Partial Panel: Your Life In Your Hands

Whether scare tactic or sales pitch… or maybe an altruistic safety warning sent to every instrument-rated pilot in the land, one aviation company has the right idea. They just sent out a letter to ‘all IFR pilots’, to communicate important safety information related to flying partial panel. With that letter were several enclosures: a safety warning letter, a service letter (another warning), a five-by-eight inch pre-punched POH insert with (you guessed it) a safety warning, and a copy of the FAA Aviation Safety pamphlet FAA-P-8740-52, ‘The Silent Emergency’.

Y’know what? I’m glad they sent this stuff! It never hurts to be reminded how easy it could be to find yourself sweating in the clouds, especially if:

  • You don’t have a back-up pneumatic source for air driven gyros, or a back-up electric attitude gyro
  • You (or your FBO) have had your pneumatic system on the ‘deferred maintenance’ program, or
  • You haven’t gone partial-panel with your friendly local CFI in quite a while. Even the ‘standard’ training may not be enough to recognize a gyro instrument about to go Tango Uniform.

See the articles ‘Flying Blind‘, ‘IMC With No Gyros Part II‘, and ‘Surviving Instrument Failure‘, for some excellent survival tips. And there’s more to it. Sure, once you know what’s wrong, you can do something about it. But it’s that transition state, such as when the attitude indicator is ever so slowly keeling over, that’s the kicker.

Whether the air pump goes, or any other part of the pneumatic system, the gradual change is what leads to spatial disorientation and loss of control

Some pilots have suffered instrument failure while IFR, recognized the problem, gone partial panel en route, and then lost control during high task-load periods — like trying to shoot an approach. Remember that highly publicized case of the well known Bonanza pilot who had a vacuum failure and lost it over Thanksgiving in 1999 (see ‘IMC With No Gyros‘), then smeared his airplane, himself, his wife, and his younger daughter over an entire street in Newark NJ? He was a CFI at my home airport in Maryland, an ex-Israeli Air Force pilot, and I was told, had a penchant for giving partial panel rides to fellow pilots. (Sorry, Itzhak … no one’s immune.)


  1. Avoid high-workload situations, before getting into the plane.
  2. Keep that vacuum (or suction) gauge in your scan. If it doesn’t read somewhere between 4.5 and 5.5 — watch out! (Your POH will say what the normal range is.)
  3. Install an annunciator light!
  4. PRACTICE — especially if you fly your airplane for business purposes and frequently ‘have to get there.’
  5. The self-enforced TBO: replace parts after so many hours, no matter what.
  6. If your airplane doesn’t have a back-up system, get one! If you haven’t got one and don’t have a back-up, don’t fly IFR. Sure, it’s legal to fly IFR without a backup, but so is walking in an open field … during a thunderstorm.
  7. Never make control inputs based on the attitude indicator alone.
  8. Constantly cross-check all of your instruments.
  9. Have something handy to cover up faulty gauges.
  10. Don’t be afraid to yell for help. Ask ATC for ‘no-gyro’ vectors … yell ‘Mama!’ if you have to (mayday would work better, though) … get on top, get out the side, just get yourself to VMC, ASAP!

In February of 2003, I received another letter from this same company, again warning about mandatory inspection intervals and replacement times for various components used in pneumatic systems powering air-driven pumps, and containing a summary of mandatory service instructions for their pneumatic components, as well as a reprint of their original June 2001 Pilot Safety Warning.