February 21, 2012

Where Am I? An explanation of today's twitter post.



I had some fun on twitter today when I posted this picture and commented "Anyone like to guess where I'm standing? "Somewhere on an MD80" will not be counted as a correct answer;)"

I suppose it wasn't too difficult a challenge.  Unlike movies that portray actors crawling around in huge crawl spaces above passenger compartments or vast electronics bays, most airplanes have precious few places not readily visible by the public.  After all, it's all about revenue and if there isn't a seat bolted to the floor it's wasted space. 

The picture was taken while standing in the left wheel well of an MD82...at least I think it was an MD82.  Could have been an MD83...I honestly don't remember.  A quick look at my logbook would tell, but unless you're in the cockpit with a view of the fuel panel, there really isn't much of a difference.  That's the left hydraulic reservoir on the right, the transfer hydraulic pump on the bottom, the spoiler depressurization valve in the middle and the small round hole in the top right corner of the picture is...believe it or not...for viewing the down-lock stripes on the left main landing gear.

MD82 Landing Gear Handle
and "Down and Locked" Lights
Picture this...you're on the final approach course, intercept the glide path and lower the gear.  But the gear doesn't come down.  I should say, you don't know if the gear came down because one or more of the green "down and locked" lights did not illuminate.  There's a small pin that pops up from the center console in the cockpit that indicates the nose gear is down.  A little strange, yes, but it's a mechanical indication that the nose gear is down and it works every time.  The main gear is a different story and this is where it gets interesting.

I won't tell you exactly where this is because I really don't want you looking for it the next time you are fortunate enough to ride on one these fine machines, but there is a viewing port in the cabin that can be used to visually inspect the condition of the main landing gear.  To gain access, one of the pilots would walk to the cabin and count in the appropriate direction from the over-wing exits to find the correct row of seats before commencing the process of ripping up carpet.  Again, I'm not telling which direction or how far because I really don't want you looking for it.  I know this sounds ridiculous, but the carpet is held down with velcro, so theoretically, it should come up easily.  The pilot would then remove a small, round access port and peer through a periscope device to the two stripes that, if the gear is down and locked, would be lined up.  The strips are painted orange to make this process a little easier and there's even a light that shines on said stripes that's required to be operational for the aircraft to be dispatched for revenue flight. 

One more thing...the periscope is located inside the right wheel well, so in order to view the down and locked stripes on the left main gear, there's a small, round hole cut into the bulkhead between the two gear wells to facilitate viewing of the stripes on both main gear assemblies with a single periscope.

Strange?  Yes.  Does it work?  I don't know anyone who's actually had to do this, but I'm told it has been done and that it worked.  Hopefully I will never have to prove it myself or explain to some poor soul why I'm tearing out the carpet beneath his seat.

3 comments:

  1. I was on a flight to LA years and years ago where this procedure was used.

    We came in on final, pulled up. After an announcement, the F/O came in the cabin with a somewhat sheepish expression, pulled up the carpet, put some little tube into a hole, looked through it, announced all was well and got a round of applause from the passengers.

    We landed soon after.

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  2. Good story, John! I'm racking my brain to remember which airplane I flew that had this similar feature. A de Havilland Dash 7 or 8 I think. Goofy, but apparently effective!

    Great post n pic. I would have a similar shot in the well of my A320, with the overlarge hydraulic pump (PTU); good idea for a post, lol!

    capnaux.blogspot.com

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  3. Great post. I really love my pilot service. I can call and get a ride nearly anywhere I want. It makes personal travel so much easier.

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