Dear all,

I have been observing the pre-flight walk around performed by airline pilots before take-off on many smaller jets, including E-195, A320 series and 737. This walk around also includes a look into the engine, probably to make sure no damage has occurred from FOD or bird strikes.

Now, I wonder how this is done on larger jets, where the engines are hanging a couple of meters above ground (in particular the outer engines of a quad). I would guess that the pilot will be handed over a ladder or similar.

Finally, I totally struggle to imagine how this check is performed on tri-jet's nr. 2 engine: a bucket truck would probably be necessary to get you to the required height, but you won't see anything on a Lockheed Tri-Star unless you take a wild toboggan slide down the S-duct...
So, would the nr. 2 engine be waived from this inspection, assuming their position sufficiently reduces the risk of damage?

Many thanks for enlightening me!
Hendric

I think (wild guess!) that most large jets are normally only flown for 1 sector, and then the daily inspection will be done by the engineers. So any FOD, bird strikes or other damage will be spotted by them. Smaller jets like the E-jets and the 320 will do multiple sectors, with no engineer tending to the aircraft. So any damage will have to be discovered by the pilots. Not sure how high up the engines are on a CRJ, so interested to hear how it's done on T-tail aircraft.

Double Post...........

With Large aircraft AMT's will perform required servicing and do a pre-flight inspection prior to flight. So for the flight crew, a walk around is somewhat redundant as the aircraft has already been verified as airworthy and released for flight. Sometimes the F/O or F/E will do a walk around and other times not. Final acceptance of the aircraft for flight is always at the flight crews discretion.

IDK about a Tri-Star, but on a B-727 there is an access door at the bottom of the S-duct for inspecting the engine fan. The preflight is performed by AMT's using any equipment required to meet the preflight requirements.

I suppose the risk of damage decreases the further away from the ground the engine is, so the problem does resolve itself somewhat.

The empennage is also fairly high up and there's some stuff to look at there. A good flashlight is essential.

TOGA10 wrote:

I think (wild guess!) that most large jets are normally only flown for 1 sector, and then the daily inspection will be done by the engineers. So any FOD, bird strikes or other damage will be spotted by them. Smaller jets like the E-jets and the 320 will do multiple sectors, with no engineer tending to the aircraft. So any damage will have to be discovered by the pilots. Not sure how high up the engines are on a CRJ, so interested to hear how it's done on T-tail aircraft.

Plenty of widebodies flying about in Asia on 2-5 hour sectors.

I think you are missing the point. The aircraft is inspected by shop and inspection and is not released to the flight crew until it is serviced/inspected and verified as airworthy. Go into any airlines records and you will see how this is set up in a fail safe manner to insure only an airworthy aircraft is released for flight.

stratclub wrote:

IDK about a Tri-Star, but on a B-727 there is an access door at the bottom of the S-duct for inspecting the engine fan. The preflight is performed by AMT's using any equipment required to meet the preflight requirements.

The TriStar also had a fan access door in the S-duct.

I think you are missing the point. The aircraft is inspected by shop and inspection and is not released to the flight crew until it is serviced/inspected and verified as airworthy. Go into any airlines records and you will see how this is set up in a fail safe manner to insure only an airworthy aircraft is released for flight.

BA operates B767-300ER on European flights. They will have a maint inspection around midnight, then the flight crews do the PDI for the four sectors until the following night. No maintenance involvement unless called.

The TriStar also had a fan access door in the S-duct.

Been in there many times! But this door was not accessible to the flight crew. It required a tall set of steps, then opening the engine cowls, (or crawling in through the oil inspection door, not recommended as the area was full of oil and water) The engine cowls were big and heavy.
But maint did not access the Nbr 2 engine fan on every transit. Only when required (like when it was snowing)

stratclub wrote:

I think you are missing the point. The aircraft is inspected by shop and inspection and is not released to the flight crew until it is serviced/inspected and verified as airworthy. Go into any airlines records and you will see how this is set up in a fail safe manner to insure only an airworthy aircraft is released for flight.

Engines that wouldn't be normally accessible (think MD11, L1011, B727, etc) from the ground will usually have a card assigned to look at the engines at a prescribed interval. At my operator, the #2 engine of the MD11 is looked at, at a minimum, every 9 days. The 9 day hard time is applicable to all our aircraft/engines. And, it's just a general visual inspection for damage.

Maintenance does perform a visual inspection of the #2 inlet during snow and freezing precipitation. This is to ensure the inlet is free from debris, and not a check of the engine, per se.

Starlionblue wrote:

I suppose the risk of damage decreases the further away from the ground the engine is, so the problem does resolve itself somewhat.

I don't have data to support this, but I know, I've worked on blades/inlet cowl on the inboard engines of B747 than the outboard.

stratclub wrote:

I think you are missing the point. The aircraft is inspected by shop and inspection and is not released to the flight crew until it is serviced/inspected and verified as airworthy. Go into any airlines records and you will see how this is set up in a fail safe manner to insure only an airworthy aircraft is released for flight.

Inspection does nothing on transit checks and nowadays on shorter sectors aircraft are no longer looked over nor released by maintenance.

7673mech wrote:

Inspection does nothing on transit checks and nowadays on shorter sectors aircraft are no longer looked over nor released by maintenance.

Maybe where you work

7673mech wrote:

stratclub wrote:

I think you are missing the point. The aircraft is inspected by shop and inspection and is not released to the flight crew until it is serviced/inspected and verified as airworthy. Go into any airlines records and you will see how this is set up in a fail safe manner to insure only an airworthy aircraft is released for flight.

Inspection does nothing on transit checks and nowadays on shorter sectors aircraft are no longer looked over nor released by maintenance.

Still there would be an "A" check by maintenance on a calender basis and be returned to service until the next "A" check. That would be correct, wouldn't it?

Probably to answer the OP's question, depending on the specific operators operating environment, Inspection of anything that could impact safe operation of an aircraft is looked at according to the operators F.A.A approved maintenance plan. Like others have said, is the center engine inspected at every transit stop? No, not unless there is a compelling reason to because being so far off of the ground the chance of FOD is pretty remote. Also, anytime the engines are running, vibration is monitored in real time so that if there is a problem the flight crew can take immediate action well before there is a catastrophic failure.

My experience is mostly air operations for Manufacturing Flight Test and our "mission" is somewhat different than what carriers do. Our version of a transit check is also fairly abridged as well but isn't used very often because usually config and instrumentation changes are made between flights which take the aircraft off of released for flight status.

Even if maint have done a check during a turn, five mins walking round a plane you are responsible for does no harm. Maybe someone forgot or got distracted and there was an obvious problem visible on an engine inlet. No harm in a second pair of eyes for a once-over and it might just spot something that could've caused a problem.

With higher up engines it's still worth having a look- you may not be able to see the whole fan but might spot an inlet dent or possibly some blood. And unless it's a calm day engines are often spinning so you may see all the blades.

chimborazo wrote:

Even if maint have done a check during a turn, five mins walking round a plane you are responsible for does no harm. Maybe someone forgot or got distracted and there was an obvious problem visible on an engine inlet. No harm in a second pair of eyes for a once-over and it might just spot something that could've caused a problem.

With higher up engines it's still worth having a look- you may not be able to see the whole fan but might spot an inlet dent or possibly some blood. And unless it's a calm day engines are often spinning so you may see all the blades.

You are right, two pairs of eyes see more than one. But often times a walk around check performed by the flight crew looks like they just check whether the expected numbers of wheels, engines and wings are present.
For the #2 Engine on the MD11 for example, we don't check the inlet duct/fan during transit-, daily- and weekly checks. You can see the inlet cowl and the turbine blades from the ground, if they look good and the engine parameters are good, the engine is probably good. The walk around check is to be performed specifically "from the ground" according to our maintenance job cards.

Tristarsteve wrote:

...But maint did not access the Nbr 2 engine fan on every transit. Only when required (like when it was snowing)

Starlionblue wrote:

I suppose the risk of damage decreases the further away from the ground the engine is, so the problem does resolve itself somewhat.

The empennage is also fairly high up and there's some stuff to look at there. A good flashlight is essential.

TOGA10 wrote:

I think (wild guess!) that most large jets are normally only flown for 1 sector, and then the daily inspection will be done by the engineers. So any FOD, bird strikes or other damage will be spotted by them. Smaller jets like the E-jets and the 320 will do multiple sectors, with no engineer tending to the aircraft. So any damage will have to be discovered by the pilots. Not sure how high up the engines are on a CRJ, so interested to hear how it's done on T-tail aircraft.

Plenty of widebodies flying about in Asia on 2-5 hour sectors.

Of course. Forgot about that, we don't see that too often here in Europe.

Preflight checks started with small aircraft, where you could see more.
It's a tradition that's been here for a long time.
It's not an assumption that a preflight check sees EVERYTHING that could be wrong. It's added insurance to possibly spot anything that doesn't look right.
Due to this, if the engine is too high, you don't look at it. It doesn't mean there's not other regular maintenance and checks at regular intervals.

Thanks to all for the highly interesting insights!
Hendric

The walk-arounds are done when pax and baggage are being loaded. Decades ago, I was taught that the rampers are to check that doors and panels are flush (fuselage and nacelles). Is that still the case?

WPvsMW wrote:

The walk-arounds are done when pax and baggage is being loaded. Decades ago, I was taught that the rampers are to check that doors and panels are flush (fuselage and nacelles). Is that still the case?

Yes. We also confirm that they've done so with the call "Cockpit to Ground, confirm all doors checked, closed and locked" before pushback.

Chemist wrote:

Preflight checks started with small aircraft, where you could see more.
It's a tradition that's been here for a long time.
It's not an assumption that a preflight check sees EVERYTHING that could be wrong. It's added insurance to possibly spot anything that doesn't look right.
Due to this, if the engine is too high, you don't look at it. It doesn't mean there's not other regular maintenance and checks at regular intervals.

Well said. The 'tradition' part cannot be overstated. Could walkarounds be skipped? Yes, but ask any US pilot who has done it since his first C-150 flight or his first T-37 flight, and he would probably reply with an incredulous "what?". It's just a last visual inspection to give the pilots a warm fuzzy and still required by all US airlines as far as I know. The only time during my 40 year mixed career that it was omitted was during an active scramble in F-4s. As an aside, it was nice to have a big wing and fuselage overhead (like a 747) while doing a walkaround when it was raining cats & dogs in DTW or SEA.

RetiredWeasel wrote:

As an aside, it was nice to have a big wing and fuselage overhead (like a 747) while doing a walkaround when it was raining cats & dogs in DTW or SEA.

If you’re under the wing or fuselage, are you really doing a good walk-around?

fr8mech wrote:

RetiredWeasel wrote:

As an aside, it was nice to have a big wing and fuselage overhead (like a 747) while doing a walkaround when it was raining cats & dogs in DTW or SEA.

If you’re under the wing or fuselage, are you really doing a good walk-around?

Of the 100 plus items stated in the Operating Manual that you have to check, probably 75% of them could be seen by not sticking your body too far out into the rain. Some though would require stepping out into the open, but the airframe did provide some relief from 'looking like you fell into a swimming pool.'

Why have I never seen a walk-arounder holding an umbrella? Or wearing a shell or parka? Even in SEA!
Is the flight deck umbrella a MEL item?

WPvsMW wrote:

Why have I never seen a walk-arounder holding an umbrella? Or wearing a shell or parka? Even in SEA!
Is the flight deck umbrella a MEL item?

Some FO's/SO's did carry small umbrellas. However most front end aircrews like to pack very light because US airlines require the pilots (and flt attendants) to roll/carry their bags everywhere. The pilots, before EFB's, also had 25 lb flight bag to carry also, so few packed rain gear. Winter overcoats were carried if operating in the North during the winter and they were a pain to carry around. The airlines (at least the one I worked for) were too cheap to include umbrella's in the aircraft for walkaround use.

While my statement was made tongue-in-cheek, I do appreciate the drawing. I do have one disagreement with it, and will check our AOM concerning the path to be followed. If you want to get a good sense of the condition of your flight controls, flaps included, you really need to walk about 10 feet aft of the wings, especially when that wing starts so far up. That way you get a decent look at the trailing edge, where a considerable amount of damage occurs.

I’ve seen flight crew walk around with an umbrella. Personally, I don’t think they’re much use, because a big part of the walk-around has you looking up.

Many carry small umbrellas in their flight bags. It seems like an item that would be lost a lot if it came with the plane.

At my operator, heavy winter jackets are added to the cockpit closet when the winter season starts and removed when it ends. You might not always be able to distinguish the jacket from a distance because there's a high viz vest on the outside.

Thanks for the picture of an official walkaround route.

When I started at a Line Mtc station in 2005 DL did not have a 'official' mtc route. We were given a checklist of items to check on the night layover. Each mechanic made their own route. Same was true at a couple of turboprop airlines I had worked for in the 90's.

After the NW merger our program added a lot of the NW paperwork. Most of which the DL guys found to be geared towards mechanics that had never seen a plane. I have always gone counter clockwise around the plane. The new official walkaround was like the drawing, clockwise. One of the very young (never seen an airplane before NW) guys thought it crazy that I would continue to do my walk counter clockwise.

One of the very young (never seen an airplane before NW) guys

How can you inspect an aircraft for condition if you have never seen one before. Surely you must have some training before you do a walkround?

Dalmd88 wrote:

Thanks for the picture of an official walkaround route.

The picture in our AOM has the crew walking counter-clockwise, with the line behind the wing.

As for maintenance, I know I’ve seen one, but can’t find it anywhere. As I recall, it was a CCW walk-around that mimicked the flight crew’s, or did the flight crew’s mimic maintenance?

Personally, I think the diagram is a loose guideline that the individual will tailor to their particular circumstance. As long as the required places are looked at, you should be good.

Tristarsteve wrote:

One of the very young (never seen an airplane before NW) guys

How can you inspect an aircraft for condition if you have never seen one before. Surely you must have some training before you do a walkround?

Simple they are guys straight out of A&P school. They were hired by NW to break an AMFA strike. They had what one would call a 'wet ticket' AKA the ink on their A&P isn't dry it's so new. The only experience they had was what NW told them. Premerger DL hired very few low experience A&P and sent them directly to Line mtc. Most spent a few years in ATL working heavy checks and had years of military or commuter airline experience.

Things are different now. I know a couple of guys that work as airframe fleet teams. The guys you call when you are really stumped for a solution to an ongoing problem. One guy called them for a inop nav light. So what have you done far? Nothing, what should I do? Try changing the F**king light bulb before you waste my time, was their answer. Fixed, move along, nothing to see here folks. That is the next Gen of mechanics. They did not grow up fixing stuff on the farm or working on Dad's race car. My first boss said, "I grew up on a farm" was the magic phrase to get hired in his shop. Jim had a bunch of faults, but he was 100% correct on that fact. Farm boys and girls can fix shit with very little help.