Forum: General F-22A Raptor forum

"Increment 3.2 was to add an improved SDB capability, an automatic ground collision avoidance system for low level operations and ..."

So he had the software to cut off his oxygen supply (he couldn't reach the emergency pin because he was strapped down in bulky cold weather clothing), but he didn't have the ground avoidance software that was planned, but not ready in time.

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hcobb wrote:

"Increment 3.2 was to add an improved SDB capability, an automatic ground collision avoidance system for low level operations and ..."

So he had the software to cut off his oxygen supply (he couldn't reach the emergency pin because he was strapped down in bulky cold weather clothing), but he didn't have the ground avoidance software that was planned, but not ready in time.

This is just a continuation of what seems to be a recurring impression that the "software" is somehow wrong and to blame. That's just not the case. The software was designed based on the hardware, and it functioned per design.
The simple fact is that for this hardware failure you have to make a choice. Do you:
(A) Isolate the leak (close the valves) to prevent a potential fire, with the consequence that OBOGGS will shut off and the pilot will have to rely on an alternate source of oxygen.
Or,
(B) Leave the valves open to maintain however much O2 flow to the cockpit you can get, with the consequence that you are significantly increasing the risk of fire.
Obviously, choice A was made. Made years ago by the program (LM and USAF) in consideration of all the tradeoffs and consequences based on the best data available. The "software" simply executes this choice, and it functioned as designed and expected.

Again, I come back to the pulling of the ring as the big issue. Seems to me like they should not allow gear in the cockpit until the have adequately demonstrated that you can still perform key functions (like pulling the "ring") with any/all combinations of "stuff".
One thing I find curious in the report was that there was no mention of the RAM air selector position. As I posted earlier, he seems to have skirted right along the edge of the ram air envelope, but that is a key element of the air cycle system and it seems like it should have at least been mentioned.

As to the auto-GCAS reference above, I would be curious to see where you got that. The thing is that AGCAS development has been started and stopped several times (via customer funding on, funding off), for at least the last 7 years. Last I heard (several months ago) it was back to off, with no plans to implement, but that has probably changed since then (possibly more than once).

Salute!

Gonna go with you, Raptor-Claw.

The emergency oxygen doofer should be easy to reach regardless of how you are dressed.

I also don't understand a "panic" if the complete air system shuts down ( aircraft action or manual action) to the cockpit. Unless that jet has an extremely leaky cockpit, there's plenty of air to breath at 50,000 feet if cabin altitude is 14,000 feet or so - the 5 psi delta most jets use. That number comes from my Viper and Sluf and Voodoo experience back in a galaxy far away. So take off the mask and breath what's left in the cockpit until lower.

Sad deal, and disturbs me.

Gums sends...

Gums wrote:

Salute!

I also don't understand a "panic" if the complete air system shuts down ( aircraft action or manual action) to the cockpit. Unless that jet has an extremely leaky cockpit, there's plenty of air to breath at 50,000 feet if cabin altitude is 14,000 feet or so - the 5 psi delta most jets use. That number comes from my Viper and Sluf and Voodoo experience back in a galaxy far away. So take off the mask and breath what's left in the cockpit until lower.

I'm curious if the pilots on the forum can comment on whether removing the mask would be allowed or recommended per check lists or training in this situation?

Another question, would alerting lead of the situation have been normal/recommended?

I remember a situation at Hill where a pilot had a "smoke in the cockpit" situation and alerting lead allowed him to pass a step that help clear the cockpit to the task-saturated pilot...

ruderamronbo wrote:

Gums wrote:

Salute!

I also don't understand a "panic" if the complete air system shuts down ( aircraft action or manual action) to the cockpit. Unless that jet has an extremely leaky cockpit, there's plenty of air to breath at 50,000 feet if cabin altitude is 14,000 feet or so - the 5 psi delta most jets use. That number comes from my Viper and Sluf and Voodoo experience back in a galaxy far away. So take off the mask and breath what's left in the cockpit until lower.

I'm curious if the pilots on the forum can comment on whether removing the mask would be allowed or recommended per check lists or training in this situation?

Another question, would alerting lead of the situation have been normal/recommended?

I remember a situation at Hill where a pilot had a "smoke in the cockpit" situation and alerting lead allowed him to pass a step that help clear the cockpit to the task-saturated pilot...

I'm not USAF (active, yet) but from the Air Force Auxiliary (CAP) leadership training I've received, mixed with common sense, informing flight lead about a potentially serious situation would be highly recommended.

Raptor DCTR, your right, why was ram air not selected as the air source immediately after the bleed hot caution not mentioned or identified as a contributing factor, A two minute review of the data recorder. How much would this change the scope of the investigation?

Why exactly is terrain avoidance software not standard in all modern aircraft? Price?

Price and reliability. How would you like to test that one. 99.999% of the time it wouldn't be needed so i dint think they could even justify the costs.

Terrain avoidance software in various forms has been in modern jets like the F-16 for years. This software tells the pilot to pull up to avoid collision with the ground/water. However, an unconscious pilot can't respond and a disoriented pilot may not be able to respond properly in time. What that software doesn't do is automatically take control of the jet to prevent collision with the ground/water. The technology to implement AUTO ground collision avoidance has been available for many years. It has been thoroughly tested and works well. It is costly; but, the cost is easily justified when you count the number of aircraft destroyed and pilots killed because the system wasn't available. Combat capability improvements frequently win out over safety improvements (i.e. don't believe the safety is paramount blab); and, there are those who don't think the jet should automatically take control away from the pilot.

Forum: General F-22A Raptor forum

F-22 oxygen system malfunctioned moments before crash