New fears over Nimrod spy plane safety

New concerns are being raised about the safety of the RAF's Nimrod spy planes, following an investigation by Panorama.
One of the aircraft crashed in Afghanistan last year, shortly after air-to-air refuelling, killing all 14 people on board.

There have been two serious mid-air incidents since the crash, both after refuelling, the BBC programme found ....

news.bbc.co.uk...

This is quite a scary situation to be in, as (to my knowlage) the nimrod is still the front line RAF spyplane, and is relyed hevly upon by supporting aircraft, if there is a problem with the nimrods mid air refuling then we might be at a sever disadvantage, especially if they have to ground them all.


(edited to fix link )

[edit on 3-6-2007 by asala]

IFR has always been the most dangerous portion of a mission. If there's a problem occurring because of it then it can become a very serious problem. It will cut down on range and loiter time if they have to stop refueling until they fix the problem. We used to have two C-135s that had an IFR receptacle on them, but if they ever tried to use them they'd probably explode they hadn't been used in so long.

It could well be that the Nimrod is a fine aircraft by itself, but in proximity to a tanker aircraft that it's geometry may make it more susceptible to vortices ?

Possibly a redesign of the refueling probe so that it extends a few metres above the fuselage rather than flush with it would help.

Shouldn't forget either the issue of tired crews being asked to do a complex manouvere after hours of monotonous flying. Airline crews would not be allowed to fly such hours because of occupational health and safety concerns.

[edit on 3-6-2007 by sy.gunson]

The first incident involved a failure of the fuel lines INSIDE the aircraft, generating the explosion that caused the loss of the airframe. The probe has worked fine for many years, it's probably just that the fuel lines are getting old, and they're difficult to maintain, buried as deep in the airframe as they are.

Yeah I agree with both Zaphod and sy.gunson, and I would add that part of the problem maybe a critical press crossed with the old bogeyman of the Nimrod's Comet heritage.

However I am surprised that the refueling lines were the pressumed culprit in the Nimrod loss. If they are as deeply buried as Zaph eluded then they should (presumably) be solid fixed lines rather than synthetic flexible ones and regularly flushed to inhibit corrosion. Otherwise if they are flexible then they should be accessible for regular checks and periodic replacement. I should clarify that I am making a guess here as I have not worked with inflight refueling systems. Also hasn't most of the Nimrod fleet undergone major rebuilds and upgrades in recent years? Surely fuel lines would have been checked and upgraded as needed. Or perhaps faulty replacement lines are the problem?

Now here is another thought, what if most of the problems are being caused by tank trimming issues and have little or nothing to do with fuel lines? (the Afghanistan crash not withstanding)

LEE.

It depends on where the lines are at in the system. Some of them are fairly easy to get access to, others are in portions of the airframe that you can't easily get to without doing a tear down inspection. Some of the fuel lines run right over the cockpit, and along the side of the fuselage down to the fuel tanks.

Originally posted by thebozeian
Also hasn't most of the Nimrod fleet undergone major rebuilds and upgrades in recent years? Surely fuel lines would have been checked and upgraded as needed. Or perhaps faulty replacement lines are the problem?

The one that went down last year was an MR2, whereas the rebuild's (MRA4's) haven't entered service yet.

Originally posted by stumason
The one that went down last year was an MR2, whereas the rebuild's (MRA4's) haven't entered service yet.

AWST a few weeks back indicated there may be a major delay in fielding the MRA4's due to funding and tech issues. Has the press in the UK reported anything about that?

The airframe in its basic configuration has been pretty sound over the years, it may just be a run of bad luck.

AWST a few weeks back indicated there may be a major delay in fielding the MRA4's due to funding and tech issues.

This is fairly old news Fred, the IOC of the Nimrod MRA.4 was originally set for 2003, until the tech and funding issues kicked in.

The funding crisis is due to our ongoing commitments in Iraq and Afghanistan, with there also being fears that it could affect our Typhoon and F-35 procurement if it goes on too much longer. The 'tech' issues are, in some cases, quite comical. Early on it was found that the precision engineered CAD designed new wings wouldn't fit the fuselages because, whilst the wings are all modern, precise and accurate to the nth degree, the fuselages were all hand built and each was slightly different to the others. This meant that although the first wing set fitted the plane it was measured up for, none of the others matched *their* particular fuselage and, to further complicate matters, each case of misalignment was different so there was no possibility of a simple universal fix.

Now it has been found that the plane suddenly porpoises in level flight and will not right itself, never a problem with either the previous Nimrods or the Comet and so almost certainly to do with the new wing design and how it distributes lift in relation to the old fuselage and tail. The fix for this is, at least, straightforward but also adds to cost and timescale.

I always wondered why they decided to keep the old fuselages and 're-life' them instead of just building complete new Nimrods, now I guess the RAF and MoD are wondering why too.

I only hope it doesn't go the same way as the Nimrod AEW.3 as their appears to actually be nothing wrong with the mission systems or the planes performance and capabilities, its just the silly little things that nobody considered that are holding things up, along with the perennial lack of cash.

The airframe in its basic configuration has been pretty sound over the years, it may just be a run of bad luck.

I think the stock phrase is 'unforseen circumstances'. Remember though that this is not a simple systems upgrade, the planes are 80% new, including those whizzy new wings and engines, not that its any excuse.