Lost propeller

[JDNSW]

A Regional Express Saab lost its starboard prop over the SW suburbs on approach to Sydney this afternoon. The landing was completed without further incident. The propeller has yet to be found.

[weeds]

Whoops......

[weeds]

Rex pilot keeps his cool in mayday call after propeller falls off Sydney-bound aircraft - 9news.com.au (http://www.9news.com.au/national/2017/03/17/14/33/rex-aircraft-lands-in-sydney-without-propellor)

[JDNSW]

According to the ABC there was no Mayday, but rather a Pan call.

John

[weeds]

Umm, what a pan call.....??

[JDNSW]

Next step down from a Mayday call. Used where there is not imminent danger to a flight, but there is enough going on to need to urgently notify Air Services what is happening. In this case Air Services need to know that a delayed landing or a requirement to go round is not a good idea, and it enables the captain to specify which runway he needs in the expectation that everyone else will be delayed to allow it.

This is perhaps a good example - a twin engined aircraft on approach with one engine ceasing to work would definitely require a pan call. If it was on takeoff or if it was a single engined aircraft, a mayday call would be indicated. Also, a Mayday call would be indicated if there was other damage or if the engine failure was something that could affect the other engine, such as running out of fuel, or if the aircraft was unable to maintain flight and control on one engine.

A significant difference is that a pan call is directed to a specific recipient, usually air traffic control or flight information, where a mayday call is directed to anyone listening. A mayday call by an aircraft on approach to a major airport would cause substantial disruption to its operation, mobilising emergency services etc.

[weeds]

Thanks John...good call by the pilot than not causing mass disruption......

Bet the passengers were nervous.

I landed in Brisbane today just before the tornado....

[BigBlackDog]

Kind of surprised they haven't found it yet, they are a big prop unit and it looks like it come off entirely from the gearbox from the pictures. Oops

[Hugh Jars]

The prop is probably hanging over someone's bar . Good luck getting it back :)

[JDNSW]

There is always the possibility that it landed in a body of water, such as Prospect reservoir, and there are still a few patches of bush. Presumably at that stage of approach it would be spinning fairly fast, and it is not clear to me what it would do aerodynamically - it may have travelled a fair distance horizontally as it fell, in an unknown direction. Not as if it were something that you could assume would lose airspeed rapidly and fall pretty much straight down, subject to wind.

[rick130]

Many years ago an old friend who worked for a time as a commercial pilot lost a prop on a twin not long after they'd left Bankstown.
Can't recall what type of plane, either a Beech or Cessna and was doing a Bank run out west when a vibration started and all of a sudden one engine lost a prop somewhere over Lake Burrogorang. (Warragamba Dam)

It'd only just been serviced.

[bob10]

A photo of the end result.

Emergency landing after passenger plane loses propellor in flight (http://thenewdaily.com.au/news/state/nsw/2017/03/17/rex-plane-loses-propellor/?utm_source=Responsys&utm_medium=email&utm_campaign=20170317_PM_Update)

[bob10]

Just a heads up. There are three priority signals in radio communications, the distress, urgency, and safety signals.

The Distress Signal....MAYDAY MAYDAY MAYDAY.

Has absolute priority over all other transmissions, and indicates the station sending is threatened by grave and imminent danger, and requests immediate assistance. It must not be used at any other time, and severe penalties exist for those who do.

The Urgency signal....PAN PAN PAN PAN.

Used when a distress signal is not justified, but when the sending station has a very urgent message to transmit concerning the safety of the station or a crew member.

The Safety signal......SECURITE SECURITE SECURITE [pronounced securi-tay]

indicates a station is about to broadcast an important navigational or weather warning.

These are for vessels at sea, but I'm sure it applies to all civilian radio comms.

[ramblingboy42]

Bob, are you involved in marine rescue? .....I am.

Dennis

[JDNSW]

These are for vessels at sea, but I'm sure it applies to all civilian radio comms.

I don't know about all, but they do apply to aviation.

John

[JDNSW]

The prop is probably hanging over someone's bar . Good luck getting it back :)

If it is, it is a big bar. It is a large four bladed prop. Latest article I have seen says it appears to have been lost about over Camden at about 6,000ft. There is a lot of open country round there.

[Hugh Jars]

If it is, it is a big bar. It is a large four bladed prop. Latest article I have seen says it appears to have been lost about over Camden at about 6,000ft. There is a lot of open country round there.

Yep. Around 8 feet blade span :)

[carlschmid2002]

Umm, what a pan call.....??
PAN Possible Assistance Needed.

[bob10]

Bob, are you involved in marine rescue? .....I am.

Dennis

Been there, done that.Worst thing I did was get my radiotelephone operators certificate of proficiency.You see , back then it cost $20 per year to join the VMR, about $200 to attend TAFE to get the ticket. No brainer. Only thing is, I sat in the radio room from then on. I also did the inshore Navigation course, the seamanship courses, all taught by the same TAFE teacher that taught the TAFE course. Even though I rarely ventured out on the vessel, I decided I would give the VMR 4 years of my time, as payback for the qualifications.Good people, learnt a lot.

[kogvos]

PAN Possible Assistance Needed.
That's just a backronym. The original comes from the French word panne. Similar to mayday (venez m'aider) and most of the others such as securite, seelonce, etc.).

[carlschmid2002]

That's just a backronym. The original comes from the French word panne. Similar to mayday (venez m'aider) and most of the others such as securite, seelonce, etc.).
It's a level down from a Mayday. If I was onboard I think a Mayday might have been more appropriate and a "Land as soon as Possible" just in case the same bloke fitted both props. I do fly in in helicopters so I guess losing a "prop" for us is very serious.

[PhilipA]

I note in the paper this morning the pilot reported an "uncalled for engine reaction" or something similar prior to losing the prop.

This led me to remember the doco on Beaufighters recently where the pilots would put the engine on full power if they saw oil pressure dropping and when it seized the prop would fly off and not create drag.

Leads me to wonder if the motor seized .

Regards Philip A

[Pedro_The_Swift]

just a noob question,,
would losing a prop cause the engine to over rev?

[mick88]

I am only guessing, but perhaps the engine seized, then the prop sheared off!
My uncle who is 93 and still living, flew on Beaufighters (30 Squadron RAAF) during world war two and says if during combat they sustained damage to an engine, they would then try to flee the combat zone and head for the open sea, with the damaged engine running at full revs, so that once it seized the prop would shear off. They would then put the plain down in the open sea and be rescued by one of the Catalina's, that were normally skirting the battle zones for these situations. This happened to my uncle three times in his WW2 service.
I assume they didn't perform very well on one engine, they were known to be very "twitchy" on take off with two engines, due to the fact that the engines were very powerful, so maybe landing on a strip with only one corkscrew going was extremely difficult.


Cheers, Mick.

[Hugh Jars]

If the engine didn't seize, there should be separate overspeed protections built in for the propeller and engine itself.

[101RRS]

The engine is a gas turbine so at the revs they spin they do not seize - they disintegrate with turbine blades going every where and fire and flame outs - that did not happen so more like a failure in the output end of the gearbox - as mentioned fatigue in the shaft is a likely option.

The other option is that it did loose one one blade and the immediate imbalance ripped the who lot out. I guess we have to wait and see.

Garry

[bob10]

That's just a backronym. The original comes from the French word panne. Similar to mayday (venez m'aider) and most of the others such as securite, seelonce, etc.).

As the RN would say, back in the day, all disasters came from the French.

[justinc]

Looks like the actual whole shaft has sheared inside the reduction box/ planetary assembly... very very lucky it didn't slice through the fuselage. They are a big bladed prop...😮

[JDNSW]

Sheared or just detached? - I don't know what holds the shaft in, but seeing it is normally 'pulling' it will have some sort of thrust bearing, possibly a tapered roller bearing, and if this fails, could it leave the thrust (pull) unsupported, or just supported by an alloy case - which would very rapidly wear away. This scenario could result from loss of oil in the reduction box.

[101RRS]

Well according to the news, vibration started 25min out of Albury and at 18,000' - so the aircraft would have been near Tumut - the engine was shut down and descended to 8000'. If the engine is like most other turbo props with the prop feathered it should not be able to rotate but they did not say if could the fully feathered and locked.

The prop fell off over Camden some time after the engine was shut down. Questions are being asked why the aircraft did not divert to Canberra when the problem first arose - most likely would have arrived before the prop fell off.

It looks like the crack started sometime back and questions are being asked why this had not been picked up in routine maintenance.

I guess we now need to wait for the report. It is not clear at this stage whether the prop was turning or not when it fell off.

Garry

[BigBlackDog]

The engine is a gas turbine so at the revs they spin they do not seize - they disintegrate with turbine blades going every where and fire and flame outs - that did not happen so more like a failure in the output end of the gearbox - as mentioned fatigue in the shaft is a likely option.

The other option is that it did loose one one blade and the immediate imbalance ripped the who lot out. I guess we have to wait and see.

Garry

The prop will have governing protection and overspeed protection, on top of that the engine fuel control will protect the prop from overspeeding a higher speed and also protect the core both by limiting fuel supply to combustion chamber.

But that's irrelevant if it was already stopped I guess.

[JDNSW]

Latest article in the SMH says the shaft sheared between the prop and gearbox, and Rex are removing all prop shafts and gearboxes in the same series from all of their aircraft pending the outcome of the investigation.

[carlschmid2002]

Early days yet but questions are being asked why he didn't divert to Canberra.

[weeds]

Early days yet but questions are being asked why he didn't divert to Canberra.

Because the passengers would have been late for their commitments in Sydney....saved the airline some money on additional flights.

[BigBlackDog]

Early days yet but questions are being asked why he didn't divert to Canberra.

Gives me the .... when media/"experts" do this. There would have been a decision process between the 2 pilots and probably the company. Does a Saab 340 fly on one engine? Clearly it does. Do you expect something to just fall off your plane? Erm, no. Sorry everyone we didnt pack our crystal balls today.

[carlschmid2002]

Gives me the .... when media/"experts" do this. There would have been a decision process between the 2 pilots and probably the company. Does a Saab 340 fly on one engine? Clearly it does. Do you expect something to just fall off your plane? Erm, no. Sorry everyone we didnt pack our crystal balls today.

Well I work in Aviation Safety and I must admit I do not know all the facts but it does seem highly unusual that they didn't put it on the ground at the first opportunity. Most twins do fly quite well on one engine but they don't know what damage had occurred and they are carrying paying passengers. Unless they had a real good reason like weather, runway length or the availability of emergency services the question has to be asked.

[Hugh Jars]

There's a whole bunch of reasons why they may have chosen not to land at the nearest suitable. CAO 20.6 follows:

3.2 The pilot in command of a multi-engine aircraft in which 1 engine fails or its rotation is stopped, may proceed to an aerodrome of his or her selection instead of the nearest suitable aerodrome if, upon consideration of all relevant factors, he or she deems such action to be safe and operationally acceptable. Relevant factors must include the following:
(a) nature of the malfunctioning and the possible mechanical difficulties which may be encountered if the flight is continued;
(aa) the nature and extent of any city, town or populous area over which the aircraft is likely to fly;
(b) availability of the inoperative engine to be used;
(c) altitude, aircraft weight, and usable fuel at the time of engine stoppage;
(d) distance to be flown coupled with the performance availability should another engine fail;
(e) relative characteristics of aerodromes available for landing;
(f) weather conditions en route and at possible landing points;
(g) air traffic congestion;
(h) type of terrain, including whether the flight is likely to be over water;
(i) familiarity of the pilot with the aerodrome to be used.

Depending on the runway/s in use, should RWY 35 have been the only operational runway on the day, manoeuvring for the approach would have taken them over some of the highest terrain in Australia. I don't know what the SAAB's single engine ceiling capability was under the conditions on the day, but it may have been lower than the lowest safe altitude to the south of Canberra. A pretty good reason for NOT going there IMO :)

[carlschmid2002]

I am sure their thought processes will all come out in the final report from the ATSB which will probably arrive in about 2 years by which time we will all have forgotten about this incident. An engine failure by itself would not raise any eyebrows but to actually lose a part of the aeroplane which could have done who knows what damage is certainly interesting. I was in a Black Hawk when an input model self destructed on approach to the helipad at Isurava on the Kokoda trail. This is the connection between one engine and the transmission. The engine shutdown with built in overspeed protection. It was a loud bang with associated puff of smoke and other than the indications that one engine had lost power it is very hard to fully assess the full damage. We were heavy at 20000 lbs and the pad was at 6000 ft. Luckily there was low ground and a valley to the left to regain airspeed and we turned straight to Kokoda and put it on the ground ASAP. That 10 min transit to the only possible landing point seemed like an eternity to me. We go by "Land as soon as practicable" or "Land as soon as possible" An engine failure would be the first, after a loud bang we chose the latter.

[JDNSW]

The prop is said to have landed in the Camden area. Last time I looked at a map Camden is a lot closer to Sydney than Canberra. A diversion perhaps to Bankstown might be worth considering, but the distance is not much different. Or did they mean Camden?

[101RRS]

But the initial incident of the vibration, shutting down the engine and decending from 18,000ft to 8000ft all happened just west of Canberra, the propeller fell off some time later when over Camden.

I guess investigators will quizz the pilot as to what his logic was and we can only second guess. However irrespective of how well the aircraft flies on one engine, this is a major emergency for any twin engined aircraft. I have been in a 4 engined aircraft where one is shut down to conserve fuel but never in a twin - been in them where one has had to be shut down as a precaution (as I guess this SAAB was) but we always diverted where possible.

I guess all will become clear after the report is completed.

garry

[bob10]

The prop left the aircraft horizontal.

Regional Express grounds further five planes amid investigation into lost propeller | The New Daily (http://thenewdaily.com.au/news/national/2017/03/20/regional-express-grounds-five-planes-lost-propeller/?utm_source=Responsys&utm_medium=email&utm_campaign=20170321_TND)

[101RRS]

Propeller found in Revesby - near Bankstown - no where near Camden.

[JDNSW]

Actually in Georges River National Park. Which might explain why it has taken this long to find.

[Hugh Jars]

I have been in a 4 engined aircraft where one is shut down to conserve fuel but never in a twin - been in them where one has had to be shut down as a precaution (as I guess this SAAB was) but we always diverted where possible.

garry

Used to fly P-3's, Garry?? ;)

[101RRS]

Only as a passenger a few times.

[goingbush]

How the hell did they find that ?? Like a needle in a haystack !

Rex Express plane propeller found in Sydney bushland - Yahoo7 (https://au.news.yahoo.com/nsw/a/34744421/rex-express-plane-propeller-found-in-sydney-bushland/#page1)

[VladTepes]

Made a meme..... (Let's see how far we can get this spread.. post it on all the aviation forums etc you're on! )

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