Aspen Slope 2% ???

[Lead Sled]

DP climb gradients are not dependent upon the number of operating engines and should not be confused with FAR 25.111 takeoff path or 25.115 takeoff flight path obstacle clearance requirements. Rather, the IFR DP climb requirements represent a "plane" below which an aircraft should not penetrate while conducting a normal ("all engine") IFR departure. There was never an intention of making this a one-engine inoperative requirement as this was already addressed by the operating regulations, Subpart I, FAR 121 &135.

An FAR 121 or 135 operator should have performed an analysis for obstacle clearance with a continued takeoff with one engine inoperative after V1 as required by 121.189(d) or 135.379(d). You can have a contractor like Jeppesen Op's Data compute the analysis for you, or if performance data in not available in Jeppesen's computer database for your aircraft, you can receive the "raw" obstacle data and do the computations yourself using the climb gradient and takeoff flight path charts provided in the AFM. You will find, in many instances, that a special engine out departure procedure is provided as an escape route for a continued takeoff with one engine inoperative. This may or may not follow the ground track of the published DP.

If you operate under FAR 121 or 135, a VFR departure does NOT relieve you from meeting your one-engine inoperative requirements under 121.189(d) or 135.379(d). For example, electing to depart KASE and flying VFR "down the valley" doesn't make you legal in this sense.

There are no one engine inoperative obstacle requirements specified in 91.605 for FAR 91 operators. The only requirement is comply with the minimum one-engine inoperative climb gradient for certification (2.4% gross gradient 2nd segment, etc).

Engine-out obstacle clearance doesn't end at 1,500 ft either. FAR 121 &135 operators also have a requirement for enroute obstacle clearance. It is for this purpose that the net enroute climb gradient charts are provided in the AFM. These operators must demonstrate either a positive net enroute flight path that clear all terrain & obstacles 5 SM either side of track by 1,000 ft, or that the net enroute flight path allows for a continued flight from cruising altitude, following an engine failure, to an alternate airport (as specified under the applicable rules, such as 135.387) which clears all terrain and obstacles by 2,000 feet 5 SM either side of track. In this instance, the engine is assumed to fail at the most critical point enroute.

In both instances, the aircraft must demonstrate a positive slope 1,500 ft above the airport of intended landing following an engine failure. If the second method is used, the operator must designate the airport(s) used as an alternate in the flight plan and that (those) airport(s) must meet the minimum weather requirements for an alternate. This does not relieve a pilot from landing at the nearest suitable airport following an engine failure. This is merely a dispatch requirement.

'Sled

 

[falconpilot]

With a down hill slope brake energy may be a concern . I do agree with one thing is that your take-off roll is shorter but how about accelerate and stop distance they don't print numbers in the afm for more than -1% so is it legal.??

If you are limited by VMBE (brake energy) this problem can be solved by reducing V1 to VMBE... This is called "unbalancing the field"... This technique is used when your V1 comes out to be greater than VMBE... HOWEVER.... This can only be done if your accelerate stop distance is not greater than runway available... (OBVIOUSLY)... Bottom line.... KASE is a pain in the arse if your not in a powerful airplane... The climb gradient out of KASE is obviously for obstacle clearance. In VMC you see and avoid... But in IMC you better be on top of your game if something goes wrong...

 

[cherokee]

OK sled,

So what limits most operators is not so much the fact that you have accepted the DP since that is based on 2 engines but the fact that 121 and 135 guys have to meet single-engine obstacle requirements. How about when a DP has a minimum climb gradient published on the chart such as a runway requiring 400'/nm up to a certain altitude say for an obstacle. Does this change things in terms of requirements that you meet it single engine or does it not matter... all DP's assume 2 engine?

Also, I always thought that you couldn't use "see and avoid' in VFR to allow you to avoid the 121 and 135 obstacle requirements. Sounds like Falcon disagrees...or is is he talking 91 only? I think you ALWAYS have to clear obstacles regardless of wx 121 or 135.

Thanks

 

[Kingairrick]

Shouldn't all this be on the "legal, but stupid" thread?

 

[AZ Typed]

So help a FNG 135 fella out and put it in practical language:


1. can you depart IFR in VMC without getting nailed by the Feds if you cannot meet the climb gradient (I think the answer is no based on this post)

2. under 135 you must meet the climb gradient under all conditions (I think the answer is yes, again based on this discussion)

3. if you cannot meet the climb gradient, no matter what the wx, you must lighten the fuel load (to meet the gradient) and get gas somewhere, correct? (I think the answer is yes)

4. the whole second segment climb gradient as a % is new to me. I have always been taught the get a rate of climb out of the aircraft based on groundspeed. In the 121 world it was done for us. Now in the 135 world I'm tossed into the % concept. How do you determine the % second segment climb for the airport? Rise over Run? Can you give an example at say, ASE? FS did a terrible job covering this and I knew one day I'd be heading to ASE.

Thanks for the help!

AZT

 

[cherokee]

Shouldn't all this be on the "legal, but stupid" thread?

Yes, exactly, I'll tell my clients and boss that it's "stupid" to go in and out of Aspen. What was I thinking? Perhaps you don't fly in and out of there, but a lot of us do and it is actually not very "stupid" to know performance in great detail when you operate there.

 

[Kingairrick]

Actually, I do. I'm lucky now to be in 3 hole Falcons. I used to do it in the King Air regularly, and come non-stop back to FL. I wasn't being condecending. We all have to do things sometimes that aren't exactly ideal, just the best option...every time I think to myself; "This is pretty f'ing stupid, how can I minimize the risk?"

This is an interesting discussion though. Typical of the FAA, the regs are so convoluted that you can have so many different opinions, all by highly experienced professional pilots. I have always believed that the DP had to be met with one engine inop. Sled is pretty convincing, and now I'm not sure. The ex Lear guys I fly with all say that ASE is not technically legal in the older Lears because of the max slope thing. Once again, different opinions from different highly qualified people.

Oh yeah, one more thing; depending on which model HS-125 that is in your profile, it might really be "stupid." No, really...

 

[prpjt]

. How about when a DP has a minimum climb gradient published on the chart such as a runway requiring 400'/nm up to a certain altitude say for an obstacle. Does this change things in terms of requirements that you meet it single engine or does it not matter... all DP's assume 2 engine?

This is a cut of a draft of AC 120-OBS-11. Looks like the fed's are trying to clear up this matter. I don't know if this has been relased as an AC. I highlighted some of the pertinent language.

TERPS CRITERIA VS. ENGINE-OUT REQUIREMENTS:

Standard Instrument Departures (SIDS) or departure procedures (DPs) based on U.S. Standards for Terminal Instrument Procedures (TERPS) or ICAO Pans-Ops are based on normal (all-engine) operations. Thus, engine-out obstacle clearance requirements and the all-engine TERPS requirements are independent. Engine-out procedures do not need to meet TERPS requirements. Further, compliance with TERPS climb gradient requirements do not necessarily assure that engine-out obstacle clearance requirements are met. Terminal instrument procedures typically use specified all-engine climb gradients to an altitude, rather than certified engine-out airplane performance. Terminal instrument procedures typically assume a climb gradient of 200 feet per nautical mile (nm) unless a greater gradient is specified. For the purposes of analyzing performance on procedures developed under TERPS or Pans-Ops, it is understood that any gradient requirement, specified or unspecified, will be treated as a plane which must not be penetrated from above until reaching the stated height, rather than as a gradient which must be exceeded at all points in the path. Operators must comply with FAR requirements for the development of takeoff performance data and procedures. There are differences between TERPS and engine-out criteria, including the lateral and vertical obstacle clearance requirements. An engine failure during takeoff is a non-normal condition, and therefore, takes precedence over noise abatement, air traffic, SID’s, DPs, and other normal operating considerations.

 

[LJ45]

Stupid?

Stupid! we all do things that are "calculated risk". I think you have a bigger chance of something else happing on your trip to ASE besides the engine quitting at V1.

By the way, has a corporate Jet ever lost an engine out of ASE, or another airport like ASE and couldn't climb thus crashed?

I was told at my last Citation recurrent that the whole Citation fleet has never had an actually V1 failure.

I tend to go with Lead Sled and his info being practical, logical and most consistent info over the last several years from the industry

 

[SabreFlyR]

I was told at my last Citation recurrent that the whole Citation fleet has never had an actually V1 failure.

This is not true. I have a very good friend who on takeoff in a Citation 500 left most of the turbine section of one of the engines on the runway a few years back.

 

[LJ45]

This is not true. I have a very good friend who on takeoff in a Citation 500 left most of the turbine section of one of the engines on the runway a few years back.

Before or after V1?

 

[Lead Sled]

This is a cut of a draft of AC 120-OBS-11. Looks like the fed's are trying to clear up this matter. I don't know if this has been relased as an AC. I highlighted some of the pertinent language.

TERPS CRITERIA VS. ENGINE-OUT REQUIREMENTS:

Standard Instrument Departures (SIDS) or departure procedures (DPs) based on U.S. Standards for Terminal Instrument Procedures (TERPS) or ICAO Pans-Ops are based on normal (all-engine) operations. Thus, engine-out obstacle clearance requirements and the all-engine TERPS requirements are independent. Engine-out procedures do not need to meet TERPS requirements. Further, compliance with TERPS climb gradient requirements do not necessarily assure that engine-out obstacle clearance requirements are met. Terminal instrument procedures typically use specified all-engine climb gradients to an altitude, rather than certified engine-out airplane performance. Terminal instrument procedures typically assume a climb gradient of 200 feet per nautical mile (nm) unless a greater gradient is specified. For the purposes of analyzing performance on procedures developed under TERPS or Pans-Ops, it is understood that any gradient requirement, specified or unspecified, will be treated as a plane which must not be penetrated from above until reaching the stated height, rather than as a gradient which must be exceeded at all points in the path. Operators must comply with FAR requirements for the development of takeoff performance data and procedures. There are differences between TERPS and engine-out criteria, including the lateral and vertical obstacle clearance requirements. An engine failure during takeoff is a non-normal condition, and therefore, takes precedence over noise abatement, air traffic, SID’s, DPs, and other normal operating considerations.

Prpjt...
Thank you. I was getting tired of typing.

The simpliest way I could probably state it is: The aircraft certification requirements will only get you to 1500' while clearing any obstacles. That's basically pattern altitude and if you've got a problem at that point you come back and land. Above 1500' and you're flying a DP and all gradients are based on "normal" (all engine) climb performance. If you can't make that then you have to have an "out". In our case, we had Jeppesen provide us with an "escape" or alternate procedure that we can fly that will keep our nose out of the dirt.

Don't feel bad if you misuderstood this. It's been misunderstood ever since Wilbur tried explaining it or Orvil, who coincidently, got it wrong. I know that I was taught wrong at FlightSafety and every other school for 20 years. It wasn't until a couple of years ago that I sat down with someone who really knew and understood it and was able to pound it into my thick skull.

A couple of months ago at our 6-month recurrent our FlightSafety instructor once again started to explain it wrong. We had an interesting discussion and he wasn't buying any of it. There happened to be, in our class, one of their part-time instructors who also happens to be a prominant aviation attorney and aviation magazine contributor. He was finally able to set the performance instructor straight.

If I was an FAA inspector and I wanted to wreak a little havoc with the Aspen pilot pool, I wouldn't worry too much about guys on take off. Where I would want to talk to them is right after landing. I would be most interested in knowing their landing weight verses their Approach Climb capabilitiy from the appropriate Approach Climb chart out of the flight manual. Watch out, it can be very restrictive.

Perhaps Kingairrick had it right when he said that perhaps this thread ought to be moved to the "Legal, but stupid" thread. However, it's important that we understand this stuff. You 121 guys have it easy - you've got folks to figure this stuff out for you. You 135 and us 01 guys have to fend for ourselves. In the past, how many of us have postponed or canceled flights that would otherwise have been completely legal? I know that I have. Airports like Aspen should be respected not feared. Like I said in an earlier post - it has to be very VFR before we either go into or fly out of Aspen. We're very fortunate, the boss has a ranch in Grand Junction and it's no big deal if we can't do ASE for whatever reason.

'Sled

 

[SabreFlyR]

Before or after V1?

After V1. Flew it around the pattern and landed.
The manufactures do not know everything that happens to their aircraft. The only way for them to know is if the operator tells them. In this particular case the engine was removed sent to the overhaul shop and reinstalled. Over the years I've heard some real bs from these guys.

 

[LJ45]

After V1. Flew it around the pattern and landed.
The manufactures do not know everything that happens to their aircraft. The only way for them to know is if the operator tells them. In this particular case the engine was removed sent to the overhaul shop and reinstalled. Over the years I've heard some real bs from these guys.

Thanks for the info, I thought it sounded like propaganda!

 

[bigD]

A couple of things:

1) This is a really, really good thread. Especially for someone like me still down at the bottom working my way up. Even if the topic doesn't directly apply to me, I've learned an amazing amount regardless.

2) You guys are friggin' nerds! Especially you Lead Sled!

 

[Lead Sled]

A couple of things:

1) This is a really, really good thread. Especially for someone like me still down at the bottom working my way up. Even if the topic doesn't directly apply to me, I've learned an amazing amount regardless.

2) You guys are friggin' nerds! Especially you Lead Sled!

Have you been talking to my wife?

'Sled

 

[HMR]

2) You guys are friggin' nerds! Especially you Lead Sled!

Oh man, if you only knew... Sled's like a celebrity at FSI.

I've sat next to him at recurrent. Any question the instructor can't answer gets thrown to 'Sled. He just sits there until called upon. I've yet to see him get stumped. The guy could build an Astra or Lear Jet out of old beer cans with a butter knife. I think I'd be better off just giving him 15 grand and sitting in his living room for an evening. Plus I'd get some of his wife's amazing cooking. That alone would be worth the $$$.

And yes, I was at his last performance class where this whole single-engine TERPS stuff came up... again. I think I saw the instructor burning the FSI syllabus after class.

Now don't get me started on his co-captain. Although the guy looks like Brad Pitt and flies like Bob Hoover, he's about as sharp as a water balloon.

 

[English]

Ah! Now it is all clear! HMR and Lead Sled...who would have thought....

 

[prpjt]

With all of this talk of FS;..... Sled ? YOU wouldn't have the initials R.B. would you? Just wondering. Your take on this subjuct is very familiar.

And English, how's the 4 treating you? No hijack intended.

 

[English]

The 4 is great and fun. I'm down to only washing it once a week now