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-   -   Another great escape for Valley Hawk crew! (https://www.pprune.org/military-aviation/525218-another-great-escape-valley-hawk-crew.html)

Force For Good 8th Oct 2013 19:53

Another great escape for Valley Hawk crew!
 
BBC News - Hawk jet makes emergency landing at RAF Shawbury

Said to be XX303, a Hawk T1 from 208 Sqn.

That's two successful emergency landings in a month, both of which ended up in the grass beyond the end of the runway :eek:

TorqueOfTheDevil 8th Oct 2013 22:38

A yellow Sea King arrived on scene within 5 minutes. Bristow will struggle to match that!;)

AGS Man 9th Oct 2013 05:47

One report says multiple birdstrike and another says engine malfunction. Either way another good result for ESCO who make the Barriers now.:ok:

Eclectic 9th Oct 2013 10:11

The chances of losing motive power are obviously far higher in a single engined plane. So it is a good job our new F35s are not single engined.

Doh!

CoffmanStarter 9th Oct 2013 11:51

So glad to hear that the crew are OK ...

Photos here from Shropshire Star

RAF Valley Hawk Emergency

KPax 9th Oct 2013 13:10

I believe that all Hawks were recalled to base with 'possible fuel contamination. Quick question why is the ac sat on it's rear in the first photo.

The Helpful Stacker 9th Oct 2013 14:05


Quick question why is the ac sat on it's rear in the first photo.
Now I'm far from an expert on such things but surely if something which has a pivot point beneath it (the Hawk main wheels) goes through something which is anchored to the ground (the barrier) then the further the item with the pivot moves past the anchoring point the more likely it is that said pivioting item will tip in response to resistance from said anchoring point.

In other words, the barrier is pulling the Hawk onto its backside.

Danny42C 9th Oct 2013 15:04

The Helpful Stacker,

Reckon you're right. There'd be a certain amount of elasticity in the barrier cables, the aircraft would be pulled back onto its #rse, which dug the tailpipe in to the soft ground (look at the wheels).

Which runway would he be on ? I only ask, because when I was there in the mid '60s, one of Marshall's pilots was bringing a Vampire in on the short (23?) runway (must have been half a gale blowing). Anyway, a chap hoeing his turnips in the adjoining field was getting hacked-off with things buzzing in over his head and chucked his hoe at the Vampire. Damn near hit it, too !

Couldn't be any relation of the eyewitness, by any chance ?

D.

jayteeto 9th Oct 2013 21:16

Southerly main runway, ended up just behind the RAPRA factory, or whatever it is called these days. There isnt a lot of choice of decent runways in that part of the world.

AGS Man 10th Oct 2013 04:43

Stacker
You are basically correct.
When an aircraft engages a Barrier firstly a shear pin or similar will shear allowing the top of the net to break away from the stanchion. Tie downs (securing the net to the runway) will also break away from the bottom of the net. The bottom of the net is attached by cables or tapes to the Energy Absorbing Unit (EAU) which will pay out gradually bringing the Aircraft to a halt. As can be seen there is still tension on the net which is what has stood the Hawk on it's tail. Once the brake pressure in the EAU has been released as can be seen in the later pictures the Aircraft is back on 3 wheels. Looking at another picture it could also have used the maximum runout available (note proximity of fence and ditch) which will also have the same effect. I should add that when a Barrier Net or Arresting Cable is under tension like that you never ever go inside the Vee that is formed by the cables and the Aircraft as if something gives way you stand a good chance of losing your head!

6foottanker 10th Oct 2013 15:03

Heard part of the mayday call whilst crewing in for my flight on Tuesday morning. Called as an engine failure by the flight lead, who sounded remarkably calm under the circumstances. Not sure exactly where they were at the time, but lead asked for the wx at Shawbury, so presumaby they were at either med or hi level transit within gliding distance. Overrun barrier engagement would suggest engine out or no hydraulic landing with no brakes, and no chute on a Hawk.

gr4techie 10th Oct 2013 15:52


Quick question why is the ac sat on it's rear in the first photo.
It can also happen. If an aircraft, lets say a GR4 from the OCU just for example ;-) takes the arrestor wire and then applies the parking brake when the wire is still under tension. As the arrestor wire springs backwards, the aircraft will pivot around it's main wheels! Until the taileron is touching the ground and the nose wheel is in the air.

Rhino power 10th Oct 2013 16:52

In the first picture in Coff's link you can see that the RAT had been deployed, its stowed again in the subsequent images...

-RP

Background Noise 10th Oct 2013 17:18

The RAT pops out on engine shutdown (and then retracts as pressure dissipates) so it's unreliable as a means of diagnosis.

Rhino power 10th Oct 2013 20:04

I'd argue that given that the RAT had clearly been deployed before landing, it was actually quite a reliable means of diagnosis, to a certain extent at least...

-RP

Background Noise 10th Oct 2013 20:26

But we can't tell whether it was deployed prior to touchdown.

When the engine was shutdown, during or after barrier engagement, the RAT would have deployed. So it is not possible to determine whether it was out before touchdown.

Rhino power 10th Oct 2013 23:49

Background Noise, am i misunderstanding this? You're saying that the Hawk's RAT is deployed everytime the engine is shut down, even during normal ops? I've never noticed that before...

-RP

Bob Viking 11th Oct 2013 00:25

Another great escape for Valley Hawk crew!
 
RP.
That is correct. As the engine RPM decreases, the hydraulic pressure decreases and the RAT deploys. Without forward airspeed the RAT will re-stow itself as the pressure drops further. I forget the exact pressures for the T1 now. I've flown two other marks since then and old age is kicking in.
BV

AGS Man 11th Oct 2013 08:14

gr4techie
It actually happened at TTTE to Aircraft I40. I was on the RHAG recovery crew that day. Came as a bit of a surprise!

Rhino power 11th Oct 2013 12:53

Thanks for the clarification BV, you learn something new every day! :ok:

-RP


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