Monthly Archives: September 2015

The Big Flip, part 2

It’s happened – the aeroplane has done the first ever barrel roll inside the ASTC! It’s now belly up and ready to be mounted onto the whiffletree.

You can see a video of the action below. Our plan to flip the plane was successful but it was a tense few minutes as we didn’t know for certain that it would work .

Make sure to come back later this week to see the video of us mounting the aeroplane onto the whiffletree.

Tubes + balls = damage

It’s been another busy work at the ATSC!

The fully assembled plane!The wings are now on the aeroplane (Yay!!)…… but we’re now taken them back off! (Boo!)

The client visited our workshop last Friday to put some damage into the structure of the plane – this is all part of the tests we’re carrying out and the reason that it’s done is to investigate the ‘Damage Tolerance’ of the aeroplane.  If the aeroplane is hit during operation or tools are dropped onto it during servicing it may cause damage to the composite structure. This damage may be invisible to the naked eye but may have caused disbonds in the layers of composite. If the airframe is capable of still meeting the fatigue test with these damages introduced at the start of the test it is assumed that it will be good whilst in service. During the tests we will monitor the points where the damage has been applied to see if the surface/structure shows any sign of the damage increasing.

Drop testingTo create the damage a steel ball is dropped from a known height onto the surface of the aeroplane. If we know the height, weight, and the acceleration due to gravity (g) we know the potential energy (PE) the ball has – physics tells us this is mass x g x height. The formula gives us the PE in Joules and we make the assumption that all of that energy is transferred into the structure of the aeroplane. The impacts were carried out at three different energies so the ball has been dropped from three different heights via three different tubes cut to the appropriate lengths.

On completion of the impact damage routine we then assembled the wings onto the fuselage however the client then decided that some additional damage should be applied to the wing spar so the aeroplane is currently being disassembled.  Hopefully we can re-assemble it in the next few days and then do The Big Flip next week (we’ll keep you posted!).

In other news we’ve maintained our UKAS accreditation for flexible scope testing following our annual surveillance visit! This is an independent assessment of our testing and having this accreditation means that any customer can be sure of our test methods, and that the data that we supply back to them is traceable to an internationally used system of measurement (The SI system)  Well done team!

Photos from top: The aeroplane with wings attached!,  one of the wings with marks of where the damage has been applied (the damage is often invisible to the naked eye).

ASTC’s interesting fact of the week.

56 years ago the first man-made object to reach the surface of another celestial body impacted the lunar surface. The Russian satellite Luna 2 was launched to the moon 2 years before Yuri Gagarin became the first man in space – Russia was miles ahead in the race for space!

On the 16th September 1992 the UK left the European ERM (Exchange Rate mechanism) when interest rates peaked at 15% – how times change!

ASTC’s interesting fact of the week.

On the 8th of September 1854, John Snow removed the handle of a water pump in Broadwick street London.

This was not an act to of vandalism to frustrate the locals! He had been mapping the areas that sufferers from an outbreak of cholera lived, already suspicious that the disease was from contaminated water, he found that the pump was at the centre.

The discovery saved thousands of lives. The John Snow pub stands by the site of the pump to this day.

Have a safe drink for John tonight!

It’s no strain with these gauges

This week we have been wiring the gauges up. Big Steve has been working on getting the wires from those gauges onto the wings of the plane so we can send the recorded information to our data acquisition system.

We have switched everything round on the shop floor. The main plane fuselage has been taken off the work bench and instead the plane wing is sitting proudly on it so we can work on placing the wires for the strain gauges onto the wing. Some of them are in particularly tight spots so it’s important we have good access to the wing. We have placed wiring for the strain gauges onto the main wing spar and this is where we are looking at gathering our strain data from.20150908_141219_resized To do that, we have laid very fine wires along the structure of the wing spar which have then been threaded through and appear further along the wing. From here, we can connect them to our data acquisition system. The wing spar will slot into the spar of the other wing and they will be pinned together and can be attached to the fuselage of the aircraft.  We have been using these giant lollipop sticks to give us a bit of clearance so we don’t damage the wiring when we install the wings. The wire is extremely fine and fragile so it’s crucial they are well protected… and it gives everyone in the office an excuse to eat their body weight in Magnum ice creams, so there have been no complaints from the team (no ice creams were harmed in the course of the installation)!

The project is progressing and we are moving forward with the instrumentation. The wing is finished and we have to wire up the gauges on the vertical stabiliser and then we will be in a position to start fitting the wings together in preparation for the big flip, which will hopefully be soon – time is flying!

In addition, Phil has been creating attachment eye bolts with necks that will be sitting at the top of the Whiffletree. 20150908_141844_resized (1)He will attempt (how very cheeky!) to gauge up the eye bolts to see if we get a good response in measuring the loads from each point at the top of the whiffle tree. This should give us a better understanding of what is going on within the structure, so fingers crossed!

The boys have had their paint brushes out and painted the fuselage of the plane, it’s looking very smart. The cleaners have been in to have a bit of a talk to us, so we are on our best behaviour to keep the workshop area clean.

Little Steve’s boiler has broken, he’s had to come to the AMRC especially early this morning so he can have a shower, desperate times call for desperate measures. Lynne has been on her holidays to whisky country on the west coast of Scotland (alright for some!) and Shane has also been to Scotland. He has been to Prestwick, Glasgow to support the AMRC at the Spirit Aerospace 10 year anniversary. They were doing an airshow which featured the Vulcan, but more impressively they had created a giant plane balloon structure which took 6 hours to make (Shane is a bit disappointed he couldn’t stick around long enough to help pop all the balloons!). 20150908_141737_resized (1)Also the team has been keeping their energy up with a diet of sandwiches, crisps, hob nobs digestive biscuits and chocolate – the Whiffletree project is hard work so it’s vital the office stays at peak performance.

 

Photos from top: Painted plane fuselage, strain gauges featuring lollipop sticks, Phil’s eye bolt and office rations.

 

Getting it right first time

Steve and Steve have started laying the strain gauges. They’ve been cleaning and degreasing the surfaces and have already laid about a quarter of the total required.

There is a lot more to laying a gauge than just sticking it on, including cabling and testing it afterwards – we are getting there though. We’re taking our time as we like to get things right first time.

It’s a bit quiet in the Centre this week as there are only four of us in. There is just the two Steve’s and our two apprentices (and they take a bit of managing ). In actual fact, Jake has been with us for exactly three years today, which officially means he has finished his apprenticeship. He’s looking for a promotion already!

The loading profiles have also arrived from our customer so we can start looking at programming and doing the documentation. The load cell that is going on the end of the actuator has gone off for calibration.

Jake has been machining some eyelets so we can put strain gauges on the whiffletree so we can monitor what loads different points of the rig are seeing and also working on building and attaching the two clevises that are going to be attached to the front right wing of the plane.

The customer is also popping by this week to check on our progress. We’ll start looking at fitting the wings soon so exciting times!