Hey gotta question for some Gurus.

On Friday BA flt 253/252 was delayed. My father was on the flight and the story being told to the PAX were that one of the engine starters was broken and they would have to start the aircraft engine manually.

Now not knowing the full tech details I am wondering what or how that is done!


It wasnt a cross bleed, as from what i have heard, that would mean that the starter would still be functioning and its just getting its bleed from the other engine than the APU.

Flight 252 left GCM later than it was suppose to (after the origional delayed departure time) and then the same happened with the NAS dep to LHR. I am thinking that this may be due to the "manual" start procedure. Anybody know any details on this?

It must have been a bad start Valve. If the starter was broken, there is no way to turn the eng to start it on the ground. They must have tried to troubleshoot the start valve or did not have one in stock, so the MTC guy had to manualy open and close the start valve during start. Or they changed it that cause the delay. HTH

[Edited 2011-06-05 16:16:53]

If the starter was broken, the engine could not be started. The start valve failed to open when selected. In order to manually start the engine, a 3/8" drive extension (24"+ long) on a 'T' handle is inserted into a hole in the cowl and into a receptacle in the start valve. The valve is opened by turning the wrench. The engine start is coordinated with the flight deck and at 50% N2, the tool is turned back to closed and removed.

Pretty standard for large engines.

Quoting N901WA (Reply 1): . If the starter was broken, there is no way to turn the eng to start it on the ground

While you would never see it happen in Civil Aviation there is a way to start an engine if the starter is inop. I know it can be done on turboprops, Im not sure if it would work on turbofans. Sorry not trying to side track the thread but it's an interesting side note.

It's called a buddy start. http://www.youtube.com/watch?v=bXj0sQzljUw

Looks like a recipe for a FOD disaster...

A similar thing happen to me on a AA MD-82 flight from Tennessee to DFW. The right engine started up but fine but the left engine did not. The capt. said that we needed assistance to start the left engine. As I looked out my window I saw the MTC guy drive an APU unit right next to the engine and run some sort of lines into the engine. What he did I have no clue but i could only guess he was jump starting the engine. It was scary because if the the engine needed to have the APU start it, I was hoping the engine would shut off in mid flight. The flight did land safely at DFW..but it was scary.

I realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going. Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air? I certainly wouldn't expect this to happen in any commercial application, but if you had a slightly broken empty aircraft on the ground in a war zone, could you get it out of the area this way?

Maybe I'm just nostalgic about being able to push start cars in the old days.

Quoting aklrno (Reply 6): I realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going. Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air? I certainly wouldn't expect this to happen in any commercial application, but if you had a slightly broken empty aircraft on the ground in a war zone, could you get it out of the area this way?

I believe the quad jet suggestion could be done legally on a ferry flight with no passengers. Could be wrong though. Other suggestions probably could all be done, so long as there are no passengers on board also, so long as you have enough runway, tire speed limit and braking capability - may need to have near empty fuel tanks for that one. Problem would come with boarding the passengers: I'm not sure on the rules for that. You may need to board them on the side with the fully functional engine, shut down.

Interesting though.

Quoting lke2fly (Reply 5):

That sounds an awful lot like an airstart. Even with earplugs, those are loud procedures.

Quoting aklrno (Reply 6): Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air?

Technically it is possible but the amount of paperwork that would precede the procedure would be enormous and no passengers would be allowed on board during the procedure.

Quoting thegeek (Reply 7): Problem would come with boarding the passengers: I'm not sure on the rules for that. You may need to board them on the side with the fully functional engine, shut down.

I remember reading somewhere that it is allowed and sometimes still done when an aircraft lands at a remote airport with an inoperable APU. Passengers board via the side where the engine isn't running.


A little OT

Quoting aklrno (Reply 6): Maybe I'm just nostalgic about being able to push start cars in the old days.

I had to push my car down the hill to start it last month. The battery was dead and really needed to be replaced which fixed the problem. Gotta love stick shift cars and living on a hill   Pushing a 2ton Saab down a flat road cannot be fun. Downhill on the other hand is hilarious.

Quoting bj87 (Reply 9): I had to push my car down the hill to start it last month. The battery was dead and really needed to be replaced which fixed the problem. Gotta love stick shift cars and living on a hill Pushing a 2ton Saab down a flat road cannot be fun. Downhill on the other hand is hilarious.

I had a car with an automatic transmission which could be push-started.

Who, here, can tell me what kind of car, and which transmission, that was?

Quoting fr8mech (Reply 2): In order to manually start the engine, a 3/8" drive extension (24"+ long) on a 'T' handle is inserted into a hole in the cowl and into a receptacle in the start valve. The valve is opened by turning the wrench.

On a CF6, but on an RB211, you have to open the right fan cowl to get a socket on the start valve drive. Then shut the cowl when the engine is running.

On the Trident we used to have a procedure for an inop starter.
A blanking plate was carried on every station. You started an engine, then removed the starter with the engine running and fitted the blanking plate. Not as easy as it might sound! The starter drive was spinning as you took it off, and it was like holding a hot gyroscope in your hands. Then you fitted the good starter on the other engine, and started it normally.
The starter was fitted to the gearbox with four special nuts that were easy to remove, but the whole procedure was prone to failure, and would never be allowed in todays Health and Safety environment.

Also in those days when the APU was inop, ground engine starters were rare on small European airports, so we had a long section of start hose. A relief Trident was flown out, and the hose connected between the two aircraft to use the APU of one aircraft to start the engines of the other.

[Edited 2011-06-06 06:15:50]

Quoting sccutler (Reply 10): I had a car with an automatic transmission which could be push-started. Who, here, can tell me what kind of car, and which transmission, that was?

Maybe a late 1970's Honda Civic, with the "Hondamatic" semi-automatic transmission?

Quoting lke2fly (Reply 5): What he did I have no clue but i could only guess he was jump starting the engine.

He hooked up a pneumatic cart and then manually operated the start valve.

Quoting lke2fly (Reply 5): It was scary because if the the engine needed to have the APU start it, I was hoping the engine would shut off in mid flight.

You can do windmill restarts in flight...that's not an option on the ground.

Quoting aklrno (Reply 6): I realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going.

I don't think you can taxi fast enough to windmill start any modern engine.

Quoting aklrno (Reply 6): Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air?

Technically, yes. Legally, no (unless for flight testing).

Quoting aklrno (Reply 6): I certainly wouldn't expect this to happen in any commercial application, but if you had a slightly broken empty aircraft on the ground in a war zone, could you get it out of the area this way?

Yes.

Quoting thegeek (Reply 7): I believe the quad jet suggestion could be done legally on a ferry flight with no passengers. Could be wrong though.

Long thread on the topic: http://ww.airliners.net/aviation-forums/tech_ops/read.main/286524/

Short version is that it's been done in the past and it's technically possible, but the regulators wouldn't approve it today.

Tom.

Quoting sccutler (Reply 10): I had a car with an automatic transmission which could be push-started.

An Alfa Romeo 156 Selespeed would fit the bill, but I don't believe they were that popular in your neck of the woods.

Didn't Volvo / Daf / whoever also have an infinitely variable automatic that was basically a rubber band around a cone? Can't see any reason why that couldn't be push started either. (Variomatic?)

[Edited 2011-06-06 10:12:16]

Quoting aklrno (Reply 6): realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going.

No. The pressure and volume of air required to to spin the compressor up to a sufficient speed cannot be attained at taxi.

Quoting aklrno (Reply 6): Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air

Possible in theory. Engine inop ferries are certainly possible on 3 and 4 engine aircraft, but I think the legal issue would arise from departing in an aircraft with a known defect and no remedy in place. A quick check of the MEL's I have handy do not show any relief for starters. I have heard stories of this being done with a Falcon 50, where the crew took off, on 2 started the engine with the inop starter in the air, then came back for the pax, but that would be done under part 91 ops.

Quoting aklrno (Reply 6): I realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going. Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air? I certainly wouldn't expect this to happen in any commercial application, but if you had a slightly broken empty aircraft on the ground in a war zone, could you get it out of the area this way?

I was at my fathers place yesterday. He told me a story, about his time at De Havilland in the 60's, in the flight test dept. A pilot from a middle eastern airline told them about being at a remote airport and not having enough battery power to start all the engines. So they decided to start the other engines during the takeoff roll, but forgot to energize the ignition and wound up taking off with just two engines running. The plane was a Comet 4.

Quoting sccutler (Reply 10): I had a car with an automatic transmission which could be push-started.

1950-73 Chevy with the 2-speed Powerglide transmission?

Quoting Kaiarahi (Reply 17): 1950-73 Chevy with the 2-speed Powerglide transmission?

Been there done that, just push it up to about 20 mph in neutral and drop her into drive with the key on (they did not have column lock back then).
The Powerglide was the only transmission that had a rear pump that did not have an over running clutch.
My newest vehicle has a 6 speed with lock up torque converter, it stays pretty busy. You can hardly imagine how doggy your vehicle was with a transmission that only shifted once when you left a stop sign. Although the Powerglide still very popular in drag racing it has a lot of beefed up parts.
In 56 they changed the shift lever sequence to P-R-N-D-L the in the 55 and previous the sequence was P-N-D-L-R and the Turboglide retained the P-N-D-L-R until its demise in 60 or 61. Many people while trying to accelerate would manually down shift the transmission to low and overdue it and pull the lever down into reverse. The instant deceleration would cause the drivers weight to shift and push down even harder on the accelerator (no seat belts back then) causing all sorts of issues. The funniest one would be watch the passenger to have to wipe his face off the windshield.
OK enough thread drift.

Okie

Quoting thegeek (Reply 7): I believe the quad jet suggestion could be done legally on a ferry flight with no passengers.

Not legally. Ferry flights require the amount of power plants the aircraft comes with to be operative at takeoff.

Quoting lke2fly (Reply 5): It was scary because if the the engine needed to have the APU start it, I was hoping the engine would shut off in mid flight.

Pray tell, why???

Quoting aklrno (Reply 6): I realize this suggestion borders on lunacy, but I wonder if it would work if you used one engine and a fast taxi to get the other going. Or if you had a 4 engine plane could you take off on 3 and start the fourth in the air? I certainly wouldn't expect this to happen in any commercial application, but if you had a slightly broken empty aircraft on the ground in a war zone, could you get it out of the area this way?

Well first you'd have to find someone who doesn't value their certificate at all, because trying that will get it yanked, post haste.

Even if that's not an issue, no it couldn't work. Primary reason? You'd be windmilling your compressor blades with nowhere near enough speed. Ground idle is at an RPM that is significantly higher than the airflow you'd find at all points along a takeoff run. This is evidenced when you can "see" thrust (really heat/ambient temp difference of course...) on an idling or taxing AC. It's also why you experience suction anywhere near the front end of a turbine on the ground to the degree that one would. The exhaust (and correspondingly the blade RPM) velocity coming out the back is a lot faster than what you'd be able to get that plane up to on a runway.

A neat thought experiment to be sure. But I wouldn't bet a hard earned certificate on it...

Quoting sccutler (Reply 10): I had a car with an automatic transmission which could be push-started. Who, here, can tell me what kind of car, and which transmission, that was?

Looking at my Chilton's Truck repair manual that covers all trucks sold in the USA from 1955 to 1971, just about any Chevy or GMC light truck with an automatic fits the bill on this   You have to get the vehicle going 20-30 MPH depending on the rear end gearing (with the transmission in drive), and turn the ignition on   Wouldn't work on a modern vehicle, though (due to the federally mandated steering column lockout)  

Quoting lke2fly (Reply 5): It was scary because if the the engine needed to have the APU start it

I worked for a cargo airline that did not have APUs in their DC-8s. Every time a plane left you had to air-start it. During the summer they would only start two engines in gate and then start the others during taxi. Airplanes are air-started all the time. Just an FYI.

Quoting lke2fly (Reply 5): A similar thing happen to me on a AA MD-82 flight from Tennessee to DFW. The right engine started up but fine but the left engine did not. The capt. said that we needed assistance to start the left engine. As I looked out my window I saw the MTC guy drive an APU unit right next to the engine and run some sort of lines into the engine. What he did I have no clue but i could only guess he was jump starting the engine. It was scary because if the the engine needed to have the APU start it, I was hoping the engine would shut off in mid flight. The flight did land safely at DFW..but it was scary.

What you describe is an "air start" and is very common more so than the OP situation. An air start occurs when the APU is inop and it is a common deferral. Since the starts on most airliners are pneumatic they need air to start them. With no APU they have to bring an air start cart or "huffer" to the a/c to put air in the system to start one engine and then they usually push off the gate and cross bleed air from the running engine to start the other engine or engines. What the OP had happen is a bad start valve (also deferrable) but a mechanic has to depending on engine usually puts and 3/8 T handle on the valve and is in communication with the flight deck to tell the mechanic when to open and close the valve.

Quoting wn700driver (Reply 19): believe the quad jet suggestion could be done legally on a ferry flight with no passengers. Not legally. Ferry flights require the amount of power plants the aircraft comes with to be operative at takeoff.

No it does not..You cannot do what reply 6 suggested take off on 3 and start 4th in the air. But you can special ferry with no passengers a 4 engine aircraft on 3 engines
Quote:

§ 91.611 Authorization for ferry flight with one engine inoperative.
(a) General. The holder of an air carrier operating certificate or an operating certificate issued under part 125 may conduct a ferry flight of a four-engine airplane or a turbine-engine-powered airplane equipped with three engines, with one engine inoperative, to a base for the purpose of repairing that engine subject to the following:

(1) The airplane model has been test flown and found satisfactory for safe flight in accordance with paragraph (b) or (c) of this section, as appropriate. However, each operator who before November 19, 1966, has shown that a model of airplane with an engine inoperative is satisfactory for safe flight by a test flight conducted in accordance with performance data contained in the applicable Airplane Flight Manual under paragraph (a)(2) of this section need not repeat the test flight for that model.

(2) The approved Airplane Flight Manual contains the following performance data and the flight is conducted in accordance with that data:

Although it is not always a good outcome
http://www.nytimes.com/1995/02/18/us...ines-ends-in-crash-fatal-to-3.html

[Edited 2011-06-07 20:53:08]

I think we should distinguish between an Air Start, and an external Bleed Air Start.

Air Start is using the Ram Air Effect in flight to get the turbine turning, then adding ignition and fuel.

External Bleed Air Start is using the Bleed Air from a Huffer. Engines don't care whether the Bleed Air comes from a Huffer, APU or Cross-bleed Manifold. As long as the correct pressures and temps are there, they can turn.

Nothing dangerous either about external air.

Erich

Quoting SAAFNAV (Reply 23): I think we should distinguish between an Air Start, and an external Bleed Air Start.

Erich, Here in the US it is common to refer to air start as an external "huffer" engine start and not the ram air in flight start you describe.

Quoting stratosphere (Reply 24): Erich, Here in the US it is common to refer to air start as an external "huffer" engine start and not the ram air in flight start you describe.

Same here in Sweden. If the APU is inop, the crew orders an Air Start, and a big truck arrives (that usually doesn't work because it is only used every 10 days).

We've got this far without us who work on the ramp and call them Air Starts, not realising that the rest of you image this means flying through the air, not pumping air from a truck.

And I would say, more than likely, what happened in the OP's incident was an external Bleed Air start.

Quoting stratosphere (Reply 24): Erich, Here in the US it is common to refer to air start as an external "huffer" engine start and not the ram air in flight start you describe.

Granted, that's understandable to talk about it, IF you already know the procedure and the difference.
People talking about taxiing fast enough to Ram Air Start... Just had to put it out there.


On a by note, the other day a Start Valve was stuck on the C-130. The trainee flight engineer had to get out, put the ladder against the engine, open the cowling and tap the Valve until the Prop started turning.
I sure wouldn't like to be 6in away from a massive prop spinning at ~700RPM.
Regards,

Erich

Quoting SAAFNAV (Reply 27): People talking about taxiing fast enough to Ram Air Start... Just had to put it out there.

I was just in a playful mood when I started that discussion. I'm starting to regret it.

Quoting SAAFNAV (Reply 27): I sure wouldn't like to be 6in away from a massive prop spinning at ~700RPM.

At least he was behind it. Being in front would be much worse.

Quoting aklrno (Reply 28): I was just in a playful mood when I started that discussion. I'm starting to regret it.

Not a bash at you, really. Just so the OP understand it.

Have a good day.

Erich

Quoting SAAFNAV (Reply 29): Quoting aklrno (Reply 28): I was just in a playful mood when I started that discussion. I'm starting to regret it. Not a bash at you, really. Just so the OP understand it. Have a good day. Erich

No probem. No offense taken. Just like to stir the pot from time to time.

In true A.net fashion

Quoting KELPkid (Reply 20): Looking at my Chilton's Truck repair manual that covers all trucks sold in the USA from 1955 to 1971, just about any Chevy or GMC light truck with an automatic fits the bill on this You have to get the vehicle going 20-30 MPH depending on the rear end gearing (with the transmission in drive), and turn the ignition on Wouldn't work on a modern vehicle, though (due to the federally mandated steering column lockout)

The column lock would disengage when you put the key at on as far as I know, engine running or not. Granted it's not push start, but if you're doing 40-50 MPH, put the transmission in neutral, quickly cycle between ON and ACC to shut down the engine, then put the transmission in D again, the engine will restart right away, because there's still enough hydraulic pressure in the transmission (or if the torque converter in engaged).

From a standstill, I doubt it would be easy, but the steering well will definitely be unlocked as soon as you turn the key to ON. I had to coast one time into a gas station that way, ran out of gas at the top of the hill, and managed to make it to the station at the bottom on neutral with the leftover speed. The gas station attendant commented on how my car was very quiet and that he didn't hear me pull in. Indeed it was heh.

Air starts are fun  Did many a huffer jobs in MCO when I sue to work for DL/OH on the ramp back in my early college summers. The RJs were pretty straight forward (just like any a/c I guess. Connect the huffer, start her up (still at idle), wait for the guy on the headseat to give you the signal to introduce air; bring up the pressure, open the valve and wait for #2 to run up fully. Those little DAVCO huffers were pretty LOUD though. Seemed much louder than the newer units used on Delta's narrowbodys.

Quoting FlyASAGuy2005 (Reply 33): Those little DAVCO huffers were pretty LOUD though. Seemed much louder than the newer units used on Delta's narrowbodys.

Sure can get screechy.Talking about The loudest noise would be using a Pneumatic Jet starter on a JT8D  .

Quoting HAWK21M (Reply 34): Sure can get screechy.Talking about The loudest noise would be using a Pneumatic Jet starter on a JT8D .

I think you'd make the faint at heart run and hide behind the shiny, "quiet", green jet engines!!

Quoting HAWK21M (Reply 34): Talking about The loudest noise would be using a Pneumatic Jet starter on a JT8D

I think the BAC 111 starter is MUCH louder than a 737-200 starter.

Correct me if I'm wrong, but I believe the engine start sequence/systems are the same across the 757 and 767.

About a year or two ago I was sitting at LAX aboard my packed UAL 757 ride to Charlotte via ORD (second leg was a US Airways A319 that ended up blowing a tire). Naturally, I dialed in Ch9 and listened in to a rather interesting series of events. We pushed back in to the alley at LAX, and at I heard Engine 1 motor up and catch. I heard nothing from engine 2, and at that moment I heard the lady Captain call for a patch to maintenance. Evidently the start switch was not staying in the GND position, and was immediately snapping back over to OFF.

I listened as 2 other aircraft behind us repeatedly kept asking for updates from our crew as we continued to block the alley. Meanwhile maintenance determined that the engine could be motored over "manually" by holding the engine start switch in the GND position, introducing fuel at N2 20%, and manually switching the start switch back to OFF. It worked and they MEL'ed it to ORD complete with a very bright tag the mx crew tossed up to the flight crew through an open window.

That was a first. More interesting to me was the baffled mind of the Captain and the sharper "willing-to-troubleshoot" attitude of the younger first officer.

Quoting okie (Reply 18): In 56 they changed the shift lever sequence to P-R-N-D-L the in the 55 and previous the sequence was P-N-D-L-R and the Turboglide retained the P-N-D-L-R until its demise in 60 or 61.

I can confidently tell you that my '61 Impala with a Turboglide had P-R-N-D-Gr ; the "Gr" was "Grade Retarder," the Turboglide's way of allowing you to use engine braking.

I was always told that the Turboglide was the only auto you could push start. Then, along comes KELPkid...

Quoting KELPkid (Reply 20): Looking at my Chilton's Truck repair manual that covers all trucks sold in the USA from 1955 to 1971, just about any Chevy or GMC light truck with an automatic fits the bill on this You have to get the vehicle going 20-30 MPH depending on the rear end gearing (with the transmission in drive), and turn the ignition on Wouldn't work on a modern vehicle, though (due to the federally mandated steering column lockout)

...so I guess my whole premise was wrong anyway.

Miss that old '61 with its 348 Turbo-Thrust, and Turboglide.

Quoting mrskyguy (Reply 37): That was a first. More interesting to me was the baffled mind of the Captain and the sharper "willing-to-troubleshoot" attitude of the younger first officer.

Probably because the Captain is responsible for the ship, including the actions of the First Officer ... while the First Officer always has an "out". "The Captain let me do it".

I would guess that Captain was lass baffled, and more cautious.

I remember a similar event happening when I was young around 2000 or 2001. We were flying on a TWA 767-200 from JFK-SJU (the ship was N604TW) and I remember hearing them start engine #1 and not starting #2 (back then single engine taxi was uncommon and not SOP like it is today). The captain came on and said that the starter valve was stuck and they would need to taxi over to the maintenance pad to have them stick a long tool into the starter valve to open it manually. So we taxied from one end of the old T5 (gate 25, over by twy D) over to the maintenance pad across from main terminal (by twy DA). We shut down, and spent about a half hour while maintenance did some work and finally got both engines started. We took off and continued for a normal (and very enjoyable flight).

I always wondered if they fixed the issue while we were waiting or just manually opened the starter valve, since I wondered how they would get the engine started for the return flight.

::Sigh:: I miss TWA and the sound of those old JT9D powered 767's...