IS&S

Radar, or radio, altimeter only works up to 1500' - 2500' AGL depending on the model.

It's use is intended to be in the last 1000' of landing and give you precise height over the ground. That assumes the approach path is level to the runway. It is required for CAT2 & CAT1 approaches.

Readings will vary if you are flying level over uneven terrain.

PS. See Wikipedia for radio vs. radar - https://en.wikipedia.org/wiki/Radar_altimeter

From the legal point of view, a radio altimeter is – according to article 1.108 of the International Telecommunication Union´s (ITU) ITU Radio Regulations (RR)[1] – defined as «Radionavigation equipment, on board an aircraft or spacecraft, used to determine the height of the aircraft or the spacecraft above the Earth's surface or another surface

...

As the name implies, radar (radio detection and ranging) is the underpinning principle of the system. The system transmits radio waves down to the ground and measures the time it takes them to be reflected back up to the aircraft. The altitude above the ground is calculated from the radio waves' travel time and the speed of light.

Without the ISS ADC you would not have obtained RVSM compliance. The radio altimeter should be a Sperry/Honeywell AA 215.

Radar, or radio, altimeter only works up to 1500' - 2500' AGL depending on the model.

It's use is intended to be in the last 1000' of landing and give you precise height over the ground. That assumes the approach path is level to the runway. It is required for CAT2 & CAT1 approaches.

Readings will vary if you are flying level over uneven terrain.

PS. See Wikipedia for radio vs. radar - https://en.wikipedia.org/wiki/Radar_altimeter

From the legal point of view, a radio altimeter is – according to article 1.108 of the International Telecommunication Union´s (ITU) ITU Radio Regulations (RR)[1] – defined as «Radionavigation equipment, on board an aircraft or spacecraft, used to determine the height of the aircraft or the spacecraft above the Earth's surface or another surface

...

As the name implies, radar (radio detection and ranging) is the underpinning principle of the system. The system transmits radio waves down to the ground and measures the time it takes them to be reflected back up to the aircraft. The altitude above the ground is calculated from the radio waves' travel time and the speed of light.

IS&S

Michael, Not to stop your exciting posts about your journey but what were some of your criteria for, and where did you get your knowledge on 501Sp’s to be comfortable to pull the trigger? Folks over the years have said the list is endless on got ya’s so I have always just put it on the back burner.

Anything bad can happen with an old airplane. Lots of scary, expensive systems lurk in these things. I'll try to explain my reasoning which some may or not agree upon. If you approach these older airplanes with doing a massive pre-buys and expecting the seller to fix everything to like new condition; you're probably going to miss out on the deals. I took an experienced Citation guy along too to help with the vetting.

I didn't do much pre-buying on this airplane other than make sure the motors were OK. The right just had a fresh hot inspection which gave me some comfort. We boroscoped the left motor (well actually already done for us). Other than checking for corrosion (none found), I took a systems based approach (does all the expensive stuff work like the radar, pressure, boots, A/C, avionics) and then flew it home with a healthy chunk of money in escrow for any systems that I may have missed (there wasn't anything major). Lastly, is price. What price can I buy the airplane for today and sell it in 3 years and have it not sit on Controller for 2 years? Buy the airplane for close to what you could sell the motors and other big stuff for and not get too hurt financially. It usually works out ok but I'm sure there is some risk in getting burned. I feel way better buying an old Citation than an old piston twin. Most of my airplane $$ misery has come from buying Continental motors in Beech Barons, go figure.

Fascinating read on the economics of the scrap business. Seems like you have a reeeeeel narrow window to find airframes that are both cheap and desirable. Almost seems like the best thing would be to find a totally airworthy plane with good program engines

great article on scrapping, I really enjoyed it.

Good article would have been great by framing the underlying economic parameters of the industry. Total revenue. Margins. By aircraft by part. Also,answer the question why if so little value exists why are the costs so high to the end user? Characteristics of a death spiral you ask me


Also 200 airframes in 10 years? Less than one a month?. Seriously labor intensive. Where are the bots?

Costs are high because they can be. Substantial natural barriers to entry and competing new parts prices are super high. If there’s any lesson here it’s to buy your own parts plane.

Robots disassembling an old airplane. Can’t see that. Their whole business model requires very carefully getting it all apart intact.

Heck, man! I don't know of any small business person who'd barf up that data to a journalist.


At best, a journalist with gumption and no deadlines might make a run at the math on their own.

I thought it was very interesting how the one company in MO has spawned others. I bet those back stories are interesting....

I'm back from X-mas at the inlaws, skiing, and visiting friends in Denver. We made it from Denver to FL non-stop with 800lbs remaining in flawless weather (obviously my IFR reserves or night reserves are higher). The airplane really performed admirably and I'm starting to get cautiously comfortable in it. This was about an 11 hour trip total. I think I can reliably bank on 335kts, 3.5 hours, and 1100lbs first hour, 800lbs second , 750lbs third and 600lbs for the descent. It lands in about 2000 ft with the reversers and takes off in about 2,500ft. It's very comfortable and easy to fly with absolutely no bad habits or vices. Nothing broke on this trip and the plane is currently squawk free other than the radio altimeter that flips out up high. I'm really happy with this purchase and think it is going to serve my longer travel needs perfectly and about as economically as possible. I think the variable costs are under $400 an hour if you carefully plan your fuel stops. The fixed costs are about $2,000 a month including hangar and hull/liability insurance along with my estimated maintenance costs. I don't think you can operate a P Baron or 421 for these costs.

Here's a video of her landing today coming back home. My mom and dad were taking care of the cats and chickens and came out to greet us.

https://www.youtube.com/watch?v=dup26342mYA

Nice!