't know that AH. Thanks for mentioning it. I'm often looking at the new things that RNP offers, not so often considering the quirks of ILS or other approaches. Not an IFR pilot myself, so I can only relate to the specs I'm reading on paper, not the real experience of doing it.

Your A220's are "best equipped + best serviced", aren't they?

 

[Alistair_Heaton]

Well they are the latest gen FBW, But as this is an avionics software function which only really drives the commands given to the autopilot basically everything which can do basic RNP approaches can be software upgraded to do it. So 737 NG/MAX and proper airbuses can do it. Our q400's were used to do the testing of it 3 years ago. It doesn't use SBAS so only LNAV/VNAV is required which gives 350 ft minimums instead of the LVP 250ft mins.

It does take a bit of faith to chuck everything out and just monitor. The go arounds can get quite technical because they can be quite tight on airspeed and lateral limitations. But I found if you cheat and just stay in approach configuration press the toga button and once you start climbing get the gear up and don't try and be fancy and it does its job. When they kill an engine half way through the approach its pretty much a none event because the drop in performance makes life easier. I believe they are changing the procedures at OEM level for these approaches so the go around you only press the TOGA and get the gear up. We did most of the sim session at Salzburg last approach after doing 4 approaches they cleared the clouds and it was remarkable watching it snake itself between the mountains.

And no they are not best equipped. There are various options which the boss didn't pay for. Like qwerty keyboards and built in electronic flight bag. But by all accounts from company's that have them he made the right choice. But the basic model has all this good stuff.

Best serviced, well its the best maint setup I have worked with in my career. There are still software bugs that they are working through, still enough nuisance resets to fill a 50 page manual but every software upgrade they are getting chased out. There is a major hardware mod coming through for the engines next year to deal with that vibration issue leading to compressor failure. But that's not a line maint function. The day today stuff is pretty good most faults are dealt with by a black aircraft reset which takes 15 mins. The other good thing is the machine records everything so there is very little scope for pilots not putting stuff in the techlog. VNAV and decent profile still need a bit of tweaking and also the TO to climb thrust swap over for noise abatement profiles but that's not a big issue.

Air France have just completed technical build up for theirs getting delivered, and they are already pushing for a cs500. Once they have them I expect Airbus will ramp up the clearing of software bugs.

Its not only aircraft in front that can cause wobbles, some airports when a fire truck goes round the parameter track everything on the ILS will give it a bit of a left then a bit of a right. The Q400 was murder for it if we had a heavy in front of us in Copenhagen it Snaked all the way down until it had landed and cleared the runway. I used to just fly them manually and ignore the beam bar kicking left and right.

As for that dancing stuff I managed to dodge that thankfully thanks to covid. I was in isolation when our lot did it

 

[1503-44]

Likely excuse. I know you're in there somewhere.

 

[Sparweb]

That's amazing - I've been on flights where the jet jiggled a bit left and right on approach, and I just chalked it up to wind shear. Now I know: it could be the Esso fuel truck rounding the threshold! LOL

When they kill an engine half way through the approach its pretty much a none event because the drop in performance makes life easier.
That sounded funny on first reading, but then I also thought in terms of basic airmanship, this should never be a reason to worry. It was something my instructor was always harping on during my approaches - be stabilized, maintain a steady GS. It was always important to set up the plane to need the least amount of power to get to the runway.

 

[1503-44]

My instructor taught me to land with throttle at idle for both crosswind and final legs. Upwind, turn 90, carb heat on, cut throttle.

 

[Alistair_Heaton]

if you have a look at airports which have a CAT ii/III ils approach the actual ils hardware is exactly the same as CAT I.

But have a look at the taxi chart you will see there are CAT II and CAT III hold points which may be much further away from the runway than the CAT I.

When low vis procedures kick in and CAT II/III approaches are being conducted a protection area is activated round the runway and they start using those holding points instead. Separation on finals is increased vastly. And on the ground ops side there may be traffic lights turned on in various places to limit where vehicles can go.

There is other requirements to do with backup generators and lighting and to be honest pilots don;t really need to know about them. We just get cleared for a CAT II/III approach and by ATC saying that it means all the protections are in place and alive.

If your flights were on a Q400 the jiggle is for different reasons but I think I have deviated away from drone issues enough and if you want I can tell you about it in the pub.

Light aircraft that's the way I taught my students as well. We call it a glide approach. To be honest if your flying the Jet right you go flight idle in cruise at top of decent and if you do everything right the power only comes up again at 1200 ft above touch down point when your at Vref + 5 gear and flaps out. I used to be pretty rubbish at it. But something must have clicked subconsciously because if I get a clear decent these days I pretty much do it every approach only taken me 500 hours on the machine for it to click though

 

[Alistair_Heaton]

The problem is when your approaching the airport your normally quiet light in the grand scale of things. But there is no change to the amount of power available. But your weight power ration is huge..

So if you hit toga and get rid of most of the drag the thing climbs like a homesick angel and accelerates fast. So me cheating leaving the drag out means its performance is reduced. Loosing an engine gets rid of 60% of your performance.

As I am sure you know the radius of turn is linked to your speed so the faster you go the wider the arc.

With these approaches you don't have much room to play with so if you go to fast you will go past the normal turn point and come into conflict with the terrain. When you do a missed approach on these things its extremely important to follow the approach laterally until you get to the miss approach point which is on final pointing at the runway. You have a max pitch up limit as well. So if you press toga and the autothrottle gives you max continuous thrust which is about 20k x 2 on the A220. You then get rid of your drag by reducing flap and taking the gear up you very quickly have the machine hitting its max pitch limit to try and control the speed. Then your into an overspeed situation and going faster than the procedure allows and you miss your turning point. So quickly have to kick the At out because its not reacting fast enough and manually reduce thrust and then your stall speed starts being an issue because your in a turn and you have just got rid of lift flap. I just found it much easier to keep going in approach configuration until it got round the corner with full power on speed under control and climbing. Yes you are not climbing at max rate but everything is under control because your still on the approved lateral profile so your terrain safe. Flaps is out so no issues with stall margin Once your pointing at the runway and its safe in front get the drag in and you have no constraints for speed which may be as low as 160 knts before the turn.

Engine failure your going to be climbing at V2 +10 which for us is max 155 knts with flap 2 (limit 210knts) so you don't have to do anything special. Just press the toga button select gear up and flap 2 and watch it fly it and accelerate when you get to MSA and clean up the rest of the flap.

There is talk of a change to the autotrottle TOGA logic so the amount of power it gives is not the max every time but weight related but I suspect this will be years away.

This isn't just an issue with jets the Q400 was an utter bitch on max power and go around and it was very common for people to over speed the flaps and bust go around altitude. I used to cheat on that as well and just stick in 60% torque and that used to give me a 1000ft/min climb rate and stable speed of about 160knts which made everything lovely and slow. If we were max landing weight I would get 600ft/min climb so I would then feed a bit more power and get the autopilot back in for the level off which it could do easily at 1000ft/min and didn't manage doing 4500ft/min with max power take off flap and the gear up.

 

[dik]

I love the expression...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Sparweb]

AH,
Thank you again for all the insight. You're right though - these are Pub stories!

It has revealed to me a potentially life-saving new General Aviation airmanship practice. If drones are suspected in the area, reducing throttle to idle on final approach is not recommended. The reason being that the rotating propeller can deflect parts of the drone rather than allow it to strike your windshield. The prop will be damaged but not disabled by the impact, while the impact of the drone on the windshield could be life-threatening to the pilot, and at the very least the cracking, penetration, and wind stream would be very hazardous and disorienting during the landing.

The average size of consumer drone is about 12 inches, while a 2-bladed propeller turning at 1600 RPM while the aircraft is flying at 100 knots will have an propeller blade advance rate of 6 inches. Meaning every 6 inches the aircraft flies forward, one of the prop blades passes by. It is possible to destroy the drone, before it can strike the windshield as a solid mass, and small particles of debris will impinge on the windshield instead. The average person should know that light aircraft do not have windshields like cars, which are impact-resistant laminated tempered glass. That is too heavy for light aircraft. Small planes usually use single sheets of polycarbonate as a windshield, which are much easier to penetrate than an auto windshield.