Beechjet Anti-Skid Off on the Rollout???

[abenaki]

Could use some input from some Beechjet drivers......

Was talking with some friends today who operate a brandy-new Beechjet. This is their first jet after operating pistons and some turbines for a number of years. Their contract pilot has a "technique", if you will, of choosing to turn off the anti-skid if he looks like he's coming up a little short on runway. His rationale' is that if it looks like he's going to run off the end, it's better to lock up the brakes to avoid doing that. Apparently he did it the other day and flat-spotted two tires to the tune of some major bucks.

Now, this is one I've never heard of anywhere including FSI and flying several planes with anti-skid systems......I figure the best deceleration under ANY circumstances is with the anti-skid on letting the computer set the braking pressure just this side of impending lock-up. Skidding will ALWAYS increase distance used, will it not? I cannot fathom a scenario where turning OFF the anti-skid is going to help.

I figured this "technique" was just another one of those bizarre rationalizations that just don't add up to anything but a lot of hu-ha. Something like the RJ guy I knew who used to used the speed bakes in the flare or the X guy who pops the reversers before the nose-wheel touches down.....not the best idea in a X.

Your comments would be appreciated.

 

[2000flyer]

While not having flown a Beechjet, I just can't imagine turning off the anti-skid system in any aircraft for landings. Sounds like this chap got some bad information somewhere, or devised a bad rational of his own.

I'd hate to see the NTSB final report on this guy should he blow the tires....then run off the runway and they find a perfectly good anti-skid system in the OFF position.

I'd be interested to also hear from Beechjet drivers if this is a common practice.

Regards,
2000Flyer

 

[rice]

Here I sit just shaking my head!
Some yahoo is out there flipping off the anti-skids for apparently no good reason, flat-spotting tires, costing some company lots of dollars and generally making a fool of himself.
And I'm sitting here behind this f%*$en geek machine for the 76th day after being laid off!!!!!! Some things just aren't right in this world.

Sorry guess I just needed to vent.

Y'all have a nice day now,

Rice

 

[stingray]

Who ever is telling your friends to turn off the anti skid is on Crack?
Lets turn it off, so we can now blow some tires. Which almost Happened to them. (2 flat tires)
Turning off the anti skid actually increases the landing distance. (check the numbers)

with the anti skid ON you can get on the brakes as hard as you whant and the brakes should not lock up. (Maximum braking without locking up)

If this guy is ending up with a little less runway sometimes, (Why is that?), does his approachs suck to begin with, extra speed, coming in hi, or floating down the runway to grease it. (doesn't know when to do a go-around) maybe
It sounds like this guy teaching your friends has some piss poor techniques. Keep The Anti-Skid ON

 

[LrBob]

hell blowing a couple of tires in the bahamas sounds like a good idea-a margarita please

 

[Joe Jet Pilot]

What?

Tell your friends to find a new contract pilot. In the beechjet, you do not have anti-skid if the wheel speed is below 24 knots, if I recall correctly.

What some people will do is taxi with the anti-skid off if the breaks are grabby.

All of the normal performance charts are based on anti-skid being on. PM me if you need any additional info.

 

[helpmerhonda]

I would definitely second what joe joe pilot says. You don't want to fly a Beechjet with out the anti skid on or inop condition. You can turn it off for taxi to and from the runway but last before take-off item or call is annunicator panel is clear, ie antiskid light is out. On landing, aircraft at 50 ft over numbers should be Vref and throttles going to idle. Every 10 kts over Vref is equal to 1000' of runway consumed before touchdown due to float. Bechjet landings are easy to grease on compared to the Citation CE-500 thru CE-560 Ultra aircraft. Good idea to dump the yaw damper at 50 ft as well otherwise its difficult to make a highspeed tawi way exit with it on. Dump the yaw damper early like 500 agl and the airplane behaves like a V-tail Bonanza in turbulance. The owners need to get themselves a new pilot who not afraid to make a go-around when things are not quite right. Any way, that's my .02 cents worth.

 

[DLF8108]

YES, KEEP THE ANTI-SKID ON (Beechjet Anti-Skid Brakes)

Flew the T-1A (USAF version) for three years. That model had Anti-Skid protection at speeds greater than 14 kts. The APPROVED braking technique (per the AFM) was to maintain continous pressure on the pedals and let the A/S do its job.

From personal experience, you could feel the A/S cycle if you pressed too hard above 75-90kts (depending on gw)...below approx 60kts at all gross weights the A/S power brakes worked VERY well & the acft decelerated quite nicely...A/S hardly ever cycled at all.

Unless faced with a multiple-emergency or situation wherein the AFM has no guidance...I would FOLLOW THE AFM.

DLF8108

 

[hawkerjock]

The only time I know of to turn the antiskid off on a landing roll is if the brakes are not working. However after 3 long seconds you are to place the antiskid switch back to on and 9 times out of ten the brakes will be there. Seems to be a bigger problem in the Diamond though. Sounds like this guy is jumping the gun a bit.

 

[irapilot]

I think he could get the aircraft to stop sooner if he just left the gear up, right? I mean, it is the same logic almost as turning the anti-skid off. May as well just unfasten your seatbelt too.....might speed the egress from the aircraft.

My gawd, it always blows my mind when pilots "re-invent" the wheel.