EE Lightning Question Re. Cable Engagements

[Madbob]

The F.6 I think had a hook fitted and could engage RHAG-type arrestor gear.

The question is, was this a once-only use if the approach end was engaged or were multiple engagements allowed before the airframe became too "stretched"?

What was the max weight and speed for engagement? Was this an airframe limit or the max energy absorbing limit of the arresting gear?

Are there any first hand stories to tell?

MB

[JW411]

I watched one at close quarters from the cockpit of my Belfast at the holding point of 09 at Gutersloh whilst he tried to take the touch down RHAG at Gutersloh after a hydraulic failure.

Unfortunately for him, despite touching down on the first bit of concrete in the undershoot, the hook bounced right over the cable and there he was gone at speed down the runway.

He managed to stay on the runway for a bit but then swung off into the boonies in a cloud of dust. A fast-moving bonedome shortly afterwards reassured us that he was OK!

[lightningmate]

Approach-End RHAG engagements were not cleared for the Lightning, overrun only. The Gutersloh event may have been a displaced main wheel alignment problem rather than hydraulics; therefore a bit unusual. Whatever, the aircraft was not stressed for approach end RHAG engagements.

lm

[norwich]

I know nothing about your quest for info, but do have this photo of the hook, City of Norwich Aviation Museum.

Keith.

http://i261.photobucket.com/albums/ii58/keithnewsome/nch%20museum/DSC_0037.jpg

[JW411]

ATC told me to hold while they recovered a Lightning in an emergency with a hydraulic problem.

He came down finals with the hook hanging down and touched down on the first few feet of the concrete undershoot (about 1000 feet before the touch down RHAG).

Why would he have done that unless he intended to hook the RHAG?

Whatever the problem, we felt sorry for him when the hook bounced over the wire.

[lightningmate]

The reason the hook bounced and missed the cable is apparent from the illustration norwich has posted. Essentially, the hook shoe is on the end of a strip of 'spring-steel' with no means of holding the shoe firmly down, apart from the spring effect and gravity. Hence, when the aircraft lands with the hook deployed the shoe will re-bound off the runway initially and invariably miss the cable. Aircraft with an approach-end RHAG capability have additional means of holding the hook shoe on the runway at touch-down, although hook bounce can still occur.

The Lightning hook was never intended for approach-end engagements and release was only anticipated when firmly on the runway and heading for the overrun cable.

I have no idea why an apparent pre-meditated approach-end engagement was contemplated at Gutersloh, had the wire been hooked, consequent airframe damage may well have been worse than anything occurring due to the hydraulic problem.

lm

[CharlieJuliet]

The Aircrew Manual (dated June 82) that I have says that the arrester hook fitted to the F Mk6 is cleared for use at all aircraft weights. It also says that use with the RHAG Mk 1 is safe up to speeds of 170 knots. Given a touchdown speed of 165 knots approach end engagements should be OK. I remember that on one occasion one of the pilots lowered the hook early to take the overrun cable, and by the time the aircraft arrived there the hook was worn out!

[JW411]

Isn't it interesting how some say that what I observed cannot be done whilst others say that it was perfectly OK.

I know less than nothing about Lightnings but I have regaled at least three of my WIWOL mates with the Gutersloh tale and not one of them told me that I must be mistaken.

[320psi]

:bored::bored::bored::bored::bored::bored::bored::bored::bor ed::bored::bored:

[BOAC]

There was a recurrent requirement to 'practise' RHAG engagements. I did one at Leuchars. I cannot recall the speed restriction, but it was traditionally done on the 'approach end' cable, starting as far back as possible towards the start of the runway, and engaging both burners. I would guess less than 100kts would be right.

If I recall correctly, in an emergency the hook was 'normally' to be dropped AFTER passing the approach end cable, if rigged. Apart from anything else, it would make a mess of OC Ops' runway otherwise!