Ask The Pilot

[ChrisGibbs]

When cleared to pushback does Ground, as part of the push back clearance, tell the crew which way the aircraft needs to be facing on completion of the push or does the Pilot communicating with the tug tell the tug driver which way they need to be pointing (South, East, West, North)?

 

[tgh]

Chaotic glider prelaunch

Controls Harness Airbrakes Outside Trim Instruments Canopy

 

[jb747]

Nmemonics. Used by many pilots, and taught right from basic training. It works for many people but not for others. Personally I never used them, preferring to use entire words. Airbus teach ‘flows’, in which they lay out the flow of switches over the panels...that works quite well. For me to learn a sequence, I used to learn the words, and once I had them I’d apply them to large coughpit images to teach myself the flow.

It’s probably a good example of the different ways that people learn the same things.

 

[jb747]

Gear and flap to assist with pitch control. Sorry I don’t understand the aerodynamic relationship here. Can you please elaborate

I’m sure AV will give you more as it relates to his sim exercise. There’s a difference in philosophy between QF and Virgin in that QF does the sims as stand alone exercises. They will normally schedule them in pairs simply for convenience, but they could be up to 2-3 months apart when the schedules don’t work. Other annual training items, such as security and EPs generally happen in their month of expiry. Other airlines might have recurrent training weeks, when the bunch them together.

In an aircraft, pretty well every change in configuration (or even movement of a control) will have multiple effects. These effects are also often speed dependent, so normally their magnitude changes as an aircraft accelerates or decelerates. In the case of landing gear; when you lower the landing gear, you add a lot of drag which is very low on the aircraft. That tends to pitch the aircraft down, so you’ll need nose up trim. Unless you counter it, that drag will also slow the aircraft, so you’ll need a greater angle of attack to make the same lift (i.e. to fly level); so that means more aft stick, which will lead to more nose up trim. If you decide that you don’t want to let the gear’s drag slow you down, you’ll need to add extra power. Most engines have a low thrust line, so any power increase pitches the aircraft up. The overall result of gear + sufficient power to hold the speed will differ amongst aircraft types.

At a constant speed...extending some flap will pitch the aircraft up, and you need nose down control input and trim to control it. As flap is normally extended with the aircraft decelerating, you will have an initial pitch up, followed by pitch down as it slows.

Speed brakes along the top of the wings give a pitch up effect. If you add power against speed brake (obviously not a normal technique) that added power will also add to the pitch up.

 

[AviatorInsight]

Memory items: what do you do to memorise the memory items? Any memorable mnemonics?

In medical world We have “DRABC”
Causes of Acute Pancreatitis: “I GET SMASHED”

I used to when flying pistons, things like BUMFISH (brakes, undercarriage, mixture, fuel pumps/ fullest tank, instruments, switches (lights), hatches and harnesses secure), or PUF on mid final (pitch, undercarriage, flaps).

The jet memory items are a bit different. It's more of a scan flow along with words. For instance, during the 737 endorsement I could never remember the after landing sequence, so I started with probes engines strobes and then worked my way down from there.

Gear and flap to assist with pitch control. Sorry I don’t understand the aerodynamic relationship here. Can you please elaborate

Throwing flap out will change the centre of pressure further aft of the centre of gravity and pitch the nose down. When dropping the landing gear, the nose wheel moves aft and the CG moves closer to the CP, the moment arm causes a slight pitch up. The thing to remember here is that there was considerable elevator control going on and the stabiliser was trimmed to its extremes, it wasn't a big change in pitch but it was noticeable in that it helped in stability and relieved some pressure.

 

[AviatorInsight]

When cleared to pushback does Ground, as part of the push back clearance, tell the crew which way the aircraft needs to be facing on completion of the push or does the Pilot communicating with the tug tell the tug driver which way they need to be pointing (South, East, West, North)?

This is a very much, it depends answer unless ATC give us instructions otherwise. SYD will always go tail north for DOM 2/3. There are standard disconnect points on the apron that corresponds to each bay. So when we get cleared to push the tug driver knows where to disconnect. On occasion we've been told to disconnect at a different point, usually to allow another aircraft onto a gate in front of us.

CNS and OOL are classic examples of where ATC can instruct us to pushback facing in a different direction to the departure runway due to inbound traffic. In this case we will notify the tug driver to put tail north/south.

 

[flyer89]

I used to when flying pistons, things like BUMFISCH (brakes, undercarriage, mixture, fuel pumps/ fullest tank, instruments, switches (lights), hatches and harnesses secure), or PUF on mid final (pitch, undercarriage, flaps).

Don’t forget your CLEAROF checks.

 

[jb747]

It's worth noting that AVs answer re trim changes, is almost the exact opposite of mine. That just goes to show that all aircraft are different, and you need to fly the aircraft you're in... FBW masks these changes too...so they disappear most (but not all) of the time.

 

[jb747]

When cleared to pushback does Ground, as part of the push back clearance, tell the crew which way the aircraft needs to be facing on completion of the push or does the Pilot communicating with the tug tell the tug driver which way they need to be pointing (South, East, West, North)?

ATC will add any particular instructions to the clearance as they see fit. It may include a direction for the tail, a facing direction, instructions to pull or push clear of a bay, or you could be told to pull/push to a particular point. The direction of the push can be counter intuitive, so you need to be careful to pass it on exactly.

 

[I love to travel]

While this is fresh in my head....

Two days of sim as part of my routine cyclic check.
Day 1. Check day.
This was relatively straight forward. We’ve now gone to a first look approach to sim checking where it gives the airline a good snapshot of where the crew lie in terms of performance and management. The Capt got off easy on this one. Depart SYD for MEL, above transition there was a master caution where an entry door was deemed to be unsafe. We conducted the checklist and made an immediate return to SYD. The weather condition got worse and worse as we approached so we set up for an auto land. No dramas, that’s the Captain’s part done.

Next was mine. Departure from runway 35 at CBR. At V1 I got an engine failure with severe damage. Flew the engine out procedure and returned to land via the ILS runway 35 once all checklists were complete. This was left for me to manage and coordinate as part of my command assessment for the future. Fairly straight forward.

Once on the ground was a reposition for a one engine inop missed approach to clean up. Finally a ground proximity into terrain with the escape manoeuvre was done. One each. End.

Day 2. Training.
Ok so there was A LOT in this one compared to yesterday. First up flight was from MEL-CHC set up as EDTO (the new ETOPS ;-)). Was also 1°c outside so lots of procedures for cold weather operations done (de-ice). On the push back we got the first engine started but the second engine failed to start up. On checking the circuit breakers I found one that was popped just behind the captain’s shoulder. Got approval to reset it and then was a good start. All ops normal until about FL180 when a weather warning from ATC saying that volcanic ash had been reported by previous aircraft. As soon as we noticed the engines started playing up, the captain initiated a descending 180° turn to exit. The engines flamed out and I was running the loss of thrust on both engines memory items. We managed to get both of them back at about FL120. We returned to MEL, conducted an ILS and on short final got a single engine failure. Touched down. Exercise over.

Next, I had to fly an approach to the circuit break off and circle to land on an adjacent runway.

Finally, and I’m sure this is what everyone has been waiting for, the runaway stabiliser. So being a hot topic at the moment, we spent a bit of time on it. Firstly, the check captain just told us to depart. At about 500ft the trim started running away from me and it wasn’t commanded. We recognised it and I just adopted the airspeed unreliable power settings to try and bring the nose down (I had uncommanded nose up trim). Luckily on the NG, I held the electric trim in the opposite direction to stop the runaway until we cut out the switches. So far so good.

Next departure the checkie told us to depart and we noticed the aircraft rotating early. We got airborne got the gear up and about 1000’ the trim immediately went to 0. Well that was intense. Full back stick was required by the captain. His feet were up on the foot rests to help him hold it, so I got to the memory items fairly quick and cut out the switches. Now the fun part. I tried trimming the aircraft nose up with manual trim but it was extremely difficult. We were on climb and only doing about 200kts. So we coordinated between us for the captain to let go of the control column and I would then frantically trim back as fast as I could before he had to take control back. We oscillated like this for a good 5 mins. A lot of trim wheel turns were required to get it back to the normal range. We managed to get it to about 3000ft by this stage. Needless to say, I was exhausted and out of breath but kept turning as if my life depended on it. I couldn’t imagine what it would have been like for the crew on the ill fated flights. Once we had it under control the checkie rolled the trim in again and asked to use gear and flap to help with the pitching on the nose up/down. It definitely did make a difference and something I’ll be taking away from it. I learnt a lot from this exercise and will be interesting to read the final reports.

Do you feel safer or better now about the Max after the sim?

 

[AviatorInsight]

Do you feel safer or better now about the Max after the sim?

A tactic I used in the NG to minimise the runaway before we could cutout the stab trim switches was to trim in the opposite direction. When I did it again and this time not using that tactic, the capt certainly had to get onto it quickly. By this stage the trim was right on 0.

Until I get into the Max sim and see for myself what MCAS actually does (given there’s not many Max sims out there) it’ll be good training.

To put it bluntly, I’m glad I’m not flying it and Virgin have delayed orders.

Edit: NG and Max have same characteristics of electric trim during a runaway. Brain is still fried from last sim and now I’m heading from MEL to BNE for my low vis approval, so I need to be in another mindset. Thanks JB.

 

[jb747]

In the 767 and 747, moving the yoke in the opposite direction to any trim runaway would stop it. Thankfully manual trim wheels were already history.

As I understand the MAX/MCAS you can trim against it, and that actually stops it for a while...but MCAS will restart, and it has a trimming rate that is much greater than any pilot trim input.

 

[AviatorInsight]

In the 767 and 747, moving the yoke in the opposite direction to any trim runaway would stop it. Thankfully manual trim wheels were already history.

As I understand the MAX/MCAS you can trim against it, and that actually stops it for a while...but MCAS will restart, and it has a trimming rate that is much greater than any pilot trim input.

Ah yes you’re right. Well it’ll be interesting to see when I get into Max sim if my tactic of just holding the switches in the opposite direction will hold it long enough to get the switches cut out before it gets too bad.

 

[flyer89]

As I understand the MAX/MCAS you can trim against it, and that actually stops it for a while...but MCAS will restart, and it has a trimming rate that is much greater than any pilot trim input.

Am I right in thinking there’s a temporary cutout (that is limited by time?) and a permanent cutoff available for MCAS?

 

[ChrisGibbs]

Saturday 13 July YSSY was down to using RWY25 for take offs and landings from the morning through until around 2:00PM. I came in from WSSS on the delayed QF2 service just prior to 0600 landing on RWY34L and was then on QF439 YSSY - YMEL using RWY25 operated by a 738. Do the 738's, A330's and larger still derate the take off on RWY25? The reason I ask is the acceleration and climb rate seemed greater than normal. Is the lack of a derated takeoff more about the terrain clearance on the extended centreline of RWY25 as opposed to RWY25 being 2500m (approx) in length which is similar to RWY 16L/34R?

 

[Himeno]

A few days ago, EJ and KL jets at AMS both got push back clearance, and backed into each other.

Anyway for the flight crew of one aircraft to know if the aircraft behind them has gotten push clearance, or was the above a case of the ATC, 2 sets of ground crew and both flight crew not paying attention?

 

[jb747]

Am I right in thinking there’s a temporary cutout (that is limited by time?) and a permanent cutoff available for MCAS?

If you trim against the MCAS, it cuts out for a few seconds. If the conditions that triggered it are still applicable, it will then restart. It can keep this cycle up, using up to 10 seconds of trim (a LONG time) and at a very high rate of trim input, until all of the trim is applied.

The permanent fix is to turn off power to the stabiliser entirely (STAB TRIM CUTOUT). This stops the MCAS, but also stop pilot inputs of electric trim. That leaves the trim wheel, which is very slow, and which may not actually have enough mechanical authority to move the stab at all at high speeds. With no way to move the stab electrically, and limited ability by the trim wheel, the aircraft is essentially unflyable. That possibly explains why the Ethiopian crew turned the stab power back on.

 

[jb747]

Saturday 13 July YSSY was down to using RWY25 for take offs and landings from the morning through until around 2:00PM. I came in from WSSS on the delayed QF2 service just prior to 0600 landing on RWY34L and was then on QF439 YSSY - YMEL using RWY25 operated by a 738. Do the 738's, A330's and larger still derate the take off on RWY25? The reason I ask is the acceleration and climb rate seemed greater than normal. Is the lack of a derated takeoff more about the terrain clearance on the extended centreline of RWY25 as opposed to RWY25 being 2500m (approx) in length which is similar to RWY 16L/34R?

Looking at the weather conditions at the time, I expect that there was a fair expectation of windshear. If that is the case, then you won’t derate at all, but will use TO/GA. In more benign conditions, there’s no problem with derating on the shorter runways. The performance application will come up with an appropriate level for the conditions.

 

[jb747]

A few days ago, EJ and KL jets at AMS both got push back clearance, and backed into each other.

Anyway for the flight crew of one aircraft to know if the aircraft behind them has gotten push clearance, or was the above a case of the ATC, 2 sets of ground crew and both flight crew not paying attention?

As best I can see on the video, neither aircraft has an engineer walking them out, so they’re reliant on the tug driver to look out. But, his field of view is actually blocked by the aircraft, so he really can’t see much at all. Both sets of aircrew seem to have done the right thing. ATC should never have issued the clearance for KLM...and once they became concerned, instead of a discussion should have issued an instruction to stop every push on the frequency. ALL AIRCRAFT PUSHING STOP IMMEDIATELY. STOP. Or something to that effect. I’ve heard ATC in LAX issue a similar instruction, though I never found out why.

Beyond that though...stuff happens.

 

[jb747]

.... and now I’m heading from MEL to BNE for my low vis approval, so I need to be in another mindset.

Have fun with that. Whilst I expect that the flying in low vis is always done by the captain, good support makes a huge difference. It’s simple enough when it’s working, but of course, you only ever see that once or twice in the sim.