Initial interview at SFO Oct. 3rd

[HeavyWrenchFlyer]

Hi everyone, Just got the call for the Oct. 3rd intitial int. at SFO for the DEFO so I'm going into high gear getting ready. If anyone has the latest gouge especially what used to be in the few hotmail accounts I would really appreciate it if you could e-mail it to me at since the few hotmail accounts seem not to be working anymore. Also what are the latest recommandations on prep material? Reading thru the posts it seems like they might have changed the old material... or have they?!!

Thanx in advance.

[extreme P]

The gouge is now online, no more hotmail accounts. www.jetthrust.com
Look under general aviation discussions.

[HeavyWrenchFlyer]

Thanks, but the site seems to have problems lately, can't register. But I'll keep trying, thanks anyways.

[shroom]

I may try to change my date because of a scheduling conflict, but if I can't I will be in SFO on the 4th.

[Beech19]

duff Gen

Hi guys

I've also got an SFO interview coming up. I've been going through 'Ace the technical pilot interview' , but some of the answers don't match up to some of my other books. Have any of you had any similar problems?

The discription of dutch roll says that "...the outer, upward wing stalls and loses all lift..." isn't it the fin that causes the oscillation?
Another is the question "how does VMCA/G vary with C.G. position" is VMCG not based on the rudder and main gear? or is it affected by C.G. the same wat VMCA is.

Would appreciate a bit of light.... Cheers

[Avee8tor]

Originally Posted by Beech19

Hi guys

I've also got an SFO interview coming up. I've been going through 'Ace the technical pilot interview' , but some of the answers don't match up to some of my other books. Have any of you had any similar problems?

The discription of dutch roll says that "...the outer, upward wing stalls and loses all lift..." isn't it the fin that causes the oscillation?
Another is the question "how does VMCA/G vary with C.G. position" is VMCG not based on the rudder and main gear? or is it affected by C.G. the same wat VMCA is.

Would appreciate a bit of light.... Cheers

ACE has many, many errors in it and not just the harder to understand questions, real simple ones are in error.

The dutch roll is initially started by the action of a yawing moment. This causes the outboard wing in the yaw to travel outwards changinging it's angle of attack and "projected" length to the airflow. This causes it to create more lift starting a rolling movement and so the cycle begins. Thats why you stop the roll with ailerons and not the rudder.

[600rvr]

1st interview

Handling the big jets has a decent explanation of dutch roll, you can find it on amazon or other book websites, the latest issue also has some interesting stuff on the 747. I just had the 1st interview, just got a call for the second, the training captain at the interview was really big on performance questions. Ie: what is v1, vr, v2, why are they what they are, what are they predicated on. Why is the split on the 744 between v1 and vr larger on the 744 than a small corporate jet, (my current ac) he was also big on segment climbs, diff between stopway, clearways, and what exactly is balanced field length etc... The performance section in ace is a pretty good help. hope this helps....

[HeavyWrenchFlyer]

I have found quite a few mistakes in various technical prep books in answers, explanations and calculations, 'Ace the technical ...' by Bristow and the one by Air Inc. .

The one book that ALL these books can't even come close to when it comes to accuracy is 'Aerodynamics for naval aviators', it's a bit dry to read but it's top info which the other books try to emulate. It doesn't cover weather and such though, just aerodynamics, propultion, performance, etc...

[cpnkirk59]

To Beech19

You asked "Another is the question "how does VMCA/G vary with C.G. position" is VMCG not based on the rudder and main gear? or is it affected by C.G. the same wat VMCA is".

The calculated VMCA/G that you read off the charts doesn't change - it's been calculated on the worse case condition, i.e. an aft CG. This is because the moment arm between the CG and rudder is at its shortest and is at its weakest in terms of having a "center of pressure" that controls the the Yaw in an engine out situation. So, the real answer is that VMCA/G goes down with a forward CG - based on the one condition thats been chosen, i.e. some of the others can be calculated and some can't and they are put in the various charts. Things like most critical engine, windmilling and/or feathered props are also assumed when applicable. Density altitude is calculated into the various charts for the obvious reasons. Any questions?

RP

[cpnkirk59]

Heavywrenchflyer

I have an interview on the 3rd also, at 3pm. My name is Randall Bancroft and I'll look for you.

RP

[Beech19]

Climb gradients

Thanks for those answers guys.

Here's another that has me stumped

" Do large twin engined jets climb out at a steeper angle than 4 engined jets?
If so why?
Why do the have more excess thrust?"

Okay, the part of the question helps answer the first 2 parts. But i can't find any answers as to why Large twins would have more excess thrust.

Thanks for the help

[extreme P]

Engine failure on a twin means you lose 50% of your thrust vs: 25% on a four engine machine thus the steeper climb angle.

[Beech19]

Thanks Ex P, that makes sense to me.

But with all engines running, is your thrust to weight ratio approximatly the same on a twin as it is on a four engined?

[HeavyWrenchFlyer]

Originally Posted by Beech19

Thanks Ex P, that makes sense to me.

But with all engines running, is your thrust to weight ratio approximatly the same on a twin as it is on a four engined?

Higher thrust to weight ratio for a two engine aircraft compared to four engine. If 100,000 pounds of thrust is needed for a 700,000 pound aircraft to meet the climb requirements (FAR 25.121) in case of loss of one engine then each of the engines would have to be rated at 100,000 pounds giving the aircraft 200,000 pounds of total thrust. The 777-300ER has 230,600 pounds of total thrust (115,300 each) and has a max gross weight of 759,000 Ibs.


But if the same weight class example aircraft has four engines then it would only need 133,000 pounds of total thrust, so if one engine is lost on takeoff (33,000 pounds of thrust) then it would still have the 100,000 pounds of thrust available to meet the performance criteria. The 747-100 has 184,000 Ibs of total thrust (46,000 Ibs each) and has a max gross weight of 735,000 Ibs.

The comparison of these two aircrafts' power to weight ratios shows the differrence.

There's no requirement or guarantee for a transport category aircraft to lose more than one engine on takeoff and be able to continue if at max takeoff weight. There are enroute two engine out requirements that require slightly more thrust than what I used in my example four engine aircraft, and there are ETOPS requirements and considerations which raise the two engine aircraft thrust even higher than what's needed for the one engine out takeoff climb such as ability to maintain higher altitudes on one engine for fuel burn range reasons.

[Beech19]

Thanks

Cheers HeavyWrench, appreciate it

[HeavyWrenchFlyer]

Cheers,