Auto Pilot

[Gary_Moore]

Hello I was just wondering how much time an airline pilot spends in control of the aircraft. IS it a case of 30 secs after take-off the you switch to autopilot and then take it off a few secs/mins before touchdown.
Obviously I realise the weather will affect this but in general how much time do you guys spend ''flying'' the aircraft.
Are there certain rules SOP's saying you must not disengage the a/p on the approach untill a certain point or can you take control from say going through FL100

Thanks

Gary

[notdavegorman]

To some extent it depends on personal preference.

Some guys bang in the a/p as soon as possible (in my aircraft, the 737, the minimum height is 1000', i.e. ~20 seconds after takeoff), and don't take it out again until about 500' before touchdown.

Other pilots like to hand fly from takeoff until reaching cruising altitude, then take the a/p out at top of descent.

Myself, I will use the a/p as much as possible in poor weather or in a busy traffic situation, this gives me more mental capacity to steer around thunderstorms or keep an eye on what the other aircraft are doing. Conversely, assuming the circumstances are right, i.e. weather is good, airspace isn't too busy, my colleague's workload isn't too high with radio calls etc, and I'm in the mood, I will often hand fly from takeoff until passing 10000' and will disengage the a/p again when descending through 10000'. I think my philosophy is basically in line with what my airline's SOPs, which are to use the automatics when it's advantageous to do so, but to keep in good hand flying practice.

BTW, your comment about "taking control" by disengaging the a/p isn't quite right. Whilst it's true the aircraft can fly itself along a pre-programmed route (in a Boeing using LNAV and VNAV), in real life the Pilot Flying (PF) will make many interventions to speed, altitude and directions as circumstances dictate, for example Air Traffic Control instructions, keeping the a/p engaged. The PF is in control at all times, and sometimes when quick interventions are needed, example on a short final on the approach if you're too high/fast, actually using the a/p actually requires more 'skill' than simply taking the a/p out and making corrections by hand.

Hope this gives a flavour of real life line flying.

[Junkflyer]

I fly the 747 classics, we aren't allowed to use autopilot after t/o until flaps are up (above 3,000') and must be off by 50 ft. under d/h or mda. No autoland for us. Most hand fly up to 10, 18 or cruise altitude and disconnect it at different times depending on outside factors, fatigue etc.

[zerozero]

Hi Junkflyer.

I also fly the Classic and I'm wondering about the flaps up limitation on the autopilot.

At my company we're restricted to 1200' unless coupled for an autoland.

I suppose I can understand your autoland limitation but I don't follow the flaps up limitation.

Is that just company policy or is there a more technical reason?

Thanks.

[b747heavy]

I too fly the classic 747 and we have a policy that the Auto Pilot must not be engaged until the aircraft is above MSA and clean. As for descent, it is up to the PF as to when hand flying comes back in, however we promote as much hand flying as possible.

Heavy...

[Capt Claret]

Autopilot Limitations from the B717 FCOM.
During takeoff, do not engage the autopilot below 200' AGL.

For non-precision approaches, the autopilot must be disengaged no lower than the applicable minimums minus 50 feet.


Company SOP;
On takeoff don't engage until 400' AGL
During approach disengage by minima minus 50'

[Old Smokey]

Autopilot Limitations from the B777 FCOM and Company SOP.

The Auto-Pilot must be disengaged at all times when below 200 feet AGL, except during Auto-Land operations.

Company SOPs leave it pretty much to the pilot's discretion when hand flying may be carried out, most pilots engage it somewhere between 5000 and 10000 feet, earlier during complex SIDs.

Company SOPs do dictate that the Auto-Pilot MUST be engaged by the IAF during Auto-Land operations, and during particularly noise-sensitive SIDs, such as at Manchester.


Capt Claret, your remark "During approach disengage by minima minus 50' " prompts me to ask out of curiosity, doesn't the B717 have an Auto-Pilot Go-Around mode? If it does, it surprises me because you'd now be committed to a hand flown missed approach if no visual contact.

Regards,

Old Smokey

[Capt Claret]

Smokey, yes it does but the Australian infrastructure doesn't support Autoland.

The 50 feet below DA/MDA allows the autopilot to stay engaged and thus execute a coupled missed approach if no visual contact at the minima.

If visual contact is lost below the DA/MDA then one hits the TOGA button/s and quietly :8 calls one's partner to engage autoflight. :}

[Junkflyer]

Hello Zerozero,
That comes from the limitations section of our manual so its company policy, not sure where it comes from as far as is it a hard Boeing limit or if its for another reason.It doesn't actually say 3,000 ft that's just our typical departure profile pitch to 500 fpm climb at 3,000agl to accelarate for clean-up.
Looking at the manual here are the specifics:
Minimum altitudes for a/p use: (except as noted)- 1200 ft agl
Non-ils: 50 ft below mda/dh
Ils: tch (threshold crossing height) less than 47'- 150' agl; tch above 47'-100' agl
Do not engage a/p prior to flap retraction.
Do not use Altitude Select if vert spd is greater than 5,000 fpm.

[Old Smokey]

Capt Claret, I should have read your post more carefully. I interpreted the "minimina minus 50'" statement as before the minima, in much the same way as I'd interpret FAF minus 2 miles as 2 miles before the FAF.

Thanks for the clarification, we have very much the same limitation.

Regards,

Old Smokey

[Gary_Moore]

Thanks for your replies guys, I was terrified that I was going to do all this training and spend all this money to become an airline pilot to role down a runway pull back on the control collum then press a button and sit for 4+ hours sitting doing nothing but looking out the window untill I unflip the switch 50ft above the ground.

Cheers guys

Gary

[zerozero]

Gary, don't worry it's even more boring than that!

Junkflyer, thanks for that.

Safe flying.

[AerocatS2A]

Gary_Moore, don't worry about it, once you get to fly the bigger stuff, the challenge and joy comes more from managing the flight rather than manipulating the controls. I love flying, have done a lot aerobatics etc, but there's no point hand flying at FL350 in the cruise when you could be drinking a cuppa and playing around with the FMS trying to remember how to use it properly.

From the Dash 8 FCOM:

A/P not to be engage prior to 1000' after take-off or go-around, and it is to be dissengaged no lower than 200' AGL on approach.

Capt Claret do you fly the B717? If so, are you enjoying it? I had my first flight as a pax in one a couple of days ago from Ayres Rock to Perth, I was quite impressed, particularly when I compared it to the subsequent BAE146 flight to Broome the next day.

[OLBA18]

Autopilot on at approx 200 feet as the gear is coming up and off somewhere below 1000. There seems to be no point hand flying a 320 once you've performed the rotation - it just increases everyones workload. If I decide to do a raw data approach then I'll turn everything off around 15000 and enjoy flying the approach, but otherwise I must say I find no joy in following the flight directors so I let the autopilot do it.

[Old Smokey]

I think that you nailed it AerocatS2A, on the 'bigger stuff', MANAGING the flight rather than manipulating the controls is far more satisfying. Like yourself, if I'm feeling like a good bit of real 'hands on', an hour or two of aerobatics in a Tiger Moth dusts out all of the cobwebs. As for the B777, where I do my 'day job', a delightful aircraft to OPERATE, but I wouldn't pay 20c at an amusement parlour to 'fly' a B777.

Some 'biggish' aircraft like the DC9 were a sheer delight to fly AND to manage, but the degree of flying 'niceness' of more modern aircraft depends largely on how much feel the Primary Flight Control computer programmer has allowed for you.

I have to agree completely with OLBA18, hand flying on 'modern era' aircraft which were built to fly using automatics increases EVERYONE's work-load. As for hand flying at cruise level, spare the passengere the ordeal. They're well accustomed to aircraft gyrations during the manoeuvering phases of flight, Departure and Arrival, but deserve consideration during the stable phases of flight. When you turn the Seat Belt sign OFF, turn the Auto-Pilot ON :ok:

Regards,

Old Smokey