Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

S61N Reject after CDP

Wikiposts
Search
Rotorheads A haven for helicopter professionals to discuss the things that affect them

S61N Reject after CDP

Thread Tools
 
Search this Thread
 
Old 4th Sep 2001, 19:45
  #1 (permalink)  
Thread Starter
 
Join Date: Aug 1999
Location: Malaysia
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Question S61N Reject after CDP

I would like to seek the opinion of other S61N drivers on doing a rejected take off immediately after achieving CDP on an Oblique take off ( CDP 50ft 20 kts) and Ground Cushion (CDP35 kts 20ft) if there is still a lot of runway remaining.. say 5000ft. In our ops manual, our brief for the take off is.."if engine fails after CDP continue the take off and rejoin for landing". It looks ridiculous that with over a mile of runway available and at such low altitude we should risk doing a single engine circuit.The flight manual has a phrase that says.."at CDP after forward input of cyclic no rejects should be attempted.So at the moment, our training cell has verbally told us not to do a Group A take off even though we are within the WAT limit but instead to do a Modified Group A take off (CDP 300ft 45 kts). Any inputs esp by North Sea S61 operators are appreciated.
wong is offline  
Old 4th Sep 2001, 20:31
  #2 (permalink)  
 
Join Date: Oct 1999
Location: Den Haag
Age: 57
Posts: 6,298
Received 351 Likes on 197 Posts
Smile

I can't speak about the S61, but in general terms the use of remaining runway for a rejected takeoff is condoned. In fact, part of the OPC briefing stresses that although there may be sufficient runway remaining to reject after TDP, for the purposes of the test the candidate should consider himself (or herself) commited to continuing.

In some ways CDP is a better description of the point as it states it to be a critical decision, rather than the takeoff decision. The inference in the former is that you now have a choice after CDP compared to prior, where with TDP it tends to imply you are commited to continuing in the same way as for fixed wing.

One proviso though is that you are now entering the realms of subjectivity when deciding on your new comittal point. What you consider to be the latest point from which you can still make the runway may not be the same as your colleague's. So there are dangers involved in advocating a reject after CDP.
212man is offline  
Old 5th Sep 2001, 02:38
  #3 (permalink)  
 
Join Date: Aug 1999
Location: Under a date palm.
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Cool

It's a long time since I flew a 61 but 'subjectively' :-

35kts = 3550 feet/min groundspeed so 5000 feet = 1 min 20 secs plus a bit to the end of the runway. Should be plenty of time to react and land if you wanted to in the example you give.
Remember the Garuda DC10 who had an uncontained no 2 fail above V1 and rejected/overran?
Killed a couple of people but arguably saved several hundred!
It's your call on the day, just do it well!
stormcloud is offline  
Old 5th Sep 2001, 03:21
  #4 (permalink)  
 
Join Date: Jul 2001
Location: the cockpit
Posts: 1,084
Received 1 Like on 1 Post
Cool

I agree with the above comments - although I too am not an S61 pilot - because I think the problem is applicable to all twins. These days we tend to get a bit wrapped around terminology and definitions without considering application.

I'll use the following terms: CDP = Critical Decision Point and infers take off , LDP = Landing Decision Point.

The critical areas of the decision points are exactly opposite, i.e. before LDP you have a choice, AFTER LDP you are committed, whereas BEFORE CDP you are committed, and after CDP you have a choice. Forcing you to go around rather than reject after CDP is removing the flexibility of the concept. It is akin to forcing you to commit to landing before LDP!!

Please forgive me for suggesting this wong but if your ops manual "tells" you that you have to go around then either
1) Your management needs to revisit the concept of CDP/LDP because they have missed the inherent flexibility of the terms, or
2) They have mandated this in an attempt to cover their own backsides by removing a possible judgement call from your hands.

A way around this? Failure after CDP, convert to the pre LDP approach so you have a choice!! Just jokes, but it shows the way in which we can get too wound up over mandating reactions to terminology and not leaving it up to the poor blighter on the spot - you. I would suggest you are the aircraft captain and if you can justify the reject, ****** the ops manual!!

We adopted a second call during take off (dual or single pilot/crewman). The first call would be CDP as usual, but then the second was "committed" which meant committed to take off. This call was made when, in your judgement, you could no longer safely reject the take off and were committed to climbing out. On a runway, for example, there would be a call of "CDP" by the pilot not flying at the required height/airspeed, followed by a period in which there was a choice of rejection using runway remaining if required, followed finally by the "committed" call from the pilot flying which alerted the crew to the fact that you no longer had a choice. During helipad departures, the call committed would happen as soon as CDP was attained and the nose lowered for acceleration. The same calls could be made during the landing phase at/around LDP.

Sorry if I have confused the issue...Good luck.
helmet fire is offline  
Old 5th Sep 2001, 12:50
  #5 (permalink)  
 
Join Date: Apr 2001
Location: South East Asia
Posts: 92
Likes: 0
Received 0 Likes on 0 Posts
Exclamation

Suggest you consult your training department again 212 if you think rejecting after CDP is condoned. That is part of the briefing for a check ride and is only for a check ride in order to simulate a shortage of reject area. If there is safe reject area available the safest thing to do is land, not continiue and risk a further failure or fire.
To the best of my knowledge the only time that one is committed to a takeoff after forward cyclic input is on a rig type vertical takeoff where the only landing area available is directly under the aircraft.
vertalop is offline  
Old 5th Sep 2001, 19:35
  #6 (permalink)  
 
Join Date: Aug 1999
Location: Spain
Age: 78
Posts: 65
Received 2 Likes on 2 Posts
Cool

As an S61 pilot, with experience on both the 212 and the AS332, I would like to raise a couple of points. First of all, with 5000 ft of runway remaining, I would reject, unless I was on a base check. Even then, if it was for real and not induced, I would still reject. As aircraft captain, the ultimate decision is yours. Secondly, the 212 section of the ops manual states, I seem to recall, that when operating over inhospitable terrain, that an automatic reject should not be carried out following an engine failure, but the captain should assess the fly-away characteristics of the aircraft. Finally, IMHO, a second call of "committed" would only serve to complicate things.
Attila is offline  
Old 6th Sep 2001, 21:50
  #7 (permalink)  
 
Join Date: May 2001
Location: U.K
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Post

Having flown the S-61 in various roles, I would suggest that like most things in aviation stay flexable in your approach to this.
At MTOW with no wind and high temperatures, the calculated performance will always alow you to fly away having suffered a failure of a engine at CDP. Once you have pulled to droop and accelerated and then recovered the RPM you are safe. If you then find that there is runway ahead and you have time then why not run it on? What you must not do is screw up the fly away because you are rushing to get it on the ground.
One thing at a time!
You also must tell the other bloke what you are thinking of doing and fully brief it.

Hope this helps
Flat Erik is offline  
Old 6th Sep 2001, 21:55
  #8 (permalink)  
 
Join Date: Aug 1999
Location: Spain
Age: 78
Posts: 65
Received 2 Likes on 2 Posts
Wink

Flat Erik - I concur. Let's not lose sight of the real aim, to keep the aircraft flying.
Attila is offline  
Old 7th Sep 2001, 20:08
  #9 (permalink)  
 
Join Date: Oct 1999
Location: Den Haag
Age: 57
Posts: 6,298
Received 351 Likes on 197 Posts
Question

Vertalop,
I think you may have contradicted yourself there? In the first instance you question my point about condoning a rejected takeoff after CDP, then later on you say if there is sufficient space available the safest thing is to land. How exactly does that differ from what I said?

The reference later to not automatically rejecting comes from the Ops manual, not the FM, and refers to a failure prior to TDP where a water/swamp landing may result and given the forgiving nature of the 212 it may be possible to avoid landing (or it may not!).
212man is offline  
Old 7th Sep 2001, 20:49
  #10 (permalink)  
 
Join Date: Apr 2001
Location: South East Asia
Posts: 92
Likes: 0
Received 0 Likes on 0 Posts
Red face

Sorry 212 in a rush and misread your comments.

Just to confim my view..Failure before CDP - Land. Failure after CDP and before committed -probably land. After committed - go around. Committed is at cyclic input on rig take-off. :o
vertalop is offline  
Old 7th Sep 2001, 22:00
  #11 (permalink)  
 
Join Date: Mar 2001
Location: Scotland
Age: 71
Posts: 64
Likes: 0
Received 0 Likes on 0 Posts
Post

I agree with vertalop's last post. My relatively new experience in the civvy world is that, during LPC/OPC check rides, trainers tend to emphasise the "training world" ie briefing continued take offs after CDP, bomber command circuits after engine fires etc in order to complete the emergency check list drills. Completing a power check! Why?

This is fine as long as we practise relanding occasionally when there is suitable surface beneath us. Me personally, if I have an engine fire, I will land ASAP!
Tuckunder is offline  
Old 8th Sep 2001, 02:31
  #12 (permalink)  
 
Join Date: Sep 2001
Location: USA
Posts: 52
Likes: 0
Received 0 Likes on 0 Posts
Post

Just an unwashed redneck bush pilot here....err...the argument as I see it is whether it should be mandatory to ignore a 5000 foot runway in front of me should something go tits up on takeoff. Now you hi-faluting Northsea Commanders all have said your piece...my turn!

If you can land back safely and in control of the aircraft, without further diminishing the current hull value of the reusable container you are driving....for crying out loud...land back! All this fancy talk about TDP/CDP...etc...bores me......you are wanting super hero pay...and that is why you are supposed to be able to make these earth shattering decisions....so put down the checklist, put aside the ops manual, ignore the managments latest policy letter....and fly the aircraft. The last place I wish to be with a sick bird is in the air.

Did the North Sea bit guys...back in the cowboy days in 58T's single pilot with the old decca....same emergencies then...less bureaucracy....same principles apply today. Know your aircraft's performance and fly to the safe side!
heloplt is offline  
Old 8th Sep 2001, 06:25
  #13 (permalink)  
 
Join Date: Sep 2001
Location: Texas
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Wink

Mr Helloplt

You are all wet, I agree with 212man and helmet fire. The more 3 or 4-letter identifiers you can come up with, the more detailed you can make the Pilots Takeoff Briefing and don’t forget the Co-Pilots Briefing, the safer the flight will be. Where do you get this “Fly the Aircraft”. Procedure is the most importance thing, follow the procedure, and nothing will go wrong.
Gutless is offline  
Old 8th Sep 2001, 07:07
  #14 (permalink)  
Nick Lappos
Guest
 
Posts: n/a
Post

The problem with Cat A/Group A procedures is that the acronyms are consistant. Why don't we do what they did to N2/Np/Nf or TGT/EGT/TOT/T5/T4.5? With just a little creativity, we can really confuse the situation and ourselves.


PS That 5000 feet of runway ahead is an offer that I doubt I could turn down, and I would certainly question someone who gave up all that comforting length for an unnecessary trip around the patch. Nice to see the consensus in all the comments above!
 
Old 8th Sep 2001, 10:13
  #15 (permalink)  

Just Dropped In
 
Join Date: May 2001
Location: um....er.....
Posts: 130
Likes: 0
Received 0 Likes on 0 Posts
Post

Despite what Gutless said, the pilots priority is 'Fly the Aircraft'
(I'm hoping he said it 'tongue in cheek')

Given the scenario here I'd be looking to reject the take off & get the aircraft back on 'terra ferma'

Each scenario must be assessed individually, hence we get trained & paid to make decisions. Company manuals simply cannot allow for every eventuallity, & to restrict yourself to their exact wording in the event of an emergency is unrealistic.
There is no right answer, but whichever course of action you take you must see it through to a safe conclusion.
Flying away, 'around the patch' & back in isn't the most direct route. However is does allow you to settle the aircraft into a safe flight regime, complete all relevant drills & set yourself up nicely for the subsequent single engine approach. As such it isn't an unsafe way to conduct business & could prove safer than rushing to put an aircraft back on the ground.
That said, you as the handling pilot may happily look ahead & believe that all that tarmac provides you with ample room to conduct a safe reject.
I recall the S-61 being a pleasant old girl to handle a reject in, although if memory serves she does take a fair while to stop in light winds.
The most important thing is to ensure that you Fly the Aircraft , earn your pay & bring the people in the back (& hopefully the airframe) back to earth as safely as possible! If that is acheived the actions you've taken were right.
Roofus is offline  
Old 8th Sep 2001, 12:36
  #16 (permalink)  
 
Join Date: May 2001
Location: perth
Posts: 231
Likes: 0
Received 0 Likes on 0 Posts
Post

I would find it difficult to understand how management or training pilots would want you to fly an aircraft with an engine failed AWAY from a runway in front of you. Imagine the situation where your engine failed due to a fuel contamination while youre flying downwind trying to get back to where you just left. I think management would be unimpressed in that situation. I would just get the helo back on deck if your experience tells you its possible. Whats important is avoiding an accident, and if going around does that, its the captains call.

The question is, where am I flying to after CDP with an inoperative engine? In this case, straight in front on a beautiful 5000ft runway, perfect.

For training purposes, the training captain will obviously want to see you fly away if its possible. Like the old saying goes, "if you think training is expensive, try having an accident"

Sometimes the obvious choice is the right answer.

[ 08 September 2001: Message edited by: sling load ]

[ 08 September 2001: Message edited by: sling load ]
sling load is offline  
Old 8th Sep 2001, 19:16
  #17 (permalink)  
 
Join Date: Oct 1999
Location: Den Haag
Age: 57
Posts: 6,298
Received 351 Likes on 197 Posts
Unhappy

Gutless,
I'm not sure why you felt the need to include me in your sarcastic diatribe; nothing I had said earlier disagreed with what you or heloplt have said. I agree with Nick that the introduction of more terms to describe the same thing has confused the issue further though I firmly believ that briefs should be jusr that-brief- with only variables for a particular situation included. In training the full brief is required, to demonstrate that the pilot does in fact know it but it is not expected for each takeoff and landing.

I think it should be born in mind that this predicament can be present with much less than '5000 ft' of runway, and this is where the danger creeps in. In training you do not practice a rejected takeoff after TDP/CDP and so are not familiar with how the a/c behaves say from a 80 kt climb at 800 ft/min at 500 ft. You are familiar with how it behaves at TDP though. You may have 50 hours on the s-61 and now be flying the s-76, totally different animals in terms of reject distance. You may be the co-pilot handling and feel that you are better off rejecting, the captain might disagree-not the time for a discussion. The thread about the 76 wheels up landing highlights a potential danger (confusion over whether the a/c was to continue or reject. It was not on approach).

The list goes on with argument and counter argument. I also tend to agree that it's one of the decisions that actually we get our pay for.
212man is offline  
Old 9th Sep 2001, 09:29
  #18 (permalink)  
 
Join Date: Jul 1999
Location: Warrington, UK
Posts: 3,840
Received 77 Likes on 32 Posts
Cool

To my mind, the Clear Area take off is design for a "clear area", ie the distance required for you to clear any obstacle given your a/c weight, OAT and windspeed on the day in question. For my aircraft this varies between 100 to 200m. Obviously on check rides you are required to demonstrate that you know and can carry out the correct actions for an engine failure after CDP (usually a nanosecond after in my experience).

On the airfield that I operate from I have between 500 and 1200m of "clear area", giving the opportunity to land straight ahead if required.
MightyGem is offline  
Old 9th Sep 2001, 09:53
  #19 (permalink)  
 
Join Date: Aug 1999
Location: Gold Coast, Australia
Age: 75
Posts: 4,380
Received 25 Likes on 15 Posts
Arrow

In response to the original posting, I couldn't think of a useful or valid reason why a prudent pilot wouldn't reject, post engine failure, to a useable strip of runway straight ahead.

Apropos the other comments re vertical departures, etc. My understanding of a vertical, or helipad, departure usually dictates a fairly steep pull backwards as well as up, in order to keep the helipad ahead of the helicopter in the event of a reject back onto the deck before CDP. My experience was that this was seldom, if ever, used on offshore helidecks. The CDP on a normal departure from the hover over a NS deck is usually that close to the height AMSL, that no further vertical transition is required. The main concern was to ensure that the tail cleared the deck edge should you have to nose over to pick up Vyse following an engine failure after rotation. Fortunately the S61/Sea King never let me down, although I often wondered (worried?) about that long stretch of fuselage behind me on some departures

I do recall a brief period back around 1977 when BA S61's were departing Sumburgh main runway with a (vertical) helipad type departure, much to the amusement of other operators. Never got to the reasoning behind that

Currently I have stopped operating my BK117 from helipads at 6000ft amsl with helipad procedures, as in previous years. Experience has shown that I have about 1500ft of steep valley to fly down post engine failure to build up to Vyse, rather than the stress of a vertical, backward departure followed by an OGE transition to forward flight. Apart from being reasonably uncomfortable in some wind conditions, it became really tedious explaining why we followed such procedures, especially to other pilots!!
John Eacott is offline  
Old 9th Sep 2001, 15:21
  #20 (permalink)  
Thread Starter
 
Join Date: Aug 1999
Location: Malaysia
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Post

Thank you for all the inputs. I am still puzzled as to why the Sikorsky S61 Flight Manual states that after the forward cyclic input at CDP, no attempts to reject should be carried out. This phrase was put at the notes for a ground cushion and oblique take off. It would be less confusing if they had made some qualification to that statement that if runway lenght is still available, then a reject may be still possible.
wong is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.