757-200 performance

[jumpseater]

Bird Strike

After the bird strike, the boroscope would take probably 6-8 hours to do, engine cool, panels off, rummage around, diagnose and panels back on, then normally a ground run to establish all ok. This is assuming that in Buttholeville in the Land of Bumbly Boo there is a qualified engineer and the relevant inspection kit to hand.
Frequently there is no damage found, but traces of blood can give the game away. In simple terms the greater the mass of the bird the larger the damage/potential damage, with a single hit. Also frequently the smell of burning flesh/roast chicken type smell gets in to the cabin through the aircon systems, so the pax/cabin crew might be aware before the flight crew, if no engine indications vary. A bird strike can also damage subsequent systems, for example an aircraft recently is suspected to have lost hydraulic fluid due to a bird hitting the noseleg, and rupturing a hydraulic pipe leading to loss of steering (not 757) on landing, so theres plenty of potential for a 'simple' bird strike to have significant consequences as part of a sequence of events.
Try typeing 'bird strike' into photo search on airliners.net to get some idea of damage etc
rgds
js

[prb46]

Thanks JS.
Problem I have is that reastically,how long would it take to get
3 fan blades?The boroscope and two qualified engineers are
available in west Africa.Are there spare blades in the UK?
Anyway they go to Joburg and hire a van to head north but
never make it,hence the crew decide to take a crippled aircraft.

Anyway,been up all night working on another chapter,and I'm
afraid I have another question.Please don't laugh if it just
wouldn't happen.

You are doing a CAT3 landing.Weather is naff.(I won't ask
at this time how you set it up)
You are at say 150ft and it trips or deselects whatever.From
memory the capt has his hand hovering above the throttles.
Given the fact you have a full payload,but not heavy on fuel,
could you pull out or would the aircraft not respond in time?
Would you get a warning that the autoland has tripped?
If even a a lower altitude it fails,would you then just continue
the landing even though you can't see a thing?

Thanks again and please don't shout at me if it's a silly question

[jumpseater]

Re supply chain, it could be very quick if the blades are in stock in serth efrika for example, and are of the right spec/mod status. AOG supply can be lightning quick at times, at others though... If its Africa then supply logistics could become very fraught especially the payment side of things, unmarked US dollars for example. When workin in a different environment I knew it was not unusual to have to carry cash to do deals in certain countries to grease palms etc. Perhaps your guys aren't carrying enough 'grease' to make it happen crossing the border?, you know, 'special' import duty

[dusk2dawn]

You are at say 150ft and it trips or deselects whatever.

Here I think you have to be more specific. CAT III ILS requires all 3 fully functioning Flight Control Computers (autopilots).
One FCC or its required subsystems may be(-come) inoperative and still permit an autoland but at higher minima (CAT II).
To go-around or continue will be a question of actual weather.

If you insist on a go-around I'll suggest a ground equipment failure like runway lighting, unauthorized runway intrusion or ILS failure.

the capt has his hand hovering above the throttles.

During the final approach the capt will have his hand on the thrust levers with a finger (thumb) ready to press the go-around button.

Given the fact you have a full payload,but not heavy on fuel, could you pull out or would the aircraft not respond in time?

No worries, mate That is, it will start to climb using only moderate thrust - stabilizing at a climb rate of 2000'/ minute to the preset go-around altitude. Gear is normally retracted when climb is indicated and flaps left extended untill final go-around altitude (the flaps part may vary from operator to operator).

Would you get a warning that the autoland has tripped?

An onboard system (or ILS-signal failure) will show up in the ASA, autoland status annunciator, as an audible click and display of NO LAND 3 and LAND 2, indicating that the system has degraded to CAT II but still capable of autoland. - if remaining systems are OK.

If even a a lower altitude it fails,would you then just continue the landing even though you can't see a thing?

Only CAT III with no decision height permits landing without any visual contact at all.

If the go-around is initiated very late (just before touch-down) the wheels may actually touch the runway before the go-around climb is established. Legal and safe.

[Greek God]

Hi
Operations Vary but it would probably be the FO doing the flying under "monitored approach" procedures. - All the Fo will ever do is go around while the Capt is able to concentrate on getting the required visual refs for landing. Cat 2 minima is usually 100 ft 300 RVR. 3a is 50 / 200 while Cat 3 b is 14ft/75 m RVR. 757s are only normally 3B certified. Larger & other types go to cat 3 C which is 0/0 I believe.
Calls will be "Alert height" at Cat 1 minima "100 to go" at Cat 3 min +100ft ie 114ft and "decide" at mins or 14 ft. The response is "check" to all except the decide call when it is either "land" or "go around"
The GA from 14 ft will normally not result in a touch town but can do depending on weight Density Alt etc as already mentioned.
Our call was "Go around flap 15" positive climb by 3 different indications then "gear up" to acell alt normally 1000ft AAL then clean up as per normal.
Hope it helps
GG

[Bealzebub]

-------------------------------------------------------------------------------
757s are only normally 3B certified. Larger & other types go to cat 3 C which is 0/0 I believe.
-------------------------------------------------------------------------------

The 757 is as good as it gets in civil air transport operations.

There are no other types that operate to cat 3C as it is practically impossible. No visibility, is fine to land, and in reality anything that is certified 3b has this ability. However zero vis precludes taxying off the runway, which would effectively close it. Until somebody invents a zero visibility taxying facility 3C remains useless.

[Greek God]

Thanks Beazle for correcting me - I just thought 747s had even lower minima than Cat3B
Regards GG

[prb46]

Well you guys fly a beast of an aircraft!!!Every problem I raise
the aircraft and crew can deal with it.Should have used a
BAC1-11.
What is the go-around button and what does it do.Does it set the
levers or just takes the autoland out?
Anyway back to chapter one where they are trying to leave Africa.
For obvious reasons they make a high speed taxi to use the whole runway(which is more than adequate in length)
For certain reasons this is blocked off.You turn right and aim for
an exit taxiway about a quarter down.Plan is to backtrack,use
the turning circle,and proceed as normal.Well apart from the fact
you are going to have an engine failure!!!
This doesn't happen and you have to use the runway length
available,so you turn right and start your run.
The question I have is would you know from the charts(jepps.
aerads)how much runway you have.I seem to remember they
just give you a full runway length.Then how long would it take
for you to rework your figures,or would it not matter?
One last one.
Given the fact that the crew do know there is damage to the
number two,would it make more problems on a rated take-off
when it goes,or does it make no difference?
Thanks again

[Sir Loin]

After the bird strike, the boroscope would take probably 6-8 hours to do

Is that work to rule jumpseater!!!

The borescopes will more likely take 2-3 hours to get wrapped up, however, it is quite rare, especially in high bypass ratio engines, for birds etc to be ingested into the core engine and damage the HP comp or turbines. That is not to say it doesn't happen, rather it doesn't happen very often. More often than not, the birds end up fairly harmlessly (for the engine!!) going down the bypass, causing only fan damage.

Usually most of the blade damage can be blended out with files and micromesh, dependant on the area of the blade damaged, but it would be unlikely that only 3 blades for example would be damaged beyond limits. Damage usually occurs to most of the fan, and certainly, if blade replacements are required the whole of the fan would usually be replaced. However, given the circumstances that this crew find themselves in, I feel that a bit of blending would be sufficient to allow themselves to get the hell out of Dodge!!!

I myself have seen some VERY gash blending to a Tornado engine which would usually have to be replaced, to allow the A/C to get home and change it there.

I may be wrong also, feel free to correct me, but I have never heard of a birdstrike occuring during taxying. Birdstrikes in my experience have usually occurred in the climb-out or during the circuit phase.

Hope this is of some help.

[jumpseater]

birdies

Sir Loin, nah! not a work to roole guv! I've been involved in looking at them for a couple of months now, and the quoted para below is a reasonably accurate fag packet calc!, but they are closer to 6 as a rule if I were to be pushed on it!

After the bird strike, the boroscope would take probably 6-8 hours to do, engine cool, panels off, rummage around, diagnose and panels back on, then normally a ground run to establish all ok'. Pls bear in mind that this is not with someone pointing a gun at you!. (Thinks..... Suggestion Box....How to reduce Boroscope times!)

In my findings, yes lots of times we have 'no damage', but we have to check thouroughly, not implying here that you blunties don't! I do know of an incident where a small number of blades had to be replaced rather than the fan, but you are generally correct, its normally workable (blending), or knackered!

'I myself have seen some VERY gash blending ' tut tut, course, if you took your time, say 6-8 hours......

'birdstrike occuring during taxying' very rare indeed, however found 3 cases in my 'exercise', This may be, (sweeping statement to follow), due to the Mil engines being noisier than civil types, thus scaring birds away as they approach. There are however a significant number whilst the aircraft is 'on the ground' i.e. touch down/roll-out and standing the throttles up/rotate. I'm sure knowing this stuff is indicative of needing to spend more time in the pub.....

[prb46]

Thanks for your replies.
Well I do know of a 767-200 ingesting one during taxi.
I believe ATC reported it as the crew knew nothing about
it.Extensive fan damage.Replacement blades finally arrived
on the island,only to find they were the wrong ones!
Aviation for you..

[prb46]

Well I'm upping the tempo a bit now.
I have just been reading an old Bristol evening post I found
in my parents attic.Friday 05 1954.My father flew the old Lancaster so kept loads of anything to do with aviation.
Front page is of a BOAC Britannia crash landing on a test flight
onto the Severn mud and the picture shows just the tail when
the tide came in.Same cover reports a jet flying under the
suspension bridge with startled people watching it go under them.Wonder if they had breath tests in those times?
Anyway the question I have is relevant to this post.
If you are on the take-off climb and have a huge bird strike,
one hitting the f/o's screen,one or two on the nose,and you then
suffer basically a two enginge failure.One keeps going for a while
and you continue to climb at a reduced rate.You are heading north,land to the left,sea to the right.The other engine starts to
play up and you have not got the power to return to your airfield.
Given the fact you are going down,would you aim out to sea?
Would you keep the gear up,and how would you land.I presume
you would try to get the tail down first,but is this something that
you practise in the sim.We have all heard about 'in the event
of a ditching'but in reality what chances do you have?
If you managed a safe ditching would the pilots leave through
their windows,or would the Capt stay on board as on ships to
ensure all pax are off safely before getting out?Also how long does the aircraft stay afloat for or is that dependant on damage?

Oh well back to looking out of my window over the suspension bridge.If someone else goes underneath,I bet I will be in
the supermarket!!!Seems from a later copy that ATC wasn't
that good at that time as they never found out who did it.
There were four aircraft over Bristol so 'Not me Guv'

Regards as always

[jumpseater]

multi strike

You'd ideally (not!), want to hit a flock of Gulls or some Canada Geese for some damage like that. Depending on the altitude of yourstrike and one engine still giving some power, one assumes you may have departed the airport by a few minutes or so, as they don't return immediately, so you'll need some birds know for @rsing around at altitude!

Try these for size, both copyright from 'Sharing the Skies'.

The first apart from being a turboprop, nearly meets your requirements to the letter in your 'storyboard',

On October 4th, 1960, a Lockheed Electra encountered a flock of European Starlings just after becoming airborne from Boston’s Logan International Airport. Starlings fly in dense flocks of individual birds weighing about 80 grams each. Numerous birds were ingested into three of the four turboprop engines. The number-one engine had to be shut down; numbers two and four lost power. The aircraft lost speed, stalled and crashed into Boston Harbor. Of the 72 persons on board, 62 died and 9 were injured.

On the night of January 9th, 1998, a Delta Airlines B727 departed Houston, Texas. At about 6,000 feet the aircraft struck a flock of migrating Snow Geese and suffered extensive damage to all three engines, the leading edge slats, the radome and the airspeed pitot tube—damage due in part to the aircraft’s involvement in a trial to assess the efficiency gains of high-speed departures. The crew successfully returned to the airport and there were no injuries. An FAA search will bring the full reports up no doubt, but the aircrew here could maybe put that into a 757 context, which I too would be interested to read!

[Sir Loin]

Jumpseater,

tut..tut.. If you had took your time, say 6-8hours

How dare you sir. What a vicious slur upon my technical integrity

As I said, I SAW some gash blending, a man of my calibre could never be a party to such things

No, I agree that things are very different in the military and civil sides of aviation, and cooling times etc, are rarely an issue "Wear some gloves then" being the usual reply to requests for time to let the engine cool!!

Very interesting about the idle birdstrikes however. In all my years I had never before heard of a birdstrike whilst A/C were taxying. You learn something new every day

[mono]

Wearing gloves is all good and well. But what will you tell the boss when the boroscope kit turns to mush and melts due to the heat. Then you WILL HAVE to change the engine. You HAVE to let the engine cool. Not so you might burn your delicate pinkies but so you don't destroy the tooling!!

As an aside, the 757MM states that boroscope can be deferred for (I think) 50 tech log hrs even if there is evidence of core ingestion (smell of cooked chicken in the cabin, blood/feathers on the core IGV's, etc) as long as the engine parameters were normal.

In my experience (20 yrs 757's) I have never pulled an engine due to birdstrike damage, despite having had several go through the core.

[Sir Loin]

Thank you for that excellent information regarding engine cooling Mono.

I have often wondered over the years why all my tooling has turned to mush

Sorry to hijack the thread, but there's nothing quite like being patronised to stir the emotions.

[prb46]

SPITFIRES RULE
Sorry not to have replied earlier.Yes the book will be available
in Canada.Have just got back from South Africa which was a
hair raising experience.Joburg no problem but the drive to
Mozambique and Rhodesia is not something I would recomend.
Maybe I was just unlucky.
Anyway,the book is now just to be called 'Flight 101'and if
the b......ds get their way,will be available in December,but if
I get my way will be February.Will let you know nearer the time.
Well,suffering from jet lag so going to crash out.