Testing the brakes during initial taxying

[Centaurus]

Have just watched fascinated the flight of an original FW190.

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

As the aircraft starts to taxi, it stops momentarily as the pilot tests the brakes and then continues to taxy.
A gentle touch of the brakes after the aircraft had rolled a few feet was a technique widely taught in the military when I learned to fly in 1951 and has been part of flying training in many civilian flying schools even today.

Airliners don't do it, however, and I wonder why?

[Chesty Morgan]

I do it. I'd much rather know they work before I need them.

It may be a hangover from my first type, 146, on which we had to test both brake systems, IIRC. But I also seem to remember it being written in the Part A back then.

[HeartyMeatballs]

The A32S does. A gentle tap of the breaks ensures the brakes are functioning correctly and are being supplied by the correct hydraulic system.

[Dan Winterland]

And if the A320 has the new hydraulic architecture, you do it anyway, just to make sure they're working. No need for the PM to check the system has changed over to green though.

[bugged on the right]

It's a good idea, like a brief prod during the early part of the landing rather than the later. A300 was a check for no pressure on the brake indicator.

[Genghis the Engineer]

It was normal when I was backseating British military aircraft under flight test in the mid 90s.

It's normal on the couple of civilian flying schools that I instruct with now.

So far as I know, it's pretty universal.

G

[Herod]

Doesn't everybody do a quick dab on the brake in their car? Much more likely to fail than those of an aircraft.

[ZeBedie]

Never had the brakes fail in a car. Aeroplane, more than once.

[JW411]

Always checked the brakes on taxi-out on every aircraft I ever flew.

[SRS]

brake check on Airbus aircraft was required but not on any Boeing aircraft I have flown.

[Captain Dart]

It is a requirement in my airline to do a brake check on initial taxi in the A330 and A340.

I also always do it in the military trainers that I fly. Especially the Nanchang with pneumatic brakes.

[ICT_SLB]

Nearly lost my coffee every time with the brake check on our flight test aircraft - and that was after both the electrical & mechanical hydraulic pumps had been verified during start.

[evansb]

Early aircraft had mechanical brakes, and older aircraft with hydraulic brakes seldom have redundant, let alone brake failure warning light systems like a modern motor car.

During pre-flight walk-around, a cursory look at the brake cables, (if mechanical), checking for obvious leaks, the condition of the hoses/lines and the thickness of the pucks, if visible, was not just de ri·gueur but necessary.

I remember flying the Bristol 170 Freighter equipped with pneumatic brakes.
Regardless what the air pressure gauges read, it was considered prudent for the pilot to check the effectiveness of the brakes more than once prior to take-off. The moisture contained in the air of the aircraft compressor frequently froze before it could reach the brake shoes during winter at Arctic latitudes. Also remember only two wheels had brakes on the Bristol, not six wheels or more like on a modern airliner.

With all the redundant safety systems in a modern airliner, I personally consider testing the brakes during taxi a throw-back to simpler times, i.e. a tradition. One invariably has to brake the airliner prior to taking the active runway anyway..which I would consider a pre-flight test.

Here is a photo of an upgraded Beech 18 brake. To paraphrase Yogi Berra, "You can see a lot of things just by looking.."
http://i1047.photobucket.com/albums/b477/gumpjr_bucket/Beech%2018%20mod.jpg

[emeritus]

I recall back in the 50's when flying the Aero Clubs Auster one always tested the brakes to confirm that they were still inoperative !!

Emeritus.

[Centaurus]

It's a good idea, like a brief prod during the early part of the landing rather than the later

Interesting. I have never heard of that before on any aircraft type. Caution however. Don't try that on an aircraft that doesn't have anti-skid brakes otherwise a good chance of bursting a tyre at high speed. Plus a sure way to tip it up on the nose if landing a tail-wheel type

[Johnflex]

Not a good idea to check immediately after landing in case of a "Lock On" and never on a wet runway for two reasons. 1. Possibility of Aquaplaning. 2. If the wheel does not spin up straight away due to standing water superheated steam can eat the rubber!