Crossing Military Arrester Gear

[The Real Slim Shady]

Arriving at a joint civil / military base in Southern France yesterday I was advised that the arrester gear was raised 7 cms above the runway.

I elected to land between the 2 gears, 1 at the touchdown end and the other at the stop end and taxi over the stop end gear very slowly, less than 10 kts GS.

I couldn't find any info in the AOM or Ops Manual about trampling arrester gear but can't see that my little airliner is designed to cross them at speed, especially when a CHAG (Chain Arrester Gear) is a variation on a QE2 anchor chain!

Any opinions or definitive references for info?

[Techman]

Boeing's Aero magazine had an article about this a few years ago.

Read all about it (http://www.boeing.com/commercial/aeromagazine/aero_13/runway.html)

[Linton Chilcott]

The military operators of our type of small turbo prop (J31) apparently use a 10 knot limit for trampling a raised arrestor gear.

Because we have different engines / propellers, we have adopted a 5 knot limit just in case.

Note that, normally, the approach cable will be DOWN: rubber grommets are pulled to the sides of the runway, therefore the cable will be flush with the runway, or even recessed into a slot in the tarmac. In this case, there will normally be no limit to the speed for crossing it.

The overrun cable is often UP: In this case, trampling it at speed may cause it to bounce up after the gear crosses it, snagging undercarriage doors or props. It's normally up, so that a military aircraft suffering brake failure on landing can simply drop the hook and snag the Rhag.

Changing from UP to DOWN normally takes about 10 minutes (ground staff have to drive out to the cable, and slide the grommets to the sides of the runway).

Cables are normally positioned about 1000 - 1500 feet in from the thresholds.

I would not aim to land, or take-off, rolling across a raised cable. And if landing beyond a raised approach cable, it may be difficult to see / judge where the cable actually is.

[The Real Slim Shady]

I chose to land between, and take off between the cables - no performance problem, rather than trample them at any speed just in case the cable kicked up after the nose gear ( two high pressure chined tyres) passed over.

My concern was that the aerials and drains on the underside of the fuselage may be damaged if the cable was lifted into the fuselage and / or it may damage the main gear or strut.

If it is sufficiently robust to stop, say an F4, it wouldn't have much trouble stopping a 36 tonne twin jet !

[MMEMatty]

I recall reading an "I Learned About Flying From That (ILAFFT)" article about a chap who was cleared for an immediate take off at a joint civil / mil airport in the states as there was a big fast mean fighter jet coming quickly down the approach. So he trundles out, noswheel goes over the rope very nicely, thankyou very much, but the mainwhells of his C150 do a very good impression of a naval aircrafts arrestor hook, and snags the aircraft nicely on the runway.

Unalbe to go back, and with the arrestor cable stopping forward motion, our intrepid narrator decides to apply throttle. no luck. more throttle. still nothing. only with full throttle and his passenger pusing the cable down to let the wheels pass over it (if my memory serves me correct) lets the aircraft continue. He takes off and the fighter has a late clearance to land.


If there was a point to me reciting this story, i have long since forgotten what it was.


Matty