REFLECTOR: 'Standardized' High Precautionary Approaches

Tue Jan 25 12:25:52 CST 2005

Bob,
I flew a lot of those instructing at Kingsville.  We had a 9000' 150 
kias, gear down high key and regs required aborting the approach at 
500'.  However, in light of the fact that the last 500' is 90% of the 
maneuver, we Marines cheated a little and went ahead on to touchdown.

In my Velocity 173FG I've had a lot of practice PAs, two actual flame 
outs and a number of PAs with severe power degradation.  I've figured 
out pretty much what works for me.
1.  My best glide speed, from what idle / partial belly board tests I've 
done seems to be around 90 kias.  I would use 100+ kias into the wind 
and 80 or less downwind (wind has a HUGE effect on glide range, and 
adjusting speed is really important.  Several carefully documented tests 
(near home of course) from say, 10,000' down to pattern altitude with 
the engine actually shut down is IMO the only way to get reliable glide 
data for MY airplane.  A couple of passes shut down will enable me to 
determine how much belly board it takes to cancel idle thrust, and then 
I can simulate engine out with acceptable accuracy.
2.  My experience has been that a 3-key HPA is a luxury I'm not going to 
get in the real world.  It's OK as a starting point for training, but 
being proficient at 360* approaches at idle doesn't really prepare me 
for an engine failure from gawd knows where. 
3.  Success in this endeavor happens on final approach.  Hitting high 
key and middle key don't prove a lot (particularly in light of the fact 
that they're only relevant in the unlikely event your failure occurs 
*very* close to home.  The deal is to intercept the glide slope 
somewhere, at some airspeed, and from that point, energy management is 
*everything*.  It takes some practice to figure out S-turns and 
particularly high-dipping as energy management tools.
4.  I owe my success in actual circumstances to my earlier decision to 
"practice like I play".  I always shoot a practice PA all the way to 
touchdown.  It's the only way to learn or evaluate energy management 
skills.  Low passes ensure that my first realistic PA will be my first 
*actual* one.  I don't want that.

Flying a tight pattern, chopping power at the 180 and treating every 
approach as a simulated engine failure has a lot to recommend it.

What works for me ... Jim S.

Bob Jackson wrote:

> In the Navy we used to fly High Precautionary Approaches (HPAs) for 
> emergency engine out landing practice.  We had published procedures 
> -- for example, starting over the intended landing point at 7000 feet 
> altitude and circling, in one 20-30 degrees angle of bank turn (180 
> KIAS) with the gear down (no flaps), around for the landing (at 
> approx. 130 KIAS).  This for a jet with about a 11:1 (clean) glide 
> ratio. 
>  
> Now, we're getting close enough to completing our Velocity to be 
> thinking about HPA procedures for our plane during initial flight 
> testing.  We definitely don't plan on shutting down our engine, but 
> since we have done some major custom modifications to it, we are 
> interested in the accumulated experience of the flying Velocity 
> community with (simulated) engine out precautionary approaches. 
>  
> I've been reading the Reflector now for over five years, and I don't 
> remember ever seeing any discussion, or even a mention of procedures 
> for Velocity precautionary approaches.  There is also not to my 
> knowledge a precautionary approach procedure that is published or 
> 'standardized' by the factory, although I know that basic engine out 
> procedure practice is a normal part of all Velocity transition 
> training conducted by Nathan Rigaud. 
>  
> Basic engine out procedure training, like the factory's, is typical of 
> general aviation.  But it's a little surprising to me that the 
> experimental aircraft community has not apparently created a more 
> standardized procedure, more similar to the old military HPAs, 
> including recommended entry altitudes, pattern configuration, speeds, 
> descent rates, check-point altitudes, etc..  Before GPS and moving map 
> navigation, it was much harder to estimate range to an intended 
> emergency landing point, and this I believe was the motivation for the 
> creation of a circling high precautionary approach by the military -- 
> it gave you altitudes for an overhead or abeam entry that could be 
> used without the need for any estimate of range (assuming you could 
> get back overhead a strip). 
>  
> Even today, given the likelihood that most of our own early flight 
> testing will be done almost directly overhead Sebastian field, knowing 
> some 'pattern numbers' for doing a circling HPA landing approach seems 
> to make a lot of sense for us.  One good way to develop and practice 
> HPA procedures, and even (I hope) to draw some initial pattern 
> 'numbers' is with Microsoft Flight Simulator 2004.  For less than $30, 
> plus a joystick and a freely downloaded plug-in software model for the 
> Velocity XLRG, it's hard to hurt anything but your pride in the 
> simulator!  Using this simulator, I've created the following HPA for 
> the Velocity that seems to work well and to be easy to fly with 
> confidence during a 'dead stick' landing:
>  
> 1.  _/Entry/_.  Start directly overhead the landing point, and on 
> landing heading, 1800 ft AGL, 100 KIAS glide  (100 sec to landing).
> 2.  /_Pattern_/.  One 20 deg. angle of bank circle -- 100 KIAS glide, 
> gear down, 900 ft AGL abeam the landing point  (50 sec).
> 3.  /_Base Leg_/.  450 ft AGL, 100 KIAS, gear down with 90 degrees 
> more to turn onto final  (25 sec).
> 4.  /_Landing_/.  Slow below 100 KIAS only when you're sure the field 
> is made.
>  
> Of course there are many variables that can affect an actual HPA, 
> particularly the wind.  But the pilot also has some variables he can 
> control, like angle of bank and when he puts down the gear.  On a 
> short field, it can be just as dangerous to land fast as it is to land 
> slow (if short!).
>  
> Based on the performance of the Velocity in FS2004 -- at 100 KIAS, 20 
> degrees angle of bank, and power at idle, the Velocity loses about 
> 1800 feet per 360 degree turn with a 1050 fpm descent rate, and the 
> aircraft is about 5400 feet from the runway at the 180 'abeam' point.  
> In FS2004, the Velocity has a gear up, 0 deg. angle of bank, 100 KIAS 
> glide ratio of about 11:1, however I've heard that in the real world 
> it's closer to 12.5:1, even with the gear down!
>  
> /_My questions for the guys flying the Velocity in 'real world' are_:/
> a)  Do you have a HPA pattern and pattern 'numbers' that you trust?
> b)  Have you flown the Velocity in FS2004 and do you trust it?
> c)  Do you know an RPM and MAP that simulates engine out 
> performance (zero thrust, feathered drag)?  Has anyone used a 'feeler' 
> gauge on their prop flange to detect the zero thrust condition?
> d)  Can someone with a GPS and the ability to log aircraft performance 
> data (like with the Blue Mtn EFIS) do some simulated power off, 80/100 
> KIAS, gear up/down, 0/20 deg. angle of bank, glides to establish some 
> real world glide ratio data (selfishly, I would prefer data for the 
> XLRG, but any data will help, especially others in the community).
>  
> Sorry for the long post.
> Bob Jackson
>
>------------------------------------------------------------------------
>
>_______________________________________________
>To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
>Visit the gallery!  www.tvbf.org/gallery
>user:pw = tvbf:jamaicangoose
>Check new archives: www.tvbf.org/pipermail
>Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20050125/a1189c86/attachment.htm