777 engine test run

[Waterside 4]

If you're getting tired of cleaning your driveway from snow, well just get one of these ;-)

 

[Rations 102]

It must be quite an experience standing just meters in front of one of the most powerful aircraft! The scene reminds me of one of those beast taming scenes. . . .

[Kerlix 99]

I really love how #2 is sucking up snow and clearing the pavement in front of it. If I could only put on on the hood of my car, I'd never be late to work again. Plows? Pffft. What plows? I make my own path.

[Jeff_B 8]

Nice one.

 

Can someone explain how/why/when this is required? Is it after so many hours on the engine it is req'd? Or the aircraft has been sitting idle for certain amount of time? (picked a fine day to do it!)

 

What are they doing - monitoring the engine parametres (obviously i guess) at different thrust levels/ratings? Who does it - a pilot or engineer?. What exactly is the checklist/criteria for this procedure that must be met / ticked off prior to despatch for next flight etc?

 

Very curious. ((( Iove to be the guy standing in front!! )))

[Boeingtripleseven 1]

To Jeff_B. After the routine maintenance an engine ground run is carried out to check for leaks from serviced components. A run is necessary to build up the required fuel and oil pressure in the various systems. At 80% N1 speed (the fan rotor is N1) the fuel pressure is over 550psi.

[Waterside 4]

Nice one.

 

Can someone explain how/why/when this is required? Is it after so many hours on the engine it is req'd? Or the aircraft has been sitting idle for certain amount of time? (picked a fine day to do it!)

 

What are they doing - monitoring the engine parametres (obviously i guess) at different thrust levels/ratings? Who does it - a pilot or engineer?. What exactly is the checklist/criteria for this procedure that must be met / ticked off prior to despatch for next flight etc?

 

Very curious. ((( Iove to be the guy standing in front!! )))

Haven't tried it on the T7 yet, but did it on the CRJ-200 and ATR a lot. As Boeingtripleseven already has explained is such a test required after bigger checks on the engine or after an engine change.

During an engine test run, you'll check that the engine is running normal and that all systems are working good.

The test run is run by an engineer certified to taxi the airplane and perform these checks there is a special maintenance checklist for these test runs. Well at least at my airline we used special ones, beside of the standard checklist.

[Talek 20]

Wow this so dangerous, if the guy who is standing front of the plane moves a few meters to left or right, he's going to be aspirated by the engine

[Jeff_B 8]

Thanks to the above replies.

[KriVa 307]

Talek: not really....

 

The Inlet danger zones are:

Engine Idle: 15ft (4.6m)

Breakaway Power (just enough to start taxiing): 28.5ft (8.7m)

Takeoff Power: 63ft (19.2m).

 

He's got more than enough room.

[Houghton11 12]

I'm more impressed with the special run-up bay. Never seen one of those before.

[mrifixplanes 1]

Nice one.

 

Can someone explain how/why/when this is required? Is it after so many hours on the engine it is req'd? Or the aircraft has been sitting idle for certain amount of time? (picked a fine day to do it!)

 

What are they doing - monitoring the engine parametres (obviously i guess) at different thrust levels/ratings? Who does it - a pilot or engineer?. What exactly is the checklist/criteria for this procedure that must be met / ticked off prior to despatch for next flight etc?

 

Very curious. ((( Iove to be the guy standing in front!! )))

 

Hi,

 

As that is my video I'd thought I'd give you some insight into how/why/when although Cimber has already explained some of the reasons a test is carried out.

 

At the Engineering base at Heathrow we do what are known as 'A' and 'B' checks, 'A' checks are carried out about every 3 months and 'B' checks are once a year. An 'A' check lasts about 24 hours and a 'B' check lasts about 48 hours with engineers, technicians, and mechanics working around the clock to complete the tasks involved in that check. The tasks include aircraft normal and back-up systems being function tested, serviced, and inspections are carried out and any defects are rectified.

 

After every visit to the hangar, the aircraft is towed into the run pen for an engine run. The type of run varies depending on what work has been carried out and on what systems. A normal 'A' check would result in an idle run only. This is to ensure no leaks are present in the disturbed systems. If the fuel system is disturbed anywhere (even just replacing a fuel filter), a high power run such as this is carried out. The high RPM is required to get maximum pressure from the high pressure fuel pump. Other high power runs are carried out for various reasons. A vibration survey would be one example, using the engine's on board sensors to monitor vibration readings throughout the power range of the engine. The onboard maintenance computer can then calculate if and where any balance weights need to be added.

 

The tests are carried out by a qualified engineer in accordance with the appropriate manual and the appropriate measurements monitored. He is in contact with an engineer or technician on the ground (as seen in the video) via a headset which is plugged into a panel on the nose landing gear. The ground man is there to give the all clear for engine start and run and can notify the flight deck of any abnormailities or safety concerns. Engine intake guards are normally used but on this test, with uncertainty regarding the grip available, the engineer didn't want to take the risk of the aircraft sliding into said guards. Other safety measures were put in place. The ground man is standing as far forward as the headset lead would allow, which is about double the intake safety distance and all other personel are well clear.

 

Wouldn't mind answering any further questions if you have them.

 

Cheers

[Rations 102]

As that is my video I'd thought I'd give you some insight into how/why/when . . . .

 

At the Engineering base at Heathrow we do what are known as 'A' and 'B' checks, 'A' checks are carried out about every 3 months and 'B' checks are once a year. . . .

 

Wouldn't mind answering any further questions if you have them.

Welcome to AVSIM!

 

Thanks for the thorough and well-written response. Can C and D checks be performed at the same location?

[Datalink 26]

 

Welcome to AVSIM!

 

Thanks for the thorough and well-written response. Can C and D checks be performed at the same location?

 

Indeed, welcome to avsim. Thank you for you're videos on YouTube, I always enjoy watching and reading you're responses. I hope you continue to contribute here.

[7neophyte7 30]

I assume that the brakes prevent that the airplane moves? Then they are very strong with such power.

[mrifixplanes 1]

Welcome to AVSIM!

 

Thanks for the thorough and well-written response. Can C and D checks be performed at the same location?

 

 

Kind words indeed, thankyou. C and D checks are completed at the airline's engineering base at Cardiff for 777 and 747, these are referred to as 'Majors'. 767 Majors are carried out at the Heathrow base.

 

 

Indeed, welcome to avsim. Thank you for you're videos on YouTube, I always enjoy watching and reading you're responses. I hope you continue to contribute here.

 

Thanks, I was just looking through the Youtube Analytics page and discovered that Avsim was where quite a lot of the view count was coming from, thought I'd take a look to see what was being written about them here

 

I assume that the brakes prevent that the airplane moves? Then they are very strong with such power.

 

Yes, it's just the park brake holding the aircraft. There are chocks near to the wheels but not right up against them. The 777 has 12 mainwheels and each are fitted with multiple rotor carbon brakes, there are 6 pistons on each brake pack operating at 3000psi. I'd have to measure the diameter of the piston to calculate the force but they are at least an inch so that would give 14137lbs on each brake at least