Text Box: WARBIRD NOTES #26   15 Jun 99  (3)    
GEAR RETRACTION AFTER TAKEOFF
  This subject rears it ugly head now and again on the airshow/fly-in circuit, each time quickly provoking a heated discussion.  Loud voices are heard, "I'm right!"  No, I am!"  "NO WAY, THIS IS THE ONLY RIGHT WAY!"  And so it goes.  Along with what controls airspeed, pitch or power, it's another one of those aviation arguments that's just never gonna be settled, looks like to me!  Do I have some feelings about it?  Sure, and we could discuss them here, they might be of some value to someone who is trying to analyze the pros and cons so he can approach it with a better understanding.  (Well, at least he can say he listened to some of the arguments - on both sides!)

  One camp opines, “I don’t retract my gear until I can’t land on the remaining runway.”  The other says, “I retract it immediately after takeoff and start getting rid of the drag”.  Obviously, (well, I think they do, anyway) both sides have a credible point.  But still the question remains, “who’s right?”  Further discussion probably lends ammunition to both sides, it’s just that the situations and the airplanes may be completely different. 

 

  A very experienced pilot, after reading this, related one of his earlier (mis)adventures.  He feels (I do also) that the above wording should be changed to “I don’t retract the gear until I can't land on the remaining suitable surface”.  In other words, don’t just consider the runway, take into account the overrun and area beyond the runway.  You and he and I all know that this is one of those situations that are different each takeoff.  He recalls taking off from an 8,000’ runway in a Cessna 172, the instructor cut the engine at about 30’.  He said that he finally got the thing stopped, using the maximum technique, about 50’ into the overrun.  Just for the record here, they both said, ”That just can’t be right”, since they still had about 5,000’ of runway remaining when the engine failed!  So, they did it again, this time he held it in level flight for a little bit while the flaps were extending with slightly better results.  But the fact remains that you aren’t gonna get any warning here, you'll have to play the cards as they were dealt and it‘s probably gonna take a lot more than you figured on to get it stopped.

 

  Several years ago I had the pleasure of checking out a pilot in the Hellcat and the Corsair.  I use the word pleasure for several reasons, mostly because he happened to be one of the best “sticks” I’ve been associated with.  For his checkout, I’d done all I could standing on the wing of the Hellcat talking to him.  I then jumped into the Corsair and followed him out to the runway to observe his flying from a “chase“ plane.  I watched his initial takeoff from a position directly behind him, all control usage was perfect.  Liftoff followed shortly and I just about had heart failure at that point, I barely discerned any daylight under his wheels when his gear started to retract!  After my heart made it back out of my throat I joined on his wing and we briefly discussed it on a discreet frequency.  To make a long story short, he had always flown USN combat airplanes in this fashion, it made perfect sense to do that off a carrier, given the instant altitude and considering the lack of runway ahead.  To my USAF eyes, however, it was just the opposite.  By the way, the session from then on was absolutely devoid of other problems and I was unable to find even one small item - other than the retraction - to debrief at the conclusion of the flight. 

 

  So, what’ve we learned here?  First off, I’d say that if you’re operating off a carrier, then you may as well retract the gear immediately - as soon as you can reach the gear lever.  Now, let’s briefly discuss a landing gear with a rather complicated retracting system, maybe something like a Mustang with its sequencing valves.  Once you start the gear retracting, you really need to let it fully complete the retraction process before you put the handle down again, else you are probably gonna really screw up the sequence with who knows what results.  So, if you’re on a runway that offers adequate runway after liftoff to land on, then maybe you'd save a lot of explaining if you’d delay retraction just a bit so that if the engine snarfed and gave up, you’d be in a position to land immediately.

 

  We should mention a characteristic of the P-47.  In my experience a good percentage of the Jugs seemed to want to “skip” once after liftoff, just seemed to be the nature of the beast.  So I sure wouldn't want to be explaining to the owner or the FAA why I’d started the gear retraction and then inadvertently touched down again, cause all sorts of damage, don’t you know!  And, while we’re on this subject, this is another airplane that the pilot’s manual very specifically cautions you to let the gear completely reach whatever position you put the gear handle in before you reverse the handle position. 

 

  Well, fine.  Now then, how about a gear of a simple design with no sequencing valves, able to have its sequence reversed without any problems?  Well, if you think you’re able to contend with the multiple demands of a failing or malfunctioning engine, extreme rudder changes and still be capable of remembering to put the gear handle back down - then more power to you!  But you really need to think about it now, not then! 

 

  We absolutely need to mention here that some airplanes demand that you initiate the gear retraction process immediately after being absolutely sure you’re airborne.  Among them is the Grumman F8F Bearcat.  This airplane has a comparatively low airspeed by which the gear must be completely stowed in the wells, otherwise the hydraulic system simply cannot contend with the pressures required to finish the job. And, (whooooo-wheeeeee!), this Cat accelerates very rapidly.      

 

  Now what about a WW II bomber?  Well, here we need to obtain SSES (Safe Single Engine Speed) just as soon a possible after liftoff.  Most of those things had somewhere in the vicinity of 20 or 30 MPH between liftoff and SSES.  For instance, the B-25 lifts off at around 115-120 MPH if you raise the nosewheel about 6 inches or so off the runway.  Then it needs 145 MPH for its SSES.  So, you need to retract the gear and start drag reduction just as soon as you are absolutely sure you are airborne and not gonna touch the runway again.

 

  

Still writing:

 

bam!  gear up quick , “must be a hot pilot, huh”?  mentality  , sorta like low flying always impresses me (the wrong way)

 

Helcat inteceptor climb

 

be careful of dogma/“always”/“nevers”!

 

FAA sez?:

 

R. Sohn   ©    1999


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