L-29 TFBs and PEC Mil-Specs

OLYMPUS DIGITAL CAMERA

Tower-fly-by has always been one of the most precise methods of altimeter calibration. As part of an exercise preparation at ITPS, I flew on a number of TFB test points in the Czechoslovakian Aero L-29 Dolphin to verify the limited numbers found in the AFM and check Mil-Spec compliance.

While the concept of the Flight Test Technique is pretty straightforward, the data reduction and analysis required for Mil-Spec compliance is not. Is there more than one Mil-Spec? Which one should be chosen? What do they require? Are they currently cancelled?

l29-TFB

In short, the MIL-I-5072-1 covers all types of pitot static tube operated instrument systems while MIL-I-6115A deals with instrument systems operated by a pitot tube and a flush static port, as is recommended by USN TPS. The quantitative numeric side of the tolerances described in the above two specs is exactly the same. USAF however, seems to have taken those specs a step further through  MIL-P-26292C(USAF), which puts more focus on high Mach number and supersonic region and defines the tolerances based on parameters derived from dimensional analysis (ΔP/qc) rather than absolute tolerances in knots and ft. For data presentation purposes, all specs require analysis of the errors to sea level conditions vs. indicated speed parameters, which again is not a single step process.

While all specs are currently cancelled without replacement, probably due to the many new and non-traditional air data systems and the air data computers used, they remain a good guidance especially for older airplanes.

Unsurprisingly, as the figure below shows, the L-29 failed to meet the  MIL-P-26292C(USAF):

MIL-P-26292C-L29

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Joined the Flight Test Technical Committee of AIAA

AIAA logo_FTTC

The American Institute of Aeronautics and Astronautics (AIAA) is unarguably the world’s largest technical society dedicated to the global aerospace profession. Being a member of it till 2008 (currently Senior Member status), I have just been accepted as a member in the Flight Test Technical Committee. Great honor for me to serve with other technically distinguished individuals in an organization that sets itself as a highlighting example among similar entities.

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Saturday fun

172_IFR_night

Starting with morning skydiving back-flips and a downwind landing(!), late afternoon and night IFR training flights, and the late evening baking of nistisima apple pies, last Saturday sounded like fun!

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Ferrying from Ontario to Alabama

ON_to_AL

An L-39 ferry flight took place from CYXU to KGAU. Nice experience of an international hopping flight at 300kts ground speed, crossing the always “interesting” US border, watching the climatic change but also the cultural changes on the way to lower latitudes.

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Journal publication as a lone author

JoAE_publication

My latest paper just received online release and is expected to get published soon in the printed version of the Journal of Aerospace Engineering. Besides being my first post-PhD journal publication, the other reason of being of certain importance is of myself being a lone author.

“The lone author has all but disappeared. In most fields outside mathematics, fewer and fewer people know enough to work and write alone.” [1]

“The effort and initiative required to publish alone suggests an independent and tenacious scientist — both highly desirable qualities in any researcher.” [2]

References

  1. M. Greene, The demise of the lone author, Nature 450, 1165 (20 December 2007)
  2. K. Hallock, Qualities of a lone author are beneficial to science, Nature 452, 282 (20 March 2008)
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New year, new goals (2016)

lake_view2016

Main goals for the new year still remain on the professional side. Increase of productivity through increase of effectiveness, focus, speed and minimization of wasted working time. In addition, education in some new scientific areas and finally upgrade of my pilot licenses.

This blog is (un)fortunately targeted only over aerospace and technical subjects. However, I would like to express my deepest appreciation to some remarkable individuals that in one way or another have expressed personal interest in myself. I just feel it is not my time yet.

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Super Tucano Qual Eval, Reno NV

Super_Tucano

A qualitative evaluation flight of the A-29 Super Tucano for the Advanced Trainer and Close Air Support (CAS) roles took place in Reno Nevada. Great opportunity to test fly a high performance turboprop with some highly experienced fighter pilots.

Starting from cockpit evaluation and building up to open loop flying qualities, performance, handling qualities and basic aerobatics work. As part of the tactical assessment a number of simulated CCIP profiles were flown using MK82 bombs. A few “peculiarities” were discovered and discussed with the test pilot students and operational pilots, but not significant enough to affect the overall conclusions.

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