Airliners at Displays and Limitations

[Wageslave]

There's a thread running here entitled "787 video of stunts" (sic) that contains an assertion from the pilots involved that they never exceeded 45' from the vertical and another from an observer who insisted they did, and by a long way. We know this video resulted in some extreme looking manoeuvres that were a result of clever camera angles and editing but it got me thinking.

When a public transport aircraft is displayed there often seems to be a need to present it as though it were a fighter - heaven knows why - which results in unpleasant words like "stunts" being attached to it but we all know the limitations of our particular mounts and its pretty hard to put together a spectacular display when adhering to these (though clever display design and viewing angles help).

So do these display aircraft (think Farnborough, Paris etc) actually get taken beyond their published limitations in terms of bank and pitch bearing in mind you'd have to downgrade the control laws in an 'Bus to do that (I've never flown a fbw Boing) or do they really stick to the numbers?
If they do exceed them how is this achieved from a procedural point of view? Does the display authorisation OK this? The manufacturer? What do the insurers say? The maintenance organisations? Are they on experimental C of As that exempt them from normal limitations? It's hard to imagine that Flight Ops Inspectors turn a blind eye in this litiginous day and age.

How does it work?

[Snakecharma]

Don't know most of the answers to your many questions but would say the least reliable person to be making a judgement about the attitudes display aeroplanes reach is an observer on the ground.

If the pilots flying the machine said they didn't then I would think they didn't. Certainly there are enough recorders onboard to give them the evidence they need to back up their assertions so you would think that they are less likely to be telling porkies, and given the display routine is tightly scripted, practiced and approved by numerous people someone going rogue on the day is less than likely I would think - certainly in this day and age.

That said I saw an AN124 at the Richmond bicentennial air show in 1988 (in Australia for those that don't know) put on an absolutely cracking display that was awesome and breathtaking to watch and resulted in the crew going to the beach instead of doing the display for the rest of the trade days at least (can't remember if it flew a tamer version on the public days)

https://youtu.be/N5d91CIowtM

[Capn Bloggs]

awesome and breathtaking to watch and resulted in the crew going to the beach
That was the idea! :D

[MarkerInbound]

At least on the Boeing side there are no "published limitations in terms of bank and pitch."

[Snakecharma]

Yes, I suspect you are right Bloggsy!

I assume you were there with your pointy?

[Capn Bloggs]

I assume you were there with your pointy?
I was there, upside down... ;)

[Snakecharma]

I imagine, given the era, that every man and his dog came over in the machine to "support" it and it went home loaded to the gunwales with western goods.

Whenever an aeroplane is being delivered by Airbus, Boeing or Embraer to airlines from a certain very large communist country to our north, 20-30 people troop over for the acceptance and delivery, with about 2 blokes doing all the work (which is just doc review - they rarely step on board the aeroplane) and when it leaves it is chock a block with everything they can get their hands on, including a kazzilion rice cookers.

Very funny to watch....

[FullWings]

Angle of bank or pitch doesn't break aircraft, load factor and speed exceedences do. I can’t see the problem with competent pilots displaying airliners within their structural limits.

Some nice wing-overs and controlled low turns would be much better for the airframe than running in straight and level at 1,000’ and doing a 3g pullup. And look better...

[barit1]

Not only eastern bloc.

DLH bought their 747-200 fleet in 1978-79 and had an inspection/acceptance crew on site in Everett. When the final ship was delivered, it brought the whole crew home - along with a couple boats and a C-172 (for the flying club) in the hold.

[Wageslave]

I can’t see the problem with competent pilots displaying airliners within their structural limits.


That's missing the point.

The flight manual states max angles of pitch and bank that may not be exceeded. Airbi cannot exceed those limits, they won't let you unless you do some pretty drastic restructuring of systems to get into degraded control laws, which again isn't allowed.

How do display pilots get around that?

[Romasik]

That's missing the point.

The flight manual states max angles of pitch and bank that may not be exceeded. Airbi cannot exceed those limits, they won't let you unless you do some pretty drastic restructuring of systems to get into degraded control laws, which again isn't allowed.

How do display pilots get around that?
Airbus doesn't have protections (except load factor protection) in alternate law which is easy to get into. And this is even not a direct law. Just press couple of push buttons. It's not allowed for regular pilots in normal operation. But manufacture test pilots and their operation are in a different league.

[FullWings]

The flight manual states max angles of pitch and bank that may not be exceeded.
I’ve just looked through the Boeing FCOM and FCTM for the 777 and can’t find any limitations on pitch or bank, apart from when you’re in close proximity to V2 or minimum manoeuvre speed, which is sensible. Yes, bank angle protection comes in at around 35-40degs, but it’s not stated anywhere I can see as a limitation...

[EMIT]

Limits

Wageslave, the limits in civil aviation that you seem to have in mind, like 30 degrees of bank, are just operational "limits" - the companies don't want you to exceed those numbers because they would probably frighten the customers.
The civil aircraft themselves do not care about bank or pitch limits so much. Like already stated, angle of attack, G and speed are real limits for the airframes and you can rest assured that the display pilots will respect those.
The flight control limits of Airbus are a lot more relaxed than you seem to think. The bank limit is 66 degrees, which, if applied in a level turn, would coincide with the G limit of 2,5 G. Of course, Bitchin' Betty will yell BANK ANGLE if you go well over 30 degrees bank.
Pitch is not limited by itself, but is certainly limited by available speed and power. No chance to pull an airliner over the top into a half loop.
The maneuvers only LOOK spectacular, in terms of achieved pitch and bank, they ARE NOT really, from a pilots perspective. The trick is to have a light aircraft and use full thrust, contrary to the commercial practice of minimising thrust use.
When you bring an empty aircraft to an overhaul facility, just do your standard trick of flying at V2 + 15 kts during the take-off and all onlookers will think that you are doing a display. Just don't be lazy to only use 15 degrees of pitch attitude and disregard the speed going way over the SOP speed of V2 + 15, what many "real civvy" pilots would do, out of fear that their "excessive pitch" would somehow get them clobbered.

[Chris Scott]

Quote from Wageslave:
"We know this video resulted in some extreme looking manoeuvres that were a result of clever camera angles and editing but it got me thinking."

Could this frame be from one of the videos you had in mind?

http://i1104.photobucket.com/albums/h335/Chris_Scott_46/Clive%20Leyman%202015-06-19_062445%201_zpspzaldwnt.jpg

I made some measurements and calculations based on the length of the a/c (which I assumed was a dash-9), an assumed width of the runway and the spacing of its distance-to-touchdown markings. Surprisingly, the result was a pitch-attitude of only about 31 degrees.

[mustangsally]

It is frequently the operating company that puts limits on pitch and roll. One airline limits vertical pitch to eighteen degrees up. I've seen another at twenty two degrees. Another limits roll to less than thirty degrees with a target of twenty five degrees. Load limits are for structural life. Put a six g pull one time and park it. Put a 1.5 load and fly twenty years.