Flybe

[MarkD]

Have P&WC come up with a reason for the seemingly high problem rate with the PW150s?

[southender]

Tilewood

I posted on the subject of Flybe's equipment on the Southend - Jersey route earlier this year. The informed reply was that it was rostered for BAe 146 operation, but whenever I've seen the flight it has been Dash 8-400 operated.

Is any reason for this known as the additional seats on the 146 would surely help out the over booking.

Cheers

Southender

[tilewood]

I believe that 146/RJ equipment was expected to be used as the season built up this year.

I understand that the ex Turkish RJ's which flybe were planning to introduce during the summer were found to have serious
corrosion of the fuel tanks, and therefore withdrawn. This left
flybe with a jet capacity problem.

That could explain the continued use of the Dash8-400.

[Snigs]

Search me, but an engineer recently ventured the idea that they have been derated so much, that they're running for long periods in a regime that they weren't designed for.

Increases turbine life, sure, but what about compressor blade vibration??

Other than that, lovely engine...

[MarkD]

Snigs

are just the Flybe engines derated or all Q400 PW150s?

[Irish Steve]

Increases turbine life, sure, but what about compressor blade vibration??

Well, if significant flutter on the trailing edge of the exhaust is a symptom of vibration in other areas, then the 400's definitely have a problem.

I watched the Stbd engine exhaust on a flight from DUB to EXT a while back, and from about 15 Ft after take off until touchdown, there was a significant flutter on the exhaust on the inboard edge, covering an area of about 15 Cm, and fluttering over probably 1 Cm either side of normal position.

It was more pronounced while flaps were deployed, but still continued after power reduction in the climb, and in cruise and descent.

I would be concerned that an ongoing flutter of this magnitude is going to lead to stress cracking sooner rather than later.

Maybe it's not significant, but it's certainly disconcerting to watch, particularly when it's constant.

[Snigs]

Well, if significant flutter on the trailing edge of the exhaust is a symptom of vibration in other areas, then the 400's definitely have a problem.

Glad to say that is not the case, all aircraft have bits that vibrate a lot, and it can concern the layman, but rest assured that this is not a problem. On the contrary if structures such as those weren't allowed to vibrate then there would be problems!!

Believe me, no engine is free from issues on a new application, there is already a fix in place, it's now about the physical act of implementing it.

BTW Irish Steve forgive the pedantry but flutter is (basically) defined as vibration of increasing amplitude, leading to failure, so what you witnessed is not flutter.

MarkD, yes, no need for any extra power on that airframe, it goes like sh*t of a shovel (comparatively) anyway!

[Irish Steve]

BTW Irish Steve forgive the pedantry but flutter is (basically) defined as vibration of increasing amplitude, leading to failure, so what you witnessed is not flutter.

Ok, so if a 20 cm section of the rear edge of the inner skin of the exhaust moving from side to side at a significant rate and with a significant amplitude is not flutter, what is it? It was a lot more than vibration, and because it was very localised, I'm fairly sure it was an airflow induced issue.

Over time, I suspect that the amplitude would increase, as the strength of the material was weakened.

As far as I was concerned, it looked to me like a spacer or similar had been omitted, or had been lost, and if the area concerned continued to do what ever we want to call the movement, I would be concerned that stress fatigue cracking could become a problem sooner rather than later, given the amplitude and frequency of the vibration.

We're not talking a little bit of movement here, we're talking a high enough frequency that it was not "countable" by a significant level, and the area involved was sufficiently large for it to be very noticable. I've done a lot of flying on similar turbo prop aircraft, and never seen anything like this on other types, and if I can, I do watch what's going on around me. I've flown on 400's before, in similar seats, and not observed this on other aircraft, hence the comments.

This happened some months ago, and at the time, I mentioned it to some friends who are much more closely connected to aviation maintenance type issues, and they were sufficiently concerned at the description I gave them to that they passed it on to "higher channels" that they knew. I'm not a complete layman where some of these issues are concerned, which was why it got mentioned to them, as it was certainly something that appeared to me at least to be unusual.

Don't get me wrong, I'm not taking a dig at FLybe on this, I've never had any issues with them, (as SLF), and their services have always been reliable on the DUB routes I've used, and in a "former" incarnation, they were a nice crowd to do ramp turnrounds for as well .

[Maude Charlee]

No doubt you informed the crew long before your 'friends'?

[MOR]

significant flutter on the exhaust on the inboard edge, covering an area of about 15 Cm, and fluttering over probably 1 Cm either side of normal position.

Nah, Snigs is right... some parts are supposed to move. The exhaust on the F27 used to move around a lot, in fact I once had one break when it was prevented from moving by a badly secured cowling. It grew a 15cm crack in 20 mins flight time... spent a day or two in GCI waiting for a new one.

More to the point, unless you actually KNOW that there was a spacer or other part missing, you should really say nothing - because inferring that a part was missing is needlessly damaging to the reputation of flybe's engineers.

I agree with Maude Charlee - unless you immediately informed the crew of what you saw, you shouldn't be mentioning it now.

[Irish Steve]

unless you immediately informed the crew of what you saw, you shouldn't be mentioning it now.

In this brave new post 9-11 and low cost short turn round world, it's hard to get to talk to anyone on the aircraft these days, and the chance of getting to talk to the flight deck crew is practically zero. The "friends" I am referring to are both involved directly with the aviation industry, one is a licenced engineer, the other has been involved at a very high level of aviation training on technical and design matters for many years, so this wasn't "idle chit chat"!

On the basis of their evaluation of my report, I reported it to the people (within Flybe) that needed to know, within a few days of the flight.

During the flight, it wasn't a sufficiently serious issue to be causing concern about the safe conduct of that flight, and it wasn't the best of weather, so both cabin crew and flight deck had plenty to occupy them, and there's no easy way to discuss something of this nature without the risk of raising unneccessary worry to other passengers in the immediate vicinity, if they happen to half hear part of the conversation.

I've done enough flying as SLF and pilot that I wasn't concerned for the safe operation of that flight, but I was concerned that if the same symptom continued, there was a risk, as mentioned by MOR, that a problem could occur that would disrupt normal operation.

The fact that I didn't get any form of response was dissapointing, but not altogether unexpected.

It's been mentioned now only because the possibility had been raised within this thread that there might be a problem with the 400's with engine vibration.

I made a contribution that I felt was appropriate, and have already done what I felt was needed at the time.

I seem to recall that this is supposedly a discussion forum, and there's no rules that say we can't talk about issues that may be relevant!

[MOR]

In this brave new post 9-11 and low cost short turn round world, it's hard to get to talk to anyone on the aircraft these days

Let me help you then...

1) Look above you and locate overhead Passenger Amenity Panel.
2) Locate crew call button.
3) Press it.

During the flight, it wasn't a sufficiently serious issue to be causing concern about the safe conduct of that flight

How do you know? Are YOU an engineer?

I've done enough flying as SLF and pilot that I wasn't concerned for the safe operation of that flight

Good for you. However, as you don't know jack about the aircraft or its systems, perhaps you would be doing everyone a favour by reporting what you saw.

I was concerned that if the
same symptom continued, there was a risk, as mentioned by MOR, that a problem could occur that would disrupt normal operation.

On some aircraft, cracking of the exhaust duct can lead to the serious risk of fire within the engine nacelle. Any crack that starts CAN (but may not) propogate extremely quickly. I know because it happened to me once, we ended up shutting down the engine 10 mins into the flight with a fire warning in Zone 3 of the nacelle.

Think back to Kegworth. If the pilots had known what the passengers were seeing, the chances are they would have landed safely. You are not in a position to make the judgement about what is important and what is not. Why not let the pros deal with it? Not reporting ANYTHING out of the ordinary is irresponsible.

Nothing irritates me more than SLF/spotters/armchair experts who fulfil the adage "a little knowledge is a dangerous thing"...

[Irish Steve]

perhaps you would be doing everyone a favour by reporting what you saw.

I did, in a non emotional and non stressed manner, subsequent to the flight, by E-mail to the operator's maintenance base, having made sure first that I wasn't over reacting to something that got my attention.

Please let's not over react here, this was the inner skin of a double skin exhaust, at the very trailing edge of that unit, external to the nacelle.

The movement I saw was airflow induced, and changed with flap settings and speed, so as far as I could tell, it wasn't engine vibration related, but it could have been. I was more concerned that on a relatively new type, it might not have been spotted and reported, which could lead to maintenance failure issues at a later stage. That's not good for any operator.

I'm not going to prolong a discussion that's not going very far, specially when I get the level of sarcasm that's being shown here, I did what I felt was appropriate at the time, and made the people that needed to know aware of what I'd seen, and I'm not about to get hung out to dry for mentioning it now as part of a discussion thread about possibly related items.

No, I'm not an aircraft engineer by trade, but I have a long background in engineering, have worked alongside and assisted licensed engineers on commercial size aircraft, owned and operated my own light twin for a while, and have done all of the theoretical work on the professional licences and passed them, (pre JAA) so I do have a pretty strong knowledge of aircraft sytems and the like. The only reason I'm not flying professionally is because of Saddam, the timing of gulf 1 blew my window of opportunity, and once over 40, airlines lose interest!

I'm also aware that trying to have a private conversation with the cabin crew when seated in a window seat is almost impossible, and I wasn't about to start worrying people sitting around me.

The phrase don't shoot the messenger comes to mind.

As I've said before, I have no anti anyone agenda, I'm not trying to make waves for anyone, or to knock an aircraft or operator.

I have thought back to Kegworth, I got very much involved with the concept and implementation within a major airline of the MCC training that came in as a result of that accident, and if I'd been there and seen what the passengers did, I doubt it would have made much difference, and if I were to make the sort of waves today that would have been needed then to get the flight deck crew's attention, I would probably get accused of air rage.

I hope that's clear, and as far as I'm concerned, that's the end of the discussion if it's going to continue as an attack against me, I've better things to do with my life

[MOR]

I got very much involved with the concept and implementation within a major airline of the MCC training that came in as a result of that accident

Lol haven't laughed so much in ages...

[prob30]

Sadly MOR is at it again! Now im beginning to realise that he is one of those flybe "during the waa-ar" ex F27 jockeys we all know and love so well. Muchos grande fish in an ever-so tiny pond.

Irish Steve you did what you thought was right in the way you thought was right. no one has any reason to criticse you. MOR's explanation of how to use the call bell is simply rediculous.

MOR would you have said the same to Irish Steve in the bar over a pint? Nah.

[MOR]

Bet your ass. Foolishness should be challenged wherever you meet it. Especially in the form of a "I once did some ATPL exams so I know all about aircraft systems". As we all know (well most of us), ATPL exam content bears no similarlity to real life.

Anybody with an ounce of professionalism assumes nothing and questions everything.

Now would you have said that you said above to me in a bar over a pint?

Didn't think so...

[Snigs]

BTW Irish Steve forgive the pedantry but flutter is (basically) defined as vibration of increasing amplitude, leading to failure, so what you witnessed is not flutter.

Irish Steve, perhaps I should have been a little more specific, flutter is (basically) defined as vibration of rapidly increasing amplitude, leading to certain failure in a short period of time, so what you witnessed is not flutter.

Is that a bit better?

Now, I'm not criticising you for doing what you did, you felt it was right to do so, but don't belittle my input. Having spent over 10 years in stress and vibration engineering, and in particular relating to engine and airframe design and structural integrity, I do know what I'm talking about.

Very briefly to try to explain, have you heard of an S-N curve. S = Stress, N=Number of cycles (of vibration) before failure.

If the stress induced in the structure is high, then the number of cycles the structure will endure is low, and vice versa. There comes a point where the induced stress is so low that the structure will endure an infinite number of cycles, and hence never fail.

I suspect that the induced stress in this structure is pretty low (but I haven't done and FE Analysis on it, so what do I know?)

Now that I'm flying these things I'm as worried as the next guy that things will unexpectedly fail, but I know that these things have been designed with high margins of safety, and are tested thoroughly. So, generally I'm happy with life!

[grow45]

FlyBE Unplugged

I hope I am misinterpreting what the FlyBe web site is saying but it looks like passengers are going to be subjected to an in flight radio station on all FlyBe flights. - http://www3.flybe.com/news/0509/05a.htm. whether they like it or not

I dont recall the Q400 having sockets for headsets in the pax seats so I presume everybody has to listen to it whether they like it or not. Can anybody confirm.

Thanks

g45

[Hey there]

I think it's just Flybe-speak for having promotional messages on the PA system, exactly the same as Ryanair and others who have ads for their food and drink sales etc. on the track with some Norman and his Organ-esque music.

Personally, I'm surprised Flybe didn't issue a press release to say the sun rose this morning.

[Megaton]

Four or five tracks played endlessly. They're turning me off some of my favourite music.