Ask The Pilot

[Saab34]

What is your pet hate around something the previous crew did/left to the aircraft that gives you the coughs when you operate the next flight?

 

[jb747]

What is your pet hate around something the previous crew did/left to the aircraft that gives you the coughs when you operate the next flight?

Not so much what they did to the aircraft, but the ones who took their time vacating the coughpit, having a half hour debrief, in MY preflight time. You're done. Get out.

 

[AviatorInsight]

What is your pet hate around something the previous crew did/left to the aircraft that gives you the coughs when you operate the next flight?

People who treated it like their own garbage disposal. I’ve found wrappers, crumbs, left over food, coffee cups, the list goes on.

I’d hate to see the state of some of these people’s homes.

And exactly what JB said, particularly when there’s a short 30min turn. Get out.

 

[Saab34]

Interesting. Who is responsible for cleaning the coughpit? Once a night gets a vacuum and wipe down all the screens? Or does the engineers only touch screens, buttons, etc?

 

[jb747]

Mostly our coughpits were pretty clean of debris. The bins were removed during every turnaround and they were 'vacuumed' with the cabin. But the cleaners never touched any panel, and the engineers only did so to leave new grease stains. As a spot for developing new organisms, coughpits would be hard to beat.

 

[AviatorInsight]

Interesting. Who is responsible for cleaning the coughpit? Once a night gets a vacuum and wipe down all the screens? Or does the engineers only touch screens, buttons, etc?

Our engineers are the ones who keep the flight deck clean once they put it to bed for the night.

I’ve never understood the need to touch the screens and leave big fingerprints all over them. But they should be cleaned as well when the daily check is done.

 

[OZDUCK]

Until I see something official, it actually smacks of that old saying..."what's it doing now". Which was uttered by a lot of people in the early days of electric jets, who generally didn't actually understand what they'd selected or programmed.

Re that Air France incident on a B777 it seems that you were pretty right about the cause of this incident. It appears that the aircraft was doing what it was told to do and surprised the pilots by doing so However it was not helped that the two pilots were making simultaneous but different control column inputs. Apparently Air France is still having problems with coordination of crew actions. Poor CRM I guess or am I just misunderstanding the meaning of that phrase?

At 07:51:16,, the captain commented that the plane was going left. The control columns were then desynchronized for 14 seconds due to opposing forces. The captain held the control column in a slightly nose-down position while the co-pilot made several, more pronounced, nose-up inputs. Two brief episodes of wheel desynchronization were also observed.

and

At 07:51:25, ---- The two pilots continued to simultaneously make inputs on the controls

The Aviation Herald

Aviation Herald - News, Incidents and Accidents in Aviation

avherald.com

 

[jb747]

If the captain wanted to fly it, then the words are "taking over", or some variation. Looks very much like an own goal.

Looking at the weather, with cloud down to 300 feet, I wouldn't have been disconnecting to fly the approach manually in the first place.

 

[Saab34]

Does the Airbus not have a PRIORITY LEFT function? Does that not cancel out all inputs from the FO?

 

[OZDUCK]

Does the Airbus not have a PRIORITY LEFT function? Does that not cancel out all inputs from the FO?

This plane was a Boeing 777.

 

[mjt57]

Does the Airbus not have a PRIORITY LEFT function? Does that not cancel out all inputs from the FO?

I'd have thought, Airbus or Boeing, that when the Captain says "my aircraft" that the FO keeps his mitts to him/herself.

 

[jb747]

I'd have thought, Airbus or Boeing, that when the Captain says "my aircraft" that the FO keeps his mitts to him/herself.

It’s rather like the song “My boomerang won’t come back”…. First you have to say it.

 

[jb747]

Does the Airbus not have a PRIORITY LEFT function? Does that not cancel out all inputs from the FO?

Moving on from the fact that the aircraft in question was a Boeing, and it takes quite substantial pressure to split the controls....

Airbus has a 'dual input' warning if the joystick is moved simultaneously on both sides. Either side can press an override button to establish priority.

 

[AviatorInsight]

In light of the recent announcements made by Virgin to acquire 4 Max-8s and Max-10s, I had been scheduled to complete the MAX differences training.

Side note: This month is full of checking and training (annual line check, max differences training, and my cyclic - 3 days instead of 2, focusing on a 1-day check and 2 days of training).

Before I go into the training on the MAX I will preface this by saying that I in no way forgive Boeing or defend them for not putting in these additions to prevent the terrible accidents from occurring. The proper training and information in my opinion was absolutely needed to be given to pilots, as I have found out. Yes, it is a 737, but it feels like a completely different aircraft in terms of the screens and functionality, so the training is definitely needed!

First up, the most noticeable thing was the engine power! Definitely a lot more thrust and it's absolutely needed for the increase in take-off weight by about 20 tonnes. No breakaway thrust was required to get the aircraft moving from a stopped position. The pitch couple is also much more noticeable, ie, you add thrust, and the nose comes up and vice versa.

Next, everyone's favourite topic...the flight controls. I won't go into too much detail as the additions don't affect normal flight however it really is a nice bit of kit. The one I found really impressive was the emergency descent speedbrakes. The spoilers are now fly by wire. Electrically controlled and hydraulically actuated.

This means that on an emergency descent (depressurisation only) when the flight crew raise the speedbrakes, the control unit raises them further automatically. This increased our descent rate from 3800fpm to a staggering 9300fpm!

Other items include elevator jam landing assist, landing attitude modifiers (more so for the -10), manoeuvre load alleviation, and ground spoiler control modules.

MCAS
I've put this under its own heading because I'm sure it'll bring more questions. The MCAS and speed trim system have been dramatically overhauled (for the better!). There are now a lot more redundancies and limits put into place to reduce the amount of trim activation during a non-normal event.

To put this into practice, we put the aircraft (sim) into a deep stall. Some pilots may remember the old stick pusher system. While it's technically not a stick pusher, at the point where the MCAS activates to bring the nose down, the hydraulic system doubles the pressure to the control column momentarily. I tried hanging on to this for demonstration purposes, and it was really overpowering. In that instant, the aircraft recovers really quickly.

Now after MCAS activates nose-down trim, (it is now not running as quickly or for as long as it used to) the trim is taken off again once the aircraft is unstalled.

Trim Runaway
This was next in the sequence and is now really a non-event. For anyone asking if the control column cut out is there. Boeing has added a retrofit software design that acts as a cut-out (for forward control column inputs only) and a redundancy system on top of that.

I actually tried to let it run a bit however, it was quite easily managed now with the other pilot. The technique I used was to trim nose up (in this case) and when I had the aircraft as close to trim as possible I got him to cut out the main and back up stab trim cut out switches. This allowed me to then manually use the trim wheel for smaller inputs even as I was the pilot flying.

Conditions for MCAS operation now include:
- Autopilot disengaged. So if the autopilot is engaged, MCAS cuts out. This could create another problem by pilots throwing the aircraft at the autopilot and getting it to fix the problem. Which to activate on the 737 isn't so simple as pushing the button.
- Flaps UP
- Angle of attack above a certain threshold.
- Up to 0.84 Mach
- Only activated 10 seconds after take-off.
- New flight control computer software that has an angle of attack comparison.
- A maximum command limit meaning it no longer trims full nose down as we saw in both accidents. This allows full elevator authority.
- Only one MCAS activation (nose down trim) per event. So if the aircraft exceeds a high angle of attack MCAS will only activate once, not continuously. If there's another high angle event and the threshold is exceeded, it will activate again. For those inclined by numbers, the maximum amounts are 2.5units of nose-down trim at low Mach and 0.65units at high Mach.
- When activated, the system records a snapshot of the stab trim position, and the nose down limit is established from here. So it won't give a full go of the trim if it is already near the maximum limit.
- Once the angle of attack is reduced below the threshold, the stab trim inputs are reversed.

Finally, there is a flight control computer trim monitor function. This is currently used on the NG model during a dual autopilot landing only, but on the MAX, it is now monitoring during all stages of flight, providing additional protection against a runaway stabiliser caused by erroneous computer commands.

There were also a few system changes with the engines, starting, and fuel system warning lights, the most noticeable would be the APU. It has a similar design to the 787 with a new inlet door.

Again I must reiterate that I in no way excuse the manufacturer for the massive oversight of the MAX program. Having said that, the right information is now out there (and plenty of it!) for the crew. The simulator training should have been done from the inception of the aircraft into service and is such a valuable tool. I could have read about the changes until I was blue in the face. However, it's not until I see something physically that I can then understand how the whole thing works as opposed to a system in isolation.

Given this training, I am looking forward to flying to MAX8 and the -10 (if it gets certified by DEC 2022) and would gladly put my family on it. I understand not everyone will feel the same, and that's ok, that's the brilliant thing about choice.

Here's to looking up!

 

[Saab34]

Very good detail and thanks for taking the time to post that.

AV does it feel like a whole new type? or just a NG with bigger screens. I assume it handles much the same in flight?

 

[RooFlyer]

Thanks for all of that, AV, much appreciated.

 

[AviatorInsight]

Very good detail and thanks for taking the time to post that.

AV does it feel like a whole new type? or just a NG with bigger screens. I assume it handles much the same in flight?

It does feel a little bit like a new type. The screens have so much more detail on them and will take time to get used to. The way in which we operate the aircraft in terms of procedures, such as who gets the engine instruments (this can be transferred between screens), is still yet to be determined.

Flying wise, it feels much better than the NG sim that's for sure! It could be that it is still very new. I'll have to wait for the actual aircraft but I doubt it would fly very differently. Even the -10 with the trailing link main landing gear is designed to feel the same, just gives us more clearance during the landing.

 

[Welsh-Kiwi]

Thanks for the insights AV - very informative.

 

[jb747]

Nice to hear that the stick cutout is back. Auto start?

 

[AviatorInsight]

Nice to hear that the stick cutout is back. Auto start?

Haha not that quite advanced. But there’s an extended motoring to prevent bowing of the N2 rotor. This is done automatically and fuel won’t be introduced until EGT is below 135° even with the fuel control switch to idle.