F15s Showing their age ! !

[Pete Da Bear]

Am I the only one to notice the rise in IFE situations at Lakenheath and resulting "taking the cable" landings ? 4 or 5 since 21 Jan to my knowledge, also an increase in jets going "tech" on the ground. Idle speculation on my part but I wonder if age is catching up with them or maybe a change in maintenance programs. Maybe even a tightening up of criteria that deem an aircraft airworthy. Interested to know others thoughts and if anyone has inside info they are able to share.

[reaper493]

Over the years, I've seen a fair few jets at LN declare IFE's for something trivial, I think it's just the way they do things in the US.

A USAF exchange pilot on a typhoon once requested the cable at Coningsby as he had a warning light in the cockpit, he requested the fire engines and ambulance were all waiting at the end of the runway, and to follow him back to parking whilst he was being towed.

Could it also be down to LN being monitored more then ever, with the drawdown of the C's and the arrival of the F-35s?

[Blackcat1]

Well they are 35 . I ache a lot these days so I sympathize

[raptor9]

Guess it would depend somewhat on what the warning light was referring to!!. It wouldn't be just a warning light. They all mean something.!

[Pete Da Bear]

by reaper493 » Mon Mar 07, 2022 3:50 pm

Over the years, I've seen a fair few jets at LN declare IFE's for something trivial, I think it's just the way they do things in the US.

A USAF exchange pilot on a typhoon once requested the cable at Coningsby as he had a warning light in the cockpit, he requested the fire engines and ambulance were all waiting at the end of the runway, and to follow him back to parking whilst he was being towed.

Could it also be down to LN being monitored more then ever, with the drawdown of the C's and the arrival of the F-35s?

Indeed the USAF does work in mysterious ways. Even before the uptick in monitoring though an emergency landing drew comments due to the rarity of such events.

Well they are 35 . I ache a lot these days so I sympathize

35 years of having the granny caned out of em so yes no surprise things are less robust nowadays.

[Crusty]

I imagine a lot of it will be Avionics and other Electrical systems, over time things like Capacitors dry out and the more delicate components succumb to the 1000s of hours of vibration.
Anything from original build that's still present will be well tired now

[Snoop 95]

I imagine a lot of it will be Avionics and other Electrical systems, over time things like Capacitors dry out and the more delicate components succumb to the 1000s of hours of vibration.
Anything from original build that's still present will be well tired now

Just like my 25-month-old washing machine!!!

[Andy_99]

I agree they do seem to be declaring a number of IFE's recently although added to that the Spotters car park & forest entrance at the Heath are more crowded than ever so more people to witness the events.

One thing that's become apparent in the last few weeks is the uptick in the number of people with eye's on tracking sites & buying scanners, Covid I think started the craze with people being restricted to home taking more of an interest on what's in the skies around them. Then of course you have the Ukraine situation with clips from Flightradar, Freedar etc. showing people that anybody can see what's going on (although they don't grasp that the aircraft they see want to be seen).

The number of posts on the various groups on FB asking 'What's he doing circling there' or 'Why did the Typhoons disappear from tracking' being 2 of the most asked questions.

Obviously the the media have cottoned onto this as well with the Endless 'No Story scoop Stories' I think one of the best so far was 'RAF Typhoon Jets Witnessed in Lincolnshire Skies' in a Lincolnshire based paper.

[Phil Standfield]

I agree they do seem to be declaring a number of IFE's recently although added to that the Spotters car park & forest entrance at the Heath are more crowded than ever so more people to witness the events.

One thing that's become apparent in the last few weeks is the uptick in the number of people with eye's on tracking sites & buying scanners, Covid I think started the craze with people being restricted to home taking more of an interest on what's in the skies around them. Then of course you have the Ukraine situation with clips from Flightradar, Freedar etc. showing people that anybody can see what's going on (although they don't grasp that the aircraft they see want to be seen).

The number of posts on the various groups on FB asking 'What's he doing circling there' or 'Why did the Typhoons disappear from tracking' being 2 of the most asked questions.

Obviously the the media have cottoned onto this as well with the Endless 'No Story scoop Stories' I think one of the best so far was 'RAF Typhoon Jets Witnessed in Lincolnshire Skies' in a Lincolnshire based paper.

Try being in the South/West with Devonlive reporting, also Dorsetlive going the same way. Don't have a hot drink while reading them

[bizfreeq]

They really are poor aren't they!

[Andy_99]

We had 'Military Jets Spotted in the North East & Yorkshire' today.

Shock Horror

[gyvespa]

“ I imagine a lot of it will be Avionics and other Electrical systems, over time things like Capacitors dry out and the more delicate components succumb to the 1000s of hours of vibration.
Anything from original build that's still present will be well tired now”

Possible but unlikely.

Solid state stuff doesn’t dry out and is sealed in a ‘can’ containing helium which is inert so nothing corrodes or oxidises.

Electronics in military aircraft are VERY high quality. Thoroughly tested, aged by baking, thoroughly tested again. Often to limits tighter than the specification requires to allow for any slight drift due to age or temperature. All assemblies are spun in a centrifuge to at least 5000G, some higher spec stuff is 10000G. Samples are also vibrated, salt sprayed and generally tortured then tested again. If anything fails then the whole batch is put under scrutiny.
All results are kept for 10 years (I think) in case of problems. The equipment that you need to test it costs about the same as a decent house (yes really).
The whole manufacturing process from procurement to assembly to testing is rigidly laid down by MIL Specifications.
Think of the worst job for paperwork that you’ve ever done then double or triple it and audits are a real giggle too (not).
Once you realise the specs that they are made to, remember that you then have dual or triple redundant systems as back up plus being a digital system there is some degree of error checking too.
In case you are wondering, nope civvy stuff isn’t quite up to the same spec as a rule, still good quality though.
Hydraulics are often an issue because seals do dry out and perish, flexible hoses too. I’m sure these parts are made to a tight specification but they are wear items with a limited lifespan.
In case you are wondering I’ve worked in both industries.

Some bedtime reading
https://en.wikipedia.org/wiki/MIL-STD-1553

[TealRain]

“ I imagine a lot of it will be Avionics and other Electrical systems, over time things like Capacitors dry out and the more delicate components succumb to the 1000s of hours of vibration.
Anything from original build that's still present will be well tired now”

Possible but unlikely.

Solid state stuff doesn’t dry out and is sealed in a ‘can’ containing helium which is inert so nothing corrodes or oxidises.

Electronics in military aircraft are VERY high quality. Thoroughly tested, aged by baking, thoroughly tested again. Often to limits tighter than the specification requires to allow for any slight drift due to age or temperature. All assemblies are spun in a centrifuge to at least 5000G, some higher spec stuff is 10000G. Samples are also vibrated, salt sprayed and generally tortured then tested again. If anything fails then the whole batch is put under scrutiny.
All results are kept for 10 years (I think) in case of problems. The equipment that you need to test it costs about the same as a decent house (yes really).
The whole manufacturing process from procurement to assembly to testing is rigidly laid down by MIL Specifications.
Think of the worst job for paperwork that you’ve ever done then double or triple it and audits are a real giggle too (not).
Once you realise the specs that they are made to, remember that you then have dual or triple redundant systems as back up plus being a digital system there is some degree of error checking too.
In case you are wondering, nope civvy stuff isn’t quite up to the same spec as a rule, still good quality though.
Hydraulics are often an issue because seals do dry out and perish, flexible hoses too. I’m sure these parts are made to a tight specification but they are wear items with a limited lifespan.
In case you are wondering I’ve worked in both industries.

Some bedtime reading
https://en.wikipedia.org/wiki/MIL-STD-1553

Thanks, a very enlightening post, for me anyway!

[Malcolm]

Mil-Std-883 is the environmental & quality standard normally called up - years of reading should anyone be interested. If you are interested report to a psychiatrist immediatley.

Mil-Std-1553 is a communications standard. Technically, F-15 doesn't use 1553 because it's a McDonnel Douglas product - it uses MacAir, although the differences are small.

European aircraft also don't technically use Mil-Std-1553 either - They use Stanag3838, and Typhoon additionally uses Stanag3910.

Yes I've spent too long in this game

[CookipediaChef]

I imagine a lot of it will be Avionics and other Electrical systems, over time things like Capacitors dry out and the more delicate components succumb to the 1000s of hours of vibration.
Anything from original build that's still present will be well tired now

If it moves, or it gets hot, it goes wrong.

[gyvespa]

Malcolm

‘ MIL-STD-1553 is a military standard published by the United States Department of Defense that defines the mechanical, electrical, and functional characteristics of a serial data bus’

‘mechanical’
1553 sort of covered what I was trying to get across.
Yes there’s lots of standards, all tedious in their detail.
But as you appreciate I did try to simplify my explanation.

If household products were made to these standards they would last for absolutely ages and probably cure the electronic waste problem. If only people could afford to buy them.

As for the psychiatrist. Nearly 30 years in the industry does have an effect, shift work, tedious testing, repetitive operations, temperature controlled environments. I worked for 20 years plus in a room that didn’t even have a bl**dy window, no natural light at all.

Not good for the soul. That’s why I got out.
It could be interesting though, just not often enough.

Take care.

[Malcolm]

Malcolm

‘ MIL-STD-1553 is a military standard published by the United States Department of Defense that defines the mechanical, electrical, and functional characteristics of a serial data bus’

‘mechanical’
1553 sort of covered what I was trying to get across.
Yes there’s lots of standards, all tedious in their detail.
But as you appreciate I did try to simplify my explanation.

If household products were made to these standards they would last for absolutely ages and probably cure the electronic waste problem. If only people could afford to buy them.

As for the psychiatrist. Nearly 30 years in the industry does have an effect, shift work, tedious testing, repetitive operations, temperature controlled environments. I worked for 20 years plus in a room that didn’t even have a bl**dy window, no natural light at all.

Not good for the soul. That’s why I got out.
It could be interesting though, just not often enough.

Take care.

Yeah, get all that. Have you still got your personal copy of the Brown DDC book

There was another spec that I was struggling to remember - Mil-Std-810. Still sends shivers down my spine.

[Pete Da Bear]

Many thanks to those who've added some fascinating incites into this topic. No surprise that there are very rigorous standards to be met. I'm sure that there is even more that goes on, into the realms of it really is "rocket science".

[teeonefixer]

Ah, good old MIL-STD-810E- I let the people with real brains sort out the qualification details with vendors!

Historically, Phantom and Buccaneer suffered from poor electrical connections or breakdown of wiring, especially difficult to address when it is built deep into the airframe. Better and later standards means that is mostly cured on modern types.

But aeroplanes, just like cars, become naturally more difficult to keep serviceable as they get older. Apart from accrued fatigue damage to be monitored and repaired, there's normal wear and tear as you keep removing and refitting parts, Environmental (corrosion in all its forms) and Accidental damage (tools slipping off or using adjacent structure to lever off stubborn parts, not only causing physical damage but also damaging the protective paint leaving a corrosion risk). This all adds up to more maintenance manhours and less aeroplanes on the flightline each morning. Then on the older platforms there is availability of parts & systems components. Many small manufacturers have been taken over by conglomerates who aren't interested in producing a handfull of Mk.1a widgets when the Mk.25 is in full production !

[page_verify]

The availability of spares is a problem for some USAF fleets, especially for those built during the 80s and 90s (F-22, B-2, B-1, F-15 etc.). Those fleets don't have a Boneyard with hundreds of spares in them nor do they have industry partners who can still make some of the much needed replacement parts. Older fleets don't have it easy either albeit for other reasons, but it's easier to get or make a replacement carburettor for an Austin Healey than it is an engine management unit for a 1989 BMW etc.

This shortage of spares within some fleets doesn't mean safety is compromised but it does mean reliability has dropped.