B737-800 AUTOBRAKE Adjustments
Joined: Sep 2010
Posts: 1,954
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From: England
LSM, 3250psi hydraulic pressure might be available to the braking system, but not necessarily the pressure used for RTO, thus 3000psi is max? Yet even this may be reduced due to anti-skid protection – which is a function of runway surface etc. Is this what you were implying?
Now, however, I suspect that whoever wrote our manuals used 3000psi for RTO as that is what the hyd. system normally produces as a maximum.
Maybe we used the same authors as Denti's mob!
Joined: Jan 2000
Posts: 860
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From: FL410
RTO uses all available brake pressure and maintains the additional capabilities of the auto brake system with their advantages.
Overriding the auto brake will allow you to put more than the available pressure onto the braes but you will loose the additional safety functions integrated within the system.
Due to the loss of the additional safety features, it is recommended NOT to override unless required, in other words, let the RTO function do its job, it's what it's designed for after all and your performance calculation is based upon that capability. Sometimes overriding is not a better option..., even if it enables additional pressure to be applied.
Overriding the auto brake will allow you to put more than the available pressure onto the braes but you will loose the additional safety functions integrated within the system.
Due to the loss of the additional safety features, it is recommended NOT to override unless required, in other words, let the RTO function do its job, it's what it's designed for after all and your performance calculation is based upon that capability. Sometimes overriding is not a better option..., even if it enables additional pressure to be applied.
Joined: Sep 2010
Posts: 1,954
Likes: 0
From: England
How can you get more than available pressure?
You may be interested to know that our EFB take off performance is predicated on using max manual braking for an RTO.
Such as?
You may be interested to know that our EFB take off performance is predicated on using max manual braking for an RTO.
additional safety functions integrated within the system
Joined: Jan 2000
Posts: 860
Likes: 0
From: FL410
Such as:
- Symmetrical braking
- controlled antiskid protection (when changing pressure using manual braking the antiskid system needs to re-adjust before engaging once more)
- engagement and proper use of the Brake Modulating Valves (Left and Right)
- autobrake shuttle valve working as commanded
- Symmetrical braking
- controlled antiskid protection (when changing pressure using manual braking the antiskid system needs to re-adjust before engaging once more)
- engagement and proper use of the Brake Modulating Valves (Left and Right)
- autobrake shuttle valve working as commanded
Joined: Mar 2007
Posts: 570
Likes: 21
From: Another Planet.
Fact: Too many aircraft of any type are over-running the landing surface due to inadequate braking in some of these accidents.
Just stop talking about it and DO it, if the cicumstances so require?!?!
Just stop talking about it and DO it, if the cicumstances so require?!?!
