CV-22 Incident at Addenbrooke Hospital

[750XL]

Forward to 2:20 for the juicy bit!

https://www.youtube.com/watch?v=ObfdLy-QlsU

[NutLoose]

Nothing like a decent pad is there.

[DogTailRed2]

Why was it visiting the hospital?

[750XL]

The 352d Special Operations Wing, located at Mildenhall, will conduct training at Addenbrooke Hospital's helicopter pad, today, April 21, 2021, during the day hours. The CV-22B Osprey will execute medical-transfer training operations and then depart the hospital shortly after. Planners for the exercise have assessed the area and our crews will follow all relevant procedures.
Should you have any questions or concerns regarding the training, you may contact the Host Nation Coordination Cell at [email protected].

Taken from Facebook

[chopper2004]

Forward to 2:20 for the juicy bit!

https://www.youtube.com/watch?v=ObfdLy-QlsU

i was there albeit the opposite and know the lad who took the video, also when the 7th SOS finest arrived on Addenbrookes helipad it as reminiscent of Brown- out / degraded visual landing.

My photos below.


https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/c34b80a6_bb30_4da2_81df_52b9c6b591a9_c555408eb2d6d231a2d7f25 804747375bf5bd030.jpeg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d432deda_8e29_450a_85ec_61e2129e81a3_61e6e4b6559124f948090b2 b55e6c2ca5c1a90a0.jpeg
https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d5dbfb3e_cc96_4919_bc05_6b0ae3acb7db_09146cb502a3c45b8944982 0ff0ffe3c2b3e4d37.jpeg
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/06ffd32e_5fb4_491b_9c8e_980828e56a3f_1bb669091aa597f31d186cc 840a61a3e7946c76a.jpeg

cheers

[27/09]

Slightly reminiscent of the RNZN Wasp that sucked up a tarpaulin and crashed at NZAP while hover taxying on 20 November 1992.

[MENELAUS]

Slightly reminiscent of the RNZN Wasp that sucked up a tarpaulin and crashed at NZAP while hover taxying on 20 November 1992.


I resemble that remark. !!

[Fareastdriver]

Reminds me of the time I picked up Officer i/c SAC from High Wycombe and wrapped the red carpet around CinC Strike Command.

[Mogwi]

I remember BN (Chinook) lifting the PSA1 strip at Port San Carlos in June 82, resulting in 2 X Sea Harriers having to land on the back of Fearless and Intrepid in Bomb Alley to refuel. We received a nice case of wine from Frearless!

Swing the lamp!

Mog

[Asturias56]

I can see a bunch of squaddies being sent to relay the strip...... hope it includes the flight crew!

[typerated]

I can see a bunch of squaddies being sent to relay the strip...... hope it includes the flight crew!

I presume you are under 30 and have this modern affliction of having to comment about everything?

[Bob Viking]

Why exactly do you suggest the flight crew should help to fix it?

Would you expect the people who installed the matting to help fly the Osprey? Probably not I would suggest. So why should the flight crew help to fix something that was probably poorly constructed in the first place?

Not everything can be blamed on aircrew you know. Even if you would love to be able to.

BV

[teeteringhead]

Serious question - if he (or she) had been ON the pad rather than alongside, would that have helped??

[ZH875]

I am sure that the person who designed the Osprey's wing/engine/blade fold/unfold mechanism must have been a Professor of Origami

[Beamr]

I wonder if the exhaust gas heat caused the issue. The matting starts loosing from the corner right under starboard engine exhaust duct.

[57mm]

Looks like the matting was made of cardboard and installed under the usual cheapest contract.....

[golfbananajam]

Planners for the exercise have assessed the area and our crews will follow all relevant procedures.

I'd love to see the assessment that resulted in the temporary? surface being lifted like this.

[[email protected]]

Teeteringhead - I'm with you - if they had actually landed ON the pad it would have prevented it from lifting and avoided digging the nosewheel in so much. Clearly not much of a recce done.

Yes, the flightcrew should be invited back to make amends - no helicopter pilot should be unaware of the problems of downwash, especially on something like a V22, and when you cause damage you should at least offer to repair it.

[charliegolf]

I was on a 230 Sqn Puma display crew with George Blackie in the last century, at a small GA airfield in Germany. We were enjoying the sunshine when a CH53 arrived for its static place in the display. We both looked at each other, the unsaid thought being, "This will be interesting!". Sure enough, a C152 and another light aircraft were flipped upside down- really easily as it happens- and quite badly damaged.

Later, in the bar, we met the crew. George, in his not overly successful version of a 'round-about-it' manner asks, "Do they not teach you f***ers about downwash in the US Air Force then?" The Aircraft Commander, without a thought replied, "That? Pft!, That's nothing but a Class C mishap. Way below the $100,000 threshold. It'll be fine." And ordered his beer. The Germans were, surprisingly, OK about it.

CG

[SATCOS WHIPPING BOY]

It could have been worse, the S$%& could really have hit the fan...

https://www.youtube.com/watch?v=XQcNwDuoxBk

[Sideshow Bob]

Is it the aircrew's fault when Planners for the exercise have assessed the area It's seldom the crew themselves who do the assessment but will get the blame when whoever did the reccie spent more time assessing the refreshment facilities rather than the operational area. Having been on the receiving end of poor reccie more than once, it's not pleasant.

[Background Noise]

Do we know whether this was existing matting or was it laid specifically for this exercise on an otherwise perfectly acceptable helipad?

[[email protected]]

What about a basic 5 S recce before landing or even an assessment of final approach? That is for the aircrew to do.

Even as they pulled pitch to take off, they should have seen the matting started to lift and held on the ground while it was checked for security - very lucky none of it went into the rotors.

[Herod]

Surely Addenbooke has a solid pad, or was it a case of it not being big enough?

[diginagain]

Surely Addenbooke has a solid pad, or was it a case of it not being big enough?
Have a look on Google Earth. Quite revealing...

[BigDotStu]

Surely Addenbooke has a solid pad, or was it a case of it not being big enough?

The current helipad is considered a temporary installation (and the matting is/was part of that). There are those who want it on top of the building, but that is very difficult (i.e. expensive) if the building wasn't built to the right specification to have one on top (and that is more about coping with worst case scenarios than just the structural strength to support the pad). The helipad is also likely to get moved (again) as a result of the continued development of the site...

The pad is indeed a 'cheap' solution - the NHS isn't made of money! I believe there are still occasions when the air ambulance actually lands at Marshalls and they ferry the patient across to Addenbrooke's by road.

[treadigraph]

It could have been worse, the S$%& could really have hit the fan...

You need a Merlin?

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/242x320/hot_air_balloon_hitting_porta_potties_d42af1f079438f43c19da8 75d2954bab60b06ff8.jpg

[NutLoose]

I rebuilt a 152 that had been flipped, we had to buy a backend off one in the USA, then join them together just aft of the windscreen. Pilot (French) was going to Paris but bad weather forced him to divert to Le Touquet airfield, imagine his surprise when out of fuel and with the weather clear he found himself over Kent, he put it down perfectly in a ploughed field in line with the furrows. Unable to fly out the USAF offered a CH53 to lift it, resulting in it upside down with the backend destroyed and the engine shock loaded.

The other was on the OCU when we took a Puma crew down to Fleetlands in a Chinook to collect a repaired Puma, hovering into the place next to the Puma it’s rotor blades did some pretty impressive movement resulting in us departing while they dragged it back in the shed to start again.

[chopper2004]

The current helipad is considered a temporary installation (and the matting is/was part of that). There are those who want it on top of the building, but that is very difficult (i.e. expensive) if the building wasn't built to the right specification to have one on top (and that is more about coping with worst case scenarios than just the structural strength to support the pad). The helipad is also likely to get moved (again) as a result of the continued development of the site...

The pad is indeed a 'cheap' solution - the NHS isn't made of money! I believe there are still occasions when the air ambulance actually lands at Marshalls and they ferry the patient across to Addenbrooke's by road.

A decade ago nearly quarter of a million quid was allocated to a proper helipad and think it was rooftop one a that to be atop or the then aptly named ATC (Addenbrookes Treatment Center). As with all good things money went st elsewhere and never happened.

Personally the temp pad should have stayed as temp pad and priority be given to construct proper hardened areas as with a lot of Hospital helipads in Europe and states.

Anyhow as of Post news, tarmac has been laid replacing the flying carpets, and G-HEMC did fly in albeit hover taxi with folks on board assessing the damage or even post debris clean up.

Minor bit of inconvenience and things be back to normal soon.

Maybe the Trust will invest in proper facilities , but Addenbrookes is a top notch Hospital one of the best in the country. Last big problem they had was several years ago was the introduction of the e-Hospital system as it was horrendous for staff and patients alike. The then CEO (ex Australian Army special forces medic ) resigned honorably as well as the financial director as the hospital was losing few million quid a week with the chaos the e System had.

cheers

[NutLoose]

Call me old fashioned but the problem was they missed the pad and landed beside it, if they had landed on then there probably would not have been a problem as the downdraft would not be trying to get under it from the side.

[Four Wings]

Wouldn't old fashioned PSP have been a better temporary solution (like for the next 40 years like one airport I once visited)?

[Blue_Circle]

Wouldn't old fashioned PSP have been a better temporary solution (like for the next 40 years like one airport I once visited)?
I have to say that as an aviation amateur I was surprised it wasn't made out of soemthing like that already for this very reason.

[sandiego89]

I am sure that the person who designed the Osprey's wing/engine/blade fold/unfold mechanism must have been a Professor of Origami

Actually quite a fascinating story about that in the excellent "The Dream Machine, The Untold Story of the Notorious V-22 Osprey" by Richard Little, that I was just re-reading. The entire book is highly recommended.

Starting around page 126 it discusses the many back and forth discussions of the highly complicated wing stow mechanism and the shipboard compatibility challenges, which drove much of the program compromises. The program was 50/50 between Bell and Boeing, with Boing responsible for the fuselage and the wing stow, but Bell responsible for the wing, and the companies could not agree for a few years on how to meet the two. The whole mechanism had to rotate without distorting the fuselage and had massively complex runs through it. The were over 40 proposals and a whole mix of metal vs composites debates and "bed frame" vs a ring mechanisms for the whole pivot section. Ultimately an old time engineer Bill Rumberger, who still kept glue and cardboard in his desk drawer to help envision designs won out/outlasted others and was nicknamed "Lord of the Ring" by his engineering buddies.

[WB627]

This is what they need if it is just temporary.....

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/600x400/helicopter_landing_mat_osprey_d5da2262dcd3edd5d72f8595cfae75 5b_803a9ae15fc0fb84468039a64e3ed1f039dded52.jpg

Faun Trackway as manufactured by the Viet Taff in Llangefni, Isle of Anglesey,

Used to rescue the Chinook that got bogged down in a field a little while ago.

[unmanned_droid]

Do we know if the matting was laid correctly? Was it pinned to the ground? if not, was it supposed to be?

[charliegolf]

With the space available on the field, they could have concreted a 30m square in 2 days. That ain't going anywhere!

[chopper2004]

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/540x960/f0fac3cb_e5d1_4a7e_910d_836610532fc8_ee0e3e13e6999ec302c2fbd aa62706981865a252.jpeg

[Stuff]

I'm told that the matting that was thrown up was not actually the helipad but was a roadway for ambulances to get to and from the helicopter to transfer patients. The smooth surface provided by the matting is required for patients with some injuries eg spinal fractures. This explains why the matting is behind the Osprey as it starts to lift.

[unmanned_droid]

Yeah I figured that the CV22 did a good job of touching down such that the ramp was right next to the matting.

[West Coast]

I'm told that the matting that was thrown up was not actually the helipad but was a roadway for ambulances to get to and from the helicopter to transfer patients. The smooth surface provided by the matting is required for patients with some injuries eg spinal fractures. This explains why the matting is behind the Osprey as it starts to lift.


Well, that could dispell some posters narratives and pet theories.

[megan]

Looking at the video the matting that blew away is surrounded by lights, such as you would expect around the helipad itself. The presumed roadway can be seen leading away in the background with a sign post, might the sign say something like STOP, or some other directive to an ambulance driver? Don't know how an airborne recce by the crew could have detected anything amiss.

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1279x578/v2_4e88b76c941d8066ebe4f492d289cae5b044dd8b.png

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/960x720/489f601f_84d3_42b3_ae37_c26ed6bb3345_3b810d5fbb5c56049470eb4 07811abf62cb40019_jpeg_7f567e5161179d2cfa445d6bd59fbedfcc687 217.jpg

[Just This Once...]

I'm told that the matting that was thrown up was not actually the helipad but was a roadway for ambulances to get to and from the helicopter to transfer patients. The smooth surface provided by the matting is required for patients with some injuries eg spinal fractures. This explains why the matting is behind the Osprey as it starts to lift.

No, the aluminium matting was indeed the helipad and the CV-22 landed as planned, ramp close to the matting that provides access to the normal helipad area.

So why not land on the aluminium matting helipad?

Well it is a V-22 so, unsurprisingly, aluminium vs jet exhaust would not end well, even if the matting was of the required size & strength.

As an aside in the photo above you can see the rotors pushed to the first forward stop after landing. This minor change of angle made a big difference in reducing heat damage to steel decks & the thermal coating and as an added bonus it provides another option for dust management. They did aim for a slightly bigger angle but you then hit friction limits.

Still, a lesson learned and nobody has proposed a tilting nacelle on future tilt-rotors.

[LowObservable]

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/1313x1566/v_22_landing_c243104ce53c110beabe96c2acc7cf494545ecfa.jpg
My favorite visualization of V-22 downwash...
https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/1954x1143/v_22_pongo_9ffa337088d2e7a456bbc68079baf93f4429b53d.jpg
...including bonus unfortunate Pongo, minding his own business, securing the LZ, and about to be engulfed in a tornado of sh1te.

[Bksmithca]

No, the aluminium matting was indeed the helipad and the CV-22 landed as planned, ramp close to the matting that provides access to the normal helipad area.

So why not land on the aluminium matting helipad?

Well it is a V-22 so, unsurprisingly, aluminium vs jet exhaust would not end well, even if the matting was of the required size & strength.

As an aside in the photo above you can see the rotors pushed to the first forward stop after landing. This minor change of angle made a big difference in reducing heat damage to steel decks & the thermal coating and as an added bonus it provides another option for dust management. They did aim for a slightly bigger angle but you then hit friction limits.

Still, a lesson learned and nobody has proposed a tilting nacelle on future tilt-rotors.
Interesting I had two thought about why they didn't use the landing pad. First was the fencing around the site. It looked close to the pad and I was thinking that the nacelle might have ended up on top of the fence. Second was watching the video I assumed that the pad was a heavy rubber pad that I seen used for temporary construction roads here in Canada. If the pad was in fact aluminum then yes the engine exhaust likely would have melted the pads.

[Mogwi]

I would have thought that pad melting would not be a factor. The Harrier was quite happy landing on aluminium planking and I never saw a melted pad. Aluminium is a very effective transmitter of heat, so local hot-spots disperse rapidly.

Mog

[Just This Once...]

Hi Mog - The Harrier had no operational need to point the hot nozzles directly at the deck for 20 minutes or more, let alone at the temperature and gas velocity produced by the Osprey. Even when pointed at the deck the Harrier hot nozzle environment is partially offset by the cold nozzles - hence why you could do press-ups without killing the main gear tyres. In comparison, the M/CV-22 had little difficulty eroding & buckling coated steel decks that had been routinely operating AV-8A/B for decades.

[unmanned_droid]

Interesting I had two thought about why they didn't use the landing pad. First was the fencing around the site. It looked close to the pad and I was thinking that the nacelle might have ended up on top of the fence. Second was watching the video I assumed that the pad was a heavy rubber pad that I seen used for temporary construction roads here in Canada. If the pad was in fact aluminum then yes the engine exhaust likely would have melted the pads.

Pretty sure its heavy plastic plates. It's kind of besides the point though.

I suspect the CV-22 is too big to land on the pad comfortably, and chose to approach, land and depart the way they did to give themselves enough room against the fence, the lighting, the signage and what looks to be a waiting area on the way to the landing pad, but still allow the ramp to neatly meet the access pathway for transfer by gurney.

The only real issue for me is that the matting does not look to have been fixed to the ground so any blast of air impinging sideways on the matting was likely to lift it. For helicopter ops I imagine this isn't an issue, but I'd still want to do it anyway. This particular use case probably never occurred to the people planning it - maybe when it was designed there were only MH-53s and MH-60s around, or maybe those design assumptions were brought forward instead of re-assessed or maybe they didn't or couldn't consult this particular 'customer'. Lots of potential holes in the cheese, could have been filled with some pegs.

[LowObservable]

If I recall correctly, the damage mechanism in cases like this is not simply wind blast. Upon encountering the ground, the downwash flow has nowhere to go except sideways and expands as a high-velocity sheet, which results in lower-than-ambient pressure because Bernoulli, and since there is air under the matting there is a pressure differential, and it doesn't take a lot of delta-PSI over hundreds of square feet of matting to generate useful lift.

I recall John Fozard saying that this phenomenon was not fully understood before early P.1127 tests until a cast-iron manhole cover became airborne during a VTO event, to the general discomfiture of those present.

[stagger]

It could have been worse, the S$%& could really have hit the fan...

https://www.youtube.com/watch?v=XQcNwDuoxBk

Off topic - but those tumbling portaloos remind me of a time I was visting one - and part way through my efforts, I was treated to an unexpected low-pass by, what I discovered when I emerged, was a Dassault Rafale practicing for an airshow that would take place later in the week.

I quite literally did, what I was in there to do!